Local control in synchronous bilateral Wilms tumor

Purpose: To evaluate the role of radiation therapy (RT), chemotherapy (CT), and surgery in the local control of synchronous bilateral Wilms Tumor (WT). Methods and Materials: Between 1962 to 1993, 45 children were treated for bilateral WT; 38 patients with synchronous tumors were reviewed. Initial surgery depended on the era of treatment and included unilateral nephrectomy (N)/partial nephrectomy (PN) and contralateral PN in 6, unilateral N/PN alone in 7, and biopsy only in 25. Chemotherapy (CT) consisted of vincristine, actinomycin-D, and adriamycin in 32 and vincristine/actinomycin-D in 6. Radiation therapy (RT) was given to 32 patients. Treatment included both kidneys in 20, unilateral kidney plus contralateral renal bed in 9, unilateral kidney in 2, and unilateral renal bed in L Follow-up was 16 months to 25 years (median: 6.3 years). Results: Local control (LC) has been maintained in 66 out of 76 sites (87%). For Stage I-II disease with initial N/PN, LC was 10 out of 12 with RT and 11 out of 11 without RT; for Stage III with initial N/PN, LC was 8 out of 9 with RT and I out of 1 without RT. Initial CT and RT was followed by delayed N/PN for 20 sites; LC was 15 out of 17 in post induction Stage I-II and 1 out of 3 in postinduction Stage III. In 23 sites undergoing biopsy and chemotherapy, LC was 19 out of 20 with RT and 1 out of 3 without RT. Seven of 23 sites had a complete response (CR) after induction CT, and LC was maintained in four out of four with RT and one out of three without RT. Univariate Cox Regression analysis demonstrated that sites receiving two drugs bad a statistically significant increase in loco- regional relapse when compared to sites receiving three drugs (p = 0.004). Major morbidities related to multimodality therapy have included renal failure in one patient and small bowel obstruction requiring lysis of adhesions in two patients. Conclusions: Local control does not seem to be compromised by renal conservation therapy. Local control is excellent in sites treated with radiation therapy in combination with three drug chemotherapy.