Association between lifestyle, menstrual/reproductive history, and histological factors and risk of breast cancer in women biopsied for benign breast disease

Abstract

Purpose Women with benign breast disease (BBD) have an increased risk of subsequent breast cancer. However, whether conventional breast cancer risk factors influence risk of breast cancer among women with BBD is unclear. In this study, we investigated the associations of lifestyle, menstrual/reproductive, and histological factors with risk of breast cancer among women biopsied for BBD. Methods We conducted a case-control study, nested within a cohort of 15,395 women biopsied for BBD at Kaiser Permanente Northwest between 1971 and 2006. Cases were women who developed a subsequent invasive breast cancer during follow-up; controls were individually matched to cases on age at BBD diagnosis. A total of 526 case-control pairs were included in the study. We calculated crude and multivariable OR and 95% CI for the associations between lifestyle, menstrual/reproductive, and histological factors and breast cancer risk using conditional logistic regression. Results Compared to premenopausal women, postmenopausal women, had reduced risk of subsequent breast cancer (OR: 0.60; 95% CI: 0.39–0.94), whereas women who ever used hormone therapy had increased risk (OR: 3.61; 95% CI: 1.68–7.75), as did women whose BBD lesion showed atypical hyperplasia (OR: 5.56; 95% CI: 2.05–15.06). Smoking, BMI, early menarche, multiparity (>=4), history of oophorectomy, and extent of lobular involution were not associated with risk of breast cancer. Conclusion This study suggests that use of HRT and having atypical hyperplasia are associated with increased risk of breast cancer among women with BBD while postmenopausal women with BBD have a reduced risk.

Risk factors for breast cancer development by tumor characteristics among women with benign breast disease

“…We utilized data from a previously designed case-control study of BBD and breast cancer risk [11], nested within a BBD cohort from Kaiser Permanente Northwest (KPNW), which provides medical care for approximately ½ million members located in Southwest Washington and Northwest Oregon. The source population was comprised of women who had biopsycon rmed BBD diagnosed between August 3, 1971 and December 31, 2006 (N = 15,395; age range 21-85 years).…”

“…One woman (selected as a control) had a BBD diagnosis in 2012. Invasive breast cancer diagnoses were obtained through record linkage with the KPNW Tumor Registry, as previously described [11]. Brie y, cases were de ned as women diagnosed with invasive breast cancer at least one year after BBD diagnosis, and no prior history of in situ lesions.…”

“…Breast cancer is a heterogeneous disease, with data strongly supporting different associations of risk factors such as parity and genetic susceptibility loci by tumor subtypes de ned by hormone receptor status and other clinical/pathologic features [7][8][9][10]. Whether similar etiologic heterogeneity exists for breast cancer arising in BBD patients is unknown, and to date very few cohort studies can assess this hypothesis [11][12][13]. We therefore assessed patient and BBD histopathological features associated with BC risk and evaluated whether relationships varied by tumor characteristics.…”

The potential interaction of hereditary and reproductive factors in the etiology of mammary gland hyperplasia: a case-control study

“…Understanding indicators of HMG in middle-aged women play an important part in public health and clinical implications. Researches have identified multiple risk factors for HMG 3 , such as late age at menopause 4,5 , nulliparity 4,5 , lacking breastfeeding 6 , high-level education 7 and family history of breast cancer 8 . Nevertheless, etiology of HMG remains largely unknown.…”

“…Family history of breast cancer is an important indicator for a woman's future risk of developing breast cancer 9 . Part of the genetic information can be explained by hereditary history 3,10 .…”