Light shed on fatigue after breast cancer

By David Douglas

NEW YORK (Reuters Health) - Breast cancer survivors often suffer from persistent fatigue, and now researchers think they may have a handle on what causes it.

Women with the problem appear to have significantly elevated levels of a marker of inflammation called interleukin 6 or IL-6, and other changes, according to a report in the journal Clinical Cancer Research.

"The study showed that there is an aberrant immune response in breast cancer survivors with persistent fatigue," senior investigator Dr. Michael R. Irwin told Reuters Health.

Irwin, at the David Geffen School of Medicine at the University of California, Los Angeles, and colleagues note that the cause of cancer-related fatigue remains poorly understood. They studied 32 women who suffered from prolonged fatigue after battling breast cancer and 18 others who did not experience fatigue. The participants were recruited at least 2 years after they had been successfully treated for cancer.

Several differences were seen between the groups. One was that cells taken from the fatigued subjects produced more IL-6, as well as another immune system compound called tumor necrosis factor alpha, in lab tests than did cells from the non-fatigued group.

The team also found that other immune system measurements were "highly diagnostic of fatigue."

"With this information," Irwin concluded, "we may now be able to identify those patients at greatest risk for persistent fatigue and develop targeted interventions early on that will lessen the severity and duration of the fatigue."

SOURCE: Clinical Cancer Research, May 1, 2006.