PHOSPHOMONOESTER IS ASSOCIATED WITH PROLIFERATION IN HUMAN BREAST-CANCER - A P-31 MRS STUDY

Phospholipid metabolism of human breast cancer was studied by P-31 mag netic resonance spectroscopy (MRS). In vivo localised P-31 MR spectra were obtained from the tumour alone using phase modulated rotating fra me imaging. For 31 tumours, median (range) phosphomonoester (PME) to A TP ratio was 1.48 (0.57-3.78) and phosphodiester (PDE) to ATP ratio wa s 1.65 (0.44-3.89). DNA index and S phase fraction (SPF) were measured by flow cytometry of paraffin embedded tissue. Twelve (39%) tumours w ere diploid and 19 aneuploid. Median (range) SPF for 29 assessable tum ours was 5.3% (0.6-28%), with significantly greater median SPF for ane uploid tumours (9.3%) than diploid (3.8%, P = 0.007). There was a sign ificant association between PME/ATP and SPF (P = 0.03) due to a signif icant correlation for aneuploid tumours (P = 0.0 1). High resolution P -31 MRS of extracts from.18 tumours (including seven studied in vivo) demonstrated that the PME peak consists predominantly of phosphoethano lamine (PE) with a smaller contribution from phosphocholine (PC) (medi an (range) PE/PC: 3.02 (1.13-5.09)). Changes in PME/ATP were observed for two tumours where tamoxifen stablised disease and may be consisten t with the cytostatic effects of this drug.