Prognostic Role of Conversion Surgery for Unresectable Gastric Cancer

The prognosis of unresectable gastric cancer is poor. Chemotherapy occasionally converts an initially unresectable gastric cancer to a resectable cancer. The responses of noncurative factors to initial chemotherapy and the outcomes of additional (conversion) surgery were retrospectively evaluated in 151 patients with unresectable gastric cancer receiving combination chemotherapy with S-1 plus cisplatin or paclitaxel from February 2003 to December 2013. Forty (26 %) of 151 patients underwent conversion surgery. After chemotherapy, R0 resection was accomplished in 32 patients (80 %). The 5-year overall survival (OS) rate among the 40 patients who underwent conversion surgery was 43 % (median survival time, 53 months). The 5-year OS rate in the 111 patients treated with chemotherapy alone was 1 % (median survival time, 14 months). Patients who underwent conversion surgery had significantly longer OS times than patients who underwent chemotherapy alone (P < 0.01). The 5-year OS rate among patients who underwent R0 resection was 49 % (median survival time, 62 months). Patients who underwent R0 resection had significantly longer OS times than those who underwent R1 and R2 resection (P = 0.03). Among patients who underwent conversion surgery, multivariate Cox regression analysis showed that one noncurative factor (odds ratio 0.49; 95 % confidence interval 0.28-0.88; P = 0.02) and R0 resection (odds ratio 0.52; 95 % confidence interval 0.28-0.95; P = 0.03) were significant independent predictors for favorable OS. Patients with unresectable gastric cancer initially exhibiting one noncurative factor may obtain a survival benefit from chemotherapy and subsequent curative surgery.