Treatment of Desmoplastic Small round Cell Tumor with Image-Guided Intensity Modulated Radiation Therapy as a Component of Multimodality Treatment

Desmoplastic small round cell tumors with EWS-WT1 fusion transcript in children and young adults

BACKGROUND

The presence of the EWS-WT1 gene fusion transcript (GFT) is characteristic of desmoplastic small round cell tumor (DSRCT), a rare and very aggressive disease for which the treatment has not yet been clearly standardized.

METHODS

This was a retrospective national multicenter analysis of young patients <30 years with tumors expressing the EWS-WT1-GFT, designed to determine whether extensive surgery had an impact on survival.

RESULTS

Between 1995 and 2006, a EWS-WT1-GFT was detected in the tumors of 38 patients, 17 (44.7%) of whom had had a different initial pathologic diagnosis prior to molecular testing. Mean age was 13.2 years (range: 4-29.7 years). Only 9 patients (24%) had localized disease. Treatment was heterogeneous. Nine patients had "limited" surgical resections and 22 underwent "extensive" surgery. Two-year event-free survival and overall survival were 14.4% and 50%, respectively. Among the five patients who were alive in complete remission, four had undergone extensive and complete surgery.

CONCLUSIONS

Detection of the EWS-WT1-GFT plays a major role in the diagnosis of DSRCT. No survival difference was observed according to extent of surgery, but complete surgery seemed to offer the best chance of long-term survival. High-dose chemotherapy or local radiotherapy did not appear to improve survival in this retrospective analysis, but larger prospective studies are needed to provide definitive conclusions on the role of these treatments.

Current concepts and future perspectives in retroperitoneal soft-tissue sarcoma management

Retroperitoneal soft-tissue sarcomas are complex, heterogeneous cancers requiring expert multidisciplinary care. They can occur anywhere in the retroperitoneal abdominal or pelvic space. Usually large at presentation they present particular challenges for both local treatment and systemic control. The most common adult subtypes are liposarcomas and leiomyosarcomas, followed by pleomorphic sarcoma/malignant fibros histiocytoma (an entity not always easily distinguishable from dedifferentiated liposarcoma). A variety of additional histotypes may also be observed, but are uncommon in the retroperitoneum, either because of intrinsic rarity or because they are usually found in other anatomic sites. The underlying biology varies according to the different histotypes. Pediatric subtypes mainly comprise extraskeletal Ewing sarcoma/pPNET and alveolar rhabdomyosarcoma. Surgery is critical for controlling these tumors and requires an aggressive approach. It may also provide useful palliation for patients with advanced slow-growing disease. Radiotherapy has acquired a definite position in attempting to reduce relapse, although prospective trials of adjuvant or neoadjuvant radiotherapy are needed. Chemotherapy has a limited role in the adjuvant setting for most forms of retroperitoneal sarcoma (excluding pediatric subtypes), but has an increasing role in advanced disease. Novel targeted therapeutic agents that target specific amplification or translocation products offer promise for subsets of these diseases.