Cyclin A activity predicts clinical outcome in oral precancer and cancer.

Accurate, predictive assessment of the behaviour of oral cancers and precancers remains elusive. Increasing dysregulation of cell proliferation is a feature of carcinogenesis, and alterations in cyclin proteins regulating cell cycle progression are involved in enhanced cell proliferation. The authors of the present study have previously demonstrated increased proliferative activity in oral dysplastic lesions and poorly differentiated carcinomas, and hypothesize that cell proliferation can be used as a predictive agent in clinical management. In this preliminary study, immunohistochemical quantification of cyclin A expression was carried out for 33 excised oral lesions (ranging from mild dysplasia to invasive squamous cell carcinoma, SCC). Clinical outcome was determined as: no disease after 2 years follow-up, persistent disease, or further disease presentation. Labelling Indices (LIs) ranged from 5.5 to 32.1%, and whilst a trend to increased labelling in increasingly dysplastic and neoplastic tissue was seen, this was not statistically significant (P=0.06). High LIs were related to poor clinical outcome (P=0.003), suggesting a definite role for cyclin A measurement as a predictive tool in clinical management.