두경부암의 종양표지자로서 Glutathione S-Transferase 파이에 관한 혈청학적 및 면역조직화학적 연구

Serological and immunohistochemical study of glutathione s-transferase pai as head and neck tumor marker

A tumor marker is useful in evaluating the stage, prognosis and treatment of cancer. Although many substances are known as tumor markers for the head and neck cancer, few substances have proven to be of much significance. GST-π is a tumor marker newly reputed for its sensitivity and specificity. The usefulness of GST-π as a tumor maker for the head and neck cancer is assessed in this paper. The author measured the GST-π levels in plasma of 25 squamous cell carcinoma patients(Group I), 13 patients with other head and neck cancers(Group Ⅱ), 25 benign oral diseases(Group Ⅲ) and 25 healthy subjects as control(Group Ⅳ) by the sandwich enzyme-immunoassay system. Using the immunohistochemical staining method, the author evaluated GST-π activity in 11 squamous cell carcinoma, 6 other head and neck cancer, 15 benign oral disease, and 5 normal tissues. The results were as follows. 1. The plasma levels of GST-π show as significant difference between each groups(p<0.01); The levels of GST-π were 43.9(48.6ng/ml in the plasma of Group I, 76.6(60.4ng/ml in Group Ⅱ, 26.5(18.5ng/ml in Group Ⅲ, and 12.7(4.9ng/ml in Group Ⅳ. 2. The plasma levels of GST-π between control and cancer patients show significant differences whereas those of benign and cancer patients are less significant. The shape of and the area under the Receiver Operating Characteristic(ROC) curve are used to assess the differentiation of each groups; The area under the curve between Group Ⅱand Group Ⅳ, Group Ⅱand Group Ⅲ, Group I and Group Ⅳ, and Group I and Group Ⅲ was 0.85, 0.72, 0.66, and 0.53 respectively. 3. The optimum cut-off value in differentiating the malignant and nonmalignant groups was 32ng/ml (sensitivity 53%, specificity 90%). Although GST-π shows a slightly low sensitivity, it is a possible tumor marker in a wide rangs of cancer. 4. GST-π was useful in monitoring the status of the patient, since it increased with the progression of the tumor and decreased after treatment. 5. GST-π was expressed as a brown pigment in immunohistochemical staining. Although some normal and benign tissues were reactive, no activity was detected in the stromal connective tissue and the cytoplasm of the tumor cells showed a homogenous distribution of GST-π is a potenitial immunohistochemical tumor maker.