Macroscopic type is implicated in the prognostic impact of initial chemotherapy on peritoneal lavage cytology-positive gastric cancer with no other noncurative factors

Initial chemotherapy (Initial-C) followed by surgery is a promising treatment strategy for peritoneal lavage cytology-positive gastric cancer (CY1 GC) with no other noncurative factors. The aim of this study was to investigate the survival advantage of Initial-C compared to initial surgery (Initial-S) for this disease according to the macroscopic type, which was associated with prognosis and the efficacy of chemotherapy in GC. One hundred eighty-nine patients who were diagnosed with CY1 GC with no other noncurative factors at four institutions from January 2007 to December 2018 were enrolled. The patients were divided into a macroscopic type 4 group (N = 48) and a non-type 4 group (N = 141). The influence of initial treatment on overall survival (OS) in each group was evaluated. In the type 4 group, the 5-year OS rates of Initial-C (N = 35) and Initial-S (N = 13) were 11.6