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-πlevels 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-πactivity in 11 squamous cell carcinoma, 6 other head and neck cancer, 15 benign oral disease, and 5 normal tissues.
@ES The results were as follows.
@EN 1. The plasma levels of GST-πshow as significant difference between each groups(p<0.01); The levels of GST-πwere 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-πbetween 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-πshows a slightly low sensitivity, it is a possible tumor marker in a wide rangs of cancer.
4. GST-πwas useful in monitoring the status of the patient, since it increased with the progression of the tumor and decreased after treatment.
5. GST-πwas 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-πis a potenitial immunohistochemical tumor maker.
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