Adjuvant capecitabine in resected biliary tract cancers: Real life data from a multicenter study (PRODIGE83-ACABi-PRONOBIL).

596 Background: Biliary tract cancers (BTCs) are rare and heterogeneous tumors with a poor survival even in early-stage patients treated with a curative surgery. Since 2019 the current standard of care in the adjuvant setting is oral chemotherapy (CT) with capecitabine for 6 months, as an option following BILCAP phase III trial results. Nevertheless, outside of this trial, real-world data are lacking. Methods: We conducted a French, retrospective, multicenter study from the ACABi-PRONOBIL cohort. Eligible patients had intrahepatic, perihilar, distal cholangiocarcinoma or gallbladder carcinoma treated by surgery with curative intent without prior therapy. Two groups were compared, patients who received capecitabine (Cape group) as adjuvant CT and patients without adjuvant treatment before 2017 (surveillance group). The primary endpoint was overall survival (OS). Secondary endpoints were disease-free survival (DFS) and toxicity. Results: 324 patients were included, 200 in the Cape group and 124 in the surveillance group. The median OS was 43.5 months (CI95%= 35.4-48.0) and 44.6 months (CI95% 37.7-54.8) in the Cape and surveillance group, respectively. ECOG performance status ≥ 2, pT3 stage, vascular and node invasion were associated with a poorer OS. The DFS was 15.8 months (CI95%= 14.1-20.3) in the Cape group and 13.3 months (CI95%= 10.1-17.5) in the surveillance group. In inverse probability of treatment weighting (IPTW) analysis we observed a significant statistical association between Cape group and DFS (IPTW HR (CI95%) Cape group vs surveillance group = 0.76 (0.60-0.96), pvalue=0.0224) but not with OS. In the Cape group, 49% of patients had at least one dose reduction, 35% had to discontinue treatment due to toxicity (mainly gastrointestinal,13.3% of grade 3-4; and cutaneous, 27% of grade 3-4). Conclusions: In this retrospective analysis, adjuvant capecitabine appears to increase DFS without statistically significant impact on OS in patients undergoing surgery for BTC, confirming in real life the BILCAP study results.