Approximately one third of women treated for breast cancer experience fatigue for the first five years after treatment, and for about two thirds of those, the fatigue will persist, the results of a long-term study indicate.

“The message is that most women are going to be doing very well, but for those who have persistent fatigue, we think there is an underlying biological syndrome,” co-investigator Dr. Patricia A. Ganz told Reuters Health.

Ganz, from the University of California at Los Angeles, and her associates previously reported that 35 percent of 1,957 women who were diagnosed between with early-stage breast carcinoma between 1994 and 1997 experienced fatigue for the first five years after treatment.

For their current study, published online in the medical journal Cancer, they recontacted the same women in 1998 who were at least five years postdiagnosis. A total of 763 women who remained cancer-free completed the second set of questionnaires.

The results showed that 34 percent were classified as being fatigued. Among those classified as fatigued during the first survey, 63 percent continued to score in the fatigued range.

Further analyses indicated that depression, pain and heart disease were significant long-term predictors of fatigue, as was treatment with combined radiation and chemotherapy compared with either treatment alone.

“When we intensively studied the biological mechanisms of fatigue in smaller groups, we found that women with persistent fatigue have abnormalities” in markers of inflammation, Ganz said. “So it appears they may have some underlying predisposing inflammatory condition” causing the fatigue that is triggered or exacerbated when they develop cancer.

“Like any other subjective complaint,” she added, “we have to believe the patient when she complains of fatigue. Then look for medical problems that may be amenable to intervention, such as anemia or a thyroid condition. If they are on a blood pressure medication, try to put them on meds that don’t contribute to fatigue.”

“And clearly a careful assessment of depression and management of pain are very important,” she added. “If we can get that under control their energy may improve.”

SOURCE: Cancer, February 15, 2006.