Controversial benefit of 5-fluorouracil/leucovorin-based adjuvant chemotherapy for ampullary cancer: a propensity score-matched analysis

Background Although surgery is the primary treatment for ampullary cancer (AC), the benefit of adjuvant chemotherapy (CTx) has not yet been confirmed. Methods AC patients who were administered 5-fluorouracil(FU)/leucovorin(LV)-based CTx after curative intent surgery between 2011 and 2019 were included. Prognosis was compared between the observation (OB) and CTx groups after propensity score matching (PSM) using perioperative variables to control differences in patient characteristics. Results Before PSM, of 475 patients, those in the CTx group ( n = 281) had worse 5-year overall survival (OS) (82.1% vs. 78.5%, p = 0.017) and worse 5-year recurrence-free survival (RFS) (54.9% vs. 75.7%, p < 0.001) than those in the OB group ( n = 194). In addition, the CTx group had a higher rate of poor prognostic factors such as a high T stage ( p < 0.001), node metastasis ( p < 0.001), and poor differentiation ( p < 0.001). After PSM, perioperative outcomes were comparable. In addition, there were no significant differences in OS (hazard ratio [ HR ], 1.085; 95% confidence interval [ CI ], 0.688–1.710; p = 0.726) or RFS ( HR , 0.883; 95% CI , 0.613 1.272; p = 0.505) between the CTx ( n = 123) and OB ( n = 123) groups even after stratification by TNM stage. Intestinal subtype showed better 5-year OS (83.7% vs 33.2%, p = 0.015) and RFS (46.5% vs 24.9%, p = 0.035) rate compared with pancreatobiliary/mixed subtype. Conclusion Patients who received adjuvant chemotherapy based on 5-FU/LV showed comparable oncologic outcomes to patients in the OB group even after stratification by tumor stage. The patients with intestinal subtype showed oncologic benefit for adjuvant 5-FU/LV CTx compared with pancreatobiliary or mixed subtypes.