Proliferating cell nuclear antigen cyclin in human transitional cell carcinoma.

OBJECTIVES

To confirm the value of the proliferating cell nuclear antigen (PCNA) labelling index in relation to histological grade, stage and 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 antibody. Immunohistochemical analysis was performed on ethanol-fixed, paraffin-embedded tissue sections obtained by endoscopic biopsy or transurethral resection (TUR). The PCNA labelling index was determined by counting 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 grade 2 tumours, and grade 3 tumours had a PCNA labelling index of 21.8 +/- 10.4%. The average labelling indices for superficial tumour (37 patients) and invasive tumour (19 patients) were 7.5 +/- 5.3% and 20.8 +/- 10.0%, respectively. A distant metastatic bladder tumour showed an average labelling index of 42.3%. To analyse survival, tumours with PCNA indices above and below the median level (12%) were compared. Those patients 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 labelling indices in recurrent and non-recurrent tumours were 6.4 +/- 0.7% and 8.2 +/- 1.7%, respectively, statistically not significant.

CONCLUSION

The higher PCNA labelling index may indicate biological malignancy. These results suggest that measurement of the PCNA labelling index in bladder cancer may prove to be an objective and quantitative assay of biological aggressiveness and provide significant prognostic information, though it does not help to select patients at high risk of recurrence in superficial tumours.