The aim of this study was to determine the correlation between changes in collagen metabolites (ICTP, mature cross-linked carboxy-terminal telopeptide of type I collagen; PINP, the amino-terminal propeptide of type I procollagen) and bone mineral density (BMD) in 206 pre- and post-menopausal breast cancer patients with non-metastatic disease. This evidence concerns the gene COL1A2 and metastatic neoplasm.