Close the left navigation

Chronic Disease Epidemiology Group

Katie M. O'Brien, Ph.D.

Katie M. O'Brien, Ph.D.

Staff Scientist
Tel 984-365-9283
[email protected]

Research Summary

Katie M. O’Brien, MSPH, Ph.D. is a staff scientist in the Epidemiology Branch, where she helps lead the Sister Study, a prospective cohort study designed to identify environmental and genetic risk factors for breast cancer and other chronic diseases in women. Within the study, Dr. O’Brien is especially interested in studying exposures that are potentially modifiable through behavioral and societal interventions, including how personal care products (especially talcum powder), exogenous hormones, and vitamin D may impact the risk of breast, ovarian and uterine cancers. Dr. O’Brien also oversees the Sister Study’s participation in several cohort consortia, through which she has led a large pooled analysis of hormone therapy use and young-onset breast cancer and an assessment of the cumulative risk of breast cancer among US women based on their breast cancer pathogenic variant status, family history, and other established risk factors.

Katie M. O’Brien, MSPH, Ph.D. completed a post-doctoral fellowship in the Biostatistics and Computational Biology Branch and continues to be interested in epidemiologic study design and methods issues. She received her B.A. in mathematics and psychology from Williams College and her M.S.P.H. and Ph.D. in epidemiology from the University of North Carolina at Chapel Hill.

Selected Publications

  1. O’Brien KM, Keil AP, Taylor JA, Weinberg CR, Polley EC, Yadav S, Boddicker NJ, Hu C, Ambrosone CB, Anton-Culver H, Auer P, Bodelon C, Brantley K, Burnside ES, Chen F, Domchek SM, Eliassen AH, Haiman CA, Hodge JM, Kraft P, Lacey JV, Lindstroem S, Martinez EM, Nathanson KL, Neuhausen S, Olson JE, Palmer JR, Patel AV, Penney KL, Ruddy KJ, Scott CG, Teras LR, Trentham-Dietz A, Vachon CM, Weitzel JN, Yao S, Zirpoli G, Couch FJ, Sandler DP. Impact of pathogenic variants and family history on cumulative risk of breast cancer in U.S. women. JAMA Oncology. In press, July 2025.
  2. O’Brien KM, House MG, Goldberg M, Jones ME, Weinberg CR, de Gonzalez AB, Bertrand KA, Blot WJ, DeHart JC, Couch FJ, Garcia-Closas M, Giles GG, Kirsh VA, Kitahara CM, Koh WP, Park HL, Milne RL, Palmer JR, Patel AV, Rohan TE, Schoemaker MJ, Swerdlow AJ, Teras LR, Vachon C, Visvanathan K, Yuan JM, Zheng W, Nichols HB, Sandler DP. Hormone therapy use and young-onset breast cancer: a pooled analysis of prospective cohorts included in the Premenopausal Breast Cancer Collaborative Group. Lancet Oncol. 2025;26(7):911-23. doi: 10.1016/s1470-2045(25)00211-6. PubMed PMID: 40609572; PMCID: PMC12233149. [ Abstract O’Brien KM, House MG, Goldberg M, Jones ME, Weinberg CR, de Gonzalez AB, Bertrand KA, Blot WJ, DeHart JC, Couch FJ, Garcia-Closas M, Giles GG, Kirsh VA, Kitahara CM, Koh WP, Park HL, Milne RL, Palmer JR, Patel AV, Rohan TE, Schoemaker MJ, Swerdlow AJ, Teras LR, Vachon C, Visvanathan K, Yuan JM, Zheng W, Nichols HB, Sandler DP. Hormone therapy use and young-onset breast cancer: a pooled analysis of prospective cohorts included in the Premenopausal Breast Cancer Collaborative Group. Lancet Oncol. 2025;26(7):911-23. doi: 10.1016/s1470-2045(25)00211-6. PubMed PMID: 40609572; PMCID: PMC12233149. ]
  3. Ogunsina K, O’Brien KM, White AJ, Chang CJ, Gaston SA, Jackson CL, Sandler DP. Hair Straightener Use in Relation to Prevalent and Incident Fibroids in the Sister Study with a Focus on Black Women. Environ Health Perspect. 2025;133(1):17004. Epub 20250114. doi: 10.1289/ehp14493. PMID: 39808082; PMCID: PMC11730732. [ Abstract Ogunsina K, O’Brien KM, White AJ, Chang CJ, Gaston SA, Jackson CL, Sandler DP. Hair Straightener Use in Relation to Prevalent and Incident Fibroids in the Sister Study with a Focus on Black Women. Environ Health Perspect. 2025;133(1):17004. Epub 20250114. doi: 10.1289/ehp14493. PMID: 39808082; PMCID: PMC11730732. ]
  4. Jukic AMZ, Sandler DP, Weinberg CR, O’Brien KM. Vitamin D status and supplementation, calcium supplementation, and timing of natural menopause. Maturitas. 2024;182:107916. Epub 20240118. doi: 10.1016/j.maturitas.2024.107916. PubMed PMID: 38266360; PMCID: PMC11000149. [ Abstract Jukic AMZ, Sandler DP, Weinberg CR, O’Brien KM. Vitamin D status and supplementation, calcium supplementation, and timing of natural menopause. Maturitas. 2024;182:107916. Epub 20240118. doi: 10.1016/j.maturitas.2024.107916. PubMed PMID: 38266360; PMCID: PMC11000149. ]
  5. O’Brien KM, Wentzensen N, Ogunsina K, Weinberg CR, D’Aloisio AA, Edwards JK, Sandler DP. Intimate Care Products and Incidence of Hormone-Related Cancers: A Quantitative Bias Analysis. J Clin Oncol. 2024;42(22):Jco2302037. Epub 20240515. doi: 10.1200/jco.23.02037. PubMed PMID: 38748950; PMCID: PMC11484790. [ Abstract O’Brien KM, Wentzensen N, Ogunsina K, Weinberg CR, D’Aloisio AA, Edwards JK, Sandler DP. Intimate Care Products and Incidence of Hormone-Related Cancers: A Quantitative Bias Analysis. J Clin Oncol. 2024;42(22):Jco2302037. Epub 20240515. doi: 10.1200/jco.23.02037. PubMed PMID: 38748950; PMCID: PMC11484790. ]
  6. Tekle H, Sandler DP, Ogunsina K, O’Brien KM. The independent and joint associations of hysterectomy and uterine fibroids or endometriosis with ovarian cancer incidence: results from a US-based cohort. Am J Epidemiol. 2024;194(2):370-8. Epub 20240724. doi: 10.1093/aje/kwae235. PubMed PMID: 39049451; PMCID: PMC11815501. [ Abstract Tekle H, Sandler DP, Ogunsina K, O’Brien KM. The independent and joint associations of hysterectomy and uterine fibroids or endometriosis with ovarian cancer incidence: results from a US-based cohort. Am J Epidemiol. 2024;194(2):370-8. Epub 20240724. doi: 10.1093/aje/kwae235. PubMed PMID: 39049451; PMCID: PMC11815501. ]
  7. Zeldin J, Sandler DP, Ogunsina K, O’Brien KM. Association of fibroids, endometriosis, and gynecologic surgeries with breast cancer incidence and hormone receptor subtypes. Cancer Epidemiol Biomarkers Prev. 2024;33(4):576-85. Epub 20240123. doi: 10.1158/1055-9965.Epi-23-1014. PubMed PMID: 38260971; PMCID: PMC10990796. [ Abstract Zeldin J, Sandler DP, Ogunsina K, O’Brien KM. Association of fibroids, endometriosis, and gynecologic surgeries with breast cancer incidence and hormone receptor subtypes. Cancer Epidemiol Biomarkers Prev. 2024;33(4):576-85. Epub 20240123. doi: 10.1158/1055-9965.Epi-23-1014. PubMed PMID: 38260971; PMCID: PMC10990796. ]
  8. Chang CJ, O’Brien KM, Keil AP, Goldberg M, Taylor KW, Sandler DP, White AJ. Use of personal care product mixtures and incident hormone-sensitive cancers in the Sister Study: A U.S.-wide prospective cohort. Environ Int. 2023;183:108298. Epub 2023/12/04. doi:10.1016/j.envint.2023.108298. PubMed PMID: 38043324; PMCID: PMC10841676. [ Abstract Chang CJ, O’Brien KM, Keil AP, Goldberg M, Taylor KW, Sandler DP, White AJ. Use of personal care product mixtures and incident hormone-sensitive cancers in the Sister Study: A U.S.-wide prospective cohort. Environ Int. 2023;183:108298. Epub 2023/12/04. doi:10.1016/j.envint.2023.108298. PubMed PMID: 38043324; PMCID: PMC10841676. ]
  9. Lovett SM, Sandler DP, O’Brien KM. Hysterectomy, bilateral oophorectomy, and breast cancer risk in a racially diverse prospective cohort study. J Natl Cancer Inst. 2023;115(6):662-70. Epub 2023/02/23. doi: 10.1093/jnci/djad038. PubMed PMID: 36806439; PMCID: PMC10248837. [ Abstract Lovett SM, Sandler DP, O’Brien KM. Hysterectomy, bilateral oophorectomy, and breast cancer risk in a racially diverse prospective cohort study. J Natl Cancer Inst. 2023;115(6):662-70. Epub 2023/02/23. doi: 10.1093/jnci/djad038. PubMed PMID: 36806439; PMCID: PMC10248837. ]
  10. O’Brien KM, Ogunsina K, Wentzensen N, Sandler DP. Douching and genital talc use: Patterns of use and reliability of self-reported exposure. Epidemiology. 2023;34(3):376-84. Epub 2023/01/19. doi: 10.1097/ede.0000000000001589. PubMed PMID: 36652669; PMCID: PMC10187135. [ Abstract O’Brien KM, Ogunsina K, Wentzensen N, Sandler DP. Douching and genital talc use: Patterns of use and reliability of self-reported exposure. Epidemiology. 2023;34(3):376-84. Epub 2023/01/19. doi: 10.1097/ede.0000000000001589. PubMed PMID: 36652669; PMCID: PMC10187135. ]
  11. Ogunsina K, Sandler DP, Murphy JD, Harmon QE, D’Aloisio AA, Baird DD, O’Brien KM. Association of genital talc and douche use in early adolescence or adulthood with uterine fibroids diagnoses. Am J Obstet Gynecol. 2023;229(6):665 e1- e10. Epub 2023/08/21. doi: 10.1016/j.ajog.2023.08.014. PubMed PMID: 37598998; PMCID: PMC10840729. [ Abstract Ogunsina K, Sandler DP, Murphy JD, Harmon QE, D’Aloisio AA, Baird DD, O’Brien KM. Association of genital talc and douche use in early adolescence or adulthood with uterine fibroids diagnoses. Am J Obstet Gynecol. 2023;229(6):665 e1- e10. Epub 2023/08/21. doi: 10.1016/j.ajog.2023.08.014. PubMed PMID: 37598998; PMCID: PMC10840729. ]
  12. Chang CJ, O’Brien KM, Keil AP, Gaston SA, Jackson CL, Sandler DP, White AJ. Use of Straighteners and Other Hair Products and Incident Uterine Cancer. J Natl Cancer Inst. 2022;114(12):1636-45. Epub 2022/10/18. doi: 10.1093/jnci/djac165. PubMed PMID: 36245087; PMCID: PMC9949582. [ Abstract Chang CJ, O’Brien KM, Keil AP, Gaston SA, Jackson CL, Sandler DP, White AJ. Use of Straighteners and Other Hair Products and Incident Uterine Cancer. J Natl Cancer Inst. 2022;114(12):1636-45. Epub 2022/10/18. doi: 10.1093/jnci/djac165. PubMed PMID: 36245087; PMCID: PMC9949582. ]
  13. Kuiper JR, O’Brien KM, Welch BM, Barrett ES, Nguyen RHN, Sathyanarayana S, Milne GL, Swan SH, Ferguson KK, Buckley JP. Combining urinary biomarker data from studies with different measures of urinary dilution. Epidemiology. 2022;33(4):533-40. Epub 2022/04/28. doi: 10.1097/ede.0000000000001496. PubMed PMID: 35473917; PMCID: PMC9585883. [ Abstract Kuiper JR, O’Brien KM, Welch BM, Barrett ES, Nguyen RHN, Sathyanarayana S, Milne GL, Swan SH, Ferguson KK, Buckley JP. Combining urinary biomarker data from studies with different measures of urinary dilution. Epidemiology. 2022;33(4):533-40. Epub 2022/04/28. doi: 10.1097/ede.0000000000001496. PubMed PMID: 35473917; PMCID: PMC9585883. ]
  14. O’Brien KM, Harmon QE, Jackson CL, Diaz-Santana MV, Taylor JA, Weinberg CR, Sandler DP. Vitamin D concentrations and breast cancer incidence among Black/African American and non-Black Hispanic/Latina women. Cancer. 2022;128(13):2463-73. Epub 2022/04/26. doi: 10.1002/cncr.34198. PubMed PMID: 35466399; PMCID: PMC9177687. [ Abstract O’Brien KM, Harmon QE, Jackson CL, Diaz-Santana MV, Taylor JA, Weinberg CR, Sandler DP. Vitamin D concentrations and breast cancer incidence among Black/African American and non-Black Hispanic/Latina women. Cancer. 2022;128(13):2463-73. Epub 2022/04/26. doi: 10.1002/cncr.34198. PubMed PMID: 35466399; PMCID: PMC9177687. ]
  15. O’Brien KM, Lawrence KG, Keil AP. The Case for Case-Cohort: An Applied Epidemiologist’s Guide to Reframing Case-Cohort Studies to Improve Usability and Flexibility. Epidemiology. 2022;33(3):354-61. Epub 2022/04/07. doi: 10.1097/ede.0000000000001469. PubMed PMID: 35383643; PMCID: PMC9172927. [ Abstract O’Brien KM, Lawrence KG, Keil AP. The Case for Case-Cohort: An Applied Epidemiologist’s Guide to Reframing Case-Cohort Studies to Improve Usability and Flexibility. Epidemiology. 2022;33(3):354-61. Epub 2022/04/07. doi: 10.1097/ede.0000000000001469. PubMed PMID: 35383643; PMCID: PMC9172927. ]