TUMOR CHARACTERISTICS AND SURVIVAL OF BREAST-CANCER PATIENTS IN RELATION TO PREMORBID DIET AND BODY-SIZE

Nutritional factors have been suggested to play an important role in t he prognosis of breast cancer through their effect on tumor characteri stics. This study evaluated four tumor characteristics and prognosis i n relation to premorbid diet and body size. From a cohort of 89,835 wo men in the National Breast Screening Study (NBSS) in Canada, data on 6 76 incident cases of invasive carcinoma of breast, on whom we had diet ary information, were used. A high energy intake lowered the likelihoo d of being ER positive and PR positive but after adjusting for ER stat us, was still associated with a higher risk of dying of breast cancer. Total fat and various types of fats were associated with a greater li kelihood that a woman would be ER and PR positive, however the likelih ood of dying from breast cancer was higher with higher fat consumption . There was no significant effect of higher intakes of beta carotene o r vitamin C on ER status, nodal status or tumor size, but a significan tly lower risk of dying from breast cancer was observed. Higher intake of carbohydrates and calcium was associated with a lowered frequency of ER and PR positive status but also with a lower risk of dying. Of t he five indicators of body size studied, higher triceps skinfold thick ness was associated with a slightly lower chance of being ER positive, PR positive, and node negative, and a significantly higher likelihood of dying. It appears that while there are significant associations be tween some of the diet and body size variables and tumor characteristi cs, the effect of most nutritional factors on prognosis in breast canc er may not be mediated via their effect on tumor characteristics.