Reviewing Phospholipid Biomarkers of Breast Cancer Metabolism in MR-Spectroscopy

Abstract

Descriptive Abstract: In the last decades, in-vivo MR-spectroscopy (MRS) was found to add significant specificity to non-invasive breast cancer diagnosis. The total-choline signal, as measured by in-vivo 1H MRS, is currently being investigated as a potential biomarker for cancer malignancy in clinical trials. This signal consists of magnetic resonances from the metabolites choline, phopshocholine and glycerolphophocholine. By Phosphorus MR-spectroscopy (31P MRS) the latter two can be resolved into single signals. 31P MRS is a suitable and non-invasive tool to study the entire spectrum of phosphorus metabolites. Understanding underlying signals of the total-choline magnetic resonance is assumed to further improve specificity of in-vivo MRS. Nonetheless, sensitivity of 31P MRS was issued to be insufficient for in-vivo examinations in clinical environments. The present review article examines the role of total-choline and associated metabolites as potential biomarker for cancer metabolism. Consequently, prospective gains in specificity of breast cancer diagnosis and prognosis are accessed. This involves promising efforts to relate multiple MRS signals with clinical finding assessed ex-vivo. Ways to translate those efforts into in-vivo 31P MRS are explored to consider future clinical potential.

Informative Extension: Concluding, total-choline is found to be a surrogate marker for the underlying biomarker phosphocholine (PC), which seems to predict breast tumor malignancy. Understanding the roles of metabolites involved in synthesis of PC is hampered by their complex interactions. The approach to use multivariate statistics to relate MRS measured quantities to a number of pathological tumor features is found to be more promising. A translation of the corresponding findings into clinical use is feasible and might add further specificity to in-vivo 31P MRS breast lesion examinations.