Significance of p53 Mutation and Expression of Rb, MIB1 in Laryngeal Squamous Cell Carcinoma

Choi, Jong Ouck; Park, Jung Soo; Kim, Yong Hoan; Choi, Geon

Abstract

BACKGROUND AND OBJECTIVES: Treatment results of laryngeal carcinoma may depend on the microscopic environment of the primary lesion. If there is an abundance of lymphatic channels, the laryngeal lesion is more likely to develop frequent cervical metastases, leading to treatment failure. Prognosis of the laryngeal carcinoma is usually determined by clinical staging. However, it does not account for the oncobiological characteristics and microscopic environments. The importance of biological markers including p53, Rb and MIB1 as a prognostic factor has yet to be determined. To determine the relationship between the prognosis and biological characteristics of p53, Rb, and MIB1 in laryngeal cancers.
MATERIALS AND METHODS
Thirty seven laryngeal carcinoma specimens were studied for p53 gene mutation by PCR-SSCP and expression pattern of Rb and MIB1 proteins by immunohistochemistry.
RESULTS
p53 gene mutation was found in 32.4% with nine cases in exon 5, two cases in exon 7, and two cases in exon 8, respectively. Higher incidence of p53 gene mutation was found in supraglottic cancer (p>0.05). Negative expression rate for Rb was 29.7% and positive MIB1 expression rate was 32.4%. There was no significant correlation between the treatment success and p53 gene mutation, expression pattern of Rb and MIB1 gene.
CONCLUSION
p53 gene mutation and expression pattern of both Rb and MIB1 showed little value as a prognostic factor. However, in cases where p53 and Rb tumor suppressor gene mutation were found in combination, the prognosis was poor. In this regard, such marker might be used as one of the important biological prognostic factors.