Biology remains the ultimate arbiter of survival in metastatic colorectal cancer. Invited commentary on “Multiple colorectal liver metastases resection can offer long-term survival. The concept of a chronic neoplastic disease.”

Colorectal cancer is the 3^rd most common cause of cancer and the 3^rd-leading cause of death in the United States. Approximately 25% of patients with newly diagnosed colorectal cancer have metastatic disease at presentation, and overall, around 60% of patients will develop metastatic disease at some point during their treatment course. The liver is the most common and often the only site of distant spread. While initially met with skepticism in the 1980s , liver resection with or without ablation is now widely accepted at the gold standard for liver-directed therapy in patients with technically resectable disease who are appropriate surgical candidates. The group from Memorial Sloan Kettering Cancer Center recently reviewed institutional outcomes from 1,211 patients from an earlier time period (1992-2004) and reported rates of actual 10-year overall survival and cure. The median disease-specific survival was approximately 5 years and estimated 10-year disease-specific survival was 34%, with an observed cure rate (defined as 10-year survival with no recurrence or resected recurrence with ≥3 years of disease-free follow-up) of 21%. There were no individual prognostic factors predictive of cure, but cure rates were <10% in patients with extrahepatic disease, margin-positive resections, carcinoembryonic antigen >200ng/ml, or >10 metastases. In patients with 5-10 liver metastases, the 10-year overall survival was 18% and observed cure rate was 13%. It must be acknowledged that without the advancements in chemotherapeutics, targeted therapy, and immunotherapy, the role and survival benefits of metastasectomy in this disease space would be far more limited.