Survival after hepatic resection in metastatic colorectal cancer. A population-based study
Linda C. Cummings, MD *, Jonathan D. Payes, MA, Gregory S. Cooper, MD Cancer 2007;109:718
 
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.
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Patients aged 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.
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.
Survival after hepatic resection of colorectal cancer metastases
Cancer 2009;115:752

Most estimates of short- and long-term survival after hepatic resection of colorectal cancer metastases are derived from surgical case series. For the current report, the authors used Medicare data to investigate operative mortality and long-term survival in a national sample and examined the factors associated with survival. Data were analyzed from Medicare enrollees (age 65 years) who were admitted to hospital between January 1, 2000 and December 31, 2004 with a primary diagnosis of colorectal cancer with resection. The sample was restricted to patients who subsequently underwent hepatic resection for liver metastases.

Of the 306,061 Medicare beneficiaries who were diagnosed with colorectal cancer, 3957 patients were identified who underwent hepatic resection for liver metastases. The crude 30-day and 90-day mortality rates were 4% and 8.2%, respectively, and the 5-year survival rate was 25.5%.  In this national study, short- and long-term survival was worse than that reported in surgical case series. Subgroups at high risk for worse outcomes include the extreme elderly and those undergoing synchronous colon and hepatic resection.