Is Nephron Sparing Surgery Justified in Wilms Tumor With Beckwith-Wiedemann Syndrome or Isolated Hemihypertrophy?

Background Patients with Beckwith–Wiedemann syndrome (BWS) or isolated hemihypertrophy (HH) treated for a Wilms tumor (WT) carry an increased risk of developing metachronous lesion. There are no guidelines on precise indications for nephron sparing surgery (NSS) in unilateral WT (UWT). The objective of this retrospective study was to delineate the indications of NSS in patients with BWS/HH treated for WT and to evaluate their outcome. Procedure All cases of BWS/HH treated for a WT according to SIOP protocols from 1980 to 2013 were reviewed. Patients were divided into two groups (G): isolated UWT (G1) and bilateral lesions (G2) with two subgroups: bilateral tumors suspected of malignancy (G2a), and unilateral tumor suspected of malignancy with contralateral nephroblastomatosis (G2b). Results Forty‐six patients were included (34 G1, three G2a, and nine G2b). Nine NSS and 25 total nephrectomies (TN) were performed in G1, two bilateral NSS and one NSS with contralateral TN in G2a, and eight NSS and one TN in G2b. The 3‐year event‐free survival was 92.3% (95% CI [77.9–97.5%]). One death occurred after a local relapse following a TN for a stage III stromal WT (G1) and another after a combined local and distant relapse following a NSS for a stage I diffuse anaplastic WT (G2b). There were two metachronous WT (4%), 3 years after a TN (G1) and 12 years after a NSS (G2b). Conclusions NSS is recommended in bilateral WT and may be an option in selected UWT patients with BWS/HH because it was not associated with an increased risk of local relapse.