Results of multimodal treatment for desmoplastic small round cell tumor of the abdomen and pelvis.

PURPOSE Desmoplastic small round cell tumor (DSRCT) is a rare aggressive malignancy that occurs in a young population with a male predominance. We studied the clinical and pathological characteristics of DSRCT and investigated the effects of multimodal therapy including aggressive surgical resection, induction chemotherapy, and external beam radiotherapy. METHODS We retrospectively reviewed and analyzed our experience with 11 histologically proven cases of DSRCT between March 2004 and October 2014. The clinical information, histological, immunohistochemistry and survival data of the patients were collected. RESULTS The median age at diagnosis was 31.4 years (range, 14-64 years) and nine (82%) of the patients were males. The most common presenting complaint was abdominal pain (72.7%). Surgical resection was attempted in five patients and included macroscopic total resection in two patients and debulking in three patients. Six patients underwent biopsy only. Eleven patients received multiagent chemotherapy. Five patients (45.5%) received radiotherapy. The median survival of patients who underwent surgical resection was 34.5 months, whereas the patients who underwent biopsy alone was 24.5 months (P<0.05). The median survival was 40.8 months in radiotherapy group, and 19.2 months in non-radiotherapy group (P<0.05). The 3-year progression-free survival rate was 27.2%. The median survival was 29 months, and the median time to local failure was 8.8 months. Cox regression analysis showed surgery and radiotherapy were highly significant in prolonging patients survival. CONCLUSION Multimodal therapy consists of combination of surgical resection, chemotherapy and radiotherapy results in improved survival in patients with DSRCT. For unresectable DSRCT, we recommend radiotherapy combined with anthracycline-based chemotherapy.