GECOP-MMC: phase IV randomized clinical trial to evaluate the efficacy of hyperthermic intraperitoneal chemotherapy (HIPEC) with mytomicin-C after complete surgical cytoreduction in patients with colon cancer peritoneal metastases.

BACKGROUND: The French PRODIGE 7 trial, published on January 2021, has raised doubts about the specific survival benefit provided by HIPEC with oxaliplatin 460 mg/m2 (30 minutes) for the treatment of peritoneal metastases from colorectal cancer. However, several methodological flaws have been identified in PRODIGE 7, specially the HIPEC protocol or the choice of overall survival as the main endpoint, so its results have not been assumed as definitive, emphasizing the need for further research on HIPEC. It seems that the HIPEC protocol with high-dose mytomicin-C (35 mg/m2) is the preferred regime to evaluate in future clinical studies. METHODS: GECOP-MMC is a prospective, open-label, randomized, multicenter phase IV clinical trial that aims to evaluate the effectiveness of HIPEC with high-dose mytomicin-C in preventing the development of peritoneal recurrence in patients with limited peritoneal metastasis from colon cancer (not rectal), after complete surgical cytoreduction. This study will be performed in 31 Spanish HIPEC centres, starting in March 2022. Additional international recruiting centres are under consideration. Two hundred sixteen patients with PCI ≤ 20, in which complete cytoreduction (CCS 0) has been obtained, will be randomized intraoperatively to arm 1 (with HIPEC) or arm 2 (without HIPEC). We will stratified randomization by surgical PCI (1-10; 11-15; 16-20). Patients in both arms will be treated with personalized systemic chemotherapy. Primary endpoint is peritoneal recurrence-free survival at 3 years. An ancillary study will evaluate the correlation between surgical and pathological PCI, comparing their respective prognostic values. DISCUSSION: HIPEC with high-dose mytomicin-C, in patients with limited (PCI ≤ 20) and completely resected (CCS 0) peritoneal metastases, is assumed to reduce the expected risk of peritoneal recurrence from 50 to 30% at 3 years. TRIAL REGISTRATION: EudraCT number: 2019-004679-37; Clinicaltrials.gov: NCT05250648 (registration date 02/22/2022, ).

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.