A breast cancer Nutrition Adjuvant Study (NAS): protocol design and initial patient adherence

To evaluate the feasibility of using a reduction in dietary fat intake as a component of treatment regimens for patients with resected breast cancer, a multi-disciplinary cooperative group protocol was developed. Females 50 to 75 years of age with stage II breast cancer who completed primary local therapy were eligible for randomization to a Control Dietary Group in which dietary fat intake was to remain unchanged from baseline level (at approximately 38% of calories derived from fat) and an Intensive Intervention Dietary Group designed to reduce dietary fat intake. Both Dietary Groups were given tamoxifen 20 mg/day. To facilitate early experience with dietary regimen delivery, patients entered during an initial pilot phase could receive any chemotherapy and/or hormonal treatment. A prerandomization nutrition 'run-in' of clinically eligible patients assessed adherence to nutrition data collection procedures and screened patients for nutrition eligibility criteria. Of 59 patients beginning 'run-in', 49 were randomized and, at present, 32 have completed at least three months follow-up. The change in dietary fat intake (as assessed by Four Day Food Records) seen in both arms is outlined below. Formula see table. The 56% reduction in total daily fat gram intake achieved in the Intensive Intervention Dietary Group suggests that protocols designed to reduce dietary fat intake in an adjuvant treatment setting can be developed and implemented using a multi-institutional, cooperative group approach.