6-ketoprostaglandin-f1-alpha and Laryngeal-Neoplasms

In order to evaluate the possible role of prostaglandins (PG) in invasion 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 mucosa and unaffected lymph nodes. The study was performed by evaluating PGE2, 6ketoPGF1 alpha and thromboxane B2 (TXB2) production by radioimmunoassay in specimens from eight patients who underwent surgical treatment. The highest rate of AA metabolism was observed in peritumor tissue. PGE2 was the main metabolite produced in all tissues and its levels were significantly higher than those of 6ketoPGF1 alpha and TXB2 (p < 0.05). 6ketoPGF1 alpha production was higher (p < 0.01) than that of TXB2 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 6ketoPGF1 alpha production was found to be almost twofold higher in tumor tissue, peritumor tissue, metastatic and non-metastatic lymph nodes as compared to control tissue. The lowest AA metabolism was found in affected lymph nodes. These findings demonstrate a different AA metabolism at primary tumor sites in comparison to healthy mucosa suggesting a prometastatic role of TXB2 and supporting the hypothesis of the occurrence of an imbalance between TXB2 and 6ketoPGF1 alpha production in favouring metastatic spread.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Aged; Carcinoma, Squamous Cell; Dinoprostone; Epoprostenol; Humans; Laryngeal Neoplasms; Lymph Nodes; Lymphatic Metastasis; Middle Aged; Radioimmunoassay; Thromboxane A2

Prostaglandin (PG) E2, 6ketoPGF1 alpha and Thromboxane B2 (TxB2) production by the tumor, peritumor and control tissue were investigated in specimens from patients (n = 11) with squamous cell carcinoma of the larynx, in relation to the extension and infiltration of the neoplasm and to the presence of inflammation, fibrosis and necrosis. In all specimens detectable amounts of 6ketoPGF1+ and TxB2 were found, but the predominant metabolite was PGE2. No differences in the levels of TxB2 and 6ketoPGF1 alpha were observed, but the only patient with lymphnodal involvement showed the lowest levels of 6ketoPGF1 alpha both in tumor and peritumor tissue. Higher amounts (p less than 0.05) of PGE2 were synthesized by peritumor tissues in comparison to control mucosa and tumor tissue independently of the occurrence of reactive infiltration. PGs synthesis did not correlate with inflammation, fibrosis, necrosis or staging of the neoplasm. However the two cases in stage T4 showed PGE2 generation at the highest levels both in neoplastic and perineoplastic tissue. These findings indicate that in squamous cell carcinoma of the larynx an increased production of PGE2 occurs, stemming not only from inflammatory cells but at least in part from neoplastic cells. This suggests that the study of arachidonic acid metabolism may contribute to characterization of the primary cancer and lead to better understanding of the mechanisms of tumor growth and diffusion.

Topics: 6-Ketoprostaglandin F1 alpha; Aged; Aged, 80 and over; Arachidonic Acids; Carcinoma, Squamous Cell; Dinoprostone; Female; Fibrosis; Humans; Laryngeal Neoplasms; Laryngitis; Larynx; Male; Middle Aged; Necrosis; Prostaglandins; Thromboxane B2