Long-term survival of peritoneal carcinomatosis of colorectal origin

Peritoneal carcinomatosis of colorectal cancer is probably best treated by cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC). In The Netherlands Cancer Institute, this treatment has been performed since 1995. The long tradition of this treatment enabled us to study long-term survival in detail.

Between 1995 and 2003, 117 patients were treated by cytoreduction and HIPEC. The aim of the cytoreduction was to remove all visible tumor. After the cytoreduction, the abdomen was perfused with mitomycin C (35 mg/m2) at 40 degrees C to 41 degrees C for 90 minutes. Survival was calculated by the Kaplan-Meier method. Survival was also analyzed for the following subgroups: no residual tumor, residual tumor < or = 2.5 mm, and more residual tumor. Hazard ratios for each of the seven abdominal regions were calculated to determine the influence on survival.

The median survival was 21.8 months. The 1-, 3-, and 5-year survival rates were 75%, 28%, and 19%, respectively. The Kaplan-Meier curve reached a plateau of 18% at 54 months. In 59 patients a complete cytoreduction was achieved, and in 41 patients there was minimal residual disease. The median survival of these patient groups was 42.9 and 17.4 months, respectively. When gross macroscopic tumor was left behind, as was the case in 17 patients, the median survival was 5 months. Involvement of the small bowel before cytoreduction was associated with poorer outcome.

Cytoreduction followed by HIPEC showed a median survival of 21 months. From 3 years on, a consistent group of 18% of patients stayed alive.