Raman analysis of microcalcifications in male breast cancer

Abstract

Microcalcifications (MCs) are important disease markers for breast cancer. Many studies were conducted on their characterization in female breast cancer (FBC), but no information is available on their composition in male breast cancer (MBC). Raman spectroscopy (RS) is a molecular spectroscopy that can rapidly explore the biochemical composition of MCs without requiring any staining protocol. In this study, we optimized an algorithm to identify the mineral components present in MCs from Raman images. The algorithm was then used to study and compare MCs identified on breast cancer pieces from male and female patients. In total, we analyzed 41 MCs from 5 invasive MBC patients and 149 MCs from 13 invasive FBC patients. Results show that hydroxyapatite is the most abundant type of calcium both in MBC and FBC. However, some differences in the amount and distribution of calcium minerals are present between the two groups. Besides, we observed that MCs in MBC have a higher amount of organic material (collagen) than FBC. To the best of our knowledge, this study provides the first overview of the composition of MCs present in MBC patients; and suggests that these patients have specific features that differentiate them from the previously studied FBC. Our result support thus the need for studies designed explicitly to the understanding of MBC.

Keywords: Breast cancer; Hydroxyapatite; Male breast cancer; Microcalcifications; Raman spectroscopy.