Determinants of cancer therapy in elderly patients

BACKGROUND: Older patients with cancer are less likely to receive definitive therapy, but the reasons for this are unclear. METHODS: All people aged 65 years or older living in six counties in New Mexico and diagnosed with breast, prostate, or colorectal cancer between May 15, 1984 and May 15, 1986 (N = 669) were interviewed to obtain information on demographics, socioeconomic status, functional status, social support, other medical conditions, and cognitive status. Cancer treatment information was obtained from the New Mexico Tumor Registry. RESULTS: In univariate analyses, the following variables were associated significantly with nonreceipt of definitive therapy for cancer: advanced age, impairment in activities of daily living, low physical activity, decreased mental status, impaired access to transportation, and poor social support. In a multivariate analysis with the above variables along with measures of comorbidity, only advanced age and decreased mental status remained significant predictors of nonreceipt of definitive surgery, whereas the effects of impaired access to transportation and low physical activity remained relatively large but no longer were statistically significant. When receipt of surgery and receipt of radiation therapy were considered separately, older age, limited access to transportation, impaired functional status, and impaired mental status all significantly predicted nonreceipt of radiation therapy, but not surgery. CONCLUSIONS: There is a decline with age in the percentage of adults with cancer who received definitive therapy independent of other potentially explanatory factors such as comorbidity. In addition, decisions about radiation may be influenced by nonmedical, potentially correctable factors such as impaired access to transportation.