whitlockite and Calcinosis

Ductal carcinoma in-situ (DCIS) accounts for 20-25% of all new breast cancer diagnoses. DCIS has an uncertain risk of progression to invasive breast cancer and a lack of predictive biomarkers may result in relatively high levels (~ 75%) of overtreatment. To identify unique prognostic biomarkers of invasive progression, crystallographic and chemical features of DCIS microcalcifications have been explored. Samples from patients with at least 5-years of follow up and no known recurrence (174 calcifications in 67 patients) or ipsilateral invasive breast cancer recurrence (179 microcalcifications in 57 patients) were studied. Significant differences were noted between the two groups including whitlockite relative mass, hydroxyapatite and whitlockite crystal maturity and, elementally, sodium to calcium ion ratio. A preliminary predictive model for DCIS to invasive cancer progression was developed from these parameters with an AUC of 0.797. These results provide insights into the differing DCIS tissue microenvironments, and how these impact microcalcification formation.

Topics: Breast Neoplasms; Calcinosis; Carcinoma, Ductal, Breast; Carcinoma, Intraductal, Noninfiltrating; Crystallography; Female; Humans; Neoplasm Recurrence, Local; Tumor Microenvironment

Breast microcalcifications are a common mammographic finding. Microcalcifications are considered suspicious signs of breast cancer and a breast biopsy is required, however, cancer is diagnosed in only a few patients. Reducing unnecessary biopsies and rapid characterization of breast microcalcifications are unmet clinical needs. In this study, 473 microcalcifications detected on breast biopsy specimens from 56 patients were characterized entirely by Raman mapping and confirmed by X-ray scattering. Microcalcifications from malignant samples were generally more homogeneous, more crystalline, and characterized by a less substituted crystal lattice compared with benign samples. There were significant differences in Raman features corresponding to the phosphate and carbonate bands between the benign and malignant groups. In addition to the heterogeneous composition, the presence of whitlockite specifically emerged as marker of benignity in benign microcalcifications. The whole Raman signature of each microcalcification was then used to build a classification model that distinguishes microcalcifications according to their overall biochemical composition. After validation, microcalcifications found in benign and malignant samples were correctly recognized with 93.5% sensitivity and 80.6% specificity. Finally, microcalcifications identified in malignant biopsies, but located outside the lesion, reported malignant features in 65% of

Topics: Biomarkers; Biopsy; Breast; Breast Carcinoma In Situ; Breast Diseases; Breast Neoplasms; Calcinosis; Calcium Phosphates; Carbonates; Female; Humans; Phosphates; Sensitivity and Specificity; Spectrum Analysis, Raman

Despite the importance of calcifications in early detection of breast cancer, and their suggested role in modulating breast cancer cell behaviour, very little detail is known about their chemical composition or how this relates to pathology. We measured the elemental composition of calcifications contained within histological sections of breast tissue biopsies, and related this to both crystallographic parameters measured previously in the same specimens, and to the histopathology report. The Ca:P ratio is of particular interest since this theoretically has potential as a non-invasive aid to diagnosis; this was found to lie in a narrow range similar to bone, with no significant difference between benign and malignant. The Mg:Ca ratio is also of interest due to the observed association of magnesium whitlockite with malignancy. The initially surprising inverse correlation found between whitlockite fraction and magnesium concentration can be explained by the location of the magnesium in calcified tissue. Sodium was also measured, and we discovered a substantial and significant difference in Na:Ca ratio in the apatite phase between benign and malignant specimens. This has potential for revealing malignant changes in the vicinity of a core needle biopsy.

Topics: Breast; Breast Neoplasms; Calcinosis; Calcium; Calcium Phosphates; Electron Probe Microanalysis; Female; Humans; Magnesium; Phosphorus; Sodium

Topics: Aortic Diseases; Aortic Valve; Aortic Valve Insufficiency; Calcinosis; Calcium Phosphates; Humans; Hypertension; Male; Middle Aged

Whitlockite (in fact magnesium whitlockite) is a calcium orthophosphate crystal in which, in biological conditions, magnesium is partly substituted for calcium. Identified in X-ray or electron diffraction patterns, it occurs in physiological or pathological conditions at extra or intratissular sites, mainly in tissues of non-epithelial origin. In a range of pathological calcifications investigated by X-ray diffraction, we noted that whitlockite appeared to be frequently associated with apatite, particularly in "dystrophic calcifications" of tuberculous origin. These personal observations could be correlated with documented data in oral pathology (dental calculus, salivary stones, and dental caries). Whitlockite deposits have also been reported in non-infectious conditions, such as in aortic media, cartilage, and bone tissue. Whereas the formation of both apatite and magnesium whitlockite appears to be caused by the binding of their constituting ions with proteolipids, magnesium inhibits apatite originating from amorphous calcium phosphate to the benefit of whitlockite formation. Possibly, the development of magnesium whitlockite may provide an interesting marker for magnesium metabolism. Further studies linking histology to crystallography might relate the crystal to issues, such as tuberculous calcifications or diseases of bone tissue, and might be useful for potential diagnostic orientation.

Topics: Calcinosis; Calcium Phosphates; Calcium Pyrophosphate; Crystallization; Crystallography, X-Ray; Durapatite; Humans; Microscopy, Electron; Pilot Projects

Granular mediacalcinosis of the aorta seems to be a forgotten phenomenon that had been intensively investigated at the beginning of the past century. Without knowledge of this older literature we were, first of all, astonished to find in histological sections from aortic aneurysms, appearing "normal" in the H&E stain, severe calcifications of the media in von Kóssa and Alizarin red S stained sections. Therefore, 24 operation specimens of aneurysms were investigated with several morphological methods. In all cases, light microscopy exhibited granular medial calcification with a slight increase of the severity in specimens from older patients. Scanning electron microscopy on paraffin sections revealed calcified globules with diameters of about 1 micron localized between the elastic laminae. By transmission electron microscopy these calcospherites occupied the space between the elastic laminae. X-ray microanalysis exhibited high amounts of calcium and phosphorus and a smaller amount of magnesium. This atomic composition supports the findings of Reid and Andersen (69) indicating that these calcifications are due to the deposition of whitlockite. These morphological findings are supplemented by a review of the older literature. The biological significance of this calcification remains unknown. On the one hand, it may be responsible for the increasing stiffness of the aorta in older age groups--and, on the other hand, a pathogenetic role for the development of dissecting aneurysms cannot be excluded. This may be supported by the effect of beta-aminopropionitril in lathyric rats with destruction of the interlaminar fibers, described by Nakashima and Sueishi (65): it seems possible that a focal increased calcification in the human aorta may disturb the connection between the elastic laminae, thus, facilitating their separation.

Topics: Adult; Aged; Aged, 80 and over; Aorta; Aortic Aneurysm; Aortic Diseases; Aortic Dissection; Calcinosis; Calcium Phosphates; Elastic Tissue; Electron Probe Microanalysis; Female; History, 19th Century; History, 20th Century; Humans; Male; Microscopy, Electron, Scanning; Middle Aged; Tunica Media