INCREASED THROMBOXANE-A(2) PRODUCTION AT PRIMARY TUMOR SITE IN METASTASIZING SQUAMOUS-CELL CARCINOMA OF THE LARYNX

In order to evaluate the possible role of prostaglandins (PG) in invas ion and metastasis of malignant cells in larynx carcinoma, arachidonic acid (AA) metabolite production by tumor tissue, peritumor tissue and node metastasis was investigated in comparison to that by healthy muc osa and unaffected lymph nodes. The study was performed by evaluating PGE2, 6ketoPGF1alpha and thromboxane B2 (TXB2) production by radioimmu noassay in specimens from eight patients who underwent surgical treatm ent. The highest rate of AA metabolism was observed in peritumor tissu e. PGE2 was the main metabolite produced in all tissues and its levels were significantly higher than those of 6ketoPGF1alpha and TXB2 (p < 0.05). 6ketoPGF1alpha production was higher (p < 0.01) than that of TX B2 and did not significantly change among the different tissues. TXB2 production was significantly increased (p < 0.05) by peritumor tissue as compared to healthy mucosa. The ratio between TXB2 and 6ketoPGF1alp ha production was found to be almost twofold higher in tumor tissue, p eritumor tissue, metastatic and non-metastatic lymph nodes as compared to control tissue. The lowest AA metabolism was found in affected lym ph nodes. These findings demonstrate a different AA metabolism at prim ary tumor sites in comparison to healthy mucosa suggesting a prometast atic role of TXB2 and supporting the hypothesis of the occurrence of a n imbalance between TXB2 and 6ketoPGF1alpha production in favouring me tastatic spread.