Surgical resection and peri-operative chemotherapy for colorectal cancer liver metastases: A population-based study

Most literature describing surgery for colorectal cancer (CRC) liver metastases (LM) comes from high volume centres. Here, we report management and outcomes achieved in routine clinical practice.

All cases of CRC in Ontario who underwent resection of LM in 1994-2009 were identified using the population-based Ontario Cancer Registry. Electronic treatment records identified chemotherapy delivery. Temporal trends are described for 3 periods: 1994-1999, 2000-2004, 2005-2009. We describe volume of resected CRCLM as a ratio of incident cases per CRCLM resection. Overall (OS) and cancer-specific survival (CSS) are measured from time of LM resection.

2717 patients underwent resection of CRCLM. Between 1994 and 2009 there was a 78% increase in case volume; from one resection for every 48 incident cases to one resection for every 27 incident cases, p < 0.001. Use of peri-operative chemotherapy increased over study periods from 44% (306/700), to 52% (429/830), to 65% (777/1187, p < 0.001). Chemotherapy utilization rates varied across geographic regions (range 43%-69%, p < 0.001). Post-operative mortality rates at 30 and 90 days were 2.5% and 4.3% respectively. Five year OS during the study periods was 36% (95% CI 32-39%), 40% (95% CI 36-43%), and 46% (95% CI 43-49%) (p < 0.001); CSS was 38% (95% CI 35-42%), 42% (95% CI 38-45%), 49% (95% CI 44-53%) (p < 0.001). The temporal improvement in OS/CSS persisted on adjusted analyses.

Outcomes of patients with resected CRCLM in routine practice is comparable to those reported from high volume centres. Survival improved over the study period despite a greater proportion of patients with CRC undergoing liver resection.