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.