EARLY BREAST-CANCER, DIET, AND PLASMA COPPER FRACTIONS

In a study of diet and early breast cancer, blood plasma copper has be en analyzed by Proton Induced X-ray Emission analysis as both total co pper (P-Cu) and that ultrafiltrable from plasma (P-edu-Cu) through mem branes with a cut-off at molecular mass 10,000 after equilibration wit h disodium ethylene diamine tetraacetic acid (EDTA) at 4 degrees C. Ce ruloplasmin (P-cer) was also measured using nephelometry of anticerulo plasmin monoclonal antibody-ceruloplasmin complexes. Dietary copper in take per day (D-Cu) was assessed over a five-day dietary record period and calculated from dietary components using a computer program. P-ed u-Cu correlated significantly with both D-Cu and ceruloplasmin while P -Cu correlated only with ceruloplasmin. Further, ceruloplasmin did not significantly correlate to D-Cu. Hence, P-edu-Cu better reflects copp er status than do P-cer or P-Cu as it relates to both the major copper enzyme in plasma and to daily copper intake. This may be important in drawing conclusions about the significance of copper in disease state s where copper fractions other than ceruloplasmin may be most importan t owing, for example, to oxidative properties. Categorization as cance r or normal, by copper parameters (D-Cu, P-edu-Cu, P-Cu, P-cer), was s tudied in multiple correlation. In particular, the ratio P-cer/P-Cu an d the ratio P-edu-Cu/D-Cu were significantly related to disease. Irres pective of age (pre- and post-menopausal), highly significant differen ces between normals and early stage breast cancer patients were seen w ith p < 0.0001 to p < 0.01. The precise role played by plasma and diet ary copper fractions deserves continued attention in view of the prese nt and earlier results in cancer studies.