[An immunohistological study on expression of glutathione S-transferase pi (form) in human endometrial carcinoma].

Ninety-five specimens from patients with endometrial carcinoma (82 of endometrial type, 6 of adenoacanthoma, 4 of adenosquamous carcinoma, 3 of atypical endometrial hyperplasia) and 13 with ovarian endometrioid carcinoma were stained immunohistochemically with a rabbit polyclonal antibody prepared against the placental form of the enzyme glutathione S-transferase pi (GST-pi). Histological studies showed that the degree of staining decreased as the tumor lost its differentiation in endometrial carcinoma, but the degree of staining was independent of the differentiation in the case of ovarian endometrioid carcinoma. A comparison between the grade of staining of GST-pi in 82 cases of the endometrial type of endometrial carcinoma and 13 cases of ovarian endometrioid carcinoma revealed a stronger stain for the endometrial carcinoma than for ovarian endometrioid carcinoma (p < 0.01, Mann-Whitney's U test). Therefore, the GST-pi value for endometrial carcinoma was different from that for endometrioid carcinoma. In general, as compared with ovarian endometrioid carcinoma, endometrial carcinoma is considered to be resistant to chemotherapeutic agents. In conclusion, these results suggest that there is an apparent correlation between the GST-pi value and chemoresistance of the tumor.