Expression of p53, bcl-2, bax and bel-xi in ductal carcinoma in situ (DCIS) of the breast

Abstract

Background: DCIS is a malignant proliferation of mammary ductal epithelial cells without invasion beyond the basement membrane. bax, p53 are implicated in regulation of apoptosis. This study aimed to clarify the role of these gene products in DCIC. Patients and methods: Immunohistochemical staining of 13 cases of DCIS with bcl-2, bax, bcl-xl and p53 was performed. Results: DCIS was graded into; 42% of low, 16% of intermediate, and 42% of high grade cases. P53 was negative in all low grades, positive in 66.7% intermediate grade, and in all high grade DCIS. Bcl-2 was positive in all DCIS with variable intensities. Bax was positive in 80% of low grade, 100% of intermediate grade, and in 100% of high grade DCIS. Bcl-xl was positive in 80% of low grade, and in all intermediate and high grade DCIS. P53 was inversely correlated with bcl-2 expression in DCIS (p<0.02). Insignificant positive correlation was present between p53 and bax expression and between p53 and bcl-xl expression in DCIS. An inverse correlation was present between bcl-2 and bcl-xl expression and between bcl-2 and bax expression in DCIS (p<0.01 for each). Positive correlation was present between bax and bcl-xl expression (p<0.000) in DCIS.Conclusions: p53 mutation is an early event in the evolution of breast cancer and its expression correlates with high grade lesions. Strong positive correlation between bax and bcl-xl, but the prognostic value of bcl-2 protein family in DCIC is still in need to more studies to be clarified.