Breast Cancer.

The pre-eminence of breast cancer as a significant cause of premature mortality and as the most prevalent cancer of women in North America justifies a major thrust in prevention. In the past, a number of hormonal risk factors were identified. Increasingly, evidence is being obtained to support the role of dietary risk factors and most particularly the total level of dietary fat. Overweight as a risk factor in postmenopausal women also points to the importance of dietary factors. It is concluded that the time is ripe for an active program of evaluating the effect of reduction in the consumption of total fat, particularly in adolescent, early adult and premenopausal women, and in reducing overweight in postmenopausal women, both as aspects of national policy and as special investigations in defined population groups.