Abstract 1769: Presence of cysts in benign breast tissue and the risk of subsequent breast cancer in African American women
Authors: Ruterbusch Julie J. , Cote Michele L. , Bandyopadhyay Sudeshna , Alosh Baraa , Abdulfatah Eman , Pardeshi Vishakha , Roquiz Woodlyne , Visscher Daniel , Ali-Fehmi Rouba 
Published: July 2016

Introduction: Benign breast disease (BBD) is an established risk factor for developing breast cancer, and certain pathologic features in benign breast tissue are more strongly associated with breast cancer risk. Most of the studies evaluating BBD and breast cancer risk have been done in primarily white populations. Our previous work among African American (AA) women with BBD suggested the presence of cysts was associated with increased breast cancer risk. This finding may be unique to AA women as other studies among white populations have not replicated these findings. We sought to further explore the association between breast cysts and breast cancer risk in our expanded AA BBD cohort.

Methods: Biopsies from AA women initially diagnosed with BBD from 1997 to 2009 were examined for 14 pathologic features, including the microscopic presence of cysts, and followed for subsequent breast cancer. The association between cysts and the other pathologic features were compared using chi-square tests, and the risk of developing breast cancer was estimated using logistic regression and summarized with odds ratios (OR) and 95% confidence intervals (95% CI).

Results: A total of 3,360 AA women with BBD have been identified and their benign biopsies reviewed. 190 women have developed a subsequent breast cancer with a mean follow-up time of 11.5 years. Cysts were present on 1,366 (38%) of the biopsies, and were significantly associated with nearly all of the other benign features evaluated: apocrine metaplasia, ductal hyperplasia, calcifications, duct ectasia, fibrodenomas, fibrosis, intra-ductal papillomas, sclerosing adenosis, columnar alterations, mucocelle-like lesions, radial scars, and proliferation with and without atypia (all p&lt;0.001). Adjusting for age and year of biopsy, cysts were associated with a 36% increase in breast cancer risk (OR: 1.36, 95% CI 1.01 - 1.82). When further adjusted for hyperplasia with atypia, the benign feature with the most established and strongest association with breast cancer risk, the risk associated with cysts was attenuated (OR: 1.20, 95% CI 0.88 - 1.64).

Conclusion: Among AA women, cysts are highly correlated with other BBD features that increase subsequent breast cancer risk, but the risk associated with cysts does not appear to be independent of hyperplasia with atypia. Understanding the etiology of BBD and cyst development may provide insight into breast tumorigenesis, and the interplay between cysts and other BBD features warrant further investigation.

Citation Format: Julie J. Ruterbusch, Michele L. Cote, Sudeshna Bandyopadhyay, Baraa Alosh, Eman Abdulfatah, Vishakha Pardeshi, Woodlyne Roquiz, Daniel Visscher, Rouba Ali-Fehmi. Presence of cysts in benign breast tissue and the risk of subsequent breast cancer in African American women. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1769.