Expression of P53 protein in laryngeal carcinoma and its clinical significance

Using the monoclonal antibody DO-7, the expressions of P53 protein in 38 cases of laryngeal squamous cell carcinoma (LSCC), and 29 cases of laryngeal benign neoplasms (LBN) were studied immunohistochemically. The results showed that: (1) 25 of 38 (66%) LSCCs, but only 2 of 29 (7%) LBNs showed expression of mutant-type P53 protein. The high rate of P53 protein expression was related to the occurrence of laryngeal carcinoma, and is valuable in diagnosis and differential diagnosis of laryngeal carcinoma; (2) in some LSCCs, the mutant-type P53 protein was also expressed in dysplastic epithelium near the cancer tissues. These epithelial cells near the tumor in which P53 gene has been altered, probably are the source or portent of tumor recurrence; (3) the five year survival rate of mutant-type P53 protein negative LSCC patients was higher than that of positive LSCC patients. The expression of mutant-type P53 protein might be related to LSCC prognosis.