A real-world, population-based study of the outcomes of patients with metastatic colorectal cancer to the peritoneum treated with or without cytoreductive surgery.

OBJECTIVE

To assess the outcomes of metastatic colorectal cancer patients with isolated peritoneal metastasis who were treated with or without cytoreductive surgery in a contemporary real-world, population-based cohort.

METHODS

Surveillance, Epidemiology, and End Results (SEER) database has been accessed and metastatic colorectal cancer patients to the peritoneum who have no evidence of other sites of distant metastases and who were diagnosed 2010-2015 were reviewed. Multivariable logistic regression analysis was then used to assess the patient- and treatment-related factors predicting the decision to do cytoreductive surgery. Kaplan-Meier survival estimates were used to compare overall survival according to cytoreductive surgery. Multivariable Cox regression analysis was additionally used to assess the impact of cytoreductive surgery on colorectal cancer-specific survival.

RESULTS

A total of 3153 records were reviewed in the current analysis. Using Kaplan-Meier survival estimates, cytoreductive surgery was associated with improved overall survival (median overall survival, 19 months for patients with cytoreductive surgery versus 12 months for patients without cytoreductive surgery; P < 0.001). In an adjusted Cox regression model evaluating the impact of cytoreductive surgery on colorectal cancer-specific survival, cytoreductive surgery was associated with better colorectal cancer-specific survival (hazard ratio for death among patients who did not have cytoreductive surgery versus patients who had cytoreductive surgery, 1.312; 95% CI, 1.175-1.465; P < 0.001).

CONCLUSIONS

Cytoreductive surgery is associated with improved survival outcomes among colorectal cancer patients with peritoneal metastasis and no evidence of other distant metastases. Opimal utilization of this intervention needs to be further evaluated in prospective controlled trials.