Gastric & Breast Cancer e-journal
DOI: 10.2122/gbc.2007.0072

 

Abstract
Bcl-2 over-expression has been previously implicated in tumorigenicity and metastatic potential in breast cancer. We postulated the augmentation of plasma levels of Bcl-2 in patients with metastatic breast cancer. This study was developed to evaluate levels of Bcl-2 protein expression in both paraffin embedded formalin fixed breast tumour tissue, and patient serum samples, and data analysed to seek any association between the two. Results were also used to seek any relationships with clinico-pathological features recorded for the patient. Immunohistochemistry was applied to tissue sections from 35 surgically removed patient tumour samples. The serum samples taken from patients were tested for soluble Bcl-2 (BMs244/3 Kit) using the ELISA technique. Tumor type, grade, size, patient menopause status and patient age, were all considered when seeking any association with the assay parameters.Our analyses show that 67.6% of the tumor sections were positive for Bcl-2 expression and 32.4% negative. The Bcl-2 protein expression in normal tissue/benign tumors were 57.12% positive and 42.85% negative. The Bcl-2 serum levels were 3.6+1.07 ng/ml in patient group and 3.23+0.06 ng/ml in control group. A weak correlation was therefore found between Bcl-2 serum levels and tissue expression of this molecule (r=0.382, P=0.049). A negative association (not statically significant) was obtained between Bcl-2 and low grade stages (r= -0.375, P=0.08). A positive and significant correlation was achieved between Bcl-2 and menopause status with r=0.523, P=0.005, and also between patient age and serum Bcl-2 with r=0.488, P=0.011. We suggest that the data presented here would suggest clinical relevance in using Bcl-2 expression as a tissue marker at the level of protein expression. In contrast, measuring serum levels of Bcl-2 would have limited clinical purpose.

Key Words: Bcl-2 serum level, Breast Cancer, tissue Bcl-2 expression