Reciprocity between lymphadenectomy quality and adjuvant chemotherapy compliance in gastric cancer: post hoc analysis of two randomized controlled trials.

Abstract

To investigate the effect of intraoperative lymph node (LN) dissection and postoperative adjuvant chemotherapy on the overall survival (OS) of gastric cancer (GC) patients and their reciprocity. LN noncompliance was defined as the absence of more than one LN station, as described in the protocol for D2 lymphadenectomy in the Japanese Gastric Cancer Association. The definition of adjuvant chemotherapy (AC) noncompliance was that the chemotherapy planned dose does not meet the requirements. Kaplan-Meier survival curves showed that the OS of patients with major LN noncompliance was significantly lower than that of patients with nonmajor LN noncompliance, and the OS of AC noncompliance patients was significantly lower than that of AC compliance patients. If there was nonmajor LN noncompliance during surgery, the OS of patients with AC compliance was significantly higher than that of patients with AC noncompliance (P = 0.035). In the case of major LN noncompliance during surgery, there was no statistically significant difference in OS between those with AC compliance and those with AC noncompliance (P = 0.682). Multivariate Cox regression analysis including AC noncompliance indicated that major LN noncompliance was an independent prognostic factor for poor OS (P = 0.012), while AC noncompliance was not an independent prognostic factor for OS (P = 0.609). Adequate lymph node dissection and adjuvant chemotherapy are both key steps to improve the awful prognosis of GC patients. Adjuvant chemotherapy may fail to remedy the poor prognosis caused by major LN noncompliance.