Risk-stratification model to select conversion surgery for advanced gastric cancer patients

OBJECTIVE: Conversion surgery is a surgery with a purpose of R0 resection in primary advanced gastric cancer (GC) that responded well to systemic chemotherapy. This study aimed to explore the efficacy of conversion surgery for advanced GC. METHODS: A total of 618 advanced GC patients receiving systemic chemotherapy were stratified into low-, moderate- and high-risk groups based on a nomogram-predicted probability of overall survival. The survival of conversion surgery and chemotherapy alone groups was compared using the log-rank test and Cox regression analysis after propensity score matching (PSM). RESULTS: A nomogram with good discrimination (concordance index: 0.65) and accurate calibration was constructed. After PSM, the median survival time (MST) of conversion surgery was 26.80 months, compared with 16.60 months of chemotherapy alone (P<0.001). Conversion surgery was associated with a longer MST for patients in the low-risk group (30.40 monthsvs. 20.90 months, P=0.013), whereas it was not associated with prolonged survival in the moderate- and high-risk groups (P=0.221 and P=0.131, respectively). CONCLUSIONS: Conversion surgery was associated with longer survival, especially for low-risk population.