Chemotherapy Impairs Cognitive Function in Breast Cancer Patients

April 9, 2017


Take-Home Message:

Chemotherapy in women with breast cancer leads to impaired cognition.


Cognitive Complaints in Survivors of Breast Cancer After Chemotherapy Compared With Age-Matched Controls: An Analysis From a Nationwide, Multicenter, Prospective Longitudinal Study

Authors: Janelsins, M.C., Heckler, C.E., et. al.
Source: J Clin Oncol, DOI: 10.1200/JCO.2016.68.5826

The goal of the investigators was to conduct a long-term study of cognitive function that was devoted to breast cancer patients. Women with stage I-IIIC breast cancer and scheduled for chemotherapy were recruited. Matched controls (women without breast cancer) were used for comparison.

The Functional Assessment of Cancer Therapy—Cognitive (FACT-Cog) consists of a series of questions that measure the cognitive function of cancer patients. It is widely considered to be very accurate and is frequently used. Subjects in this study completed the FACT-Cog within 1 week of chemotherapy start, 4 weeks after the end of chemotherapy (postchemotherapy, or time point 2) and again 6 months later (time point 3). Additionally, at each time point, they completed questionnaires to evaluate reading ability, level of anxiety and level of depression. Control subjects completed the questionnaires at the same time points.

Throughout the observation period, more patients with breast cancer had a decline in cognitive function. Control patients had virtually no changes in their scores at any time point. Compared to controls, the women with breast cancer had lower FACT-Cog scores prior to chemotherapy start. Their scores fell significantly more than the control scores did at the postchemotherapy time point. Although their scores rose at the 6 month mark, they remained lower than the control scores. Additionally, more breast cancer patients actually perceived that their questionnaire scores would be lower at the second and third time points. Type of chemotherapy had no bearing on results.

The investigators commented that the lower scores before the start of chemotherapy may have been due to comorbidities, baseline cognition, anxiety and depression. They also noted that there may have been a preexisting effect of breast cancer on cognition.

This study is the largest one to date that assesses the effects of chemotherapy on cognitive function in breast cancer patients. Its results provide opportunities to better anticipate how each patient will do, and what type of support she will need, during and after chemotherapy.