Prevention: Eliminating the Danger of Breast Cancer
Research on the causes of breast cancer provides a basis for prevention and early detection efforts. Likewise, research on prevention often provides tantalizing clues to etiology.
Research Conclusions
No projects on prevention were completed in 1997.
Research in Progress
Explaining nutritional pathways for prevention of breast cancer
Dr. Nurulain Zaveri of SRI International is developing novel chemopreventative synthetic drugs based on the structure of a compound found in green tea, epigallocatechin-3-gallate. Drugs derived from natural products have a strong appeal and a potential safety advantage over more conventional drug options. Dr. Marcia Dawson, also of SRI International found that natural retinoids do not synergize with Vitamin D; however, she has found that three retinoids, which inhibit the formation of new blood vessels, cause the death of both estrogen-dependent and estrogen-independent breast cancer cells.
Active lifestyle modification: what women can do
Dr. Catherine L. Carpenter, in her study of the impact on hormones and breast cancer risk has described the effect of lifetime physical activity on the risk of developing breast cancer after menopause. She found that women who exercised at least 13 years with duration of more than four hours per week, were almost 30% less likely to develop breast cancer than women who did not exercise. Exercise intensity and duration was also summarized prior to age 40, and age 40 or older. Women who engaged in vigorous activity (examples: aerobics, field hockey, jogging) on the average three hours or more per week from menarche until age 40, and age 40 or older were almost 50% less likely to develop breast cancer than women who were sedentary throughout their lives. During the ten years prior to the end of the study, women who engaged in vigorous activity averaging four hours or more per week were 30% less likely to develop breast cancer than women who did not exercise. These results are significant because they indicate a way in which women of all ages can lower their chances of developing breast cancer after menopause, and in particular, these results emphasize the importance of exercise in later years. Another researcher is examining one possible causal explanation of this effect. Dr. Lisa S. Shames and colleagues at the University of Southern California recently observed that moderate exercise may significantly reduce a woman's risk of breast cancer. This reduction may be due to altered ovarian function, specifically, more frequent anovulatory cycles (cycles where an egg is not produced) and/or reduced serum estrogen (and progesterone) levels in ovulatory cycles that likely contribute to a reduced exposure of estrogen to breast tissue and thus reduce the risk of breast cancer.
Recently Initiated Research
In 1997, CBCRP awarded one new grant to explore various natural and synthesized retinoids (vitamin A derivatives) as preventive agents for breast cancer.
