Key takeaways:

  • Women over 60 make up the majority of the nearly 4 million breast cancer survivors in the U.S.
  • Previous studies of cognition have focused largely on younger survivors in the short term.
  • Self-reports of cognitive issues among older survivors were related to higher levels of an inflammatory marker in the body called CRP.

Scientists are still trying to understand why many breast cancer survivors experience troubling cognitive problems for years after treatment. Inflammation is one possible culprit. A long-term study of older breast cancer survivors recently published in the Journal of Clinical Oncology and co-led by UCLA researchers adds important evidence to that potential link.

Higher levels of an inflammatory marker known as C-reactive protein, or CRP, were related to reports of cognitive issues among older survivors in the new study.

“Blood tests for CRP are used routinely in the clinic to determine risk of heart disease. Our study suggests this common test for inflammation might also be an indicator of risk for cognitive problems reported by breast cancer survivors,” said lead study author Judith Carroll, an associate professor of psychiatry and biobehavioral sciences and a member of the Cousins Center for Psychoneuroimmunology at UCLA and the UCLA Jonsson Comprehensive Cancer Center.

The study is one of the first long-term efforts to examine the potential link between chronic inflammation and cognition in breast cancer survivors 60 and older, who make up a majority of the nearly 4 million breast cancer survivors in the United States. Previous research has focused largely on younger women and women immediately after therapy, making it difficult to draw conclusions about CRP’s role in long-term cognitive problems among older breast cancer survivors. 

For the study, teams of researchers from around the country talked to, and obtained blood samples from, hundreds of breast cancer survivors and women without cancer up to six times over the course of five years. The study was motivated by hearing from survivors that cognitive problems are one of their major worries.  

Cognition was evaluated through a commonly used questionnaire that assessed how the women perceived their ability to remember things like names and directions, to concentrate, and to perform other activities in their everyday lives. The researchers found that higher CRP levels among survivors were predictive of lower reported cognitive function. There was no similar relationship between CRP levels and reported cognition in the women who had not had cancer. 

“Cognitive issues affect women’s daily lives years after completing treatment, and their reports of their own ability to complete tasks and remember things was the strongest indicator of problems in this study,” said co–senior author Dr. Jeanne Mandelblatt, a professor of oncology at Georgetown University who headed the study. 

“Being able to test for levels of inflammation at the same time that cognition was being rigorously evaluated gave the team a potential window into the biology underlying cognitive concerns,” said Elizabeth C. Breen, a professor emerita of psychiatry and biobehavioral sciences at the UCLA Cousins Center and co–senior study author.

The older survivors’ cognitive performance, as measured by standardized neuropsychological tests, did not show a link with CRP. The researchers said this may indicate that the women are more sensitive to differences in their everyday cognitive function and that their self-reports highlight changes that other tests miss. 

The authors said their study supports the need for research on whether interventions that can lower inflammation — including increased physical activity, better sleep and anti-inflammatory medications — may prevent or reduce cognitive concerns in older breast cancer survivors.