Long-term outcome of bilateral Wilms tumors (BWT).

BACKGROUND: Modern WT management consist of ample chemotherapy, nephron-sparing surgery, and, when indicated, radiotherapy. Survivors may develop renal failure or secondary tumors due to anticancer treatment. We analyzed long-term outcome (follow-up >5 years) after bilateral Wilms tumor (BWT) treatment with respect to survival, renal function, and secondary malignancies.

METHODS: From 41 patients (23 females, 28 synchronous tumors) diagnosed with BWT between 1967 and 2007, 25 (18 females, 14 synchronous) with a follow-up >5 years could be included. Of this subgroup, median age at diagnosis was 1.64 years (range 0.27-5.35), and at maximum follow-up 14.99 years (range 5.40-33.99). Data were retrospectively collected and analyzed.

RESULTS: One patient (4%) died 17.75 years after diagnosis, five (20%) had renal transplants: 3/5 after bilateral nephrectomy for Denys-Drash syndrome (DDS), and 2/5 for ESRD after an interval of 7 and 18 years, respectively. All transplanted patients remained in CR. Another three patients developed mild renal insufficiency (creatinine levels 1.3, 1.8, and 2.8 mg/100 ml, respectively; N = 0.5-1.2), combined with hypertension in 1; neither of them was transplanted. Sixteen (64%) had normal renal function and were in CR. Long-term renal function appeared significantly better after bilateral nephron sparing surgery (NSS) then after other surgical procedures (P < 0.0001). Seven secondary tumors were found in five (20%) patients, one of whom had a DDS.

CONCLUSION: Long-term 10-year overall survival was 78%. There was significant morbidity (13/25, 52%), in terms of renal failure (8/25, 32%) including renal transplantation (5/25, 20%), and secondary tumors (5/25). These findings necessitate long-term follow-up beyond childhood. Future work should be directed at reducing the harmful effects of treatment, including the increased use of NSS.