Abstract P3-12-21: Blood pressure and the subsequent risk of breast cancer: Findings from the Health Examinees-Gem Study
Authors: De la Torre Katherine , Shin Woo-Kyoung , Huang Dan , Lee Hwi-Won , Shin Aesun , Lee Jong-koo , Lee Hae-Young , Kang Daehee 
Published: March 2022

Abstract
Background The prevalence of breast cancer and hypertension has been steadily increasing over the past years, and evidence has suggested a positive association between hypertension and the risk of breast cancer. However, scarce studies have addressed the existing relationship of blood pressure components and the risk of incidence breast cancer. Therefore, we aimed to assess the association between systolic and diastolic blood pressure and the risk of breast cancer in a population-based cohort.MethodsThe research included 87,280 women aged 40 to 69 years from the Health Examinees-Gem (HEXA-G) prospective cohort study between 2004 and 2013. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured based on baseline physical examination and then categorized based on clinical hypertension international guidelines. Additionally, hypertension was defined based on self-reported hypertension diagnosis or use of anti-hypertensive medication were obtained from a baseline questionnaire. Breast cancer incidence was followed through the Korean Cancer Center Registry. Multivariable Cox proportional hazards models were used to estimate the association between SBP and DBP with breast cancer adjusted for family history of breast cancer, parity, age at birth of a first child, age at menopause, physical activity, alcohol consumption, smoking status, self-reported history of hypertension, and hormone replaced therapy used, additionally for postmenopausal women. Results A total of 1058 breast cancer cases were observed over a median follow-up of 8.4 years. Diastolic blood pressure was associated with an increased risk of breast cancer in the total population (p for trend= 0.011). In postmenopausal women, DBP equal to or over 85mmHg was positively associated with breast cancer risk (HR: 1.58 95%IC 1.18 - 2.12), whereas no association was found in premenopausal women (HR: 0.87 IC95% 0.56 - 1.35)). Similar results were found when excluding all cases of self-reported hypertension and excluded participants diagnosed with breast. cancer within the first two years of the follow-up period. Results for systolic blood pressure did not significantly affect breast cancer risk for all women or by menopausal status. Conclusion These results suggest that higher diastolic blood pressure is related to an increased subsequent risk of breast cancer. This proposes that DBP is an important factor in cancer prevention in postmenopausal women, independently of having a previous hypertension diagnosis. Further studies need to be conducted to confirm these results and clarified the utterly potential mechanisms.
Citation Format: Katherine De la Torre, Woo-Kyoung Shin, Dan Huang, Hwi-Won Lee, Aesun Shin, Jong-koo Lee, Hae-Young Lee, Daehee Kang. Blood pressure and the subsequent risk of breast cancer: Findings from the Health Examinees-Gem Study [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-12-21.