Breast Cancer Survivors Report More Cognitive Impairment After Chemotherapy

A study of breast cancer survivors’ cognitive performance before and after chemotherapy sheds light on the problem of cancer-related cognitive impairment. Researchers conducted a longitudinal study of breast cancer patients who were treated in community oncology clinics, and an age-matched noncancer control group, by testing their cognitive functioning at 3 points. The results were published in the Journal of Clinical Oncology (JCO).

The study recruited 367 patients and controls who were tested prior to initiating treatment for the cancer patients, to establish a baseline. Participants were tested using the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog), which is a tool “that was created specifically to assess cognitive challenges identified by patients with cancer.”

This test assessed participants’ perceived cognitive impairment and abilities, the impact of cognitive impairment on their quality of life, and cognitive impairment perceived by others. A lower score indicated decreased cognitive functioning. Participants were also tested to measure their baseline levels of anxiety, depressive symptoms, and reading ability as a proxy for cognitive reserve. They took the same tests after the cancer patients finished chemotherapy and then 6 months after that.

Patients with breast cancer had lower FACT-Cog scores than the controls, even before their treatment began. Post-chemotherapy, these patients reported significantly greater cognitive complaints than the controls, as their scores decreased and the controls’ scores remained level. In the follow-up test, breast cancer survivors reported slight improvements in cognitive functioning, but their scores remained significantly below the baseline level.

Over the entire study period from pre-chemotherapy to the 6-month follow-up, 36.5% of the breast cancer patients demonstrated a decline in FACT-Cog scores, compared with just 13.6% of the controls. Higher levels of anxiety and depression were predictive of lower FACT-Cog scores, as were higher cognitive reserve levels, but there was no link to educational attainment.

The study authors wrote that the results indicated that self-reported cognitive impairment “is a substantial and pervasive problem for patients with breast cancer who received chemotherapy,” and that these patients are likely predisposed to cognitive impairment due to “a combination of demographic, medical, and psychological factors.”

Cognitive impairment could be lessened, they wrote, with more successful management of anxiety and depression during chemotherapy. The results also underscored the importance of cognitive reserve, rather than education status, as a protective factor against potential impairment. The researchers plan to conduct a follow-up study with the breast cancer patients 2 years after treatment ends.

A potential solution to cancer-related cognitive impairment, also called “chemo brain,” was discussed in a JCO study that evaluated the effects of a Web-based cognitive rehabilitation program in a group of cancer patients with cognitive impairment. The participants who received the Insight intervention had significantly better FACT-Cog scores than the control group, both right after the 15-week program and 6 months later.