Expression And Clinical Significance Of MCM2,Rb And Ki-67 In Laryngeal Squamous Cell Carcinomas

Objective:To investigate the expression of MCM2, Rb and Ki-67 and its biological characteristic in human laryngeal squamous cell carcinomas(LSCC).Methods:The expression of MCM2 protein and protein Rb were detected in 60 cases of LSCC, 10 cases of precarcinoma, 10 cases of vocal cord polyps and 10 cases of normal laryngeal tissues, and Ki-67 protein were detected in 60 cases of LSCC and 10 cases of normal laryngeal tissues by EliVision TM plus immunohistochemical staining, and analyze their relations with clinicopathological characteristics.Results:The positive expression rate of MCM2 in normal laryngeal tissues, vocal cord polyps, precarcinoma, laryngeal carcinoma were 10.00%, 10.00%, 30.00% and 85.00% respectively, however, the expression level of MCM2 in LSCC was significantly higher than that in precarcinoma(P <0.05 ) and normal laryngeal tissues(P <0.01) , and was positively correlated with pathological grades, clinical stages and lymph node metastases of LSCC(P <0.05) , but it did not correlate with the site of the tumour (P >0.05) . The positive expression rate of pRb in normal laryngeal tissues, vocal cord polyps, precarcinoma,laryngeal carcinoma were were 80.00%, 80.00%, 60.00% and 36.67% respectively.The expression level of pRb in LSCC was significantly lower than that in precarcinoma(P <0.05) and normal laryngeal tissues (P <0.05) , but no difference between the various pathological grades, clinical stages, the site of the tumour and lymph node metastases(P >0.05) of LSCC. The expression level of MCM2 in LSCC was negatively corelated with pRb(r=-0.542,P <0.05); the expression level of Ki-67 in LSCC(76.67%)was significantly higher than that in normal laryngeal tissue(s30.00%)(P <0.01) and the expression level of MCM2 in LSCC was positively corelated with Ki-67(r=0.596, P <0.01). The LI of MCM2 in the 3-year survival rate of LSCC was significantly lower than that in Ki-67 (P <0.05) . On Cox regression of multivariate analysis, the LI of MCM2 perhaps is a more accurater proliferation marker than the degree of tumor differentiation; the LI of MCM2 induced worse prognosis of larynx cancer. Conclusion:Over expression of MCM2 and loss of Rb protein were related to the carcinogenesis and development of LSCC. The determination of MCM2 can be an index for estimating the level of malignancy and prognosis of LSCC.