Bcl-2 oncoprotein expression in breast cancer, its relation to estrogen and progesterone receptors and other prognostic factors

Aims of the study: To evaluate the expression of the Bcl-2 oncoprotein in patients with primary breast cancer, to correlate it with estrogen and progesterone receptors and various prognostic parameters. Patients and methods: Fifty two cases of primary breast cancer in which the estrogen and progesterone receptors statuses were previously tested by immuno-histochemical staining, were included in this retrospective study. The cases were collected from AlJamhori Teaching Hospital, Nineveh Private Hospital and Private laboratories. The expression of Bcl-2 oncoprotein was evaluated immunohistochemically; the findings were correlated with the estrogen and progesterone receptors, the age of the patients, size, type and grade of the tumor, lymph node status and vascular invasion. Results: Bcl-2 oncoprotein was detected in 24 cases of primary breast cancer (46.2%). In this study the majority of estrogen and progesterone receptors positive cases, (87.5%) and (83.3%) respectively, showed positive Bcl-2 oncoprotein expression, (P<0.001) and (P=0.0002) respectively. A significant association was found between Bcl-2 and tumor type (P=0.017). Bcl-2 oncoprotein was directly correlated with the age of the patients (P=0.0047), and inversely with the grade of the tumor and vascular invasion (P value = 0.0092, <0.001) respectively. No significant correlation with tumor size nor with lymph node status could be found, (P=0.078) and (P=0.19) respectively. Conclusions: Bcl-2 oncoprotein was positive in 46.2% of primary breast cancer. This study revealed a significantly direct correlation between the Bcl-2 and the estrogen and progesterone receptors. A significant association was found between Bcl-2 oncoprotein and tumor type. Bcl-2 was directly related to the age of the patients, and inversely related to the grade of the tumor and vascular invasion.