If the child is older than 2, has a favorable histology and/or has a tumor weighing more than 1.2 pounds, or if the patient has the anaplastic form of Wilms', the doctor may surgically remove the cancer and follow with chemotherapy. If the patient has clear cell sarcoma of the kidney or a rhabdoid (rod-shaped cells) tumor, the doctor may surgically remove the cancer and follow with chemotherapy and radiation therapy.

Stage II: If the patient has a favorable histology, treatment may include surgery to remove the tumor followed by chemotherapy. If the child has an unfavorable histology (anaplasia, clear cell sarcoma, or rhabdoid tumor), treatment may include surgery followed by chemotherapy plus radiation therapy.

Stage III: The doctor will probably operate to remove the tumor and follow with chemotherapy and radiation. If the child has a favorable histology, the physician may lower the radiation dose. If the cancer is too close to vital organs or blood vessels or is too large to remove, the doctor may perform a biopsy and use chemotherapy to shrink the tumor and possibly radiation. The doctor may be able to operate if the chemotherapy or radiation shrinks the tumor. Surgery may be followed by more chemotherapy and radiation.

Stage IV: Treatment involves surgical removal of the cancer followed by chemotherapy and radiation.

Stage V: The doctor may take out some of the cancer in one or both kidneys and remove some nearby lymph nodes to see if they are cancerous. Chemotherapy will follow surgery to shrink tumors. The physician may operate a second time to remove additional cancer, but will leave the kidneys intact as much as possible. Chemotherapy with or without radiation may follow.