Molecular characterization of apoptosis by the immunohistochemical evaluation of Bcl-2 in breast cancer

Vol. 53 No. 1, 2012


Dana Carmen Zaha, Elena Lazar

Purpose: Immunohistochemical markers are used to classify breast cancer into molecular subtypes biologically and behavior distinct. The Bcl-2 gene has been implicated in a number of cancers and it is also thought to be involved in resistance to conventional cancer treatment. The aim of this study was to investigate apoptosis in breast cancer cells and in molecular groups using IHC expression of Bcl-2. Materials and Methods: Our study included 61 patients that been followed up five years since diagnosis. The traditional prognostic factors: age, tumor size, histological type, histological grade, clinical stage and the status of the lymph nodes were used for primary morphological evaluation. Molecular classification of cases and Bcl-2 assessment was performed by immunohistochemistry in agreement with data from the literature. Results: More than an half of tumors were positive for Bcl-2 showing a favorable response to endocrine therapy. The average age of the patients, hormonal status, tumoral diameter and histological grade showed significant differences statistically. Most of positive cases for Bcl-2 belong to the luminal tumor group, while non-luminal tumors have a negative reaction. When we compared well-known histological types, we noticed insignificant issues regarding score groups for Bcl-2; in exchange, when they were compared into molecular groups, we obtained the strongest statistical correlation. Conclusions: Assessment of apoptosis by Bcl-2 leads to the identification of molecular groups with different immunohistochemical and clinical features and different survival rates, better for Bcl-2 positive tumors and worse in Bcl-2 negative tumors.

Corresponding author: Dana Carmen Zaha, Assistant Professor, e-mail:

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