Trends and Disparities in the Receipt of Treatment for Colon Cancer in Older Adults in Alberta, Canada.

[BACKGROUND] Adults aged ≥ 70 years represent approximately half of all patients diagnosed with colon cancer, but undertreatment in this population persists. Recent guidelines have aimed to reduce age-related biases in the treatment of colon cancer. We evaluated the age-related disparities in the receipt of curative-intent surgical and medical treatment of colon cancer, and their changes over time.

[METHODS] This was a population-based cohort study of adult patients diagnosed with colon adenocarcinoma between 2010 and 2018 in Alberta, Canada. Surgery receipt was assessed in patients with stage I-III disease, while systemic therapy receipt was assessed in stage III to IV disease. Patients were stratified by age at diagnosis (< 70 and ≥ 70 years). Cox proportional hazard models were used to evaluate interactions between age and treatment status, and their associations with cancer-specific survival (CSS). Time trends associated with treatment receipt were identified with multivariable logistic regression.

[RESULTS] Among the 10,838 patients included, 48% were aged ≥ 70 years. For surgery recipients, 5-year CSS was 0.90 (95% CI, 0.88-0.91) and 0.79 (95% CI, 0.77-0.80) for patients < 70 and patients ≥ 70 years of age respectively. Systemic therapy recipients aged < 70 years had a 5-year CSS of 0.57 (95% CI, 0.55-0.60), while individuals aged ≥ 70 years had a 5-year CSS of 0.51 (95% CI, 0.49-0.55). The association between treatment receipt and CSS was independent of age for both treatment modalities (P = .17). Treatment receipt trends remained consistent between 2010 and 2018.

[CONCLUSION] Despite evolving practice guidelines and non-age-dependent survival benefits, disparities persist in the receipt of treatment for older adults with colon adenocarcinoma.