BETTER BREAST-CANCER SURVIVAL FOR POSTMENOPAUSAL WOMEN WHO ARE LESS OVERWEIGHT AND EAT LESS FAT - THE IOWA WOMENS HEALTH STUDY

Background. The authors sought to determine whether prediagnosis obesi ty, body-fat distribution, and dietary intake of fats, antioxidants, a nd fiber may be related to survival after the diagnosis of breast canc er. Methods. The mortality rates of 698 postmenopausal patients with u nilateral breast cancer in a large cohort study were analyzed. Body-ma ss index, waist-to-hip ratio, and food-frequency data were collected b y questionnaire within 6 years before breast cancer was diagnosed. Res ults. Adjusted for age, women in the highest tertile of body mass inde x had a 1.9-fold higher risk (95% confidence interval = 1.0-3.7) of dy ing after breast cancer than those in the lowest tertile; adjusted for other prognostic variables (age, smoking, education level, extent of breast cancer, and tumor size), this relative risk was 1.5 (95% CI = 0 .7 to 2.9). Waist-to-hip ratio was not related to risk of dying nor wa s intake of fiber or several dietary antioxidants, Independent of othe r prognostic variables, risk of death after breast cancer was statisti cally significantly elevated, with a relative risk greater than 2.0 fa r the highest tertiles of total fat, saturated fat, and monounsaturate d fat intake, expressed as grams per day. An adjustment for energy int ake, which also was associated positively with fatality, weakened thes e associations somewhat. Conclusions. Although clinical trials are req uired, these findings support the hypothesis that a high fat intake is associated with reduced survival of postmenopausal women with breast cancer and suggest that women with breast cancer should consider limit ing their intake of fat.