T cell elevation linked with fatigue in breast cancer survivors

Nearly one third of breast cancer survivors will develop persistent fatigue of unknown origin. Now, new study findings suggest that increased numbers of circulating T cells may play a role in this fatigue.

Previously, Dr. Julienne E. Bower, from the University of California at Los Angeles, and colleagues had shown that serum levels of several inflammatory markers are increased in breast cancer survivors with fatigue. The current findings add to this by showing that the T cell compartment is also involved.”Many cancer patients get fatigue during treatment, but we decided to focus our research on those patients whose fatigue really doesn’t improve after treatment has ended,” Dr. Bower told Reuters Health. “Specifically, we’ve been interested in the role the immune system plays.””In the first study, we focused on immune activity markers,” Dr. Bower explained. “In the current one, we wanted to look more closely at the cellular immune system–specifically the T cell subset.” The results, which are published in the August 6th issue of the Journal of the National Cancer Institute, are based on a study of 20 breast cancer survivors with fatigue and 19 matched survivors without fatigue. Fatigued survivors had circulating T cell numbers that were 31% higher, on average, than those of non-fatigued survivors. The most pronounced elevations were seen with helper and effector T cells. In contrast, the two groups did not differ in the number of B cells, natural killer cells, granulocytes, and monocytes. Interestingly, the rise in T cell numbers correlated with elevated levels of interleukin 1 receptor antagonist, an inflammatory marker linked to fatigue in the authors’ earlier study.”These data suggest that there may be some chronic subclinical inflammatory process, possibly driven by the T cell compartment,” that mediates fatigue in these patients, Dr. Bower said. The new findings, if verified, could have treatment implications. For example, current treatments that block inflammatory cytokines may represent a useful therapy for this type of fatigue, she added.Dr. Bower said her group is currently involved in a study comparing fatigue in cancer survivors with fatigue in non-cancer patients. “We want to know if the fatigue looks different medically and immunologically.” (Source: J Natl Cancer Inst 2003;95:1165-1168: Reuters Health: Anthony J. Brown, MD: August 5, 2003: Oncolink)