This phase III trial studies how well combination chemotherapy and surgery work in treating young patients with Wilms tumor. Drugs used in chemotherapy work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Giving more than one drug (combination chemotherapy) may kill more tumor cells. Giving combination chemotherapy before surgery may make the tumor smaller and reduce the amount of normal tissue that needs to be removed. Giving it after surgery may kill any tumor cells that remain after surgery.

This phase III trial is studying how well combination chemotherapy with or without radiation therapy works in treating young patients with newly diagnosed stage III or stage IV Favorable Histology Wilms' tumor. Drugs used in chemotherapy work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Radiation therapy uses high-energy x-rays to kill tumor cells. Giving more than one drug (combination chemotherapy) with or without radiation therapy may kill more tumor cells.

This phase III trial is studying vincristine, dactinomycin, and doxorubicin with or without radiation therapy or observation only to see how well they work in treating patients undergoing surgery for newly diagnosed stage I, stage II, or stage III Wilms' tumor. Drugs used in chemotherapy, such as vincristine, dactinomycin, and doxorubicin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Radiation therapy uses high-energy x-rays to kill tumor cells. Giving these treatments after surgery may kill any tumor cells that remain after surgery. Sometimes, after surgery, the tumor may not need additional treatment until it progresses. In this case, observation may be sufficient.