Immunohistochemical evaluation of mitogenic activity in breast cancers by TFF1/PS2 protein and HER2 oncoprotein expression in western Algeria

Breast carcinoma is a disease with a tremendous heterogeneity in its clinical behavior. Newer prognostic factors and predictors of response to therapy are needed. The purpose of the current study was to investigate TFF1 expression in breast cancer, and its relation with tumor malignancy and proliferation measured by HER2 status. This is a prospective study conducted on 538 women with primary ductal/lobular invasive breast carcinomas in the department of pathology at the regional military university hospital of Oran (Algeria). The mitogenic activity was evaluated by a conventional immunohistochemical (IHC) approach, validated as a replacement technique for microarray analysis by labeling the antigens TFF1, HER2, ERα, and PgR. Correlations between the different parameters were carried out. TFF1 was correlated positively with hormonal receptors (HR) (P<0.0001) and negatively with HER2 (P<0.0001) and histological grade but with marginal significance (P<0.1). According to mitogenic activity, patients were individualized into two subgroups: low proliferation tumors (Luminal A) representing 51.3% of cases and high proliferation ones representing 48.7% of cases (Luminal B, Basal, HER2, Claudin-Low). Mitogenic activity majored by HER2 overexpression correlates with aggressiveness parameters such as high histological SBR grade, larger tumor size, young age at presentation, and negative TFF1/HR status. IHC methods are less expensive and more cost-effective for the establishment of molecular subclasses.