Age-related inequalities in colon cancer treatment persist over time: A population-based analysis

Background Older people experience poorer outcomes from colon cancer. We examined if treatment for colon cancer was related to age and if inequalities changed over time. Methods Data from the UK population-based Northern and Yorkshire Cancer Registry on 31 910 incident colon cancers (ICD10 C18) diagnosed between 1999-2010 were obtained. Likelihood of receipt of: (1) cancer-directed surgery, (2) chemotherapy in surgical patients, (3) chemotherapy in non-surgical patients by age, adjusting for sex, area deprivation, cancer stage, comorbidity and period of diagnosis, was examined. Results Age-related inequalities in treatment exist after adjustment for confounding factors. Patients aged 60-69, 70-79 and 80+ years were significantly less likely to receive surgery than those aged <60 years (multivariable ORs (95% CI) 0.84(0.74 to 0.95), 0.54(0.48 to 0.61) and 0.19(0.17 to 0.21), respectively). Age-related differences in receipt of surgery and adjuvant chemotherapy (but not chemotherapy in non-surgical patients) narrowed over time for the 'younger old' (aged <80 years) but did not diminish for the oldest patients. Conclusions Age inequality in treatment of colon cancer remains after adjustment for confounders, suggesting age remains a major factor in treatment decisions. Research is needed to better understand the cancer treatment decision-making process, and how to influence this, for older patients.