Immunohistochemical evaluation of Pi class glutathione S-transferase expression in invasive breast carcinoma

The aim of our work was to determine the expression of Pi class glutathione S-transferase (GSTP1) in 43 samples of invasive breast carcinoma and compare results versus normal breast cells. Breast cancer is the commonest cancer in women. Despite advances in early detection and more efficacious adjuvant chemotherapy, a part of patients with early-stage have reccurent disease. In these cases the development of resistance to therapy is observed. The glutathione S-transferases (GSTs) are potentially involved in tumour chemoresistance. Enzyme immunohistochemical method was chosen for the detection of GSTP1 and its expression was compared in breast cancer cells versus normal breast cells. We have found that majority (63%) of breast carcinomas shows GSTP1 positivity (nuclear and cytoplasmic immunoreactivity). It is expected that GSTP1 positive tumours would show a poorer prognosis than GSTP1 negative ones. Immunohistochemistry is a useful method for investigating the expression and cellular localization of GSTP1 within tumours. It may be applied to a routine clinical test and it can serve as a marker for resistance to chemotherapy (Tab. 1, Fig. 4, Ref. 20). Full Text in free PDF www.bmj.sk.