Background : The effect of adjuvant chemotherapy (ACT) on the oncologic outcomes of resected ampulla of Vater cancer (AoVCa) remains controversial. This study aims to investigate the oncologic outcomes of ACT in resected AoVCa.

Methods : We retrospectively reviewed the clinical and pathologic features and long-term survival of patients with AoVCa who underwent pancreaticoduodenectomy from 2005 to 2019.

Results : A total of 306 patients were included in the study and were divided into two groups: 124 patients who received ACT and 182 patients who did not receive ACT. Multivariate analysis was performed, lymph node metastasis (HR=3.634 [95% CI: 2.260-5.845], p<0.001) and perineural invasion (PNI) (HR=1.895 [95% CI: 1.050-3.419], p=0.034) were found to be independent factors affecting overall survival (OS), while T stage (p<0.001), PNI (HR=2.317 [95% CI: 1.467-3.659], p<0.001), and cancer differentiation (p=0.004) were independent factors affecting disease-free survival (DFS). But ACT had no impact on either the OS (p=0.207) or DFS (p=0.728) in multivariate analysis. When we analyzed OS and DFS by factor for each of the two groups, we found that the outcome of the group that received ACT was worse than that of the group that did not receive ACT in terms of OS and DFS in T1 stage patients and negative lymphovascular invasion patients, DFS in negative PNI patients and well-differentiated cancer patients.

Conclusions : In patients with resected AoVCa, ACT did not affect oncologic outcomes. In particular, ACT was associated with worse outcomes in patients with early-stage AoVCa. For effective ACT in AoVCa patients, further studies are needed to develop factor-specific treatment.