Risk factors.

Risk factors for breast cancer whose modification would be culturally acceptable have not been established. Nearly all women in the United States are at a substantial risk for the development of breast cancer. The majority of women, however, in whom breast cancer will be diagnosed will live out their lives without recurrence of the disease. Newer strategies include prevention and the development of effective chemopreventive programs. Phase III clinical trials are underway to assess the value of retinoids and tamoxifen. Phase I and II studies are underway to assess the potential of more specific treatments to inhibit growth factors important in maintaining the malignant phenotype. Obviously, more studies are needed to address this major public health problem.