Risks and benefits of percutaneous biopsy and primary chemotherapy in advanced Wilms' tumour.

Between 1982 and 1988, 36 children with advanced Wilms' tumour underwent percutaneous trucut needle biopsy followed by chemotherapy before definitive surgery. Nephrectomy was performed after a median of 14 weeks of chemotherapy. Substantial reduction in tumour bulk was achieved in 94% of patients. Biopsy morbidity was low and complete concordance between the histological assessment of the tumour in the biopsy specimen and at subsequent nephrectomy was confirmed in 26 of 28 (93%) patients. The overall clinical value of trucut biopsy was 83% (30/36 patients). Survival rates in this high-risk group were comparable to those of children with less advanced disease. Chemotherapy may be the primary treatment of choice for patients with Wilms' tumour. Percutaneous biopsy allows definition of histology in most patients without increasing morbidity.