Cardiovascular Risk Factors And Breast Cancer Incidence In The Atherosclerosis Risk In Communities Study

Research background and purposeBreast cancer is the most common female malignant tumor worldwide with an estimated incidence of 268,600 in 2019.Recent studies have indicated that breast cancer and cardiovascular disease share a number of common risk factors,which are potentially modifiable.Considering the interaction in cardiovascular risk factors,it is possible that a combination of cardiovascular risk factors could convey more information than a single factor alone.The clinical effects of clustering of cardiovascular risk factors on breast cancer incidence still remain unknown.To address this gap in knowledge,we used data from the ARIC study and made secondary analysis to explore the relationship between independent and combining effects of cardiovascular risk factors and breast cancer in women from the United States(US).Patients and methodsData from the ARIC study,a prospective cohort of middle-aged women,were used to investigate the association of individual and combined cardiovascular risk factors with breast cancer.For the present analysis,we excluded 7082 males.We also excluded 1209 subjects who had been diagnosed with breast cancer before the recruitment questionnaire.After the above exclusions,7501 subjects were included in this analysis.Cox regression was used to assess associations of cardiovascular risk factors and its components with breast cancer risk.Age was set as time scale.Followup time was defined as the time between the baseline examination until incident breast cancer,death,loss to follow-up,or last follow-up in 2013.Research results1.A total of 7501 women were included.During a mean follow-up of 19.7 years,576 women were diagnosed with breast cancer.2.White race,premenopausal status was independently associated with increased risk of breast cancer.3.Of the individual cardiovascular risk factors,only obesity was independently associated with an increased risk of breast cancer(HR 1.29;95%CI 1.04-1.61).Compared with women without cardiovascular risk factors,women having ≥3,but not those with less than 3 cardiovascular risk factors,had a significantly higher risk of developing breast cancer(HR 1.27;95%CI 1.06-1.53).4.Subgroup analyses indicated that women with ≥3 cardiovascular risk factors had higher risk of breast cancer among postmenopausal Black women,but not among premenopausal Black and White women.ConclusionCombinations of cardiovascular risk factors are associated with increased risk of breast cancer in middle-aged women,especially in postmenopausal Black women.Joint interventions to modify cardiovascular risk factors could be used to prevent breast cancer in these higher-risk individuals.