Safety and efficacy of radioembolization in elderly (≥ 70 years) and younger patients with unresectable liver-dominant colorectal cancer

Background The effects of advancing age on clinical outcomes after radioembolization (RE) in patients with unresectable liver-dominant metastatic colorectal cancer (mCRC) are largely unknown. Patients and Methods This study was a retrospective analysis of 160 elderly (≥ 70 years) and 446 younger (< 70 years) consecutive patients from 11 US centers who received RE using ytrrium-90 (⁹⁰Y) resin microspheres (⁹⁰Y radioembolization [⁹⁰Y-RE]) between July 2002 and December 2011. A further analysis was conducted in 98 very elderly patients (≥ 75 years). Statistical analyses of safety, tolerability, and overall survival were conducted. Results Mean ages (± standard deviation) in the younger (< 70 years), elderly (≥ 70 years), and very elderly (≥ 75 years) cohorts were 55.9 ± 9.4 years, 77.2 ± 4.8 years, and 80.2 ± 3.8 years, respectively. Overall survival was similar between elderly and younger patients: 9.3 months (95% confidence interval [CI], 8.0-12.1) and 9.7 months (95% CI, 9.0-11.4) (P =.335). There were no differences between cohorts for any grade adverse events (P =.433) or grade 3+ events (P =.482). Analysis of patients ≥ 75 years and < 75 years confirmed similar overall survival (median, 9.3 months vs. 9.6 months, respectively; P =.987) and grade 3+ events (P =.398) or any adverse event (P =.158) within 90 days of RE. Conclusion For patients with unresectable liver-dominant mCRC who meet eligibility criteria for RE, ⁹⁰Y-RE microspheres appear to be effective and well-tolerated, regardless of age. Criteria for selecting patients for RE should not include age for exclusion from this potentially beneficial intervention.