Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for Gastric Cancer with Peritoneal Carcinomatosis: Multicenter Study of Spanish Group of Peritoneal Oncologic Surgery (GECOP).

Background: Gastric cancer (GC) with peritoneal carcinomatosis (PC) is traditionally considered a terminal stage of the disease. The use of a multimodal treatment, including cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), can benefit these patients. Our goal was to evaluate the morbidity and survival outcomes of these patients.

Methods: This is a retrospective, multicenter study from a prospective national database of patients diagnosed with PC secondary to GC treated with CRS and HIPEC from June 2006 to October 2017.

Results: Eighty-eight patients from seven specialized Spanish institutions were treated with CRS and HIPEC, with median age of 53 years; 51% were women. Median Peritoneal Cancer Index (PCI) was 6, and complete cytoreduction was achieved in 80 patients (90.9%). HIPEC was administered in 85 cases with 4 different regimens (Cisplatin + Doxorubicin, Mitomycin-C + Cisplatin, Mitomycin-C and Oxaliplatin). Twenty-seven cases (31%) had severe morbidity (grade III-IV) and 3 patients died in the postoperative period (3.4%). Median follow-up was 32 months. Median overall survival (OS) was 21.2 months, with 1-year OS of 79.9% and 3-year OS of 30.9%. Median disease-free survival (DFS) was 11.6 months, with 1-year DFS of 46.1% and 3-year DFS of 21.7%. After multivariate analysis, the extent of peritoneal disease (PCI ≥ 7) was identified as the only independent factor that influenced OS (hazard ratio [HR] 2.37, 95% confidence interval [CI] 1.26-4.46, p = 0.007).

Conclusions: The multimodal treatment, including CRS and HIPEC, for GC with PC can improve the survival results in selected patients (PCI < 7) and in referral centers.