Correlation between reduced expression of the spindle checkpoint protein BubR1 and bad prognosis in tonsillar carcinomas

Background. Spindle checkpoint proteins such as Mad2 and BubR1 are important for chromosome segrega- tion during mitosis. The aim of the present study was to exam- ine their possible impact on prognosis in tonsillar carcinomas and their relation to clinical variables, the prevalence of human papillomavirus (HPV), p53 status, and Ki-67 positivity. Methods. We examined the expression of Mad2 and BubR1 by immunohistochemistry on tissue microarrays from 105 patients with tonsillar carcinomas. Results. BubR1 and Mad2 were both expressed in tonsillar carcinomas. Expression of BubR1 was a significant prognostic factor in univariate survival analysis. In multivariate analyses, BubR1 was a significant prognostic factor together with stage, age, and HPV status p < .01), whereas Mad2 did not show any significant correlations. Conclusion. We have shown that BubR1 expression is a novel and strong prognostic factor in tonsillar carcinomas, giv- ing additional information to the TNM stage and other known