Real-world experience of postoperative adjuvant chemoimmunotherapy in patients with perihilar cholangiocarcinoma at high risk of recurrence.

Background: This study aimed to assess whether postoperative adjuvant chemoimmunotherapy could lead to better clinical outcomes for high-risk patients with perihilar cholangiocarcinoma (pCCA).

Methods: In the cohort study, we retrospectively reviewed patients who received surgical resection for pCCA with curative intent from January 2018 to December 2021 at the Sun Yat-sen Memorial Hospital. The patients at high risk for relapse were further analyzed. Among them, 20 patients received adjuvant chemoimmunotherapy, 28 patients received adjuvant chemotherapy, and 33 patients received surgery alone. The oncological outcomes and drug-associated adverse events were evaluated.

Results: The 2-year overall survival (OS) rates in patients treated with adjuvant chemoimmunotherapy, adjuvant chemotherapy, and surgery alone were 80.0%, 49.4% and 22.6%, respectively. Univariable and multivariable Cox analyses showed that the treatment regimen and TNM stage were associated with adverse OS. Adjuvant chemoimmunotherapy led to an increase in OS compared with adjuvant chemotherapy [hazard ratio (HR) = 3.253; 95% confidence interval (CI) 1.072-9.870; P = 0.037] or surgery alone (HR = 7.560; 95% CI 2.508-22.785; P < 0.001). The median recurrence-free survival was 22.0 months for the adjuvant chemoimmunotherapy group, 17.0 months for the adjuvant chemotherapy group, and 13.2 months for the surgery alone group (P = 0.177); these differences were not significant. The chemoimmunotherapy group was associated with more frequent hematological side effects than the chemotherapy group, but the difference was not statistically significant.

Conclusion: Postoperative adjuvant chemoimmunotherapy for resected pCCA patients showed improved OS compared with adjuvant chemotherapy or surgery alone, and further prospectively randomized controlled trials are necessary to validate these results.