WINS Looks at Effects of Dietary Fat on Breast Cancer Outcomes

PHILADELPHIA—The Women’s Intervention Nutrition Study (WINS) has completed accrual, with some 2,400 women enrolled to date. The study, an NCI-funded, randomized, multicenter national trial begun in 1993, is testing the hypothesis that dietary fat intake reduction as an adjuvant to standard breast cancer therapy will reduce disease recurrence and increase survival in women with localized breast cancer.

The researchers have been able to accrue the required population of breast cancer patients and maintain sufficient dietary adherence in the intervention group to meet the goals of the study. Patients will be followed for 4 more years, according to Barbara Winters, PhD, RD, coinvestigator and coordinator of the WINS trial for the American Health Foundation.

Dr. Winters described the study and its progress at the annual meeting of the Society for Nutritional Oncology Adjuvant Therapy (NOAT).

"What we’ve done is taken basic science and epidemiologic findings that were positive and moved them forward to a clinical trial. The essentials are competent, involved nutritionists, the interest of the physician, and the ‘dose,’ which is the quality of counseling, its intensity and duration," Dr. Winters said.

Intensive Dietary Intervention

According to the protocol, the experimental group receives intensive dietary interventions: individual and group counseling sessions aimed at reducing the participants’ total fat intake to 15% of their daily caloric intake (20 to 30 g/d, depending on the woman’s weight).

The control group receives USDA/DHHS dietary guidelines and minimal intervention.

Of the women enrolled, 85% are white, 6% are black, 5.6% are Hispanic, 3.2% are Asian, and 1.2% Native American.

To be eligible for the study, women must be between 48 and 78 years old and have histologically proven, invasive, localized carcinoma of the breast, stage I/II/IIIA disease. They are randomized within 1 year of diagnosis to the fat-intake intervention group or to the control group. All of the patients who are estrogen-receptor positive receive concurrent hormonal therapy.

Long-term adherence strategies include individualized assessment of needs with booster sessions, researchers part-nering with participants, and publishing newsletters with articles addressing the concerns of the participants.

Dietary adherence is assessed with serial unannounced telephone calls by trained interviewers who are not the nutritionists who work with patients one on one.

The WINS study is not aimed at weight loss, Dr. Winters said, although women in the intervention arm of the study typically lose about 3.3 lb in their first year on the trial. The control group gains about 1 lb a year, which is to be expected in this age group.

The researchers are also looking at how their recommendations translate into actual food intake. Recommendations for six servings of bread daily, for example, are not quite matched by either group, she said. Data on supplement use are also being compiled. Eighty percent of the participants used some supplement at baseline.

The aim of the study is to provide a definitive evaluation of the effect of dietary fat intake on breast cancer patient outcome, Dr. Winters concluded.