Retroperitoneal Wilms’ Tumor ruptures not always stage IIIc

Using a CT scan to classify preoperative Wilms’ Tumor ruptures may accurately assess what patients should be upstaged, according to data from a retrospective study.

According to researchers from the Curie Institute in Paris, current International Society of Pediatric Oncology guidelines recommend that preoperative tumor ruptures be classified as stage IIIc, which usually entails the use of abdominal radiation therapy. However, the diagnostic criteria for tumor ruptures are not clearly defined.

The researchers conducted a retrospective study of 250 children treated at their institution for Wilms’ Tumor. Fifty-seven children (23%) had clinical and/or radiologic signs of tumor rupture: 39 (68%) had clinical signs and 55 (96%) had radiologic signs. All 55 children with radiologic signs had signs of retroperitoneal ruptures. Seven children also had signs of intraperitoneal rupture.

The final pathologic stage in the retroperitoneal-only patients was stage III in 22 patients, stage II in nine patients and stage I in 17 patients. None of these patients experienced abdominal disease recurrence. All patients with intraperitoneal ruptures were classified as stage III

Patients who had only retroperitoneal-only ruptures had a 100% five-year overall local control rate, whereas patients who had intraperitoneal ruptures had an 83.3% overall local control rate (P=.0015). – by Emily Shafer

Cancer. 2008;113:202-213.

The study report defines two types of Wilms’ Tumor rupture based on radiologic criteria that the researchers developed: retroperitoneal rupture and intraperitoneal rupture. Using their criteria, the researchers found that two of seven patients with both retro- and intraperitoneal rupture experienced local recurrence, whereas none of the 48 patients with only retroperitoneal rupture experienced local recurrence. Because the researchers used new definitions of rupture, and the study was retrospective and involved a small number of heterogeneously treated patients, the findings require validation. The results are most applicable to patients treated on International Society of Pediatric Oncology protocols, in which chemotherapy is administered before the tumor is resected. With the National Wilms’ Tumor Study Group/Children’s Oncology Group approach, patients undergo surgery with direct assessment of tumor ruptures before chemotherapy, thereby diminishing the need for imaging correlates.

– Jeffrey S. Dome, MD

Chief of the Division of Oncology, Children’s National Medical Center