Prognostic value of proliferating cell nuclear antigen in Wilms' tumour in children.

Aims: To evaluate the prognostic value of index Proliferating Cell Nuclear Antigen (PCNA) in Wilms' tumour in children.

Methods: The study comprised 64 children aged from 2 days to 13 years treated according to the SIOP (Society International of Oncology Paediatric) and accepted by the PPGGL (Polish Paediatric Group for the Treatment of Solid Tumours). The studies were conducted on tumour tissue removed during surgery, fixed in formalin and embedded in paraffin blocks. Sections (4 microns) were evaluated by immunohistochemistry, using the peroxidase method to determine the expression of PCNA in Wilms' tumour cells by primary monoclonal antibody NCL-PCNA from Novocastra.

Results: The percentage of immunopositive cells in particular fragments of the tumour ranged from 0--93%, mean 30.5%, median 25.5%. Mean and median values enabled division of children into two groups: Group A, where the percentage of cells staining with anti-PCNA was <30% and Group B, where this percentage was >30%. The expression of PCNA was evaluated in various stages of advancement, various histological types and depending on the course of disease. The studies revealed the correlation between index PCNA and stage of advancement P<0.01, index PCNA and histological type of Wilms' tumour P<0.025. Moreover we observed that deaths were found more frequently in tumours with index PCNA >30%, P<0.001.

Conclusions: PCNA is a useful prognostic factor in Wilms' tumour in children.