Bcl‐2 expression on fine‐needle aspirates from primary breast carcinoma

Abstract

BACKGROUND The bcl-2 gene encodes for a protein that is involved in cell death regulation. It frequently is expressed in breast tumors, in which it is associated with favorable prognostic factors. It has been suggested that bcl-2 also may act as a modulator of response to chemotherapy and/or endocrine therapy. Because fine-needle aspiration (FNA) biopsy has been established as a reliable method for the diagnosis and biologic characterization of breast carcinoma, we assessed Bcl-2 expression on FNAs from primary breast carcinoma and evaluated its correlations with other prognostic variables. METHODS Bcl-2, estrogen receptor (ER), progesterone receptor (PgR), p53 protein expression, and Ki-67 growth fraction were evaluated by immunocytochemistry on FNAs from 130 patients with primary breast carcinoma. Nuclear cytologic grade was assessed on FNA smears. RESULTS Bcl-2 was expressed in 99 of 130 FNAs (76%). Bcl-2 expression was correlated with positive ER (P < 0.001) and PgR (P < 0.001) status and inversely correlated with p53 (P = 0.0036), Ki-67 (P = 0.0073), and nuclear cytologic grade (P < 0.001). CONCLUSIONS Bcl-2 expression, evaluated by immunocytochemistry on FNAs from primary breast carcinoma, correlates with favorable prognostic features such as ER and PgR expression, p53 negativity, a low Ki-67 index, and high tumor differentiation. These results are in agreement with those found on histologic samples. As FNA biopsy is used increasingly as a primary tool in the diagnosis of breast carcinoma, Bcl-2 evaluation by immunocytochemistry on FNA may provide, in addition to other biologic variables, useful information for prognostic and predictive purposes, particularly in patients considered to be candidates for neoadjuvant treatments. Cancer (Cancer Cytopathol) 1999;87:224–30. © 1999 American Cancer Society.