Prognostic Significance of Complete Pathologic Response Obtained with Chemotherapy Versus Chemoradiotherapy in Gastric Cancer

Few studies have compared the survival advantage of complete pathologic response (cPR) achieved through neoadjuvant chemotherapy (nCT) versus neoadjuvant chemoradiotherapy (nCRT) in gastric adenocarcinoma. Our study utilizes a large national cancer database to address this question. This is a retrospective review of patients with clinical stage I to III gastric adenocarcinoma from 2004 to 2013 who received nCT or nCRT. Patients who achieved cPR were selected. Associations were evaluated using Mann–Whitney U and Fisher’s exact tests. Survival information was summarized using standard Kaplan–Meier methods, where estimates of the median and 5-year survival rates were estimated with 95% confidence intervals. A total of 413 patients who had cPR were identified. Eighty-four patients received nCT and 329 patients received nCRT. Patients in the nCRT group had higher clinical stage (88.4% vs. 75.0%) and more proximal location of tumors (95.4% vs. 45.2%). The nCT group (n = 84) had a 94% 5-year survival rate, while the nCRT group’s (n = 329) rate was 60% (p