Immune Systems in Breast Cancer Survivors Who Suffer From Fatigue Fail To Shut Off After Therapy
Breast Cancer and Fatigue
Breast cancer survivors who suffer from persistent, debilitating fatigue years after their diagnosis have something in common: their immune systems don't shut down following treatment, according to researchers at UCLA's Jonsson Cancer Center.
This constant immune system activation, which researchers discovered by measuring specific proteins in blood samples from survivors, may be causing the fatigue, UCLA researchers theorize. Their discovery may lead to behavioral interventions such as tai chi and yoga that will help alleviate persistent fatigue, which affects about a third of breast cancer survivors for years after they complete treatment.
The study is the first to look at the cellular basis for immune activation in fatigued breast cancer survivors, said Dr. Michael Irwin, a researcher at UCLA's Jonsson Cancer Center and the study's lead author. The research appears in the May 1 issue of Clinical Cancer Research, the peer-reviewed journal of the American Association of Cancer Research.
"Without knowing why this fatigue happens at the cellular level, we can't develop efficient therapies to treat it," said Irwin, who also serves as director of the Cousins Center for Psychoneuroimmunology at the Semel Institute for Neuroscience and Human Behavior at UCLA.
"Breast cancer survivors can be severely disabled by fatigue and that can dramatically impact their quality of life. That's the tragedy of our treatments for cancer," Irwin said. "We have focused on treating the disease, but we should also focus on the patient's well being later. Right now, we have no treatment for cancer-related fatigue and we need something that will allow patients to return to their prior level of functioning."
Dr. Patricia Ganz, a nationally renowned expert who has studied quality of life in breast cancer survivors for two decades, agrees that fatigue is a serious problem for survivors, a fact that their primary care physicians don't always understand.
"When breast cancer survivors talk to their physicians about being tired and how it affects their lives, they're often told that they survived cancer, so they should be grateful to be alive," said Ganz, one of the co-authors of the study. "But their fatigue is a very real problem that needs to taken seriously and addressed."
A small study at UCLA had previously demonstrated abnormalities in immune activation in breast cancer survivors. If researchers could determine the biological factors underlying this activation, and therefore fatigue, they could uncover a biomarker for the condition that could help them predict which patients would suffer from fatigue and which would not, Irwin said.
Irwin and his colleagues took blood samples from breast cancer survivors one to five years out from diagnosis and placed them into two groups, those who suffered from persistent fatigue and those who did not. The researchers measured the levels of a pro-inflammatory cytokine protein in their blood