Clinical significance of cyclin B1 protein expression in squamous cell carcinoma of the tongue

Purpose: Cyclin B1 plays an important role in control of the G₂-M transition of the cell cycle. We have shown recently that overexpression of cyclin B1 is associated with poor outcome in patients with early stage squamous cell carcinoma (SCC) of the lung. Experimental Design: To determine the role of cyclin B1 in SCC of the tongue, we analyzed tumor specimens from 41 patients with stage II-IV SCC of the tongue who underwent curative surgery using immunohistochemistry. Results: The median follow-up of all patients was 83 months. Overexpression of cyclin B1 was observed in 15 (37%) of the 41 tumors, a similar frequency to that found in SCC of the lung. Patients whose tumors showed overexpression of cyclin B1 had a poor event-free survival compared with those lacking this feature (P = 0.04 by Log-rank test). Multivariate analysis of traditional clinical/pathological factors showed that cyclin B1 overexpression was an independent prognostic indicator. Conclusions: Our study indicates that cyclin B1 is overexpressed in a subset of SCC of the tongue and is associated with a more aggressive biological behavior of the disease.