Impact of liver-directed therapy in colorectal cancer liver metastases

Background There is a paucity of data on the current management and outcomes of liver-directed therapy (LDT) in older patients presenting with stage IV colorectal cancer (CRC). The aim of the study was to evaluate treatment patterns and outcomes in use of LDT in the setting of improved chemotherapy. Methods We used Cancer Registry and linked Medicare claims to identify patients aged ≥66 y undergoing surgical resection of the primary tumor and chemotherapy after presenting with stage IV CRC (2001-2007). LDT was defined as liver resection and/or ablation-embolization. Results We identified 5500 patients. LDT was used in 34.9% of patients; liver resection was performed in 1686 patients (30.7%), and ablation-embolization in 554 patients (10.1%), with 322 patients having both resection and ablation-embolization. Use of LDT was negatively associated with increasing year of diagnosis (odds ratio [OR] = 0.96, 95% confidence interval [CI] 0.93-0.99), age >85 y (OR = 0.61, 95% CI 0.45-0.82), and poor tumor differentiation (OR = 0.73, 95% CI 0.64-0.83). LDT was associated with improved survival (median 28.4 versus 21.1 mo, P < 0.0001); however, survival improved for all patients over time. We found a significant interaction between LDT and period of diagnosis and noted a greater survival improvement with LDT for those diagnosed in the late (2005-2007) period. Conclusions Older patients with stage IV CRC are experiencing improved survival over time, independent of age, comorbidity, and use of LDT. However, many older patients deemed to be appropriate candidates for resection of the primary tumor and receipt of systemic chemotherapy did not receive LDT. Our data suggest that improved patient selection may be positively impacting outcomes. Early referral and optimal selection of patients for LDT has the potential to further improve survival in older patients presenting with advanced colorectal cancer.