Adjuvant treatment in older patients with rectal cancer: a population-based review.

Background: Little is known about the benefits of adjuvant chemotherapy (adj) in the older population with locally advanced rectal cancer (larc). We evaluated use of adj, survival outcomes, and adj-related toxicity in older patients with larc.
Methods: Our retrospective review included 286 patients with larc (stages ii and iii) diagnosed between January 2010 and December 2013 in Nova Scotia who underwent curative-intent surgery. Baseline patient, tumour, and treatment characteristics were collected. The survival analysis used the Kaplan-Meier method and Cox regression statistics.
Results: Of 286 identified patients, 152 were 65 years of age or older, and 92 were 70 years of age or older. Median follow-up was 46 months, and 163 patients (57%) received neoadjuvant chemoradiation. Although adj was given to 81% of patients (n = 109) less than 65 years of age, only 29% patients (n = 27) 70 years of age and older received adj. Kaplan-Meier analysis suggested a potential survival advantage for adj regardless of age. In multivariate Cox regression analysis, Eastern Cooperative Oncology Group performance status, T stage, and adj were significant predictors of overall survival (p < 0.04); age was not. Similarly, N stage, neoadjuvant chemoradiation, and adj were significant predictors of disease-free survival (p < 0.01). Poor Eastern Cooperative Oncology Group performance status was the most common cause of adj omission. In patients 70 years of age and older, grade 1 or greater chemotherapy-related toxicities were experienced significantly more often by those treated with adj (85% vs. 68% for those not treated with adj, p < 0.05). Conclusions: Regardless of age, patients with larc seem to experience a survival benefit with adj. However, older patients are less likely to receive adj, and when they do, they experience more chemotherapy-related toxicities.