Postoperative Complications After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Affect Long-term Outcome of Patients With Peritoneal Metastases From Colorectal Cancer: a Two-Center Study of 101 Patients

BACKGROUND: Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy is an effective but potentially morbid treatment for colorectal cancer peritoneal metastases. The impact of treatment-related morbidity on long-term survival has been reported in various malignancies, but it has never been assessed in this clinical setting. OBJECTIVE: The aim of this study was to assess the impact of major postoperative complications on oncological outcomes after cytoreduction and hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases. DESIGN: Two prospective databases were reviewed. Major complications were defined as grade 3 to 5 according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. The extent of peritoneal involvement was scored by the use of the Peritoneal Cancer Index. SETTINGS: This study was conducted in 2 high-volume peritoneal malignancy management centers. PATIENTS: One hundred one consecutive patients with peritoneal metastases potentially amenable to macroscopically complete cytoreduction were selected. INTERVENTIONS: Peritonectomy procedures and multivisceral resections were used to remove all macroscopic tumor, and mitomycin-C plus cisplatin-based hyperthermic intraperitoneal chemotherapy was used to control microscopic residual disease. MAIN OUTCOME MEASURES: The primary outcomes measured were overall and disease-specific survival. RESULTS: Mortality and major morbidity were 3.0%, and 23.8%. Median follow-up was 44.9 months (95% CI, 24.1-65.7). Five-year disease-specific survival was 14.3% for patients who experienced major complications and 52.3% for those who did not (p = 0.001). Five-year overall survival was 11.7% for patients who experienced major complications, and 58.8% for those who did not (p = 0.003). At multivariate analysis, major morbidity correlated to both worse overall and disease-specific survival, along with a Peritoneal Cancer Index > 19, and suboptimal cytoreduction. Poor performance status correlated only to worse disease-specific survival, and liver metastases correlated to worse overall survival. Longer operative time (OR, 4.1; 95% CI, 1.3-12.6; p = 0.01) and Peritoneal Cancer Index > 19 (OR, 2.6; 95% CI, 1.1-6.0; p = 0.02) were independent risk factors for major morbidity. LIMITATIONS: This study is limited by its observational design. CONCLUSIONS: The prevention of major complications, by refining surgical technique and patient selection, is crucial because it affects oncologic outcome.