Norman Boyd Visits as an HREB Distinguished Lecturer

Gretchen Gierach, Louise Brinton, Norman Boyd, and Joseph Fraumeni.

In November, the Hormonal and Reproductive Epidemiology Branch (HREB) hosted Dr. Norman F. Boyd, senior scientist at the Campbell Family Institute for Breast Cancer Research at the Ontario Cancer Institute and professor of medicine at the University of Toronto, as an HREB Distinguished Lecturer.

Dr. Boyd’s pioneering work in developing improved methods to identify components of breast tissue at increased risk of cancer, understanding the relationship between these components and other risk factors, and exploiting this information in the prevention of breast cancer has earned him international recognition.

During his visit, Dr. Boyd presented a seminar titled, “Breast tissue composition and susceptibility to breast cancer.” He discussed potential mechanisms of breast cancer risk associated with mammographic density, a strong and independent risk factor for breast cancer. Dr. Boyd explained that mammographic density, which reflects variation in the tissue composition of the breast, is influenced by some hormones and growth factors as well as genetic factors. He proposed that cumulative “exposure” to mammographic density may be an important determinant of breast cancer incidence, such that differences in the rate of change in mammographic density earlier in life may be associated with subsequent breast cancer risk. To explore this hypothesis, Dr. Boyd is leading a study of women aged 15 to 30 in which hormone levels are related to a novel, quantitative measure of breast tissue composition by magnetic resonance imaging, which reflects the presence of fibroglandular and adipose tissue. Dr. Boyd concluded that there is a need for a better understanding of the potential biologic pathways and tissue components that contribute to mammographic density and its influence on breast cancer risk.

During the remainder of his visit, Dr. Boyd met with a number of NCI investigators in informal discussions. During a luncheon meeting, Dr. Boyd led a discussion with DCEG and Cancer Prevention Fellows on various issues related to career development. He also participated in a series of roundtable discussions. One session, led by HREB fellow Gretchen L. Gierach, Ph.D., M.P.H., focused on evolving technologies to measure mammographic density, and another, led by Mark H. Greene, M.D., Chief of the Clinical Genetics Branch, dealt with the genetic regulation of mammographic density.

—Gretchen L. Gierach, Ph.D., M.P.H.