Neoadjuvant chemotherapy vs upfront surgery for gastric signet ring cell carcinoma: A retrospective, propensity score-matched study

BACKGROUND: The benefit of neoadjuvant chemotherapy for patients with signet-ring cell carcinoma of the stomach is controversial. AIM: To evaluate the perioperative and long-term outcomes of neoadjuvant chemotherapy for locally advanced gastric signet-ring cell carcinoma. METHODS: This retrospective study identified patients with locally advanced signet-ring cell carcinomas of the stomach (cT3/4 and cN any) diagnosed from January 2012 to December 2017 by using the clinical Tumor-Node-Metastasis (cTNM) staging system. We performed 1:1 propensity score matching (PSM) to reduce bias in patient selection. The histologic and prognostic effects of neoadjuvant chemotherapy were assessed. The overall survival rates were used as the outcome measure to compare the efficacy of neoadjuvant chemotherapy vs surgery-first treatment in the selected patients. RESULTS: Of the 144 patients eligible for this study, 36 received neoadjuvant chemotherapy, and 108 received initial surgery after diagnosis. After adjustment by PSM, 36 pairs of patients were generated, and baseline characteristics, including age, sex, American Society of Anesthesiologists score, tumor location, and cTNM stage, were similar between the two groups. The R0 resection rates were 88.9% and 86.1% in the surgery-first and neoadjuvant chemotherapy groups after PSM, respectively (P = 1.000). The median follow-up period was 46.4 mo. The 5-year overall survival rates of the neoadjuvant chemotherapy group and surgery-first group were 50.0% and 65.0% (P = 0.235), respectively, before PSM and 50% and 64.7% (P = 0.192), respectively, after PSM. Multivariate analyses conducted before and after PSM showed that NAC was not a prognostic factor. CONCLUSION: Neoadjuvant chemotherapy provides no survival benefit in patients with locally advanced gastric signet-ring cell carcinoma. For resectable gastric signet-ring cell carcinoma, upfront surgery should be the primary therapy.