Glutathione-S-Transferase-Pi Expression in Early Breast Cancer: Association With Outcome and Response to Chemotherapy

ABSTRACT

Glutathione-S-transferase-pi (GST-pi) is a detoxification enzyme expressed in breast cancer; however its involvement in chemotherapy sensitivity and prognosis is not well understood. We evaluated the expression of GSTpi and its predictive role of chemotherapy response. Breast tumor samples from 166 patients at stage I/II of the disease were immunostained for GST-pi, and the expression was 96 %. There was a trend toward improved disease-free survival with high GST-pi expression (p =.09). There was a statistically non-significant association between high GST-pi expression and improved outcome with adjuvant chemotherapy (p =.055). Further studies should evaluate the role of GST-pi expression in relation to response to different chemotherapies.

Keywords. :

• lutathione-S-transferase-pi
• Breast cancer
• Chemotherapy
• Prognosis and response predictions

CONCLUSIONS

In conclusion, we have shown that high expression of GST-pi is correlated with good outcome in invasive breast cancer and predicts response to chemotherapy, especially anthracycline- and taxane-containing regimens. The role of GST-pi expression in predicting response to taxanes should be further investigated in larger prospective studies.

Furthermore, in our study GST-pi levels of expression vary by age, which is an interesting finding and warrants further exploration regarding differences in toxicity to chemotherapy and response based on age in a larger study.

Declaration of Interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of this paper.