Abstract P4-01-04: Immunohistochemical and histological features of mammographic dense and non-dense tissue in breast cancer patients

Abstract

Abstract Objective: We investigated immunohistochemical and histological composition of dense and non-dense breast tissue in 18 women undergoing mastectomy as the initial treatment for breast cancer. Materials and Methods: In each mammogram, we localized the dense and the non-dense areas. We used a localization technique based on a linear approximation method with interpolation of mammogram images and breast pictures. The selected areas were retrieved during mastectomy and analyzed. Results: Estrogen and progesterone receptors, Ki-67 and CD-34, were equally expressed in both tissues, as well as the percentage composition of fat. The percentage compositions of brownish spots among dense and non-dense tissues were significantly different (p = 0.0226). The number of terminal ductal lobular units was higher for dense than for non-dense breast tissues (p = 0.0019). In the non-dense breast tissue, there were no proliferative lesions with atypia, while we found flat epithelial atypia in 3 of the dense areas evaluated. Proliferative lesions without atypia and non-proliferative lesions were found in both tissues, but they were more frequent in dense than in non-dense breast tissues (23.5% vs 11.8%, p = 0.0455, and 17.6% vs 2.9%, p = 0.0253, respectively). Fibrosis was more frequently extensive or moderate in dense tissue, while it was predominantly mild in non-dense tissue (p = 0.03). Conclusion: There was no difference in the expression of the estrogen and progesterone receptors, Ki-67 and CD-34, in the dense and non-dense tissue areas in breast-cancer women. In addition, both stroma fibrosis and epithelial proliferation were responsible for higher mammographic density. Citation Format: dos Santos CC, Marshall P, Torresan R, Tinóis E, Duarte G, Teixeira S. Immunohistochemical and histological features of mammographic dense and non-dense tissue in breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-01-04.