PROLIFERATING CELL NUCLEAR ANTIGEN CYCLIN IN HUMAN TRANSITIONAL-CELL CARCINOMA

Objectives To confirm the value of the proliferating cell nuclear anti gen (PCNA) labelling index in relation to histological grade, stage an d prognosis. Materials and methods Tissue specimens from 56 patients ( 49 men, 7 women; mean age 65 years [range 34-86]) with newly diagnosed transitional cell carcinoma of the urinary bladder were stained by an avidin-biotin peroxidase method using an anti-PCNA monoclonal antibod y. Immunohistochemical analysis was performed on ethanol-fixed, paraff in-embedded tissue sections obtained by endoscopic biopsy or transuret hral resection (TUR). The PCNA labelling index was determined by count ing the number of PCNA-labelled cells in the tissue sections. Results Grade 1 tumours averaged 5.1+/-3.0% labelling versus 10.9+/-5.2% in gr ade 2 tumours, and grade 3 rumours had a PCNA labelling index of 21.8 +/- 10.4%. The average labelling indices for superficial tumour (37 pa tients) and invasive tumour (19 patients) were 7.5+/-5.3% and 20.8+/-1 0.0% respectively. A distant metastatic bladder tumour showed an avera ge labelling index of 42.3%. To analyse survival, tumours with PCNA in dices above and below the median level (12%) were compared. Those pati ents with an index of <12% (the mean of all of the PCNA values) had a worse prognosis than those with an index of >12%. The mean PCNA labell ing indices in recurrent and non-recurrent tumours were 6.4+/-0.7% and 8.2+/-1.7% respectively, statistically not significant. Conclusion Th e higher PCNA labelling index may indicate biological malignancy. Thes e results suggest that measurement of the PCNA labelling index in blad der cancer may prove to be an objective and quantitative assay of biol ogical aggressiveness and provide significant prognostic information, though it does not help to select patients at high risk of recurrence in superficial tumours.