BREAST SIZE AND BREAST-CANCER RISK

The relationship between brassiere size, as an indicator of breast siz e, and breast cancer risk was considered in a case-control study condu cted between 1991 and 1994 in six Italian centres. Cases were 2,557 wo men, below age 75, with histologically confirmed breast cancer, and co ntrols were 2,566 women admitted to hospital for a wide spectrum of ac ute, non-neoplastic, non-hormone-related diseases. Odds ratios (ORs) o f breast cancer and their 95% confidence intervals (CIs) were obtained from multiple logistic regression equations including terms for study centre and age, as well as main breast cancer risk factors. A slight inverse relationship was observed between breast size and the risk of breast cancer, with an OR of 1.37 (95% CI 1.05-1.80) for the smallest brassiere size compared with the largest; the increase in risk disappe ared after adjustment for main recognized breast cancer risk factors, with an OR of 1,16 (95% CI 0.87-1.54) for brassiere size less than or equal to 1 compared with greater than or equal to 5. No significant he terogeneity in risk of breast cancer with breast size was found in str ata of age at diagnosis, parity, age at first birth, age at menopause, family history of breast cancer, benign breast disease, ever use of o ral contraceptives and/or hormone replacement therapy. Thus, this stud y, based on a large number of caucasian women, provides conclusive evi dence of a lack of appreciable association between breast size and bre ast cancer risk in this Italian population.