Are we undertreating rectal cancer in the elderly? An epidemiologic study

Objective: To better understand the reasons for decreased survival rates in elderly patients with rectal cancer by performing an epidemiologic evaluation of age-related differences in treatment and survival. Summary Background Data: The incidence of rectal cancer increases with older age, and localized disease can be curatively treated with stage-appropriate radical surgery. However, older patients have been noted to experience decreased survival. Methods: Patients with localized rectal adenocarcinoma were identified in the Surveillance, Epidemiology, and End Results database (1991-2002). Cancer-specific survival by age, sex, surgery type, tumor grade, lymph node status, and use of radiation therapy was evaluated using univariate and multivariate regression analysis. Results: We identified 21,390 patients who met the selection criteria. The median age was 68 years. Each half-decade increase in age >= 70 years was associated with a 37% increase in the relative risk (RR) for cancer-related mortality (RR = 1.37; 95% confidence interval [CI], 1.33-1.42); decreased receipt of cancer-directed surgery (odds ratio [OR] = 0.56; 95% CI, 0.36-0.63); more local excision and less radical surgery (OR = 0.76; 95% CI, 0.72-0.81); less radiotherapy (OR = 0.64; 95% CI, 0.61-0.67); and greater likelihood of NO pathologic stage classification (OR = 1.10; 95% CI, 1.05-1.15) (P < 0.0001 for each factor). The effect of age on cancer-specific mortality persisted in multivariate analysis with each half-decade increase in age >= 70 years resulting in a 31% increase in cancer-specific mortality (RR = 1.31; 95% CI, 1.25-1.36; P < 0.0001). Conclusions: In elderly patients, rectal cancer is characterized by decreased cancer-related survival rates that are associated with less aggressive treatment overall and decreased disease stages at presentation. Investigation into the reasons for these treatment differences may help to define interventions to improve cancer outcomes.