Jereb B, Ahström L
Acta Radiol Ther Phys Biol. 1976 Jun;15(3):219-24. doi: 10.3109/02841867609131958.
A series of 36 children with nephroblastoma treated between 1966 and 1973 was analysed. None of the patients with stages I or II and microscopic type I or II developed metastases; 5 of 7 patients with stages I or II and microscopic type III developed metastases. All patients in stage III developed metastases. Fifteen patients developed metastases after the termination of the primary treatment. Of 9 patients with pulmonary metastases only, 6 are free of disease, all patients with metastases in other sites are dead.