Sequential hepatectomy for hepatocellular carcinoma with inadequate future-liver-remnant after portal vein ligation in combination with apatinib plus camrelizumab (PLACES): a single-arm prospective pilot study

Introduction

Hepatocellular carcinoma (HCC) is the main type of primary liver cancer, with hepatectomy offering a crucial means for prolonged survival (1). However, for HCC patients with large tumors, multiple tumors, or tumors adjacent to important vascular structures, extensive hepatectomy is necessary, and radical resection may not be possible due to an insufficient future-liver-remnant (FLR) (2).

Portal vein ligation (PVL) or portal vein embolization (PVE) two-step hepatectomy has an efficacy and safety profile, with a stage-II resection rate of 60% to 80% and a complication rate of 3% to 5% (3-5). Nevertheless, the waiting period (4–8 weeks) for FLR enhancement through PVL/PVE risks of tumor progression and insufficient FLR (5,6). Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) has become an important treatment for HCC with insufficient FLR (7); however, its complications in terms of morbidity and mortality are also noteworthy (8,9).

Apatinib, a small molecule tyrosine kinase inhibitor (TKI), has been reported to inhibit tumor angiogenesis and growth through highly selective competition for the vascular endothelial growth factor receptor-2 (10). Camrelizumab is an immune checkpoint inhibitor (ICI) targeting programmed death protein 1 (PD-1) (11). The RESCUE study, in which apatinib was combined with camrelizumab for advanced HCC, achieved objective response rates (ORRs) of 34.0% and 23.8% in the first-line and second-line treatment groups, respectively (12). Recently, a global multicenter randomized controlled trial (CARES-310) demonstrated that the combination of apatinib and camrelizumab exhibited superior ORR (25% vs. 6%, one-sided P<0.0001), progression-free survival (5.6 vs. 3.7 months, one-sided P<0.0001), and overall survival (OS) (22.1 vs. 15.2 months, one-sided P<0.0001) compared to sorafenib in unresectable HCC populations. This offers a new option for first-line regimens for HCC (13). The gut microbiota and the liver interact bidirectionally through the gut-liver axis (14). Gut microbes and their metabolites can directly or indirectly modulate hepatocytes, tumor cells, and immune cells (15). The correlation between gut microbiota composition and response to ICI therapy has been observed in various types of tumors (16-18). However, the relationship between gut microbiota and the efficacy of apatinib and camrelizumab in treating HCC remains to be explored.

To address the previously mentioned limitations of PVL and ALPPS, this study was designed to evaluate the efficacy and safety of combining PVL with apatinib and camrelizumab for sequential resection of HCCs with inadequate FLR. Additionally, the study aimed to compare short-term surgical outcomes and long-term prognosis with the ALPPS-treated cohort. We present this article in accordance with the TREND reporting checklist (available at https://hbsn.amegroups.com/article/view/10.21037/hbsn-24-363/rc).

Methods

Study design

This was an open-label, single-center, prospective, single-arm phase II clinical trial conducted at The First Affiliated Hospital of Guangxi Medical University from April 2020. The trial is referred to by the abbreviated name “PLACES” study. Additionally, this study has been registered with the Chinese Clinical Trial Registry under the registration number ChiCTR2000033692. All patient in this study had signed the informed consent. The investigation had been approved by the ethics committee of The First Affiliated Hospital of Guangxi Medical University (approval number: Joint Hearing 2019 No. 014 and 2021 No. 014). All methods in this research were carried out in accordance with Declaration of Helsinki and its subsequent amendments.

Patients

The primary inclusion criteria were defined as follows: (I) age, 18 to 75 years; (II) patients with primary HCC who strictly conform to normal liver function [Child-Pugh grade A, indocyanine green retention rate at 15 minutes (ICG-R15) <10%] and normal liver as FLR/standard liver volume (SLV) <30%; patients with chronic liver disease or parenchymal injury (including cirrhosis, severe fatty liver and chemotherapy-related liver injury) as FLR/SLV <40% (19); (III) Eastern Cooperative Oncology Group performance status (ECOG-PS) score 0–1; (IV) Barcelona Clinic Liver Cancer (BCLC) stages A to C. The primary exclusion criteria were outlined as follows: (I) patients with confirmed diagnoses of intrahepatic cholangiocarcinoma, mixed HCC-cholangiocarcinoma, or fibrous lamellar cell carcinoma were excluded from the study; (II) individuals with tumors present in both the right and left lobes of the liver, making them unsuitable for radical resection, were not considered for inclusion. Additionally, patients with cancerous thrombosis in the main portal vein [portal vein tumor thrombus (PVTT)-vp4] or the inferior vena cava were also excluded from participation. Comprehensive details of the inclusion and exclusion criteria can be found in Appendix 1.

Procedures

In the PLACES study, enrolled patients initially underwent PVL of the affected liver (Figure S1). Subsequently, they received apatinib orally at a daily dose of 250 mg, in combination with camrelizumab administered intravenously at 200 mg every 14 days, constituting a 14-day treatment cycle. After each cycle, patients were assessed for eligibility for stage-II resection. The indication for stage-II resection were as follows: (I) the potential to achieve R0 resection and maintain an adequate FLR; (II) a Child-Pugh grade of A and an ECOG-PS score of 0–1; (III) absence of metastasis within the initially healthy liver and no extrahepatic metastasis; (IV) absence of cancerous thrombosis in the main portal vein and inferior vena cava; (V) no serious or persistent adverse effects from systemic therapy and no contraindications to hepatectomy. If the criteria for surgery were met, the tumor would be surgically removed approximately 4 weeks after discontinuing the medication. Following surgery, postoperative adjuvant therapy with apatinib in combination with camrelizumab would be continued for up to 1 year or until a specified treatment termination event occurred as outlined in the protocol.

Tumor imaging evaluations were conducted every 4 to 6 weeks during the first 48 weeks to assess efficacy. After 48 weeks, imaging evaluations were performed every 8 to 12 weeks until confirmed disease progression (excluding spurious progression), initiation of new anti-tumor therapy, withdrawal of informed consent, or death of the study participant, whichever occurred first. The imaging included computed tomography scans or magnetic resonance imaging of the abdomen with triple-phase acquisition. If the criteria for surgery were not met, treatment would be sustained until the conditions for surgery were satisfied or until a termination event occurred. During the screening period, treatment period, and safety follow-up period (30 days after the last dose), we would collect information including physical examinations, laboratory data, tumor imaging assessments, adverse events, and medication management. Long-term survival follow-up will continue until the subject’s death, loss to follow-up, or study termination (whichever occurs first).

Outcomes

The primary endpoint was the 1-year event-free survival (EFS) rate, which denotes the period from the date of phase I surgery to the occurrence of disease progression, postoperative recurrence, or death from any cause. The secondary endpoints included OS, ORR, stage-II resection rate and safety assessed according to CTCAE v5.0 standards. OS was defined as the time interval from phase I surgery to death from any cause. ORR was defined as the sum of the proportions of complete (CR) and partial (PR) responses. The stage-II resection rate was defined as the proportion of the treated population that successfully completed the second surgery. Response evaluation criteria in solid tumors version 1.1 (RECIST v1.1) and modified response evaluation criteria in solid tumors (mRECIST) were employed to assess the tumor response of the patients in this study (20,21).

Biomarkers analysis

To identify potential response biomarkers for the PVL + apatinib + camrelizumab approach in the PLACES group, patients with CR or PR were classified as the response group (RG), while those with stable disease (SD) or progressive disease (PD) were classified as the non-RG (NRG) based on criteria from both mRECIST and RECIST v1.1. Pre-treatment stool samples underwent 16S rRNA MiSeq sequencing. Tumors and paracancerous tissues from patients undergoing stage-II surgery were collected and subjected to RNA sequencing. Circulating tumor DNA (ctDNA) sequencing was performed on preoperative blood samples from patients achieving postoperative pathological CR (pCR) (Appendix 1).

Comparison with ALPPS cohort

Data from HCC patients who underwent ALPPS surgery between January 2012 and December 2021 were retrospectively collected from the same center (Appendix 1). The inclusion criteria were as follows: patients with clinically or pathologically diagnosed HCC who had undergone ALPPS surgery. Exclusion criteria included those diagnosed with cholangiocarcinoma, mixed HCC-cholangiocarcinoma, or other concurrent malignancies, as well as cases with incomplete medical records or follow-up data. In order to enable comparisons between the PLACES cohort and the ALPPS cohort, we refined the initial study population through propensity score matching (PSM). Propensity scores were calculated for each patient using logistic regression, taking into account the following inter-group disequilibrium and prognostic variables: gender, age, body mass index, previous transcatheter arterial chemoembolization (TACE), hepatitis B virus (HBV) infection status, presence of cirrhosis, Child-Pugh score, alpha-fetoprotein (AFP) levels, tumor diameter, number of tumors, BCLC stage, and pre-I FLR/SLV ratio. The nearest neighbor method was utilized for matching, adhering to a 0.2 standard deviation caliper and a 1:1 ratio without replacement. Post-matching, the standardized mean difference (SMD) was employed to assess the distribution equilibrium of covariates between the two groups, with an SMD of ≤0.1 indicating a favorable balance of covariates.

Statistical analysis

Based on prior studies, the 1-year EFS rate after ALPPS in China HCC patients is approximately 45% (22,23). With the assumption of a 60% rate for this study, a sample size of 30 provides a one-sided 95% lower-limit confidence interval (CI) with a margin of 0.15 from the sample proportion using Wilson’s approximation.

The efficacy analysis was based on the full analysis set, which included patients who received PVL and at least one dose of TKI + ICI. The safety analysis set was based on the full analysis set and included those who had undergone at least one safety assessment. For assessing the distribution of continuous data, the Shapiro-Wilk test was employed. Measures that demonstrated a normal distribution were presented as mean ± standard deviation and analyzed using a t-test. On the other hand, continuous data with a non-normal distribution were represented as median (P25, P75) and subjected to comparison through the Mann-Whitney U test. Categorical data were expressed as case numbers (percentages) and assessed using either the Chi-squared test or Fisher exact test. Survival analyses were conducted using Kaplan-Meier curves and the log-rank test. The Benjaminiand Hochberg method was used to correct the false positive rate for P values. For exploratory analysis, a Cox proportional hazard regression model was employed to estimate hazard ratios. Post hoc subgroup analysis was carried out to evaluate potential differences in treatment effects across various subgroups. Furthermore, interaction between the assigned treatment and subgroups was assessed using a Cox regression model. IBM SPSS 26.0 statistical software, GraphPad Prism 8.0 software and R system 4.2.1 were used for data analysis and visualization.

Results

Patient characteristics

In the PLACES study, a total of 30 male patients were enrolled between April 2020 and December 2021 (Figure 1). The trial has stopped recruiting. All 30 patients were included in the full analysis set and the safety analysis set. Among them, 13 (43.3%) were BCLC stage A, while 12 (40.0%) were BCLC stage C (Table 1, Table S1). Additionally, 29 patients (96.7%) had chronic HBV infection, 1 patient (3.3%) had normal liver function, 24 patients (80.0%) exhibited cirrhosis, and 11 patients (36.7%) had AFP levels ≥400 ng/mL. All tumors were located in the right half of the liver.

Figure 1 Flowchart of study design. FLR, future liver remnant; HCC, hepatocellular carcinoma; PD, progressive disease; irAEs, immune-related adverse events.

Tumor response and stage-II resection outcomes

The final follow-up was conducted on May 1st, 2023. The most recent assessment of tumor response was based on radiographic imaging conducted prior to stage-II liver tumor resection, the latest CT scans, or termination events (Table 2, Figure S2). In accordance with RECIST v1.1, the ORR was 26.7% (8/30, 95% CI: 14.2–44.5%), and the disease control rate (DCR) was 66.7% (20/30, 95% CI: 48.8–80.8%). According to mRECIST criteria, the ORR was 40% (12/30, 95% CI: 24.6–57.7%), and the DCR was 66.7% (20/30, 95% CI: 48.8–80.8%). Clinical subgroup analysis of tumor response did not identify any subgroup that showed greater benefit (Figure S3). The time-course data of serum AFP and protein induced by vitamin K absence-II supported the radiological evaluation of clinical response (Figure S4).

The 1-year EFS rate in the PLACES group was 63.3% (95% CI: 48.2–83.1%), indicating that this study achieved the primary endpoint. Among the participants, 20 patients successfully completed the stage-II hepatectomy, resulting in a stage-II resection rate of 66.7% (20/30, 95% CI: 48.8–80.8%) (Table S2). In the PLACE cohort, the average total treatment cycle was 8.7 cycles. For patients who completed the stage-II hepatectomy, the average total treatment cycle was 9.25 cycles, with an average of 5.25 cycles before hepatectomy and 4 cycles after hepatectomy. Figure S5 illustrates a representative case demonstrating a positive clinical response. Postoperative pCR was achieved in 5 patients (25%, 5/20). In the PLACES group, patients who achieved CR or PR demonstrated superior OS compared to those with PD (not reach vs. 17.6 months, P=0.046, RECIST v1.1; P=0.048, mRECIST). Furthermore, patients who successfully completed stage-II hepatectomy exhibited enhanced OS (not reach vs. 15.1 months, P<0.001) and EFS (not reach vs. 9.6 months, P<0.001). Additionally, BCLC stage A patients experienced superior OS (not reach vs. 22.0, P=0.01) and EFS (not reached vs. 12.1 months, P=0.03) compared to BCLC stage B-C patients (Figure S6).

Safety in PLACES cohort

In the PLACES group, every patient experienced at least one treatment-related adverse event (TRAE), with a 66.7% incidence of grade ≥3 TRAEs (Table 3). Immune-related adverse events and treatment discontinuations were higher during adjuvant therapy compared to combination therapy.

After the PVL, only one TRAE of grade 4 aspartate aminotransferase (AST) elevation occurred, with no other grade >3 TRAEs reported. The most common adverse events (≥50%) included hypoalbuminemia (93.3%), incision pain (76.7%), anemia (60.0%), and so on (Table S3). During the combination therapy of apatinib and camrelizumab, there was one patient of a grade 4 adverse event, specifically type I respiratory failure, and 22 patients of grade 3 adverse events. The most common adverse events (≥50%) during combination therapy included hypoalbuminemia (56.7%) and AST elevation (53.3%) (Table S4). After stage-II hepatectomy, the most common adverse events (≥50%) included hypoalbuminemia (95.0%), AST elevation (90.0%), alanine aminotransferase elevation (90.0%), and so on (Table S5). Four adverse events were grade >3, including thrombocytopenia, AST elevation, respiratory failure, and immune pneumonia, which led to a death event. After hepatectomy, 8 patients discontinued the combination therapy of apatinib and camrelizumab. Among these, 2 patients experienced preoperative PD, three patients refused treatment, 2 patients occurred severe adverse events, and 1 patient died due to immune pneumonia. Twelve patients continued with adjuvant therapy, showing a trend towards better OS and disease-free survival (DFS) compared to those who did not receive adjuvant therapy (Figure S7). During the adjuvant treatment, the most common adverse events (≥50%) were hypoalbuminemia (58.3%) and rash (50%), and no grade >3 adverse events occurred (Table S6). Among the four stages, hypoalbuminemia was the most common adverse event, but it was only grade 1 or grade 2.

Potential pre-treatment biomarkers of clinical response

Qualified fecal samples were collected from 26 HCC patients before treatment and were divided into RG and NRG according to RECISTv1.1 and mRECIST criteria, respectively. Alpha diversity-related indices indicated no significantly difference in species richness and diversity between RG and NRG (Figure S8A,S8B). Principal coordinates analysis and venn diagram showed that the species composition of the samples was similar although there was a tendency of dispersion among the samples (Figure S8C,S8D). At the genus level, Bacteroides in NRG was enriched and Escherichia-Shigella in RG was enriched (P<0.05) (Figure S8E-S8H). The LefSe analysis identified significant overrepresentation of Escherichia-Shigella and Enterococcus in RG, while Vagococcus showed significant overrepresentation in NRG. Tax4fu functional prediction was presented in Figure 2A,2B. Based on the median values, the high abundance group of Escherichia-Shigella exhibited a more favorable EFS (P=0.049). Similarly, the high abundance group of Enterococcus demonstrated improved OS (P=0.043) (Figure 2C,2D).

Figure 2 Potential biomarker analysis. (A,B) LefSe analysis and Tax4fu functional prediction of fecal biomass before treatment based on RECIST v1.1 and mRECIST grouping. (C,D) Kaplan-Meier curves of overall survival and event-free survival in Escherichia-Shigella and Enterococcus. (E) Differential expression genes intersection constructed RG signature and NRG signature after treatment. (F) Kaplan-Meier curves of disease-free survival in RG signature and NRG signature in cancer. (G) Kaplan-Meier curves of disease-free survival in RG signature and NRG signature in para-cancer. (H) The ctDNA mutation landscaple in patients with complete pathological response. RECIST v1.1, response evaluation criteria in solid tumors version 1.1; mRECIST, modified RECIST; LDA, linear discriminant analysis; RG, resspond group; NRG, non-respond group; mEFS, median event-free survival; mDFS, median disease-free survival; AFP, alpha-fetoprotein; BCLC, Barcelona Clinic Liver Cancer; HBV, hepatitis B virus; ctDNA, circulating tumor DNA.

Potential post-treatment biomarkers of clinical response

RNA sequencing was conducted on tumor and adjacent paracancer tissues of 13 patients who underwent stage-II hepatectomy. By identifying the common genes among positively differential expressed genes in cancer tissue and those in either the RG or NRG, an RG signature (30 genes) and an NRG signature (12 genes) were constructed (Figure 2E, Figure S9, Table S7). Based on median enrichment fraction of ssGSEA analysis, the DFS of the low expression group of NRG signature (P=0.03) in cancer tissues and the low expression group of RG signature (P=0.01) in para-cancer tissues were superior (Figure 2F,2G).

The immune infiltration analysis by the xCell algorithm revealed that, in the cancerous tissue, there was a significant enrichment of monocytes, immature dendritic cells (iDC), and NKT cells in RG, while CD4⁺ Tcm and CD8⁺ Tem cells were notably enriched in NRG (P<0.05) (Figure S10A,S10B). Conversely, in the paracancerous tissues, Th1 cells and macrophages were significantly enriched in RG, while CD8⁺ Tem cells and B cells were notably enriched in NRG (P<0.05) (Figure S10C). Further, based on the median immune score, patients with a high score of iDC (P=0.03) or a low score of CD8⁺ Tem cells (P=0.045) in tumor tissue demonstrated better DFS. Additionally, patients with a high score of Th1 cells (P=0.03) or macrophages (P=0.03) in adjacent tumor tissue exhibited improved DFS (Figure S11).

To explore the underlying molecular mechanisms of patients who have achieved complete pathological remission, phase II preoperative plasma ctDNA was tested in five pCR patients. The results showed an 80% positivity rate, with an average variant allele frequency of 3.94%. Mutation profiling revealed mutations in genes, including TP53, CTNNB1, and TERT (Figure 2H).

Comparison of clinical profile between PLACES and ALPPS group

The exploratory analysis involved 76 HCC patients who underwent ALPPS surgery (Figure S12). Following a 1:1 matching process, 25 patients from the PLACES group and 25 patients from the ALPPS group were selected. The clinical characteristics were similar between the two groups, though there was a slight degree of imbalance (SMD =0.118) observed for the previous TACE. In the ALPPS group, a total of 66 patients (86.8%, 66/76) underwent classical ALPPS. Regardless of whether it was before or after PSM, patients in the PLACES group, in comparison to the ALPPS group, exhibited a higher minimally invasive rate (P<0.001), and a reduced rate of postoperative complications (P<0.001) during the stage-I of surgery (Table S8). Meanwhile, the hospitalization costs were lower in the PLACES group compared to the ALPPS group (84,976.6 vs. 144,149.1 RMB, P<0.001), as were the total costs (120,634.4 vs. 144,149.1 RMB, P=0.02). After PSM, the stage-II resection rate was 76% in the ALPPS group, compared to 68% in the PLACES group. The median interval between procedures was significantly longer in the PLACES group than in the ALPPS group (111.5 vs. 20.0 days, P<0.001) (Table S9). In the PSM population, PLACES group was able to achieve more liver volume growth (242.9 vs. 180.4 mL, P=0.04), but the ALPPS group experienced a faster growth in weekly FLR/SLV (7.8% vs. 1.3%, P<0.001) (Table S10).

Survival analysis of PLACES and ALPPS group

The median follow-up period was 46.3 months (95% CI: 28.1–64.5) for the ALPPS group and 24.4 months (95% CI: 22.7–26.2) for the PLACES group. To mitigate any potential follow-up time bias, the longest follow-up duration in the PLACES group (35 months) was used as the cutoff time. The 1-year EFS rate in the ALPPS group was 43.4% (95% CI: 33.6–56.1%). The survival curves indicated that the PLACES group demonstrated better EFS (21.5 vs. 10.2 months, P=0.02) and OS (not reached vs. 19.5 months, P=0.02) compared to the ALPPS group (Figure 3A,3B). Following PSM, both EFS (not reached vs. 10.2 months, P=0.040) and OS (not reached vs. 19.5 months, P=0.046) in the PLACES group were superior to those in the ALPPS group (Figure 3C,3D). The subgroup analysis for OS and EFS among the clinical stratification variables was shown in Figure S13. The treatment group was identified as an independent risk factor for both OS and EFS (Table S11).

Figure 3 Survival analysis between PLACES group and ALPPS group. (A,B) Kaplan-Meier curves of overall survival and event-free survival before PSM. (C,D) Kaplan-Meier curves of overall survival and event-free survival after PSM. (E,F) Kaplan-Meier curves of overall survival and disease-free survival who completed stage-II hepatectomy before PSM. (G,H) Kaplan-Meier curves of overall survival and disease-free survival who completed stage-II hepatectomy after PSM. ALPPS, associating liver partition and portal vein ligation for staged hepatectomy; mEFS, median event-free survival; mOS, overall survival; mDFS, median disease-free survival; PSM, propensity score matching.

Additionally, we compared the prognosis of patients who underwent stage-II hepatectomy in both groups. The PLACES group, which completed the stage-II hepatectomy, demonstrated a superior DFS (not reached vs. 12.5 months, P=0.01) and OS (not reached vs. 26.1 months, P=0.003) compared to the ALPPS group (Figure 3E,3F). In the PSM population, PLACES group exhibited a significant improvement in both DFS (not reached vs. 10.7 months, P=0.03) and OS (not reached vs. 29.5 months, P=0.01) for patients with HCC who completed stage-II surgery (Figure 3G,3H). Clinical subgroup analysis for OS and DFS is presented in Figure S14. Multivariate analysis identified the treatment group as an independent risk factor for both OS and DFS (Table S12).

Discussion

It is interesting to specify the subjects in our study design, which is different from the typical conversion study design for advanced-stage HCCs and neo-adjuvant study design for early-stage HCCs. In patients with HCC, the term conversion usually refers to the conversion process of a tumour—due to the adoption of specific procedures—from an unresectable condition to a resectable one. On the other hand, neo-adjuvant treatment refers to therapies or procedures aimed at improving surgical conditions and postoperative survival in patients with up-front resectable tumours. This distinction seems simple but might be difficult in real-world clinical practice. According to the Standard for diagnosis and treatment of primary liver cancer (2024 edition) (China) (24), published by the National Health Commission of the People’s Republic of China, “conversion therapy” refers to the process by which patients with HCC who are initially not suitable for surgical resection are rendered resectable through various interventions. These interventions include functional FLR conversion and oncological conversion. The guideline specify that the FLR volume must account for more than 40% of the SLV in patients with chronic liver disease, liver parenchymal damage, or cirrhosis, or more than 30% in patients without liver fibrosis or cirrhosis, as a prerequisite for performing surgical resection. Based on this definition, insufficient FLR volume categorizes these HCC patients as not suitable for surgical resection from a surgical perspective. In real-world daily practice, a patient could have an insufficient FLR after a planned major hepatectomy. Still, the same patient can be considered technically resectable by adopting parenchymal-sparing surgical procedures or a combined resection/ablation strategy in sacrificing, for example, surgical margin. Thus, only an independent commission of expert hepato-pancreato-biliary surgeons can assess if a patient is upfront unresectable, and this commission is not present in this study. Second, in this study, some patients with stable or PD underwent resection after apatinib plus camrelizumab treatment. This means that the oncological response to apatinib plus camrelizumab was not determinant for this study’s final decision to undergo resection. Only the final FLR was considered relevant for this decision. Furthermore, among the total patients included, only 5 (16.7%) were BCLC stage B, and 12 (40%) were stage C, which were regarded as oncologically unresectable cases. These patients underwent PVL combined with systemic therapy, aiming for both FLR and oncological conversion. It is therefore we remind readers to pay attention to this point when interpreting our study.

This study assessed the effectiveness and safety of PVL in combination with a treatment regimen involving TKI and programmed death-1 (PD-1) for sequential resection of HCC with insufficient FLR. Our findings revealed that 26.7% (8/30, RECIST v1.1) or 40% (12/30, mRECIST) of patients achieved ORR, 66.7% (20/30) patients completed stage-II hepatectomy, and 5 patients (25%, 5/20) achieved pCR. Furthermore, the safety profile was manageable. The CARES-310 study reported an ORR of 25% for camrelizumab and apatinib in unresectable HCC (13). Despite the similar ORR, the tumor stage and etiology of HCC patients in our study were different. The PLACES group exhibited a similar distribution between early-stage and advanced-stage cases (43.3% vs. 40.0%). Notably, in the PLACES study, patients classified as BCLC A stage demonstrated a higher ORR compared to those classified as stage C (38.5% vs. 25%, RECIST v1.1). These observations suggest that patients with early HCC may also benefit from TKI + ICI treatment compared to the advanced group.

When it comes to tumor conversion therapy, the results in literatures have not been as satisfactory. For achieving oncologic conversion, TACE has gained widespread acceptance as a viable treatment option (25). In a retrospective analysis by Zhang et al., covering 831 patients of unresectable HCC over a decade, only 43 patients (5.2%) successfully underwent radical surgery (26). Another retrospective study comparing FOLFOX-HAIC and sorafenib in treating advanced HCC showed that 26.1% of patients in the HAIC group transitioned to the opportunity for loco-regional therapy (27). Zhu et al. conducted a retrospective analysis of 63 patients receiving TKI + ICI for unresectable HCC, and reported that 10 patients (15.9%) underwent resection after therapy (28). In a multicenter retrospective study, the combination of lenvatinib, an anti-PD-1 antibody, and TACE therapy demonstrated an impressive ORR of 80.6%. This resulted in 53.2% (33/62) of patients becoming eligible for resection (29). The stage-II resection rate in our study was 66.7%, indicating the potential for a dual transformation strategy involving both tumor control and liver regeneration in patients of HCC with inadequate FLR. This will provide a new combination therapy option. PVL reduces blood supply to the affected liver, increases portal pressure in the contralateral liver, and thereby promoting FLR growth (30,31). Additionally, although PVL has limited effect on tumor blood supply, but ischemia and necrosis of tumor cells can stimulate the release of tumor-antigens and neoantigens from cancer cells to some extent into the bloodstream. These antigens can then be presented by antigen-presenting cells to tumor-specific T cells (32). This activation of T cells is essential, but it also leads to an upregulation of inhibitory checkpoints such as PD-1. These inhibitory checkpoints can be effectively blocked by ICI, allowing for an enhanced anti-tumor T cell response.

The high incidence of hypoalbuminemia in the postoperative period may be attributed to inflammatory stimulation and a reduction in albumin synthesis following surgery (33). In the RESCUE study, the most commonly AEs associated with apatinib combined with camrelizumab for advanced HCC included hypertension, elevated AST, and proteinuria (12). While the proportion of patients experiencing hypertension in our study was less pronounced than in the RESCUE study, elevation of AST was common. In this study, the first-case patient who underwent a stage-II resection initially had a preoperative CR, but subsequently developed severe immune pneumonia within one week after surgery. This led to respiratory failure, necessitating transfer to the intensive care unit for treatment, and ultimately resulted in in-hospital death due to exacerbation of pulmonary infection. This sacrificed case suggested that patients responding to ICI immunotherapy may also be at higher risk of immune-related adverse reactions, serving as a strong cautionary note for the design of similar treatments in subsequent clinical studies.

While TKI and immunotherapy have shown promise in treating HCC patients, not all individuals benefit equally from these treatments. Lee et al. reported that the significant role of gut microbiota in influencing the immune response and prognosis of HCC patients (17). In this study, the enrichment of specific bacteria, such as Escherichia-Shigella and Enterococcus, may be associated with improved prognoses in HCC patients undergoing apatinib + camrelizumab therapy. Escherichia-Shigella, which is more abundant in individuals with cirrhosis, is associated with increased blood levels of interleukin 6 (34,35). Furthermore, HCC patients tend to exhibit a higher presence of potentially pro-inflammatory bacteria, including Escherichia-Shigella and Enterococcus, in their fecal microbiota (36). The alterations in Escherichia-Shigella and Enterococcus in HCC may influence inflammatory processes and are connected with the tumor’s response to TKI + ICI treatment. In the future, it may be possible to enhance the efficacy of TKI and ICI therapy by modifying diet, consuming specific nutrients, and using fecal microbiota transplantation to modulate gut microbiota ecology (37-39). In HCC, an increased presence of tumor-infiltrating lymphocytes has shown a positive correlation with favorable responses to ICI treatment (40). Additionally, previous research has reported that existing immune factors are associated with improved clinical outcomes in the treatment of TKI + ICI for HCC (41). Within our study, high expression of iDC in tumor tissue emerged as a potential indicator of a more favorable prognosis. Similarly, a study on apatinib + camrelizumab in neoadjuvant HCC also observed that high expression of DC in tumor tissue was predictive of favorable treatment sensitivity (42).

Numerous studies have demonstrated that ALPPS can lead to over 50% residual liver hyperplasia within approximately 1–2 weeks, with a success rate of stage II surgery exceeding 90% (7,22,43). Nevertheless, some studies have suggested that the rapid increase in liver volume and function following ALPPS may not always be consistent (44,45), and there remains debate regarding the morbidity and mortality rates in HCC patients undergoing this procedure (43,46). The lack of prior TKI and ICI treatments, as well as the non-standardized postoperative adjuvant therapy, both have an impact on prognosis. However, for exploratory purposes, a thorough review and analysis of ALPPS cases from our center were conducted after rigorous PSM and correction for follow-up time bias. In stage I surgery, as compared to ALPPS, the PLACES group does not need for liver parenchyma transaction, enabling laparoscopic procedures with shorter operative times, reduced intraoperative bleeding, and fewer postoperative complications. Among patients who completed stage-II surgery, those in the PLACES group exhibited superior OS and DFS rates, irrespective of pre- and post-PSM. Furthermore, PVL offers simplicity in operation and ease of promotion. It allows for the assessment of hemihepatic function through hemihepatic ICG-R15 during the operation (47), aids in preventing the spread of portal vein cancer thrombolus to the contralateral liver, and facilitates swift bridging of the systemic treatment.

There may be additional innovative strategies worth exploring. Reports suggest that, compared to ALPPS, simultaneous portal and hepatic vein embolization shows no significant differences in FLR hypertrophy rate and R0 resection rate, while major complications and 90-day mortality are significantly lower (48). However, a retrospective study comparing dual embolization with PVE found that 13.5% (5/37) of patients in the dual embolization group were unable to undergo the stage-II surgery due to intrahepatic progression (49). While dual embolization improved the efficiency of FLR hypertrophy, it appears to lack consideration of oncological conversion. The combination of dual embolization with TKI and ICI therapy could represent a promising avenue for further research. Furthermore, combining ALPPS with TKI and ICI therapy presents certain clinical challenges. Short-term use of TKI + ICI before ALPPS, akin to neoadjuvant therapy, may potentially improve tumor pathological response rates. However, it carries the risk of tumor progression and is unlikely to reduce—and may even increase—the incidence of postoperative complications. The short interval between the two ALPPS surgeries also limits the opportunity for TKI + ICI therapy. Therefore, administering adjuvant TKI + ICI therapy after ALPPS may be a more feasible strategy. Additionally, combining PVL with hepatic arterial infusion chemotherapy and TKI plus ICI therapy might also offer an improved approach over the current study protocol (50).

There were several limitations in this study. Firstly, the PLACES study was conducted as a single-center, single-arm phase II clinical trial, with a relatively small cohort of enrolled patients. The controlled ALPPS group was part of a retrospective cohort. To comprehensively evaluate the effectiveness and safety of our approach, a randomized controlled design would be essential. Secondly, the inclusion of only male subjects may affect the generalizability of the study results to all gender HCC patients. It’s worth noting that 96% of the patients in our study had a background of HBV infection. Consequently, the conclusions drawn from our approach may not necessarily extend to patients with other etiologies. Thirdly, the exploration of the biomarkers failed to conduct a link before and after treatment. The underlying mechanisms of clinical benefit require further investigation.

Conclusions

The innovative approach we presented here, combining PVL with apatinib and camrelizumab for HCCs with insufficient residual liver volume, showed manageable adverse events and promising clinical outcomes. In comparison to the conventional ALPPS approach, the PLACES group exhibited fewer perioperative complications, and achieved superior OS and EFS outcomes. Additionally, among patients who successfully completed stage-II resection, the PLACES group demonstrated better OS and DFS rates.

Acknowledgments

The authors would like to thank all patients and their families for their active cooperation. The authors would also like to thank Jiangsu Hengrui Pharmaceuticals Co., Ltd. for supporting this research. The authors also acknowledge Guangxi Key Laboratory of Enhanced Recovery after Surgery for Gastrointestinal Cancer, Key Laboratory of early Prevention & Treatment for regional High Frequency Tumor (Guangxi Medical University) and Guangxi Aisheng Life Technology Co., Ltd. for providing experimental conditions for this study. In addition, we thank Liling Long, Kai Hu, Hong Yang, Lin Tao, and other members of the multidisciplinary treatment team for their guidance in the diagnosis and treatment of patients.

Footnote

Reporting Checklist: The authors have completed the TREND reporting checklist. Available at https://hbsn.amegroups.com/article/view/10.21037/hbsn-24-363/rc

Data Sharing Statement: Available at https://hbsn.amegroups.com/article/view/10.21037/hbsn-24-363/dss

Peer Review File: Available at https://hbsn.amegroups.com/article/view/10.21037/hbsn-24-363/prf

Funding: This work was supported in part by Jiangsu Hengrui Pharmaceutical Co., Ltd. Besides, this research was partly supported by the National Nature Science Foundation of China (Nos. 81560535, 81072321,81802874 and 82060434), Key Laboratory of Early Prevention & Treatment for Regional High Frequency Tumor (Guangxi Medical University)-Ministry of Education (GKE2019-11, and GKE-ZZ202009 and GKE202109), Guangxi Natural Sciences Foundation (Nos. 2023JJD140130, GuiKeGong1104003A-7, GuiKeAB23026002 and 2020GXNSFAA159127), Guangxi Key Laboratory for the Prevention and Control of Viral Hepatitis (No. GXCDCKL201902) and Guangxi Key Laboratory of Enhanced Recovery after Surgery for Gastrointestinal Cancer. This work was supported in part by the Guangxi Research Basic Ability Improvement Project for Young and Middle-aged Teachers (No. 2024KY0128) and National Funded Postdoctoral Researcher Program (No. GZC20230583). The present study was also partly supported by Guangxi Key Laboratory of Longevity Science and Technology and AIage Life Science Corporation Ltd.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://hbsn.amegroups.com/article/view/10.21037/hbsn-24-363/coif). The authors reports that Jiangsu Hengrui Pharmaceuticals Co., Ltd. provided the clinical trial drugs Apatinib and Camrelizimab (free of charge). The authors have no other conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All patient in this study had signed the informed consent. The investigation had been approved by the ethics committee of The First Affiliated Hospital of Guangxi Medical University (approval number: Joint Hearing 2019 No. 014 and 2021 No. 014). All methods in this research were carried out in accordance with Declaration of Helsinki and its subsequent amendments.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Forner A, Reig M, Bruix J. Hepatocellular carcinoma. Lancet 2018;391:1301-14. [Crossref] [PubMed]
2. Kishi Y, Abdalla EK, Chun YS, et al. Three hundred and one consecutive extended right hepatectomies: evaluation of outcome based on systematic liver volumetry. Ann Surg 2009;250:540-8. [Crossref] [PubMed]
3. Charalel RA, Sung J, Askin G, et al. Systematic Reviews and Meta-Analyses of Portal Vein Embolization, Associated Liver Partition and Portal Vein Ligation, and Radiation Lobectomy Outcomes in Hepatocellular Carcinoma Patients. Curr Oncol Rep 2021;23:135. [Crossref] [PubMed]
4. Tustumi F, Ernani L, Coelho FF, et al. Preoperative strategies to improve resectability for hepatocellular carcinoma: a systematic review and meta-analysis. HPB (Oxford) 2018;20:1109-18. [Crossref] [PubMed]
5. Shindoh J, Vauthey JN, Zimmitti G, et al. Analysis of the efficacy of portal vein embolization for patients with extensive liver malignancy and very low future liver remnant volume, including a comparison with the associating liver partition with portal vein ligation for staged hepatectomy approach. J Am Coll Surg 2013;217:126-33; discussion 133-4. [Crossref] [PubMed]
6. Aloia TA. Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy: Portal Vein Embolization Should Remain the Gold Standard. JAMA Surg 2015;150:927-8. [Crossref] [PubMed]
7. Chan A, Zhang WY, Chok K, et al. ALPPS Versus Portal Vein Embolization for Hepatitis-related Hepatocellular Carcinoma: A Changing Paradigm in Modulation of Future Liver Remnant Before Major Hepatectomy. Ann Surg 2021;273:957-65. [Crossref] [PubMed]
8. van Mierlo KM, Schaap FG, Dejong CH, et al. Liver resection for cancer: New developments in prediction, prevention and management of postresectional liver failure. J Hepatol 2016;65:1217-31. [Crossref] [PubMed]
9. Lang H, Baumgart J, Mittler J. Associated Liver Partition and Portal Vein Ligation for Staged Hepatectomy (ALPPS) Registry: What Have We Learned? Gut Liver 2020;14:699-706. [Crossref] [PubMed]
10. Qin S, Li Q, Gu S, et al. Apatinib as second-line or later therapy in patients with advanced hepatocellular carcinoma (AHELP): a multicentre, double-blind, randomised, placebo-controlled, phase 3 trial. Lancet Gastroenterol Hepatol 2021;6:559-68. [Crossref] [PubMed]
11. Qin S, Ren Z, Meng Z, et al. Camrelizumab in patients with previously treated advanced hepatocellular carcinoma: a multicentre, open-label, parallel-group, randomised, phase 2 trial. Lancet Oncol 2020;21:571-80. [Crossref] [PubMed]
12. Xu J, Shen J, Gu S, et al. Camrelizumab in Combination with Apatinib in Patients with Advanced Hepatocellular Carcinoma (RESCUE): A Nonrandomized, Open-label, Phase II Trial. Clin Cancer Res 2021;27:1003-11. [Crossref] [PubMed]
13. Qin S, Chan SL, Gu S, et al. Camrelizumab plus rivoceranib versus sorafenib as first-line therapy for unresectable hepatocellular carcinoma (CARES-310): a randomised, open-label, international phase 3 study. Lancet 2023;402:1133-46. [Crossref] [PubMed]
14. Silveira MAD, Bilodeau S, Greten TF, et al. The gut-liver axis: host microbiota interactions shape hepatocarcinogenesis. Trends Cancer 2022;8:583-97. [Crossref] [PubMed]
15. Ma C, Han M, Heinrich B, et al. Gut microbiome-mediated bile acid metabolism regulates liver cancer via NKT cells. Science 2018;360:eaan5931. [Crossref] [PubMed]
16. McCulloch JA, Davar D, Rodrigues RR, et al. Intestinal microbiota signatures of clinical response and immune-related adverse events in melanoma patients treated with anti-PD-1. Nat Med 2022;28:545-56. [Crossref] [PubMed]
17. Lee PC, Wu CJ, Hung YW, et al. Gut microbiota and metabolites associate with outcomes of immune checkpoint inhibitor-treated unresectable hepatocellular carcinoma. J Immunother Cancer 2022;10:e004779. [Crossref] [PubMed]
18. Derosa L, Routy B, Thomas AM, et al. Intestinal Akkermansia muciniphila predicts clinical response to PD-1 blockade in patients with advanced non-small-cell lung cancer. Nat Med 2022;28:315-24. [Crossref] [PubMed]
19. Zhou J, Sun H, Wang Z, et al. Guidelines for the Diagnosis and Treatment of Hepatocellular Carcinoma (2019 Edition). Liver Cancer 2020;9:682-720. [Crossref] [PubMed]
20. Eisenhauer EA, Therasse P, Bogaerts J, et al. New response evaluation criteria in solid tumours: revised RECIST guideline (version 1.1). Eur J Cancer 2009;45:228-47. [Crossref] [PubMed]
21. Lencioni R, Llovet JM. Modified RECIST (mRECIST) assessment for hepatocellular carcinoma. Semin Liver Dis 2010;30:52-60. [Crossref] [PubMed]
22. Wang Z, Peng Y, Hu J, et al. Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy for Unresectable Hepatitis B Virus-related Hepatocellular Carcinoma: A Single Center Study of 45 Patients. Ann Surg 2020;271:534-41. [Crossref] [PubMed]
23. Ye C, Zhang L, Xu B, et al. Hepatic Arterioportal Fistula Is Associated with Decreased Future Liver Remnant Regeneration after Stage-I ALPPS for Hepatocellular Carcinoma. J Gastrointest Surg 2021;25:2280-8. [Crossref] [PubMed]
24. National Health Commission of the People’s Republic of China. Standard for diagnosis and treatment of primary liver cancer (2024 edition). Journal of Clinical Hepatology 2024;40:893.
25. Jiang L, Lei JY, Wang WT, et al. Immediate radical therapy or conservative treatments when meeting the Milan criteria for advanced HCC patients after successful TACE. J Gastrointest Surg 2014;18:1125-30. [Crossref] [PubMed]
26. Zhang Y, Huang G, Wang Y, et al. Is Salvage Liver Resection Necessary for Initially Unresectable Hepatocellular Carcinoma Patients Downstaged by Transarterial Chemoembolization? Ten Years of Experience. Oncologist 2016;21:1442-9. [Crossref] [PubMed]
27. Lyu N, Kong Y, Mu L, et al. Hepatic arterial infusion of oxaliplatin plus fluorouracil/leucovorin vs. sorafenib for advanced hepatocellular carcinoma. J Hepatol 2018;69:60-9. [Crossref] [PubMed]
28. Zhu XD, Huang C, Shen YH, et al. Downstaging and Resection of Initially Unresectable Hepatocellular Carcinoma with Tyrosine Kinase Inhibitor and Anti-PD-1 Antibody Combinations. Liver Cancer 2021;10:320-9. [Crossref] [PubMed]
29. Wu JY, Yin ZY, Bai YN, et al. Lenvatinib Combined with Anti-PD-1 Antibodies Plus Transcatheter Arterial Chemoembolization for Unresectable Hepatocellular Carcinoma: A Multicenter Retrospective Study. J Hepatocell Carcinoma 2021;8:1233-40. [Crossref] [PubMed]
30. Yagi S, Iida T, Taniguchi K, et al. Impact of portal venous pressure on regeneration and graft damage after living-donor liver transplantation. Liver Transpl 2005;11:68-75. [Crossref] [PubMed]
31. Ogura Y, Hori T, El Moghazy WM, et al. Portal pressure <15 mm Hg is a key for successful adult living donor liver transplantation utilizing smaller grafts than before. Liver Transpl 2010;16:718-28. [Crossref] [PubMed]
32. Sharma P, Allison JP. Immune checkpoint targeting in cancer therapy: toward combination strategies with curative potential. Cell 2015;161:205-14. [Crossref] [PubMed]
33. Soeters PB, Wolfe RR, Shenkin A. Hypoalbuminemia: Pathogenesis and Clinical Significance. JPEN J Parenter Enteral Nutr 2019;43:181-93. [Crossref] [PubMed]
34. Baltazar-Díaz TA, González-Hernández LA, Aldana-Ledesma JM, et al. Escherichia/Shigella, SCFAs, and Metabolic Pathways-The Triad That Orchestrates Intestinal Dysbiosis in Patients with Decompensated Alcoholic Cirrhosis from Western Mexico. Microorganisms 2022;10:1231. [Crossref] [PubMed]
35. Gedgaudas R, Bajaj JS, Skieceviciene J, et al. Circulating microbiome in patients with portal hypertension. Gut Microbes 2022;14:2029674. [Crossref] [PubMed]
36. Liu Q, Li F, Zhuang Y, et al. Alteration in gut microbiota associated with hepatitis B and non-hepatitis virus related hepatocellular carcinoma. Gut Pathog 2019;11:1. [Crossref] [PubMed]
37. Bender MJ, McPherson AC, Phelps CM, et al. Dietary tryptophan metabolite released by intratumoral Lactobacillus reuteri facilitates immune checkpoint inhibitor treatment. Cell 2023;186:1846-1862.e26. [Crossref] [PubMed]
38. Spencer CN, McQuade JL, Gopalakrishnan V, et al. Dietary fiber and probiotics influence the gut microbiome and melanoma immunotherapy response. Science 2021;374:1632-40. [Crossref] [PubMed]
39. Baruch EN, Youngster I, Ben-Betzalel G, et al. Fecal microbiota transplant promotes response in immunotherapy-refractory melanoma patients. Science 2021;371:602-9. [Crossref] [PubMed]
40. Ji JH, Ha SY, Lee D, et al. Predictive Biomarkers for Immune-Checkpoint Inhibitor Treatment Response in Patients with Hepatocellular Carcinoma. Int J Mol Sci 2023;24:7640. [Crossref] [PubMed]
41. Zhu AX, Abbas AR, de Galarreta MR, et al. Molecular correlates of clinical response and resistance to atezolizumab in combination with bevacizumab in advanced hepatocellular carcinoma. Nat Med 2022;28:1599-611. [Crossref] [PubMed]
42. Xia Y, Tang W, Qian X, et al. Efficacy and safety of camrelizumab plus apatinib during the perioperative period in resectable hepatocellular carcinoma: a single-arm, open label, phase II clinical trial. J Immunother Cancer 2022;10:e004656. [Crossref] [PubMed]
43. Zhang J, Huang H, Bian J, et al. Safety, feasibility, and efficacy of associating liver partition and portal vein ligation for staged hepatectomy in treating hepatocellular carcinoma: a systematic review. Ann Transl Med 2020;8:1246. [Crossref] [PubMed]
44. Olthof PB, Tomassini F, Huespe PE, et al. Hepatobiliary scintigraphy to evaluate liver function in associating liver partition and portal vein ligation for staged hepatectomy: Liver volume overestimates liver function. Surgery 2017;162:775-83. [Crossref] [PubMed]
45. Matsuo K, Murakami T, Kawaguchi D, et al. Histologic features after surgery associating liver partition and portal vein ligation for staged hepatectomy versus those after hepatectomy with portal vein embolization. Surgery 2016;159:1289-98. [Crossref] [PubMed]
46. Li PP, Huang G, Jia NY, et al. Associating liver partition and portal vein ligation for staged hepatectomy versus sequential transarterial chemoembolization and portal vein embolization in staged hepatectomy for HBV-related hepatocellular carcinoma: a randomized comparative study. Hepatobiliary Surg Nutr 2022;11:38-51. [Crossref] [PubMed]
47. Yu T, Ye X, Wen Z, et al. Intraoperative Indocyanine Green Retention Test of Left Hemiliver in Decision-Making for Patients With Hepatocellular Carcinoma Undergoing Right Hepatectomy. Front Surg 2021;8:709017. [Crossref] [PubMed]
48. Gavriilidis P, Marangoni G, Ahmad J, et al. Simultaneous portal and hepatic vein embolization is better than portal embolization or ALPPS for hypertrophy of future liver remnant before major hepatectomy: A systematic review and network meta-analysis. Hepatobiliary Pancreat Dis Int 2023;22:221-7. [Crossref] [PubMed]
49. Laurent C, Fernandez B, Marichez A, et al. Radiological Simultaneous Portohepatic Vein Embolization (RASPE) Before Major Hepatectomy: A Better Way to Optimize Liver Hypertrophy Compared to Portal Vein Embolization. Ann Surg 2020;272:199-205. [Crossref] [PubMed]
50. Gao Q, Zhu GZ, Han CY, et al. Dual transformation therapy for giant hepatocellular carcinoma: Two case reports and review of literature. World J Gastrointest Surg 2023;15:2089-97. [Crossref] [PubMed]