Correlation between Choline Peak at MR Spectroscopy and Calcium-Sensing Receptor Expression Level in Breast Cancer: A Preliminary Clinical Study
The calcium-sensing receptor (CaSR) is overexpressed in many pathological states including breast cancer. Since choline kinase may be activated in breast cancer cells by CaSR resulting in increased phosphocholine production, we sought to correlate the total choline peak in breast lesions as measured by in vivo proton magnetic resonance spectroscopy (1H-MRS) with the CaSR expression levels in surgical specimens. Thirty-six patients with breast lesions were MR scanned at 3T scanner. Tumour morphology and DCE-MR kinetics were evaluated. 1H-MRS was applied for Cho detection and compared with the CaSR immunohistochemistry analysis (score 0–5) on surgical breast specimens. Thirty-four lesions demonstrated a DCE malignant kinetics curve (types 2 and 3), while two lesions showed a benign (type 1). Twenty of the 23 breast cancer lesions (87 %) with a consistent Cho peak expressed a CaSR score of 3–5, and ten of the 11 breast lesions negative for Cho (91 %) had a CaSR score of 1–2. The two benign lesions showed a non-uniform/weak intense expression of the CaSR (score 3) with a consistent Cho peak. The presence or absence of choline peak evaluated by 1H-MRS, well correlated with the expression of CaSR in patients with breast lesions (p < 0.01), supports the hypothesis that CaSR may play an important role in the production of choline in breast cancer.