UCLA Scientists led by Julienne E. Bower, associate professor of psychology and psychiatry and biobehavioral sciences and member of Jonsson Comprehensive Cancer Center (JCCC) and Cousins Center for Psychoneuroimmunology, have identified a possible genetic risk factor for post-treatment fatigue in breast cancer patients in a study published this week online ahead of print in Journal of Clinical Oncology.
Fatigue is one of the most common and distressing side effects of cancer treatment and may persist for years after treatment is over. Approximately one third of breast cancer survivors experience persistent post-treatment fatigue that negatively affects all aspects of their quality of life. The risk factors that make these women vulnerable to persistent fatigue have not been identified, although inflammation may contribute. Inflammation is part of the body’s normal immune response, but can cause fatigue and other symptoms, such as depressed mood, memory and thinking problems, and sleep disturbance.
Bower and colleagues asked 171 women who had recently completed treatment for early-stage breast cancer to report on their fatigue, symptoms of depression, memory complaints, and sleep disturbance. Each of the women gave blood samples from which their DNA, the biological blueprint contained in all their cells, was assessed. The researchers focused on three genes within the DNA that influence the production of pro-inflammatory cytokines, which are the chemical messengers that cause inflammation in the body. There are minor variations in these cytokine genes, and some variants are associated with higher levels of cytokine production.
Results showed that women who had more of the high-production gene variants reported significantly higher levels of fatigue. The number of high-production genes was also associated with increased symptoms of depression and memory complaints.
“Many women suffer from fatigue during and after breast cancer treatment, but we still don’t have a good idea of what causes this distressing symptom,” Bower said, “This study highlights inflammation as an important contributor to fatigue, and suggests that women with genes that promote inflammation may be at risk of greater fatigue in the post-treatment period.”
These findings give doctors a new tool for identifying patients who are at increased risk of post-treatment fatigue and other side effects, and may lead to earlier application of interventions that may help curb the persistence of these symptoms after breast cancer treatments.
“For a long time we have observed that only certain women have persistent fatigue after breast cancer treatments, even when they have all had similar chemotherapy regimens,” noted Patricia Ganz, MD, professor of health policy and management at the Fielding School of Public Health, professor of medicine at the David Geffen School of Medicine, director of cancer prevention and control research at JCCC and a senior author of the study, “now this personalized genetic information may explain why some women are at higher risk of post-treatment symptoms.”
Bower’s research was supported by the National Cancer Institute, the Cousins Center for Psychoneuroimmunology, and the Breast Cancer Research Foundation.
Source: UCLA’s Jonsson Comprehensive Cancer Center