8-year follow-up of randomized trial: cytoreduction and hyperthermic intraperitoneal chemotherapy versus systemic chemotherapy in patients with peritoneal carcinomatosis of colorectal cancer.

Introduction: The treatment of peritoneal carcinomatosis is based on cytoreduction followed by hyperthermic intraperitoneal chemotherapy and combined with adjuvant chemotherapy. In 2003, a randomized trial was finished comparing systemic chemotherapy alone with cytoreduction followed by hyperthermic intraperitoneal chemotherapy and systemic chemotherapy. This trial showed a positive result favoring the studied treatment. This trial has now been updated to a minimal follow-up of 6 years to show long-term results.

Patients And Methods: For all patients still alive, the follow-up was updated until 2007. In the original study, four patients were excluded-two because of no eligible histology/pathology and two because of major protocol violations. After randomization, four patients in the HIPEC arm and six in the control arm were not treated using the intended therapy, one patient because of withdrawal, one because of a life-threatening other malignant disease and the others because of progressive disease before initiation of the treatment. During the follow-up, one patient was crossed over from the control arm and underwent cytoreduction and HIPEC for recurrent disease, after the assigned treatment was completed. The data from these patients were censored at the moment of the cross-over. Progression-free and disease-specific survival were analyzed using the Kaplan Meyer test and compared using the log rank method. The long-term results were studied in more detail to evaluate efficacy and toxicity.

Results: At the time of this update, the median follow-up was almost 8 years (range 72-115 months). In the standard arm, 4 patients were still alive, 2 with and 2 without disease; in the "HIPEC' arm, 5 patients were still alive, 2 with and 3 without disease. The median progression-free survival was 7.7 months in the control arm and 12.6 months in the HIPEC arm (P = 0.020). The median disease-specific survival was 12.6 months in the control arm and 22.2 months in the HIPEC arm (P = 0.028). The 5-year survival was 45% for those patients in whom a R1 resection was achieved.

Conclusion: With 90% of all events having taken place up to this time, this randomized trial shows that cytoreduction followed by HIPEC does significantly add survival time to patients affected by peritoneal carcinomatosis of colorectal origin. For a selected group, there is a possibility of long-term survival.