Activity of alcohol dehydrogenase (ADH) isoenzymes and aldehyde dehydrogenase (ALDH) in the sera of patients with breast cancer.

Numerous experiments have shown that alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) play a significant role in the metabolism of many biological substances. Some metabolic disorders that can lead to breast carcinogenesis may be the cause of changes in ADH and ALDH activity. In previous experiments we found a changed level of class I ADH activity in breast cancer tissues. The changed level of this enzyme in cancer cells may be reflected by the enzyme's activity in the serum. Therefore, in this study we measured the activity of ADH isoenzymes and ALDH in the sera of patients with breast cancer. Serum samples were taken for routine biochemical investigation from 45 women with breast cancer before treatment. Among all tested classes of ADH isoenzymes, only class I had higher activity in the serum of patients with breast cancer in stage IV. The total ADH and ALDH activities were not significantly higher in patients with breast cancer than in healthy controls. The changes in activity, especially in class I ADH, appear to be caused by isoenzymes being released from the organ damaged by metastatic disease.