Impact of interval timing to surgery on tumor response after neoadjuvant treatment for gastric cancer

neoadjuvant chemotherapy (NACT) followed by radical surgery is the optimal approach for locally advanced gastric cancer (GC). Interval timing to surgery after NACT in GC is controversial. The aim of this study was to evaluate the impact of NACT interval time on tumor response and overall survival.

a retrospective analysis from a prospective database was performed at a single referral tertiary hospital, from January 2010 to October 2018. Patients were assigned to three groups according to the surgical interval time after NACT: < 4 weeks, 4-6 weeks and > 6 weeks. Univariate and multivariable analyses were performed in order to clarify the impact of NACT on post-neoadjuvant pathological complete response rate (ypCR), downstaging (DS) and overall survival (OS).

of the 60 patients analyzed, 18 patients (30 %) had an interval time to surgery < 4 weeks, 26 (43.3 %) between 4-6 weeks and 16 (26.7 %) > 6 weeks. Two patients (3 %) had achieved ypCR and 37 patients (62 %) had achieved DS. There were no differences in DS rates among the interval time groups (p: 0.66). According to the multivariate analysis, only poorly differentiated carcinoma was significantly related to lower DS rates (p: 0.04). Cox regression analysis showed that the NACT interval time had no impact on OS. According to the multivariate analysis, > 25 lymph node harvested (HR: 0.35) and female sex (HR: 5.67) were OS independent predictors.

the NACT interval time prior gastrectomy for locally advanced GC is not associated with ypCR or DS and has no impact on overall survival.