Functioning of older, long-term cancer survivors: The role of cancer and comorbidities

OBJECTIVES: To examine the relative effect of comorbidities, noncancer symptoms, and cancer-related factors on the functioning of older adult long-term survivors of breast, colorectal, and prostate cancers. DESIGN: Data from in-person interviews with survivors of a tumor registry-based stratified random sample were used to test a multivariate model using ordinary least-squares regression. SETTING: Survivors were identified in the tumor registry of a National Cancer Institute-designated Comprehensive Cancer Center in Cleveland, Ohio. PARTICIPANTS: Three hundred twenty-one older (≥60), long-term (≥5 years) cancer survivors. MEASUREMENTS: The primary outcome measure, functional difficulty, was measured using Nagi's Performance Limitations Index. Predictors included a number of indicators of survivors' personal characteristics, age-related health characteristics, and cancer-related characteristics. RESULTS: The model explained 44% of the variance in functional difficulties between the cancer survivors in this sample. The strongest predictors were symptoms not attributed to cancer (β=0.28) and comorbidities (β=0.22), although cancer-related factors explained an additional 8% of the variance over that explained by demographic and noncancer health factors, with current cancer-related symptoms being a significant predictor (β=0.14). CONCLUSION: These findings indicate the importance of monitoring cancer-related characteristics along with comorbidities and noncancer symptoms in long-term survivors because they jointly affect overall physical functioning. Special attention needs to be given to women and minority cancer survivors as well.