TY - JOUR
T1 - Pregnancy-Related Factors and Breast Cancer Risk for Women Across a Range of Familial Risk
AU - Kathleen Cuningham Foundation Consortium investigators
AU - McDonald, Jasmine A.
AU - Liao, Yuyan
AU - Knight, Julia A.
AU - John, Esther M.
AU - Kurian, Allison W.
AU - Daly, Mary
AU - Buys, Saundra S.
AU - Huang, Yun
AU - Frost, Caren J.
AU - Andrulis, Irene L.
AU - Colonna, Sarah V.
AU - Friedlander, Michael L.
AU - Hopper, John L.
AU - Chung, Wendy K.
AU - Genkinger, Jeanine M.
AU - MacInnis, Robert J.
AU - Terry, Mary Beth
PY - 2024/8/26
Y1 - 2024/8/26
N2 - IMPORTANCE: Few studies have investigated whether the associations between pregnancy-related factors and breast cancer (BC) risk differ by underlying BC susceptibility. Evidence regarding variation in BC risk is critical to understanding BC causes and for developing effective risk-based screening guidelines.OBJECTIVE: To examine the association between pregnancy-related factors and BC risk, including modification by a of BC where scores are based on age and BC family history.DESIGN, SETTING, AND PARTICIPANTS: This cohort study included participants from the prospective Family Study Cohort (ProF-SC), which includes the 6 sites of the Breast Cancer Family Registry (US, Canada, and Australia) and the Kathleen Cuningham Foundation Consortium (Australia). Analyses were performed in a cohort of women enrolled from 1992 to 2011 without any personal history of BC who were followed up through 2017 with a median (range) follow-up of 10 (1-23) years. Data were analyzed from March 1992 to March 2017.EXPOSURES: Parity, number of full-term pregnancies (FTP), age at first FTP, years since last FTP, and breastfeeding.MAIN OUTCOMES AND MEASURES: BC diagnoses were obtained through self-report or report by a first-degree relative and confirmed through pathology and data linkages. Cox proportional hazards regression models estimated hazard ratios (HR) and 95% CIs for each exposure, examining modification by PARS of BC. Differences were assessed by estrogen receptor (ER) subtype.RESULTS: The study included 17 274 women (mean [SD] age, 46.7 [15.1] years; 791 African American or Black participants [4.6%], 1399 Hispanic or Latinx participants [8.2%], and 13 790 White participants [80.7%]) with 943 prospectively ascertained BC cases. Compared with nulliparous women, BC risk was higher after a recent pregnancy for those women with higher PARS (last FTP 0-5 years HR for interaction, 1.53; 95% CI, 1.13-2.07; P for interaction < .001). Associations between other exposures were limited to ER-negative disease. ER-negative BC was positively associated with increasing PARS and increasing years since last FTP (P for interaction < .001) with higher risk for recent pregnancy vs nulliparous women (last FTP 0-5 years HR for interaction, 1.54; 95% CI, 1.03-2.31). ER-negative BC was positively associated with increasing PARS and being aged 20 years or older vs less than 20 years at first FTP (P for interaction = .002) and inversely associated with multiparity vs nulliparity (P for interaction = .01).CONCLUSIONS AND RELEVANCE: In this cohort study of women with no prior BC diagnoses, associations between pregnancy-related factors and BC risk were modified by PARS, with greater associations observed for ER-negative BC.
AB - IMPORTANCE: Few studies have investigated whether the associations between pregnancy-related factors and breast cancer (BC) risk differ by underlying BC susceptibility. Evidence regarding variation in BC risk is critical to understanding BC causes and for developing effective risk-based screening guidelines.OBJECTIVE: To examine the association between pregnancy-related factors and BC risk, including modification by a of BC where scores are based on age and BC family history.DESIGN, SETTING, AND PARTICIPANTS: This cohort study included participants from the prospective Family Study Cohort (ProF-SC), which includes the 6 sites of the Breast Cancer Family Registry (US, Canada, and Australia) and the Kathleen Cuningham Foundation Consortium (Australia). Analyses were performed in a cohort of women enrolled from 1992 to 2011 without any personal history of BC who were followed up through 2017 with a median (range) follow-up of 10 (1-23) years. Data were analyzed from March 1992 to March 2017.EXPOSURES: Parity, number of full-term pregnancies (FTP), age at first FTP, years since last FTP, and breastfeeding.MAIN OUTCOMES AND MEASURES: BC diagnoses were obtained through self-report or report by a first-degree relative and confirmed through pathology and data linkages. Cox proportional hazards regression models estimated hazard ratios (HR) and 95% CIs for each exposure, examining modification by PARS of BC. Differences were assessed by estrogen receptor (ER) subtype.RESULTS: The study included 17 274 women (mean [SD] age, 46.7 [15.1] years; 791 African American or Black participants [4.6%], 1399 Hispanic or Latinx participants [8.2%], and 13 790 White participants [80.7%]) with 943 prospectively ascertained BC cases. Compared with nulliparous women, BC risk was higher after a recent pregnancy for those women with higher PARS (last FTP 0-5 years HR for interaction, 1.53; 95% CI, 1.13-2.07; P for interaction < .001). Associations between other exposures were limited to ER-negative disease. ER-negative BC was positively associated with increasing PARS and increasing years since last FTP (P for interaction < .001) with higher risk for recent pregnancy vs nulliparous women (last FTP 0-5 years HR for interaction, 1.54; 95% CI, 1.03-2.31). ER-negative BC was positively associated with increasing PARS and being aged 20 years or older vs less than 20 years at first FTP (P for interaction = .002) and inversely associated with multiparity vs nulliparity (P for interaction = .01).CONCLUSIONS AND RELEVANCE: In this cohort study of women with no prior BC diagnoses, associations between pregnancy-related factors and BC risk were modified by PARS, with greater associations observed for ER-negative BC.
KW - Adult
KW - Australia/epidemiology
KW - Breast Feeding/statistics & numerical data
KW - Breast Neoplasms/genetics
KW - Canada/epidemiology
KW - Cohort Studies
KW - Female
KW - Genetic Predisposition to Disease
KW - Humans
KW - Middle Aged
KW - Parity
KW - Pregnancy
KW - Prospective Studies
KW - Registries
KW - Risk Factors
KW - United States/epidemiology
UR - http://www.scopus.com/inward/record.url?scp=85202267282&partnerID=8YFLogxK
U2 - 10.1001/jamanetworkopen.2024.27441
DO - 10.1001/jamanetworkopen.2024.27441
M3 - Article
C2 - 39186276
AN - SCOPUS:85202267282
SN - 2574-3805
VL - 7
SP - e2427441
JO - Jama Network Open
JF - Jama Network Open
IS - 8
ER -