The ERM proteins (Ezrin, Radixin, and Moesin) and Merlin are closely related members of the band 4.1 superfamily of proteins that, when activated, interact with both membrane proteins and the actin cytoskeleton. By organizing membrane-cytoskeleton-associated complexes and creating specialized membrane domains, the ERM proteins regulate cellular activities such as survival, adhesion, and migration/invasion. The aim of this study was to evaluate the role of ezrin expression in bladder cancer progression in T1G3 bladder tumors treated with BCG. The authors evaluated the protein expression patterns of ezrin on tumor specimens belonging to 92 patients with T1G3 non-muscle invasive bladder cancer undergoing BCG treatment. The median follow-up was 84.5 months (range: 3-173). A specific tissue array was created containing three representative cores of the tumor specimens belonging to these patients. Proliferation rates were assessed by means of Ki67 staining.

Among the 92 cases analyzed, 40 of them recurred (43.5%), 17 progressed (18.5%), and 14 died of the disease (15.2%). Log-rank survival analyses revealed that an ezrin membrane expression lower than 20% was significantly associated with an increased progression (p=0.009), and shorter disease specific overall survival (p=0.006). A nearly significant association was found with disease recurrence (p=0.06). Interestingly, the low membrane protein expression patterns of ezrin correlated with high proliferation rates as measured by Ki67 staining in a significant manner (p=0.033).

The authors conclude that membrane expression of ezrin is associated with the clinical outcome of patients with T1G3 tumors undergoing BCG treatment. Protein expression patterns of ezrin were associated with tumor progression in T1G3 disease.

Presented by Joan Palou, MD, Ferran Algaba, MD, Emilia Herrera, MD, Oscar Rodriguez, MD, Jorge Huguet, MD, Antonio Rosales, MD, Salvador Esquena, MD, Humberto Villavicencio, MD, Marta Sanchez-Carbayo, MD, at the Annual Meeting of the American Urological Association (AUA) - May 17 - 22, 2008. Orange County Convention Center - Orlando, Florida, USA.

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