Treatment with chemotherapy and cognitive functioning among older adult cancer survivors.

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

DESIGN: Data were examined prospectively from two years prior to cancer diagnosis to four years after cancer diagnosis. Distinct classes of cognitive functioning were identified using latent class growth analysis techniques (LCGA). Treatment type was assessed as a predictor of class membership.

SETTING: Data were collected from a large population-based cohort in the context of the Health and Retirement Study.

PARTICIPANTS: 403 older adults with a new diagnosis of cancer, who were still alive 4 years after their diagnosis. Participants had provided informed consent for the data collection, and the use of the data was approved by the Institutional Review Board of Columbia University, Teachers College.

INTERVENTIONS: Not applicable.

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

RESULTS: Findings indicated that three 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 x treatment interaction was present, such that individuals under 80 were more likely to both receive chemotherapy and have high recall cognition.

CONCLUSIONS: Three distinct classes of cognitive functioning emerged among 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 by treatment interaction. Implications for understanding cognitive sequelae of cancer in late life are discussed.

http://www.ncbi.nlm.nih.gov/pubmed/28735719?dopt=Abstract