My research focuses on the associations between lifestyle factors, biomarkers of lifestyle and hormones, and breast cancer risk. I have studied ways women may alter their lifestyle to reduce breast cancer risk, using data from the NHS and NHSII cohorts.
In my study of potentially preventive lifestyle factors, I showed that weight loss and increased physical activity after menopause reduced breast cancer risk. As chair of an international collaborative group, I led a pooled analysis of 8 cohort studies and showed that higher blood levels of carotenoids, prominent in fruits and vegetables, significantly reduced breast cancer risk. In this and a subsequent paper, we observed stronger inverse associations with carotenoids for tumors that lack estrogen receptor expression and tumors that recurred or caused death. Continuing the examination of biomarkers that reflect both diet and endogenous synthesis, I am PI of an ongoing R01 to study circulating fatty acids and breast cancer risk in NHSII, as well as an R01 to examine metabolomics and breast cancer risk.
I also have expanded our understanding of the role of hormones in breast cancer etiology, and the intersection between hormones and lifestyle factors. I led the first extensive analysis of urinary estrogen metabolites with risk of breast cancer in premenopausal women, finding unexpected inverse associations. Building upon these findings, I have overseen several analyses to understand how lifestyle factors may impact patterns of estrogen metabolism.
As the Associate Director of NHSII, I serve as a senior scientific resource to others wishing to collaborate, help determine the scientific direction of the study, and lead students and fellows in their analyses of biomarkers of diet in relation to breast cancer risk. I also have represented the cohort nationally and internationally. I am active in teaching and mentoring at HSPH, including as the primary instructor for Epi 246: Applied Biomarkers in Cancer Epidemiology and co-instructor for Epi 205: Practice of Epidemiology.
Through contributions to the framework of the NHS/NHSII cohorts, applying the data obtained to study lifestyle factors and breast cancer etiology, collaborating with others in the field, and mentoring younger researchers, I continue my contributions to the field of breast cancer epidemiology.