Objective: To evaluate the expression of glutathione S-transferase-pi (GST-pi) in human esophageal squamous cell carcinoma (ESCC) and its correlation with the clinicopathological data.
Methods: Immunohistochemical method (labeled avidin biotin method) and ELISA were used to detect the expression of glutathione S-transferase-pi (GST-pi) in 143 cases of formalin fixed, paraffin embedded ESCC tissue sections. Serum GST-pi was determined before and after operation in 43 patients with ESCC.
Results: GST-pi was positively stained immunohistochemically in 58.7%(84/143) of ESCC and 79.6%(109/139) of surrounding noncancerous esophageal tissues (P < 0.05). The expression level of GST-pi was significantly higher in well differentiated than poorly differentiated carcinomas(P < 0.05). No significant correlation was observed between GST-pi levels and lymph node metastasis, pathological staging or long term survival. The preoperative and postoperative mean serum GST-pi levels in ESCC patients were significantly higher than those in 34 normal subjects (P < 0.05, P < 0.025); the mean serum GST-pi level in postoperative patients was lower than that in preoperative patients, but the difference was not significant.
Conclusion: GST-pi is a useful tumor marker for human ESCC.