Beta-glucuronidase, LDH and LDH isoenzyme levels and screening for gastric cancer

Lactic dehydrogenase (LDH) and beta-glucuronidase (bGLU) levels are elevated in the gastric juice of patients with gastric cancer, and these enzymes have been used as a screening test for gastric cancer. False positives are common, however, and we have measured enzyme levels, including LDH isoenzyme fraction, in tissue homogenates from resected stomach specimens and compared these with histological features. Increases in bGLU were found in carcinoma and chronic gastritis, an increase in LDH was found in carcinoma, whilst mLDH fraction was increased in chronic gastritis, carcinoma and intestinal metaplasia, particularly the sulphomucin variant. These findings indicate the basis for the screening test, and also the reason for the false positives. An elevated mLDH fraction may be a useful marker of a group at increased risk of developing gastric cancer, and worthy of long-term follow-up.