Selective Gastric Cancer Patients with Peritoneal Seeding Benefit from Gastrectomy after Palliative Chemotherapy: A Propensity Score Matching Analysis.

Background: The present study aimed to explore whether gastric cancer patients with peritoneal seeding after receiving palliative chemotherapy could benefit from gastrectomy and to identify patients with peritoneal seeding who should be selected to receive gastrectomy. Methods: A total of 201 gastric cancer patients were diagnosed with peritoneal seeding and received palliative chemotherapy. Propensity score matching (PSM) was performed to balance the selection bias. Results: After PSM, compared with non-gastrectomy group, gastrectomy group had a longer median overall survival (OS) (23.60 vs. 13.80 moths; P=0.034). Patients with R0 resection had a median OS of 43.60 months compared with 11.27 months in patients who underwent R1/2 resection (P<0.001). The median OS times between the R1/2 resection and non-gastrectomy groups were not different (P=0.139). Subgroup analysis revealed that only patients receiving more than 4 periods of first-line chemotherapy benefited from gastrectomy (P=0.018), whereas patients receiving 1-4 periods of first-line chemotherapy did not (P=0.275). Multivariate analysis showed that gastrectomy (P=0.012) and the period of first-line chemotherapy (P<0.001) were independent prognostic factors. The overall postoperative morbidity was 3.03% (1/33) in the gastrectomy group, and no treatment-related death was observed. Conclusions: The present study indicated that gastrectomy after palliative chemotherapy is a safe procedure and showed a survival benefit for gastric cancer patients with peritoneal seeding. Moreover, clinically curative R0 gastrectomy and more than 4 periods of palliative chemotherapy resulted in better clinical outcomes.