Efficacy of Preoperative Chemotherapy in Patients With Nephroblastoma and Imaging Findings Suggestive of Preoperative Tumor Rupture.

Background And Aims If Wilms tumor (WT) rupture is suspected preoperatively, it is unclear whether preoperative chemotherapy (preop-CT) can be safely given and whether such patients need to be treated according to local stage III postoperatively. Methods We retrospectively analyzed characteristics, treatment, and outcome of patients with preoperative rupture suspected by imaging and clinical symptoms in 119 patients from Germany, Austria, and Switzerland with unilateral WT treated within SIOP studies. Results There was no difference in age and gender distribution compared with the overall cohort of patients with WT. The general health condition was characterized at least severely impaired (37.8%). Eighty-nine patients 89 (74.8%) received preop-CT and 30 (25.2%) had upfront surgery. The mean tumor volume at diagnosis undergoing preop-CT was 605 mL compared with 312 mL at primary surgery. Metastases were found in 20 out of 89 (22.5%) and two out of 30 (6.7%) patients, respectively. After preop-CT, 31 patients (34.8%) had local histological stage I, 16 (18.0%) had stage II, 41 (46.1%) had stage III, and one (1.1%) had unknown. Low risk histology was diagnosed in seven (7.9%), intermediate risk in 65 (73.0%), and high risk in 17 (19.1%) patients. After preop-CT, nine patients relapsed (10.1%), compared with four (13.3%) after primary surgery. Relapses were independent of local radiotherapy. Altogether seven patients died. A total of 14 out of 31 patients (45.2%) with overall local stage I of intermediate risk after preop-CT received only 4 weeks AV without radiotherapy after surgery with 100% relapse-free survival. Conclusions Preop-CT can be given safely, and postoperative treatment can follow the histological staging and risk group, given that a thorough review of the specific situation is done.