Impact of adjuvant treatment in elderly patients with locally advanced rectal cancer: A population-based retrospective study.

Abstract

3613 Background: Little is known about the benefit and use of adjuvant chemotherapy (ADJ) in the elderly population (age ≥ 65) with locally advanced rectal cancer (LARC). We undertook a provincial review of LARC patients to evaluate the potential benefits, including survival and time to relapse (TTR), of ADJ in elderly patients. Methods: We performed a retrospective analysis of 286 LARC patients (stage 2 and 3) diagnosed between January 2010 and December 2013 from Nova Scotia, Canada, who underwent curative-intent surgery. Baseline patient, tumor and treatment characteristics were collected. Survival and TTR analysis were performed using Kaplan-Meier and Cox-regression statistics. Results: 152 patients were age ≥65, and 92 age ≥70. Median follow-up was 46 months. 178 patients (62%) received neoadjuvant chemo-radiation (NEOADJ). While 109 patients (81%) age < 65 received ADJ, only 68 patients (45%) age ≥ 65 received ADJ. Kaplan-Meier analysis revealed a significant survival and TTR advantage for ADJ irrespective of age (table). In cox-regression multivariate analysis, ECOG status, T stage, and ADJ were significant predictors of survival (p < 0.04), while age was not. Similarly, N stage, NEOADJ, and ADJ were significant predictors of TTR (p < 0.007). Poor ECOG status was the most common cause of ADJ omission. There was a significantly higher amount of grade≥ 1 chemotherapy-related toxicity experienced by patients age ≥ 65 treated with ADJ compared to no ADJ (77% vs 32%, p < 0.0001), which consisted mostly of diarrhea and mucositis. Toxicity was the main reason for non-completion of ADJ in the elderly. Conclusions: Elderly patients with LARC have significantly improved overall survival with ADJ, but the use of ADJ is lower than in patients age < 65. However, elderly patients experience more chemotherapy-related toxicities, leading to higher rates of early treatment discontinuation. [Table: see text]