Survival after hepatic resection in metastatic colorectal cancer: a population-based study.

Background: Hepatectomy is the standard of care for patients with colorectal cancer who have isolated hepatic metastases; however, the long-term survival benefits of hepatectomy in this population have not been characterized well outside of case series. For the current study, a population-based database was used to compare the survival of patients with liver metastases from colorectal cancer who did and did not undergo hepatectomy.

Methods: Patients aged >or=65 years with incident colorectal cancer who were diagnosed from 1991 to 2001 were identified from the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database. Liver metastasis diagnoses, colorectal resections, and hepatectomies were identified from hospital, outpatient, and physician-supplier claims. Patients who did not undergo colorectal resection were excluded. Five-year survival from the time of cancer diagnosis was determined by the Kaplan-Meier method. Cox proportional hazards models were used to evaluate survival.

Results: Among 13,599 patients who were identified with incident colorectal cancer and liver metastases, 7673 patients (56.4%) presented with stage IV disease, and the remaining patients presented with earlier stage disease and developed subsequent metastases. Only 833 patients (6.1%) in the cohort underwent hepatic resection, and their 30-day mortality rate was 4.3%. The 5-year survival was 32.8% among patients who underwent hepatic resection, compared with 10.5% among patients who did not undergo hepatic resection (P < .0001), and better survival was observed in the subset of patients who presented initially with disease in stages I through III. In a Cox model, which was controlled for age, sex, race, comorbidities, and stage at presentation, lack of hepatic resection was associated with a 2.78-fold increased risk of death.

Conclusions: Although hepatectomy rates among patients with colorectal cancer were low, hepatic resection was associated with improved survival.