Preoperative Wilms tumor rupture: A retrospective study of 57 patients

BACKGROUND. According to current International Society of Pediatric Oncology (SIOP) Wilms recommendations, all preoperative tumor ruptures should be classified as stage IIIc. However, to the authors' knowledge, the definition and diagnostic criteria of preoperative rupture have not been defined clearly. METHODS. The authors performed a retrospective analysis of 57 children with clinical and/or radiologic (computed tomography [CT]) signs of preoperative tumor rupture of a series of 250 patients enrolled in Wilms SIOP protocols at their institution. RESULTS. Clinical and radiologic signs of preoperative rupture were observed in 39 patients and 55 patients, respectively. The site of rupture on imaging was retroperitoneal only in 48 patients and both retroperitoneal and intraperitoneal in 7 patients. Surgery was performed after chemotherapy in 55 of 57 patients. Peritoneal disease recurrence occurred in 3 of 57 patients, including 2 patients with stage III tumors who had initial intraperitoneal rupture and I patient with a stage I tumor. Among the 48 patients who had radiologic signs of retroperitoneal-only rupture, the final pathologic stage was stage III in 22 patients, stage II in 9 patients, and stage I in 17 patients, and no abdominal disease recurrence was observed, although only 23 of 48 patients received flank radiotherapy. The 5-year local control rate was significantly higher in patients who had retroperitoneal-only rupture compared with patients who had intraperitoneal rupture (100% vs 83.3%; standard error, +/-15.2%; P =.0015). CONCLUSIONS. The use of CT scans significantly increased the number of patients who could be classified with "tumor rupture." Intraperitoneal rupture was diagnosed accurately with CT and was associated with a significant risk of peritoneal disease recurrence. In contrast, patients who have radiologic signs of localized retroperitoneal-only rupture at diagnosis most likely should not be upstaged, and their treatment may be determined according to pathologic stage only.