Hypertensive conditions of pregnancy, preterm birth, and premenopausal breast cancer risk: a premenopausal breast cancer collaborative group analysis

• Published in: Breast cancer research and treatment 2023-06, Vol.199 (2), p.323-334
• Main Authors: Nichols, Hazel B., House, Melissa G., Yarosh, Rina, Mitra, Sara, Goldberg, Mandy, Bertrand, Kimberly A., Eliassen, A. Heather, Giles, Graham G., Jones, Michael E., Milne, Roger L., O’Brien, Katie M., Palmer, Julie R., Sandin, Sven, Willett, Walter C., Yin, Weiyao, Sandler, Dale P., Swerdlow, Anthony J., Schoemaker, Minouk J.
• Format: Article
• Language: English
• Subjects: Birth; Breast cancer; Breast Neoplasms - epidemiology; Breast Neoplasms - etiology; Cancer research; Collaboration; Epidemiology; Female; Health aspects; Humans; Hypertension; Hypertension, Pregnancy-Induced - diagnosis; Hypertension, Pregnancy-Induced - epidemiology; Infant, Newborn; Infants (Premature); Medical colleges; Medicin och hälsovetenskap; Medicine; Medicine & Public Health; Menopause; Oncology; Pre-eclampsia; Pre-Eclampsia - diagnosis; Pre-Eclampsia - epidemiology; Preeclampsia; Pregnancy; Pregnancy complications; Pregnant women; Premature birth; Premature Birth - epidemiology; Premature Birth - etiology; Risk Factors; Womens health
• ISSN: 0167-6806; 1573-7217; 1573-7217
• DOI: 10.1007/s10549-023-06903-5

Purpose Women with preeclampsia are more likely to deliver preterm. Reports of inverse associations between preeclampsia and breast cancer risk, and positive associations between preterm birth and breast cancer risk are difficult to reconcile. We investigated the co-occurrence of preeclampsia/gestational hypertension with preterm birth and breast cancer risk using data from the Premenopausal Breast Cancer Collaborative Group. Methods Across 6 cohorts, 3096 premenopausal breast cancers were diagnosed among 184,866 parous women. We estimated multivariable hazard ratios (HR) and 95% confidence intervals (CI) for premenopausal breast cancer risk using Cox proportional hazards regression. Results Overall, preterm birth was not associated (HR 1.02, 95% CI 0.92, 1.14), and preeclampsia was inversely associated (HR 0.86, 95% CI 0.76, 0.99), with premenopausal breast cancer risk. In stratified analyses using data from 3 cohorts, preterm birth associations with breast cancer risk were modified by hypertensive conditions in first pregnancies ( P -interaction = 0.09). Preterm birth was positively associated with premenopausal breast cancer in strata of women with preeclampsia or gestational hypertension (HR 1.52, 95% CI: 1.06, 2.18), but not among women with normotensive pregnancy (HR = 1.09, 95% CI: 0.93, 1.28). When stratified by preterm birth, the inverse association with preeclampsia was more apparent, but not statistically different ( P -interaction = 0.2), among women who did not deliver preterm (HR = 0.82, 95% CI 0.68, 1.00) than those who did (HR = 1.07, 95% CI 0.73, 1.56). Conclusion Findings support an overall inverse association of preeclampsia history with premenopausal breast cancer risk. Estimates for preterm birth and breast cancer may vary according to other conditions of pregnancy.