Senior Scientist, Henry Ford Health System, Michigan, USA
Azadeh Stark is a cancer and molecular epidemiologist and holds the position of senior scientist at the Department of Pathology at Henry Ford Health System, Professor-in-Practice at the School of Interdisciplinary Studies at the University of Texas at Dallas and Visiting Research Professor at the School of Nursing, Chiang Mai International University in Thailand. She has authored and co-authored more than 35 peer-reviewed manuscripts and three book chapters. Dr. Stark believes the best science and the most effective population health interventions result from constructive interdisciplinary collaboration. She has been an active participants in various community health improvement projects.
Breast cancer (BC) mortality is 45% higher in African-American (AAm) than WhiteAmerican (WAm) women, despite comparable incidence rates. The scientific premise of our work has been that this higher mortality is due to biological differences between AAms and WAms. Initially, we reported that HER2+ was associated with advanced stages and poorly differentiated BC only among WAs. In the follow-up cohort study of 1,263 women, members were categorized into four BC subtype groups, Luminal A, Luminal B, EGFR2+/ER- and triple negative (TNBC). Prevalence of TNBC was higher among premenopausal (32.7%) and post-menopausal (21.8%) AAms, than premenopausal (21.5%) and postmenopausal (12.4%) WAms. African heritage was an independent risk for TNBC (OR= 1.72, 95% CI 1.17- 2.54, P=.006). We compared risk of recurrence after diagnosis of DCIS between AAs and WAs. AAms had an 8-year cumulative risk of recurrence (HR= 3.96, 95% CI 1.42-11.04). Finally, we assembled a cohort of 2,588 AAms and 3,566 WAms diagnosed with their first benign breast conditions. Members of the cohort were followed-up until the diagnosis of BC, death or departure from the healthcare system. 103 (4.1%) of AAms and 143 (4.0%) of WAms were diagnosed with subsequent BC. The 10-year risk for developing TNBC was 0.56% (95%CI,0.32%-1.0%) for AAms and 0.25% (95%CI, 0.12%-0.53%) for WAms. Among the 66 AAms who developed invasive BC, 16 (24.2%) developed TNBC compared with 7 (7.4%) of the 94 WAms (P=.01). Our findings portend that African heritage is a risk factor for TNBC and a potential contributor to disparity in BC treatment outcomes.