Desmoplastic small round cell tumor in childhood: the St. Jude Children's Research Hospital experience.

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare, primarily intra-abdominal tumor that has a poor outcome with current therapies.

PROCEDURE

We retrospectively reviewed patient characteristics, presenting symptoms, tumor pathology, treatment, and outcome of 11 pediatric patients with DSRCT at our institution.

RESULTS

The cohort included 1 female and 10 male patients. Median age at diagnosis was 14 years (range 5-21 years). In eight (73%) patients, the primary tumor was abdominal or pelvic, and in one patient each, it was submental, mediastinal, and paratesticular. Nine (82%) patients had metastatic disease. All tumors showed polyphenotypic differentiation by immunohistochemistry. The EWS-WT1 transcript was detected in six of seven tumors tested. One tumor showed rhabdomyoblastic differentiation after therapy. All patients received chemotherapy; eight underwent surgical resection, seven received primary site radiation, and four received myeloablative chemotherapy with stem-cell support. Three (27%) patients are alive 23 months, 8 years, and 10 years from diagnosis. Two died of treatment-related toxicity, six died of disease. None of the patients in whom surgery and initial chemotherapy failed to induce complete remission survived.

CONCLUSIONS

DSRCT is an aggressive malignancy that does not respond well to contemporary treatments, and patients who do not enter complete remission after initial chemotherapy and surgery appear to have a particularly dismal outcome. Patients with localized extra-abdominal disease have a better prognosis, most likely due to increased feasibility of resection. Better understanding of molecular and genetic mechanisms of tumorigenesis and treatment-related changes may contribute to development of more effective therapy for DSRCT.