Serum lactate dehydrogenase level in various malignancies

Total serum lactate dehydrogenase (SLD) values were measured and statistically analyzed with a view to testing the hypothesis that there is some association between enzymatic activity and cancer. Serum samples were collected from 205 normal persons, 201 patients with different malignant tumors and 202 patients with nonmalignant diseases. The age of patients and controls ranged from 19 to 71 years. There is a significant rise in preoperative serum lactate dehydrogenase level in cancer patients (314.56 U/l) than normal healthy individuals (105.50 U/l) and nonmalignant patients (105.87 U/l) irrespective of the site of tumor. The patient and control series did not show any significant bisexual differences. The postoperative follow-up study (breast cancer only) of SLD level indicated decreased enzymatic activity in almost all the cases. The observations of elevation of SLD in patient series than controls suggest release of LD to the surrounding medium by neoplastic cells, thereby indicating relationship between the enzymatic activity and neoplastic conditions. The results of preoperative and postoperative follow-up study of SLD activity in breast cancer prove of value in judging the effectiveness of therapy, diagnosis and prognosis of the cancer patients.