Abstract 4105: Prevalence of breast stem cells in high-risk benign breast lesions and association with breastfeeding

Abstract

Abstract Background: Invasive breast cancers contain a subpopulation of cancer stem cells that are thought to maintain the heterogeneity and self-renewing potential of the tumor. In our previously published data, we demonstrated that stem cells in normal adjacent tissues were associated with triple negative breast cancer. The objective of this study is to determine the presence of stem cells in high risk breast lesions. We hypothesized that stem cells in high-risk lesions and normal adjacent breast tissue may represent a biomarker for increased breast cancer risk. Methods: We identified biopsies from 42 high-risk women seen in the Cancer Prevention Center at The University of Texas MD Anderson Cancer Center between 1988-2011. We collected information on breast cancer risk factors. The biopsies contained high-risk lesions including ductal carcinoma in situ (DCIS) n=21, lobular carcinoma in situ (LCIS) n=5, atypical ductal hyperplasia (ADH) n=7 and atypical lobular hyperplasia (ALH) n=6. The tissues were fluorescently labeled for stem cell markers CD44/CD49f/CD133, and were scored positive if more then 1% cells were positive for all markers using an automated fluorescent microscopy software. The presence of stem cell markers was compared in the normal adjacent tissues and high-risk lesions from a subset of 25 patients. Results: We identified stem cells in 46% of samples containing DCIS, 67% of LCIS, 63% of ALH, and 70% of ADH. There was a 79% concordance in stem cell positive status between the high-risk lesion and adjacent normal tissue. Women with positive stem cell high-risk lesions had no significant difference in age at first birth (24.4 years vs 26.6 years p=0.3), parity (1.7 vs 1.9, p=0.5), or body mass index (27.8 vs 31.8, p=0.07) compared to women without positive stem cell high-risk lesions. Women with positive stem cell high-risk lesions had shorter breastfeeding duration than women without (2.4 months vs 9.0 months p= 0.05). Conclusion: This is the first report, to our knowledge, that stem cells are present in some high-risk lesions and their associated normal breast tissue. Correlation with future development of invasive breast cancer could lay the foundation for future targeted breast cancer prevention strategies. Citation Format: Rachel L. Atkinson, Fraser Symmans, Therese B. Bevers, Wendy A. Woodward, Abenaa M. Brewster. Prevalence of breast stem cells in high-risk benign breast lesions and association with breastfeeding. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4105. doi:10.1158/1538-7445.AM2014-4105