The relationship between gastric carcinoma and gastric juice lactate (L + D) and lactate dehydrogenase.

L-Lactate, D-lactate, and lactate dehydrogenase (LDH) levels were measured in the resting gastric juice of 73 patients and mean levels were found to be significantly higher in patients with gastric carcinoma than in those with benign gastric ulcer or those with normal stomachs. Raised levels of gastric juice L-lactate (greater than 1.3 mmol/l), D-lactate (greater than 0.15 mmol/l), and LDH (greater than 55 IU/1) were seen in 14 of 27 patients with carcinomas, two of 15 with benign ulcers, and six of 31 controls. Both L/D-lactate and LDH levels correlated with tumor size and depth of invasion. While six problem cases with large gastric lesions were correctly diagnosed using these indices, there was only poor sensitivity and moderate specificity, as early cancers had normal L/D-lactate and LDH levels, and these indices were raised in a significant number of controls. Thus while it is of interest that L/D-lactate and LDH are elevated in the gastric juice of patients with gastric carcinoma there appears to be little optimism for using these indices in the early diagnosis of gastric neoplasia.