Background — International guidelines recommend peri-operative chemotherapy for patients with resectable colorectal cancer liver metastases (CRCLM). Chemotherapy delivery in routine practice is not well described.
Methods — All cases of CRC who underwent resection of LM in 2002-2009 were identified using the population-based Ontario Cancer Registry. Electronic treatment records identified chemotherapy delivered within 16 weeks before or after hepatectomy. All pathology reports were reviewed to describe extent of LM. Modified Poisson regression was used to evaluate factors associated with chemotherapy delivery. Cox proportional hazards model and propensity score analysis were used to explore the association between post-operative chemotherapy and cancer-specific (CSS) and overall (OS) survival.
Results — We identified 1310 patients. Sixty-two percent of cases (815/1310) received peri-operative chemotherapy; 25% (200/815) pre-operative, 45% (366/815) post-operative, and 31% (249/815) pre- and post-operative. Utilization of chemotherapy increased over time from 51% in 2002 (57/112) to 73% in 2009 (157/216, p<0.001). Fifty-four percent of patients received FOLFOX, 41% FOLFIRI, and 10% 5-FU monotherapy. Factors that were independently associated with greater utilization of post-operative chemotherapy included younger age (p<0.001), female sex (p=0.050), shorter disease-free interval (p=0.006), and no prior adjuvant chemotherapy (p<0.001). Utilization of chemotherapy varied substantially across geographic regions (from 24% to 71%, p=0.001). Post-operative chemotherapy was associated with improved CSS (HR 0.58, 95%CI 0.44-0.76) and OS (HR 0.49, 95%CI 0.38-0.61); results were consistent in propensity score analysis.
Conclusion — Utilization of chemotherapy for resected CRCLM in routine practice has evolved with emerging evidence. Post-operative chemotherapy is associated with improved survival in the general population.
Treatments in oncology