Treatment With Chemotherapy and Cognitive Functioning in Older Adult Cancer Survivors.

OBJECTIVE: To investigate whether treatment of cancer with chemotherapy, as compared with surgery and radiation, differentially affects cognitive functioning in older adults.

DESIGN: Latent class growth analysis approach.

SETTING: Health and Retirement Study.

PARTICIPANTS: Older adults (N=403) with a new diagnosis of cancer who were still alive 4 years after their diagnosis.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Cognition (degree of immediate recall and delayed recall of a word list).

RESULTS: Findings indicated that 3 classes of cognitive functioning best fit the data, specifically high, middle, and low recall classes. Individuals treated with chemotherapy were significantly more likely to be in the high recall class, with no effect of receiving surgery or radiation. When interactions with demographic predictors were entered into the model, an Age × Treatment interaction was present such that individuals younger than 80 years were more likely to both receive chemotherapy and have high recall cognition.

CONCLUSIONS: Three distinct classes of cognitive functioning emerged in older adults with cancer. Treatment with chemotherapy predicted likely membership in the high recall class in this sample of cancer survivors; however, this was due to an Age × Treatment interaction. Implications for understanding cognitive sequelae of cancer in late life are discussed.