Background: This study estimates the usefulness of plasma GST-z:as a tumor marker for oral squamous cell carcinoma.
Methods:In a preliminary study, the plasma and serum GST-zrlevels were measured and compared. The positive rate for GST-rc was 52.7% in plasma and 20.0% in serum. Thus the plasma GST-zr was determined to be more sensitive and a useful tumor marker. Plasma GST-zc levels were measured in untreated oral carcinoma cases, recurrent oral carcinoma cases, oral leukoplakia cases and healthy controls.
Results:The positive rate was 57.1% in untreated carcinoma cases, 60.5% in recurrent carcinoma cases, 0.0% in leukoplakia cases. As for the untreated carcinoma cases, site, size, clinical stage, lymph node metastasis, and histopathological grading (WHO) were examined; but no relationship between plasma GST-~ levels and each of these factors was found. The positive rates for plasma GST-zcwere compared with those for serum SCC antigen. The plasma GST-zc showed a significantly higher positive rate and was considered more useful. Plasma GST-zc levels tended to regress into a normal range after treatment. But in those patients with recurrence regression of plasma GST-rc levels did not occur.
Conclusion:Plasma GST-zc is considered clinically reliable and useful in the diagnosis of oral squamous cell carcinoma and early detection of recurrence or metastasis.