Objective: To observe the expression of adrenomedullin (AM) in the patients with laryngeal carcinoma.
Methods: Two-step immunohistochemistry method was used to examine the expression of AM in the patients with laryngeal carcinoma. Radioimmunoassay was applied to determine the concentration of AM in the laryngeal carcinoma tissues, adjacent laryngeal mucosa of carcinoma tissues and in the plasma of patients and controls.
Results: Positive stainings for AM were found in all 21 specimen examined,distributed mainly in the cytoplasm of the laryngeal carcinoma cells. Positive stainings were more stronger in the circumference than in the center of tumor tissue for the highly and moderately differentiated tumors. While the stainings were distributed homogeneously for poorly and moderately differentiated tumors. The concentration of AM in the laryngeal carcinoma tissues (n = 44) and the adjacent mucosa (n = 44) were (49.67 +/- 28.33) pg/ml and (14.71 +/- 7.17) pg/ml (x +/- s) respectively and laryngeal tumor showed much higher concentration of AM than the adjacent mucosa (u = 135.00, P < 0.01). The concentration of AM in patients with laryngeal carcinoma of T2, T3 and T4 stage were (31.52 +/- 15.22), (56.63 +/- 18.51) and (96.12 +/- 18.22) pg/ml (x + s) respectively,and there were statistically significant difference among them. In the N stage, patients with higher stages were found to express significantly higher AM concentration, but there was not statistically significant difference between NO stage and N1 stage. In the M stage,patients with M1 stage were found to express significantly higher AM concentration (u = 31.00, P < 0.01). But there was not statistically significant difference between AM plasma concentration of laryngeal carcinoma patients and that of healthy controls.
Conclusions: The results suggested that high expression of AM in tissues of laryngeal carcinoma was related with the TNM stage of laryngeal carcinoma, AM may play an important role in the development of the laryngeal neoplasma.