The key role of correlation between MR spectroscopy choline peak and calcium sensing receptor for breast cancer: Diagnosis by a 3T MR scanner.

Abstract

e22132 Background: The Ca2+-sensing receptor (CaSR) regulates the Ca2+ signaling and its expression is present in both normal and malignant breast tissues. Recently, we demonstrated in a pre-clinical setting the CaSR expression in breast cancer mouse model by manganese enhanced MRI (Baio G et al. Eur Rad 2011). Alteration in choline phospholipid metabolism as detected by MRI, is a common feature of breast and many other cancer cells or tumors. Since CaSR-ChoK signaling plays an important role in breast cancer, we compared the MRS (MR spectroscopy) choline peak by a 3T MR scanner between calcium sensing receptor positive and negative breast cancers. Methods: Breast MRI of 16 consecutive patients with breast lesions were performed by a 3T MR and MRS findings were defined as positive by the visual inspection for the presence or the absence of choline peak. MRS imaging were compared with histologic findings and the pattern of CaSR by immunohistochemistry. The immunohistochemical results were qualitatively classified according to intensity and pattern of the staining, using a 6-point scale to score the intensity of the CaSR expression (0, absent; 5, intense, widespread expression). Results: A choline peak was present in 10 of 15 malignant lesions and the CaSR expression was between 3 to 5 score at immunohistochemestry analysis (p<.0006). In 4 of 15 malignant lesions the choline peak was absent or not consistent at the visual analysis with a CaSR patterns of 1-2. In one benign lesion (papillary hyperplasia), the choline peak was consistent and the CaSR pattern was with score 3. Conclusions: In this study we evaluated if MRS presence or absence of choline peak well correlated with CaSR positive and negative breast cancers. We observed a choline peak with an high level expression of CaSR (score 3-5) in 67% of the breast lesions, while in 27% of the lesions the choline peak was absent with a low CaSR expression (score 1-2). These preliminary results support the hypothesis that CaSR represents an important role in the production of choline in breast cancer, determining an increase of his production when CaSR is expressed at high level and implicating and absence of choline peak when CaSR is not expressed.