Metabolic classification of human rectal adenocarcinomas: a novel guideline for clinical oncologists?

Purpose. Based on previous findings in SCC of the human uterine cervix and of the head and neck, metastasis- and survival-related metabolic classification was performed in human rectal adenocarcinomas. Such a characterization is suggested as basis of a novel clinical guideline for an appropriate therapy of epithelium-derived malignancies. Methods. Tissue concentrations of ATP, glucose, and lactate in viable tumor regions of 33 pretherapeutically taken cryobiopsies from 24 patients were measured at a microscopic level using the technique of imaging bioluminescence. Results. In metastatic carcinomas, lactate levels were significantly higher (mean+/-SD: 13.4+/-3.8 vs 6.9+/-2.5 mumol/g, P = 0.0046) and glucose levels significantly lower (0.3+/-0.2 vs 1.0+/-0.4 mumol/g, P = 0.0020) than in non-metastatic carcinomas. No patients had distant metastasis with tumor lactate levels below the population median of 8.0 mumol/g or glucose levels above 0.9 mumol/g. Conclusions. These results support the hypothesis that lactate and glucose levels measured in human primary carcinomas may serve as an early prognostic tool in the clinic with regard to formation of metastasis and patient survival. The present data encourage further studies on possible strategies for a metabolic classification of tumors as a prognostic tool.