FLUORESCENCE POLARIZATION CHANGES IN LYMPHOCYTE CYTOPLASM AS A DIAGNOSTIC-TEST FOR BREAST-CARCINOMA

Lymphocytic cytoplasm from individuals with malignant disease, and fro m those without, differ in such a way as to be diagnostic both of mali gnancy generally and of specific types of cancer. Mitogenic stimulatio n of lymphocytes by phytohaemagglutinin (PHA) and antigenic stimulatio n by encephalitogenic factor (EF) and certain specific tumour-associat ed antigens, provokes changes in the structure of the cytoplasmic matr ix (SCM) which are detectable upon fluorescence polarisation. The degr ee of change is quantifiable both by calculating the polarisation rati o (PR, polarisation before and after stimulation) and the relative rat io (RR(SCM), the ratio between the polarisation obtained after exposur e to EF [P-EF] and to the polarisation measured after exposure to PHA [P-PHA). A new tumour-associated antigen specific for breast cancer, C aBr, was tested for its diagnostic efficacy in comparison with that of EF, by prospectively testing blood samples from 138 consecutive women with suspicious breast masses. The previously known discriminatory po wer (sensitivity 60.7% and specificity 90.7%) of the polarisation-deri ved RR(SCM) was reconfirmed. However, the RR'(SCM) (the new ratio usin g CaBr instead of EF), was significantly more sensitive (77.4%; P < 0. 01) and specific (94.4%) than the RR(SCM) in detecting breast cancers. The polarisation changes in the cytoplasmic matrix after stimulation by CaBr alone suggest the best discriminatory power (sensitivity 90.5% and specificity 94.4%) between cancerous and non-cancerous patients.