Peritoneal carcinomatosis in colorectal cancer: Defining predictive factors for successful cytoreductive surgery and hyperthermic intraperitoneal chemotherapy - A pilot study.

BACKGROUND: Peritoneal carcinomatosis originating from colorectal cancer (PC-CRC) carries a dismal prognosis. Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) have been offered to those patients with substantial health and economic burden, nevertheless not all patients are fitting this treatment modality and outcome is generally still poor.

OBJECTIVE: To elicit predictive factors associated with the success of CRS and HIPEC in PC-CRC patients.

PATIENTS AND METHODS: This is a pilot study including 30 consecutive patients with PC-CRC; 20 of them (66.7%) presented with metachronous peritoneal disease. All patients were planned for CRS and HIPEC with Mitomycin-C after receiving preoperative systemic chemotherapy for 3 months.

RESULTS: On exploration, CRS and HIPEC were successful in 17 patients (56.6%) who had completeness of cytoreduction score 0-1 (CC-0/1), whereas failure (CC-2) was encountered in 13 patients (43.3%). The presence of ascites, extensive peritoneal disease (PCI > 20) was significantly correlated with failure to achieve CRS and HIPEC (p < 0.001); also, the primary rectal site showed a trend towards significance (p = 0.08). The cumulative overall survival (OS) and progression-free survival (PFS) at 2 years were 66.6 and 62.6%, respectively. Patients who achieved CC-0/1 had significantly prolonged OS compared to CC-2 (p < 0.001). On multivariate analysis, the CC score and the original site were independent prognostic factors for OS (p = 0.04 and 0.02, respectively).

CONCLUSION: In patients with PC-CRC, malignant ascites and PCI > 20 are poor prognostic factors associated with failure to accomplish CRS with consequent poor survival.