Recognizing significance of propensity score matching and clinical practice in evaluating oncological survivals of pancreatic cancer

We read with great interest the article titled “Oncological survival in pancreatic head ductal carcinoma: hybrid minimally invasive versus open pancreatoduodenectomy—a single centre analysis” recently published in the International Journal of Surgery (1). This research conducted a single centre and retrospective analysis to compare the oncological survival in patients with pancreatic head ductal carcinoma (PHDC) undergoing the hybrid minimally invasive versus open pancreatoduodenectomy. The study found that the laparoscopic procedure was significantly superior in terms of intraoperative blood loss (575 vs. 600 mL, P=0.02) and operative time (413 vs. 427 min, P=0.03), and that patients who underwent hybrid laparoscopic resection of PHDC showed significantly improved oncological outcomes. This further provides strong evidence that minimally invasive pancreatoduodenectomy is safer and more feasible than an open approach. Although this meticulous work and its significant contributions are greatly appreciated, several constructive suggestions are made for future advancement.

First, it can be observed from demographic and pathological characteristics of the patients included this study, the authors took into consideration some characteristic clinical and pathological features such as age, gender, body mass index (BMI) and American Society of Anaesthesiologists (ASA) score, while as a high-quality retrospective study, the included variables are insufficient. There seemed to be a heavy selection bias between the two groups. For example, tumour size, portal vein resection, and blood transfusion were significantly greater in the open group, and the resection margin remained negative significantly more often in the laparoscopic group (2). This will result in patients with relatively poor oncological survival being assigned to the open procedure group. We propose that propensity score matching (PSM) be used to recompare the demographic data and prognostic analysis between the two groups to eliminate the influence of confounding factors on the results (3). Notably, recurrence-free survival should also be considered a significant oncological outcome for prognostic analysis.

Second, some significantly important variables that affect the oncological survival in patients with PHDC undergoing pancreatoduodenectomy were not included in this study, such as preoperative carbohydrate antigen 19-9 (CA19-9), preoperative pain, and key serum markers. This study lacks a detailed evaluation of some significant variables that could significantly affect the reported oncological survival. In a cohort study of patients undergoing pancreatic cancer resection, preoperative CA19-9 level was a strong predictive indicator of oncological survival, including overall and recurrence-free survival (4). Another multicentre study reported that preoperative CA19-9 and fibrinogen/albumin ratio were independent risk factors for oncological survival in patients with resectable pancreatic ductal adenocarcinoma (5). We suggest that the authors supplement relevant information to further assess the impact of these variables on their results.

Third, the study included patients who underwent laparoscopic procedures between 2010 and 2022, and open procedures between 2002 and 2022. with a 25-month follow-up period, coinciding with the rapid development of neoadjuvant therapy and postoperative chemotherapy, during which numerous studies reported increased survival rates for patients receiving adjuvant therapy (6). Patients with worse disease status tend to receive more neoadjuvant chemotherapy. Therefore, the authors should include neoadjuvant chemotherapy and postoperative chemotherapy as variables affecting oncological survival in their study.

In conclusion, the research published in International Journal of Surgery stands as a substantial contribution to our understanding of oncological survival in resectable PHDC using hybrid minimally invasive and open pancreatoduodenectomy. This article demonstrated the superiority of minimally invasive pancreatoduodenectomy in terms of intraoperative blood loss, operating time, and postoperative survival at 5 years compared with open pancreatoduodenectomy, and elucidate its non-inferiority. Our suggestions only serve to improve an already excellent work of research. We hope that the above revision suggestions can be taken into consideration by the authors to make this retrospective study more comprehensive and rigorous.

Acknowledgments

Funding: This study was supported by Guilin Science and Technology Plan Project (No. 20220139-5-3), The Technology Project within the No. 924 Hospital of PLA Joint Logistic Support Force (No. S2022FH01), Guangxi Healthcare Science and Technology Plan Project (No. Z-C20241574), The Fundamental Research Funds for the Central Universities of HIT.

Footnote

Provenance and Peer Review: This article was a standard submission to the journal. The article did not undergo external peer review.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://hbsn.amegroups.com/article/view/10.21037/hbsn-24-615/coif). The authors have no 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.

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. Lettner JD, Kuesters S, Fichtner-Feigl S, et al. Oncological survival in pancreatic head ductal carcinoma: hybrid minimally invasive versus open pancreatoduodenectomy - a single centre analysis. Int J Surg 2024;110:7106-11. [Crossref] [PubMed]
2. Blackford AL, Canto MI, Dbouk M, et al. Pancreatic Cancer Surveillance and Survival of High-Risk Individuals. JAMA Oncol 2024;10:1087-96. [Crossref] [PubMed]
3. Austin PC. An Introduction to Propensity Score Methods for Reducing the Effects of Confounding in Observational Studies. Multivariate Behav Res 2011;46:399-424. [Crossref] [PubMed]
4. van Oosten AF, Groot VP, Dorland G, et al. Dynamics of Serum CA19-9 in Patients Undergoing Pancreatic Cancer Resection. Ann Surg 2024;279:493-500. [PubMed]
5. Zhang XP, Gao YX, Xu S, et al. A novel online calculator to predict early recurrence and long-term survival of patients with resectable pancreatic ductal adenocarcinoma after pancreaticoduodenectomy: A multicenter study. Int J Surg 2022;106:106891. [Crossref] [PubMed]
6. Cecchini M, Salem RR, Robert M, et al. Perioperative Modified FOLFIRINOX for Resectable Pancreatic Cancer: A Nonrandomized Controlled Trial. JAMA Oncol 2024;10:1027-35. [Crossref] [PubMed]