The effect of intra-tumour heterogeneity on the distribution of phosphorus-containing metabolites within human breast tumours: an in vitro study using 31P NMR spectroscopy.

The concentration of phosphorus-containing metabolites was determined in extracts of multiple samples from six human breast tumours and in samples from normal and inflamed breast tissue. The degree of lymphoid infiltrate, necrotic fraction and tumour cell and normal tissue fraction were determined on sections taken from each of the tumour samples. In four of the tumours there was a very high degree of variation between samples in the absolute concentration of metabolites. Three of these tumours showed a high degree of intra-tumour variation in the distribution of tumour cells and of normal tissue. The other two tumours were relatively homogeneous with respect to both tumour cellularity and the distribution of phosphorus-containing metabolites. Samples from normal breast tissue was found to contain only low concentrations of phosphorus-containing metabolites. However one of the inflamed samples, which consisted predominantly of macrophages, contained high levels of such compounds. The effect of time delay between resection and freezing on the levels of metabolites in human breast tumours was also examined.