[The significance of changes in lactate dehydrogenase activity for the diagnosis and effective treatment of nephroblastoma in children].

Total serum lactate dehydrogenase (LDH) activity was studied in 65 children with nephroblastoma at stage II-IV. Total LDH activity was elevated in 87% of cases. A correlation between incidence and level of LDH activity, on the one hand, and stage size of tumor, on the other, was established. The increase in total LDH activity at stages II and III in 75 and 85.7%, respectively, was found to match those in LDH concentration 1.2-4-fold and 1.3-7.3-fold, enhanced 1.4-8.4 times. Successful radiation therapy and/or surgery was followed by LDH level coming back to normal. However, failed treatment and further progression of tumor involved persistent rise in the enzyme activity.