Enzymes, isozymes, and enzyme variants in the diagnosis of cancer. A short review.

Changes of enzyme activity in tissues, body fluids, and serum as well as changes of isozymes and enzyme variants in patients with malignancy suggest that these parameters may be used in the diagnosis of some types of cancer. A review of available information indicates that: changes of serum enzymes in patients with malignancies relate to the presence of a heavy tumor burden or of metastases, and cannot be utilized for the early diagnosis of malignancies; changes in isozyme patterns and newly developed enzyme variants may be of greater diagnostic value, although possibly not in the early diagnosis of cancer; study of enzymatic activity in body fluid may offer valuable help in specific situations; and occasionally, determination of enzymes may be of help in establishing susceptibility to malignancies.