Cancer rates, medical comorbidities, and treatment modalities in the oldest patients.

Cancer disproportionately afflicts older patients, with 56% of incident diagnoses and 71% of deaths occurring in this population. Yet little is known about the "oldest of the old", oncology patients underrepresented in clinical trials. We examined elderly veterans diagnosed with lung, colorectal, prostate or head-neck cancer in 2005 (n=194,797), analyses comparing treatment receipt by age group, 70-84 versus 85-115. Treatment was more common among younger elders, including surgery (1.3% versus 0.6%), chemotherapy (2.1% versus 0.8%) and radiation (1.7% versus 0.7%). Differences were sharper for certain cancers, e.g., chemotherapy for lung (9.0% versus 2.9%), or colorectal surgery (5.8% versus 3.4%). Cancer prevalence is high among elders yet treatment rates appear extremely low, despite evidence of well-tolerated treatment. Toxicity concerns and comorbidities may inhibit pursuit of definitive treatment. As we reconcile definitions of 'elderly' with appropriate treatment options, compassionate care requires identifying geriatric oncology guidelines that improve survival and quality of life.