EXPRESSION OF PS2 PROTEIN AND ESTROGEN AND PROGESTERONE-RECEPTOR STATUS IN BREAST-CANCER

OBJECTIVE: To investigate pS2 protein expression and estrogen (EX) and progesterone receptor (PR) status of imprints from surgical biopsies of breast cancer cases in relation to the histologic grade of malignan cy. STUDY DESIGN: The study group consisted of 50 cases of primary bre ast carcinomas. For the demonstration of pS2 protein expression an imm unocytochemical avidin-biotin complex technique was applied. Monoclona l antibody pS2 was used as the primary antibody, diaminobenzidine as t he chromogene and hematoxylin as the counterstain. For the evaluation of ERs and PRs, a biochemical method was applied. RESULTS: Sixty-two p ercent of breast cancer cases showed positive expression of pS2. Of th e 31 pS2+ cases, 74% had positive ERs and PRs. A statistically signifi cant difference was observed between pS2 protein expression, ER+, PRand histologic grade of malignancy (P <.001). CONCLUSION: Two groups o f breast cancer cases can be distinguished: one group that is ER+, PR and pS2+, with low malignancy potential, and another group that is ER -, PX and pS2-, with high malignancy potential.