MCM2: Test of utility as a molecular marker in advanced-stage oropharyngeal carcinoma

Abstract

5590 Background: MCM2 is a member of the family of minichromosome maintenance (MCM) proteins that play an important role in the regulation of DNA replication. MCM2 has been shown to be a proliferation marker in several types of tissue. In this study we examined the utility of the proliferation marker MCM2 as a molecular prognostic marker in 30 oropharyngeal squamous cell carcinomas. Methods: Parallel sections of 30 oropharyngeal tumors were stained with antibodies against MCM2. The tumor sub-sites were: base of tongue in 11 patients, tonsillar fossa in 13 patients, pharyngeal wall in 5 patients, and faucial arch in 1 patient. The percentage of positively stained nuclei was scored for each antibody. Clinicopathologic patient data were retrospectively collected from medical charts. Results: The average age at presentation was 52 years and 2 months (range 43 - 80 years) in the overall patient population. Twenty-four patients were men and six patients were women. Twenty-eight patients (93%) presented with advanced stage (Stage III and IV) disease. There was no significant difference in the proportion of cells stained by anti-MCM2 between patients who died of the disease and those who remained alive (67.6% versus 62.9%, respectively, p=.74). Similarly, employing a multivariate Cox regression analysis, risk of death was not found to be associated with elevated MCM2 expression. These findings did not vary by disease subsite. Conclusions: Our data suggest that the cellular proliferation marker MCM2 is of limited clinical utility as a disease prognosticator in individuals diagnosed with advanced stage oropharyngeal carcinoma. The role of MCM2 as a molecular prognosticator in patients with early stage disease requires further investigation. No significant financial relationships to disclose.