Research article

Expression of minichromosome maintenance protein 2 as a marker for proliferation and prognosis in diffuse large B-cell lymphoma: a tissue microarray and clinico-pathological analysis

Ellen C Obermann¹ , Philip Went² , Annette Zimpfer^2,3 , Alexandar Tzankov³ , Peter J Wild⁶ , Robert Stoehr⁴ , Stefano A Pileri⁵ and Stephan Dirnhofer²

¹Institute of Pathology, University of Regensburg, 93053 Regensburg, Germany

²Institute of Pathology, University Hospital Basel, 4031 Basel, Switzerland

³Institute of Pathology, University of Innsbruck, 6020 Innsbruck, Austria

⁴Department of Urology, University of Regensburg, 93053 Regensburg, Germany

⁵Chair of Pathology and Unit of Haematopathology, University of Bologna, Italy

⁶Institute of Pathology, University Medical Center, Hamburg-Eppendorf, 20246 Hamburg, Germany

author email corresponding author email

BMC Cancer 2005, 5:162doi:10.1186/1471-2407-5-162

Published:	20 December 2005

Abstract

Background

Minichromosome maintenance (MCM) proteins are essential for the initiation of DNA replication and have been found to be relevant markers for prognosis in a variety of tumours. The aim of this study was to assess the proliferative activity of diffuse large B-cell lymphoma (DLBCL) in tissue microarray (TMA) using one of the minichromosome maintenance proteins (Mcm2) and to explore its potential value to predict prognosis.

Methods

Immunohistochemistry for Mcm2 was performed on TMAs constructed from 302 cases of DLBCL. A monoclonal mouse antibody was used after heat induced antigen retrieval. Mcm2 expression was scored quantitatively. Positivity for Mcm2 was defined as presence of nuclear expression of Mcm2 in greater than or equal to 40 % of tumour cells. A statistical analysis was carried out of the association of Mcm2 and the clinico-pathological characteristics.

Results

Mcm2 expression was clearly evident in the nuclei of proliferating non-neoplastic cells and tumour cells. Positivity for Mcm2 was found in 46% (98/211) of analysable cases. A significant correlation existed between Mcm2 expression and presence of bulky disease (p = 0.003). Poor disease specific survival was observed in patients with DLBCL positive for Mcm2 expression in the univariate analysis (p = 0.0424).

Conclusion

Mcm2 expression can be used to assess tumour proliferation and may be useful as an additional prognostic marker to refine the prediction of outcome in DLBCL.