Survival benefit of adjuvant chemoradiotherapy in patients with ampulla of vater cancer: A systematic review and meta-analysis

Objective: We conducted a systematic review and meta-analysis focusing on the impact of adjuvant radiotherapy (RT) on overall survival (OS) in ampulla of Vater (AoV) cancer. Background: The adjuvant treatment for AoV cancer is a subject of controversy without convincing evidence from randomized study. Methods: A comprehensive search was performed in the databases of EMBASE, PubMed,Web of Science, Cochrane Library, and Ovid from inception to July 2014.We included studies, which compared survival between patients with or without adjuvant RT after curative surgery solely for AoV cancer. Hazard ratio (HR) for OS was extracted, and a random-effects model was used for pooled analysis. Results: Ten retrospective studies including 3361 patients met all inclusion criteria and were included for the final meta-analysis. Adjuvant RT was delivered with concurrent chemotherapy, mostly 5-fluorouracil, in all institutional studies. Generally, adjuvant RT groups included more patients with locally advanced disease or lymph node metastasis than did the surgery alone groups. The pooled results demonstrated that adjuvant RT significantly reduced the risk of death (HR=0.75; P=0.01). Exploratory analyses showed that patients with lymph node metastasis (HR = 0.52; P = 0.001) and locally advanced disease (HR = 0.42; P = 0.001) may also have survival benefit from adjuvant RT. No clear evidence of publication bias was found. Conclusions: This is the first meta-analysis evaluating the role of adjuvant RT in AoV cancer. Our results suggest the potential for survival benefit of adjuvant chemoradiotherapy. Further studies, preferably randomized clinical trials, are needed to confirm our results.