Multicentre study of Wilm’s tumours treated by different therapeutic strategies in two different countries

Abstract

Background and purpose According to the treatment of Wilm’s tumours, two different therapeutic strategies were established in the second half of the last century. Both National Wilm’s Tumour Study (NWTS) group and the International Society of Paediatric Oncology (SIOP) have helped to improve the clinical management and outcome of patients with Wilm’s tumours. In this study, we compared three groups of patients with Wilm’s tumours from different racial backgrounds and therapeutic strategies.
Patients and methods A clinicopathological review was carried out for 40 patients treated at Kyushu University Hospital in Japan from 1960 to 2006 according to NWTS, 79 patients treated at the South Egypt Cancer Institute from 2002 to 2009 according to the SIOP protocol and 33 patients treated at the Pediatric Surgery Department of Assiut University Hospital from 2000 to 2009 according to the NWTS protocol.
Results In the Kyushu University group, a favourable histology was diagnosed in 80% of patients and an unfavourable histology in 20% of patients. The distribution of the clinical stage was as follows: I = 40%, II =22.5%, III = 22.5%, IV = 7.5% and V = 7.5%. The 5-year overall survival was 82.5%, with the 5-year stage-related survival as follows: I= 93.7%, II =83.3%, III= 62.5%, IV = 33.3% and V = 100%. In the South Egypt Cancer Institute group, favourable histology was diagnosed in 89.9% of patients, unfavourable histology in 8.8% of patients and benign disease in 1.3% of patients. The distribution of the clinical stage (before and after chemotherapy) was as follows: I = 25.3%-50%, II= 19%-20%, III= 35.4-15%, IV = 12.5%-5% and V = 7.6%-7.6%. No case of intraoperative tumour rupture was recorded. The overall 5-year survival rate of 84% with a 5-year stage-related survival was as follows: I= 92%, II =80%, III= 50%, IV = 31% and V = 30%. In the Assiut University group, a favourable histology was diagnosed in 79% of patients and an unfavourable histology in 9% of patients. The distribution of the clinical stage was as follows: I= 39.4%, II =21.2%, III = 21.2%, IV = 12% and V =6%. The overall 5-year survival rate was 77% and the 5-year stage-related survival was as follows: I= 85%, II= 75%, III = 52%, IV = 33% and V = 33%.
Conclusion The Egyptian patients with Wilm’s tumour presented at a younger age and had less incidence of an unfavourable histology compared with Japanese patients. Preoperative chemotherapy increased the rate of stage I disease and decreased the incidence of intraoperative tumour rupture and relapse. However, there was a possibility that chemotherapy had been administered in the case of benign disease. 

Keywords: intraoperative tumour rupture, NWTS, SIOP, Wilm’s tumour