Treatment results in patients treated from 1980 to 2004 for Wilms' tumour in a single centre

The principle behind the treatment of nephroblastoma has been similar for at least 4 decades, based on vincristine and dactinomycine, radiotherapy in selected stages. The last three decades have been characterised by the aim to reduce the intensity and length of treatment. To retrospectively compare survival rates and treatment success in a cohort of patients aged under 19 years, treated from 1980 to 2004 at a single centre by five consecutive treatment protocols. The outcome was evaluated in patients treated consecutively by two protocols established at the centre before 1980 and modified in 1986, and from 1988 consecutively by three accepted protocols, SIOP9, SIOP93 and SIOP2001. Overall survival as well as event-free survival rates were evaluated by Kaplan-Meier functions in 315 patients (52.7% women). The average age at diagnosis was 3.9 +/- 2.9 years, median 3.3, range 0.01-17.2 years. Age over 12 years in 2.2% patients. The average follow-up time was 13.1 +/- 7.8, median 13.6, range 0.2-27.8 years. The original 104 weeks of protocol KDO86 treatment had a 10-year overall survival rate of 91.9 +/- 3.2%. Overall survival significantly fell with radiotherapy reduction in lower clinical stages and treatment diversification in protocols with substantial treatment length reduction. Overall survival returned to the original value of KDO86 only in 1994, when SIOP93 was accepted with a 10-year overall survival rate of 92.47 +/- 3.0% and event-free survival 85%, with similar trends in the latest protocol, SIOP2001. In the entire cohort two coincident malignancies (tumour duplicities) were found: one B-lymphoma, one neuroblastoma. A second malignancy occurred in one patient--superficial spreading melanoma. from the retrospective view the accepted SIOP9 protocol has a significantly worse outcome in both the overall survival and in event-free survival rate compared with the original therapy. Only the SIOP93 and SIOP2001 protocols accepted after 2003 have an acceptable 10-year overall survival rate (around 92%) as well as event-free survival (85%) with substantially reduced length and intensity of treatment, lowering the risk of late effects.