Neurotoxic effects of chemotherapies on cognition in breast cancer survivors

Cancer-related cognitive impairment is often referred to as 'chemobrain' and anthracycline-based chemotherapy may have greater negative effects on particular cognitive domains and brain network connections than nonanthracycline-based regimens, according to an article published online by JAMA Oncology.

Chemotherapy for breast cancer is often associated with cognitive problems in patients. However, it is unclear whether certain regimens are associated with greater cognitive difficulties than others.

Shelli R. Kesler, Ph.D., of the University of Texas MD Anderson Cancer Center, Houston, and Douglas W. Blayney, M.D., of the Stanford University School of Medicine, California, compared the effects of anthracycline and nonanthracycline chemotherapy regimens on cognitive status and functional brain connectivity in a small study.

The authors used cognitive tests and imaging data from 62 primary breast cancer survivors (average age nearly 55) who were, on average, more than two years off therapy to examine cognitive status and functional brain connectivity. Of the women, 20 received anthracycline-based chemotherapy as part of their primary treatment, 19 received nonanthracycline regimens and 23 did not receive any chemotherapy.

Women treated with anthracycline-based chemotherapy had lower verbal memory, including immediate recall and delayed recall, compared with the other two groups of women. The anthracycline regimens also were associated with lower default mode brain network connectivity, suggesting a decreased efficiency of information processing, according to the study.

Patient-reported outcomes of cognitive dysfunction and psychological distress were elevated in both groups of women treated with chemotherapy compared with patients treated without chemotherapy, the results indicate.

"These results should be considered preliminary given the study limitations of small sample size and retrospective, cross-sectional design, Larger, prospective studies are needed that include pretreatment and posttreatment assessments so that patients' individual cognitive and neurobiologic trajectories can be evaluated with respect to potential ANTHR [anthracycline]-related neurotoxic effects," the study concludes.

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Editor's Note: This research was supported by grants from the National Institutes of Health. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Editorial: Imaging Brain Networks After Cancer and Chemotherapy

"While previous studies have linked chemotherapy and cognitive decline, and a few other studies have linked treatment with differences in brain connectivity, there has been very little research comparing cognitive effects of different types and combinations of chemotherapy because most studies have been underpowered to distinguish these effects. This present study builds on preclinical work and, although modest in power to detect regimen differences, represents an important step forward while underscoring the need for larger studies," write Andrew J. Saykin, Psy.D., of the Indiana University School of Medicine, Indianapolis, and coauthors in a related editorial. (JAMA Oncol. Published online Dec. 3, 2015. doi:10.1001/jamaoncol.2015.4551. Available pre-embargo to the media at http://media.jamanetwork.com.)

Editor's Note: Funding/support disclosures were made. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Media Advisory: To contact corresponding author Shelli R. Kesler, Ph.D., call Laura Sussman at 713-745-2457 or email lsussman@mdanderson.org. To contact corresponding editorial author Andrew J. Saykin, Psy.D., call Danielle Sirilla at 317-962-4572 or email dsirilla@iuhealth.org or call Gene Ford at 317-985-8731 or email gford2@iuhealth.org.