Impact of the peritoneal surface disease severity score on survival in patients with colorectal cancer peritoneal carcinomatosis undergoing complete cytoreduction and hyperthermic intraperitoneal chemotherapy.

BACKGROUND: In patients with colorectal cancer peritoneal carcinomatosis (CRPC), only patients with a complete cytoreduction will benefit. The current selection criteria are ill-defined. The Peritoneal Surface Disease Severity (PSDS) staging was introduced as a basis of scoring patients into prognostic groups to improve patient selection. This study determines the impact on survival of the PSDS in a cohort of patients undergoing complete cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for CRPC.
MATERIALS AND METHODS: A retrospective review of two prospective databases of patients with complete CRS and HIPEC for CRPC was performed to score patients on the PSDS. Survival was analyzed using the Kaplan-Meier method. Univariate and multivariate analyses were performed to determine the impact of various clinicopathological factors on survival.
RESULTS: There were 56 patients who underwent complete cytoreduction and HIPEC. Of these, 6 patients (11%) were PSDS stage I and median survival (MS) has not been reached, 33 patients (59%) were PSDS stage II and MS was 38 months, 10 patients (18%) were PSDS stage III and MS was 24 months, and 7 patients (13%) were PSDS stage IV and MS was 7 months. Univariate analysis demonstrated the association of clinical symptoms (P = .022), PSDS (P = .002), and tumor histopathology (P = .074) as factors affecting survival. Multivariate analysis demonstrated that PSDS (P = .002) was an independent positive predictive factor associated with survival.
CONCLUSIONS: In patients with CRPC who undergo a complete cytoreduction and HIPEC, the PSDS staging system has been demonstrated to be an important prognostic indicator. It appears that even with a complete cytoreduction and HIPEC, patients with PSDS stage IV do not benefit from treatment.