Pilot study of adjuvant hyperthermic intraperitoneal chemotherapy in patients with colorectal cancer at high risk for the development of peritoneal metastases.

AIMS AND BACKGROUND: The prognosis of peritoneal metastases from colorectal cancer has recently improved with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Although outcomes are further improved when early stage peritoneal metastases are treated, adjuvant hyperthermic intraperitoneal chemotherapy has never been thoroughly addressed. This prospective pilot study assessed feasibility, safety and efficacy of hyperthermic intraperitoneal chemotherapy combined with primary curative surgery in colorectal cancer at high risk for peritoneal metastases. METHODS: Twelve patients were prospectively selected according to predetermined risk factors for the development of peritoneal metastases. Patients underwent conventional colon surgery, closed-abdomen mitomycin-C plus cisplatin-based hyperthermic intraperitoneal chemotherapy, and cytoreductive surgical procedures, as needed. RESULTS: Preoperative tumor-related risk factors were confirmed by intraoperative findings and pathological examination in all patients: minimal synchronous peritoneal metastases (n = 2), synchronous ovarian metastases (n = 1), positive peritoneal washing cytology (n = 2), primary tumor directly invading other organs (n = 6), or penetrating visceral peritoneum (n = 1). Major morbidity occurred in 2 patients and operative death in none. Median follow-up was 49 months (range, 22-72). Peritoneal metastases occurred in 1 patient and distant metastases in 2. Five-year overall survival was 83.3%. CONCLUSIONS: Preoperative/early intraoperative assessment can reliably identify colorectal cancer patients at high risk for peritoneal metastases. Adjuvant hyperthermic intraperitoneal chemotherapy is well tolerated and safe. These preliminary results would support the design of future phase-III trials of adjuvant hyperthermic intraperitoneal chemotherapy.