AB022. S4-2. Role of radiotherapy in cholangiocarcinoma

Abstract: Cholangiocarcinoma represents a heterogeneous cohort of biliary tract cancers in intrahepatic, perihilar, or distal location. Although surgical resection is recognized to offer the chance for cure, the patients with intrahepatic (IHCC) or perihilar cholangiocarcinoma (PCC) present mostly advanced disease, which results in not only limiting curative resection but also high recurrence even after resection. This notion urges active consideration of multimodal therapeutic strategies; neoadjuvant treatment converting from unresectable to resectable one and postop adjuvant treatment to reduce recurrence. With regard to neoadjuvant aim, radiotherapy in combination with chemotherapy (CRT) is gaining attention in many cancers for increasing resectability. My group investigated the efficacy of CRT as a neoadjuvant role. We identified 120 IHCC patients (pts) who were treated either with surgery (56 pts) for resectable disease or with CRT (64 pts) for locally advanced unresectable one. In CRT cohort, we achieved 25% partial response as well as 35% biologic response (>70% decrease of CA19-9), which subsequently allowed curative resection in 8 patients (12.5%). We also identified some factors associated with conversion to curative resection after CRT. Benefit of postop adjuvant treatment hasn’t been well established in cholangiocarcinoma due to limited evidence particularly in PCC. My group investigated a role of postop adjuvant treatment in 189 PCC patients involving no adjuvant (89 pts), adjuvant chemotherapy (62 pts), adjuvant radiotherapy (16 pts), and adjuvant CRT (22 pts). Adjuvant CRT produced the highest 5-year survival rate (50%) followed by adjuvant chemotherapy (26.8%) in R1 resection and stage III–IVA, which was far superior to 5-year survival 0% in no adjuvant group. Our data suggest that adjuvant CRT should be considered in high-risk resected PC patients. Taken together, radiotherapy in a form of chemoradiotherapy seems to improve oncologic outcome in cholangiocarcinoma either in neoadjuvant or in postop adjuvant setting.

Keywords: Intrahepatic cholangiocarcinoma; perihilar cholangiocarcinoma; radiotherapy