BACKGROUND: As a tumor marker, lactate dehydrogenase is widely used as a prognostic factor in malignant lymphomas and a therapeutic monitor in ovarian dysgerminoma. But in other tumors, the clinical role of lactate dehydrogenase is not clear yet. To investigate the role of LD as a tumor marker, we analyzed patients with various cancers and high LD level. METHODS: The serum LD level was assayed in the cancer patients who visited our hospital. For the patients with high LD level, isoenzyme was also assayed. The response of chemotherapy was classified according to the WHO criteria into remission, which covers complete and partial remission, stable disease and progressive disease. The relationship between the tumor response and the LD response was examined in terms of sensitivity, specificity and positive predictive value. RESULTS: A total of 100 cancer patients were found to have high LD level; among them, 76 patients underwent chemotherapy. There were 38 patients with LD increased and 38 patients with LD decreased after chemotherapy. No patient was in remission, 6 patients in stable disease, and 32 patients in progressive disease among 38 patients with increased LD level; 18 patients in remission, 10 patients in stable disease, and 10 patients in progressive disease among 38 patients with decreased LD level. The sensitivity of LD increase in the patients with tumor progression is 76.2%, the specificity 73.7%, and the positive predictive value 84.2%(71.4%, 25.0% and 76.9% respectively in stomach cancer patients). The sensitivity of LD decrease in the responsive patients is 100%, the specificity 65.5% and the positive predictive value 47.4%.(100%, 64.7% and 14.3% in stomach cancer patients respectively). The LD isoenzyme pattern was not specific in this study. CONCLUSION: Serum LD measurement may be helpful in monitoring tumor response, especially for stomach cancer, after chemotherapy.
Drug Therapy ; Dysgerminoma ; Humans ; L-Lactate Dehydrogenase ; Lactic Acid* ; Lymphoma ; Sensitivity and Specificity ; Stomach Neoplasms