Adjuvant chemotherapy for colon cancer in the elderly: moving from evidence to practice

With a median age at diagnosis of 71 years old and the aging of the US population, colon cancer commonly occurs in the elderly. Adjuvant chemotherapy has been standard of care for stage III disease following complete surgical resection since 1990, but insufficient numbers of patients over 75 years old are participating in clinical trials, and a disparity persists in the administration of standard adjuvant therapy between younger and older Americans despite a meaningful survival advantage for most patients. A large pooled analysis of seven clinical trials supports the administration of adjuvant chemotherapy to otherwise-fit elderly patients, and registry studies have confirmed similar benefits in Medicare beneficiaries. Otherwise-fit elderly patients enrolled in clinical trials do not appear to have more side effects aside from myelosuppression and fatigue. In this review, I discuss the potential benefits and harm of adjuvant therapy in older patients, with a focus on the role of comorbid illness in individualizing decision-making, current standard drug options in the adjuvant setting, and barriers to treatment. Although chronologic age alone should not be an exclusion criterion, more work is needed to establish an optimal and efficient strategy for choosing who would benefit most from adjuvant treatment following surgical resection.