OVEREXPRESSION OF CYCLIN D1 CORRELATES WITH EARLY RECURRENCE IN SUPERFICIAL BLADDER CANCERS

Cyclin D1 is a cell cycle regulator essential for G(1) phase progressi on and is frequently overexpressed in several human tumour types as a consequence of gene amplification or chromosomal rearrangements. We an alysed the expression of cyclin D1 in 75 patients with transitional ce ll carcinoma (TCC) to investigate the possible relationship between it s expression and clinical outcome as well as histopathological finding s using the immunohistochemical method, We observed strong staining (+, > 50% positive cells) for cyclin D1 in 19 cases (25.3%) and weak st aining (+, 5-50% positive cells) in 19 cases (25.3%). Overexpression o f cyclin D1 was not associated with tumour invasion. No significant as sociation was found between overexpression of cyclin D1 and tumour gra de (P> 0.05). We assessed the differences of disease-free interval in superficial tumours and actuarial survival probability in invasive tum ours according to the status of cyclin D1 expression. Tumours with (+) staining for cyclin D1 recurred much more rapidly than (-) and/or () staining tumours (P< 0.01 for-vs++; P< 0.05 for + vs ++). However, o verexpression of cyclin D1 was not associated with a shortened overall survival of patients with invasive tumours (P< 0.1). These results su ggest that genetic alteration of cyclin D1 appears to be an early even t in the tumorigenesis of bladder TCC and is associated with early rec urrence in superficial tumours.