Lactate as a possible predictor of malignency in head-and-neck carcinoma

Objective: Aim of this study: 1) Quantifcation of metabolism and energy turnover in squamous cell carcinoma of the head and neck region compared to normal oral mucosa ; 2) Correlation of these metabolism parameters to the clinical prognosis

Methods: Flash cryopreserved biopsies were analysed by bioluminescence imaging. This metabolic imaging technique allows to measure structures associated with the local metabolic concentration exclusively in areas of the biopsy. Gene expression of the lactat dehydrogenase (LDH) was analyzed by semi-quantitative reverse-transcriptase-PCR and Western-Blot in tumor slices. Healthy oral mucosa served as control. The patients survival served as a clinical parameter.

Results:

Collective	N	Glucose [µmol/g]			Lactate [µmol/g]
		Median	Min	Max	Median	Min	Max
Normal tissue	11	2,92	1,27	3,75	3,73	1,01	5,5
Tumor tissue	19	1,26	0,25	3,16	10,45	5,86	19,97

RNA as well as protein expression show that the LDH is significantly up-regulated in carcinoma of the head and neck region in comparison with normal gingiva. A comparable result was found between tumors with and without lymph node metastasis. Kaplan-Meier-Survival analysis of a group with high level lactate tumors and a group of low level tumors shows a significantly decreased survival rate for the high level lactate group.

Conclusion: The quantitative and structure-associated determination of lactate in clinical biopsies revealed differences between normal and tumour tissue. These metabolic parameters. of primary tumors seem to be promising prognostic parameters in the first diagnosis of SCC in the future.