Combined modality treatment of patients with stage IV gastric cancer with peritoneal carcinomatosis

Peritoneal carcinomatosis is associated with poor prognosis in gastric cancer patients. Stage IV gastric cancer (GC) is diagnosed in 39.8 % of patients; local metastases without evidence of distant metastases occur only in 18-20 % of stage IV gastric cancer patients. The purpose of the study was to estimate the efficacy of personalized chemotherapy in the combined modality treatment of patients with stage IV GC with peritoneal carcinomatosis. Material and Methods. Cytoreductive surgery was performed in 70 patients with GC with peritoneal dissemination. The control group patients (n=35) received postoperative chemotherapy with the FOLFOX regimen. The study group patients (n=35) received personalized systemic and intraperitoneal chemotherapy based on the expression of chemosensitivity and resistance genes. Results. The median survival time (18.7 months) in the study group patients was higher than that in the control group and in studies described in the world literature (CRS + HIPEC). Personalized chemotherapy improved median progression-free survival (PFS) by 4.6 months (29.1 %) and median overall survival (OS) by 6 months (32 %) compared to FOLFOX regimen chemotherapy. In the study group, the 1-, 2- and 3-year survival rates were observed in 35 (100 %), 9 (27 %) and 1 (3 %) patients, respectively. Conclusion. Personalized chemotherapy in the combined modality treatment can improve long-term treatment outcomes (longer median PFS and OS) in GC patients with peritoneal dissemination.