Significance of glutathione S-transferase-pi as a tumor marker in patients with oral cancer.

Abstract

The authors analyzed the clinical usefulness of glutathione-S-transferase-pi (GST-pi) as a tumor marker in patients with oral cancer. GST-pi levels in plasma of 61 patients with oral squamous cell carcinomas, 65 patients with benign oral diseases, and 78 healthy subjects were investigated with the sandwich enzyme-immunoassay (EIA) system. Elevated GST-pi levels in plasma were observed in patients with oral cancer, but patients with benign oral diseases had normal GST-pi levels. More than 70% of patients with Stage III or IV oral cancer and more than 50% of those with Stage I and II disease had elevated levels of GST-pi in plasma. Elevated levels of GST-pi in plasma were also discovered in most patients with tumor recurring after surgery before recurrence was detected clinically. GST-pi also was found to be a useful marker for evaluating the response to chemotherapy, for monitoring postoperative tumor resectability or tumor burden, and for predicting the recurrence of tumor in patients with oral cancer. GST-pi is considered to be a useful aid for early diagnosis, predicting tumor extent, and determining parameters of treatment efficacy and prognosis for oral cancer.