In a follow-up study, researchers at Moffitt Cancer Center and colleagues have found that patients who receive chemotherapy for breast cancer might experience prolonged fatigue years after their therapy. The new study, published in the American Cancer Society's current issue of CANCER, is a follow-up to a study on fatigue and chemotherapy and radiotherapy for breast cancer Moffitt researchers published in CANCER in 2007.

"Fatigue is among the most common symptoms reported by women who are treated for breast cancer," said study corresponding author Paul B. Jacobsen, Ph.D., program leader for Health Outcomes and Behavior at Moffitt.

The 2007 study found that immediately following treatment fatigue was greater in women who had received chemotherapy than in patient groups comprised of women who had received both chemotherapy and radiotherapy, radiotherapy alone, or in groups with no cancer history. Six months after treatment, women in the chemotherapy alone group reported more fatigue than the combination therapy group, the radiotherapy group, or the non-cancer group.

"On the basis of our 2007 study and the results of other studies, we hypothesized that fatigue in the group receiving chemotherapy would diminish over a three-year follow-up period, yet possibly remain higher than fatigue levels for women who had received radiation, combination therapy, or those with no history of cancer," explained Jacobsen.

The recently published follow-up study was comprised of 205 patients who had received chemotherapy compared with 193 women in a control group with no history of cancer. The controls were within five years of age of the cancer patients and lived in the same zip codes as their partner cancer patients. The average age for both groups was 55. Fatigue levels were measured at six months and 42 months.

Their new findings, however, contradicted the expectation that patients receiving chemotherapy would, overtime, experience less fatigue and eventually see their fatigue levels diminish to equal the levels of women in the other two groups.

"Contrary to our expectations, fatigue did not diminish over time for patients in the chemotherapy group," said Jacobsen, who studies the behavioral and psychosocial aspects of cancer, cancer treatment, outcomes, and cancer survivorship. "In some cases, fatigue worsened, and that finding is not consistent with prior research."

Among the possible factors influencing the long-term or worsening fatigue included the potential for weight gain, common among patients who receive chemotherapy and who, according to the researchers, rarely return to their pre-treatment weight.

One variable affecting prolonged or worsening fatigue might involve supportive care, suggested the researchers.

"This finding has important implications for patient education and for fatigue monitoring during follow-up," concluded Jacobsen. "Our results should inform patient education efforts when patients receiving chemotherapy are often told that their fatigue will gradually diminish following treatment. Health care providers may want to communicate to their patients who have received chemotherapy that their fatigue may not improve over time and may worsen."

The researchers concluded that patients should be informed about interventions known to be effective against fatigue post-treatment, such as exercise and cognitive behavior therapy.

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Provided by H. Lee Moffitt Cancer Center & Research Institute