The Role of High-Resolution Magic Angle Spinning 1H Nuclear Magnetic Resonance Spectroscopy for Predicting the Invasive Component in Patients with Ductal Carcinoma In Situ Diagnosed on Preoperative Biopsy

Abstract

The purpose of this study was to evaluate the role of high-resolution magic angle spinning (HR-MAS) 1H nuclear magnetic resonance (NMR) spectroscopy in patients with ductal carcinoma in situ (DCIS) diagnosed on preoperative biopsy. We investigated whether the metabolic profiling of tissue samples using HR-MAS 1H NMR spectroscopy could be used to distinguish between DCIS lesions with or without an invasive component. Our institutional review board approved this combined retrospective and prospective study. Tissue samples were collected from 30 patients with pure DCIS and from 30 with DCIS accompanying invasive carcinoma. All patients were diagnosed with DCIS by preoperative core-needle biopsy and underwent surgical resection. The metabolic profiling of tissue samples was performed by HR-MAS 1H NMR spectroscopy. All observable metabolite signals were identified and quantified in all tissue samples. Metabolite intensity normalized by total spectral intensities was compared according to the tumor type using the Mann-Whitney test. Multivariate analysis was performed with orthogonal projections to latent structure-discriminant analysis (OPLS-DA). By univariate analysis, the metabolite concentrations of choline-containing compounds obtained with HR-MAS 1H NMR spectroscopy did not differ significantly between the pure DCIS and DCIS accompanying invasive carcinoma groups. However, the GPC/PC ratio was higher in the pure DCIS group than in the DCIS accompanying invasive carcinoma group (p = 0.004, Bonferroni-corrected p = 0.064), as well as the concentration of myo-inositol and succinate. By multivariate analysis, the OPLS-DA models built with HR-MAS MR metabolic profiles could clearly discriminate between pure DCIS and DCIS accompanying invasive carcinoma. Our preliminary results suggest that HR-MAS MR metabolomics on breast tissue may be able to distinguish between DCIS lesions with or without an invasive component.

Fig 1. Representative HR-MAS 1H NMR spectra.

(a) Representative spectra including TSP (reference material) showing higher metabolite concentrations in pure DCIS than in DCIS accompanying invasive carcinoma. Detailed spectra from pure DCIS (b) and DCIS accompanying invasive carcinoma (c) patients are also shown with metabolite labeling. Because (b) and (c) were based on the largest peak, please refer to Table 2 for the specific values of metabolite concentrations.

Fig 2. Correlations between the tumor type and metabolite concentrations.

Box and whisker plots displaying the correlation between the tumor type and the metabolite concentrations of myo-inositol, alanine, succinate, and the GPC-PC ratio. The boxes represent the median, quartile, and extreme values for the groups.

Fig 3. HR-MAS spectra plots according to the tumor type.

OPLS-DA score (a), loading (b), and S-plots (c) of the HR-MAS spectra according to the tumor type. The score plot demonstrates a degree of separation between the two groups. The loading and S-plots identify the marker metabolites that are responsible for the separation of the pure DCIS and DCIS accompanying invasive carcinoma groups.