IMMUNOCYTOCHEMICAL STAINING OF C-ERBB-2 ONCOGENE IN FINE-NEEDLE ASPIRATES OF BREAST-CARCINOMA - A COMPARISON WITH TISSUE-SECTIONS AND OTHERBREAST-CANCER PROGNOSTIC FACTORS

The role of fine-needle aspiration (FNA) in breast cancer management i s expanding to include prognostic in addition to diagnostic studies. T his study was undertaken to compare the immunohistochemical staining o f c-erbB-2, a breast cancer prognostic factor, on cytologic FNA smears of breast cancer with that on corresponding formalin-fixed, paraffin- embedded tissue sections of the same tumor and to correlate the c-erbB -2 expression with other known breast cancer prognostic factors. FNA s mears (destained, alcohol-fixed, Pap-stained direct smears) and corres ponding tissue sections (formalin-fixed, paraffin-embedded, unstained sections) from 36 primary breast carcinomas were stained immunohistoch emically with c-erbB-2 antibody using an avidin-biotin procedure. Ten tumors (28%) showed strong positive staining for c-erbB-2 on the FNA s mear and, of those ten, seven were positive on the corresponding tissu e section and three were negative. In several of the cytology and tiss ue positive cases, staining on the tissue section was significantly we aker than on the FNA smear, Two cases involved treatment with preopera tive chemotherapy; in one of those cases, tissue staining was weaker t han cytologic staining, and, in the other case, both were negative. Co rrelation of c-erbB-2 staining with other prognostic factors showed an association between positive c-erbB-2 staining and high nuclear grade , Our results indicate that immunohistochemical staining for c-erbB-2 can be performed on destained FNA smears of breast carcinomas and may be more sensitive on the cytologic specimens than on formalin-fixed, p araffin-embedded tissue sections. (C) 1994 Wiley-Liss, Inc.