Tissue Validation of Mammographic Breast Arterial Calcification in Mastectomy Specimens

Breast arterial calcification (BAC) is a common incidental finding on screening mammograms and has been associated with cardiovascular disease in women. However, every study in this field has been imaging-based. The accuracy of mammography for detecting breast arterial calcification has only ever been measured against another radiologist reading the same mammogram, never against the tissue itself. As a result, it is not known how much calcification mammography misses, nor whether what it shows represents medial (Monckeberg-type) calcification or true atherosclerosis. This prospective observational study compares mammographic BAC with the histopathology of breast arteries obtained from mastectomy specimens. Women aged 40 years and older undergoing upfront mastectomy, without neoadjuvant therapy, for invasive breast cancer or ductal carcinoma in situ will be enrolled consecutively. Additional tissue blocks will be taken from tumour-free areas of the specimen and examined with von Kossa and elastic van Gieson stains to determine whether arterial calcification is present and whether it lies in the media or the intima. These findings will be compared with the preoperative mammogram, which is read independently and blind to the pathology result. As a secondary and exploratory objective, coronary artery calcification will be scored from staging computed tomography images already acquired for cancer staging. No additional tests, imaging, radiation exposure or blood sampling will be performed for the purposes of this study, and the surgical procedure will not be altered in any way.