Bilateral Wilms tumor. Review of outcome, associated abnormalities, and late effects in 36 pediatric patients treated at a single institution

Background. Patients with bilateral Wilms tumor have an increased incidence of associated abnormalities and nephrogenic rests and require individualized multi-modality therapy for cure. The authors reported the associated abnormalities, outcome, complications, and late effects of treatment in a group of children with bilateral Wilms tumor treated at St. Jude Children's Research Hospital, Memphis, Tennessee, over a 28-year period. Methods. The records of 36 consecutive pediatric patients diagnosed with bilateral Wilms tumor between 1962–1990 were analyzed. Biopsy material was also reviewed, with particular emphasis on characterization of nephrogenic rests and histology. Results. Twenty-nine patients had synchronous tumors and 7 had metachronous lesions. Associated physical abnormalities were present in 12 patients and involved the genitourinary, cardiovascular, integumentary, and musculoskeletal systems. The overall survival for patients with metachronous tumors (71%) was similar to that for those with synchronous tumors (70%). There was no effect of age or the presence of nephroblastomatosis. Two patients with synchronous tumors initially treated with nephrectomy eventually required bilateral nephrectomies for contralateral recurrence after chemotherapy and radiation therapy. Nephrogenic rests were present in 22 of 30 evaluable patients. Two of three patients with metachronous tumors had intralobar nephrogenic rests. Bilateral renal salvage procedures were demonstrated to be technically feasible and effective in controlling disease without compromising renal function or survival. Late effects included scoliosis in three patients treated before 1970, cardiomyopathy in one patient who received 300 mg/m2 doxorubicin and 12 Gy pulmonary irradiation, and benign tumors in two patients, one of whom also had a bowel obstruction. Serum creatinine, urea nitrogen, and blood pressure were normal in 23 of 26 survivors. Conclusions. The authors' experience supports a favorable outcome with minimal late effects for patients with bilateral Wilms tumor who receive individualized therapy at pediatric oncology centers.