The research of Celine M. Vachon, Ph.D., focuses on two main areas. Dr. Vachon works toward a better understanding of the genetics and epidemiology of mammographic density and their utility as risk factors for and surrogate markers of breast cancer risk and recurrence.
Additionally, she studies the genetic epidemiology of multiple myeloma, its precursor — monoclonal gammopathies of underdetermined significance (MGUS) — and other hematologic malignancies.
Factors influencing mammographic density. Dr. Vachon's team has confirmed the importance and reliability of mammographic density as a general (rather than regional) breast cancer risk factor years prior to cancer development; described its correlation with other breast cancer risk factors, including diet, anthropometrics and physical activity in adolescence and adulthood; and identified the first evidence for a putative genomic locus housing genes for the trait using linkage studies.
Dr. Vachon's team is extending its initial genetic studies of mammographic density to multiple study populations to identify possible genetic variation that influences this trait. The team is also conducting a study of more than 600 women to examine whether aromatase inhibitors, a widely prescribed endocrine treatment for estrogen receptor positive (ER+) breast tumors, influence mammographic density. If so, mammographic density may possibly be used as a surrogate marker to assess response to this type of therapy.
Associations between mammographic density and breast cancer. Although mammographic density is a strong risk factor for breast cancer, the mechanism by which it influences breast cancer is unknown. Dr. Vachon's team has established a cohort of 20,000 women with screening mammograms at Mayo Clinic and is following these women for new breast cancer.
Using this cohort, the team is currently examining whether mammographic density is a risk factor for all breast cancers or only for those of specific subtypes (for example, estrogen receptor positive vs. estrogen receptor negative, basal vs. luminal subtypes, high vs. low grade, and so on). The team is collaborating with investigators and cohorts at two other sites — Harvard University and University of California, San Francisco — to accomplish this goal.
Genetic risk factors for multiple myeloma and MGUS. Another research effort involves identifying genetic risk factors for multiple myeloma or its precursor, MGUS. The team recently demonstrated that first-degree relatives of those with MGUS or multiple myeloma have a twofold greater prevalence of MGUS compared with the general population.
Dr. Vachon is now interested in identifying genes that are responsible for increasing the risk of myeloma and MGUS. This research involves an ongoing collaborative genome-wide association study (GWAS) to identify and confirm potential genetic variation (single nucleotide polymorphisms, or SNPs) associated with myeloma in conjunction with investigators from Washington University, the University of Minnesota and the U.K.
Dr. Vachon and collaborators plan to examine whether SNPs found to be associated with myeloma are also associated with MGUS, using a case-control MGUS study established at Mayo Clinic.
Significance to patient care
Dr. Vachon's work on mammographic density could better inform risk prediction models for breast cancer. Likewise, understanding genes important to myeloma and MGUS will help to better understand the biology of myeloma and possibly allow for future prevention and treatment efforts.