Abdominal desmoplastic small round cell tumor: multimodal treatment combining chemotherapy, surgery, and radiotherapy is the best option.

BACKGROUND: With nearly 450 cases reported since 1991, desmoplastic small round cell tumor (DSRCT) is a rare abdominal tumor typically arising in adolescent and young adult white men. With no large series described, the best therapeutic strategy remains unclear.
METHODS: All consecutive patients treated in our tertiary care center between January 1991 and December 2013 for a DSRCT were retrospectively studied.
RESULTS: Thirty-eight patients with a median age of 27 years (range 13-57 years) were identified; 71 % were men. At the time of diagnosis, 47.4 % patients had extraperitoneal metastases (EPM): 78 % were located in the liver and 11 % were located in the lungs. Fourteen patients (37 %) were treated exclusively with systemic chemotherapy, with a median survival of 21.1 months. Twenty-three patients underwent surgery, 12 (52 %) experienced complete removal of all macroscopic disease, 5 (21.7 %) received additional intraperitoneal chemotherapy, and 7 (30 %) received postoperative whole abdominopelvic radiotherapy (WAP RT). With a median follow-up of 59.9 months, the median survival was 37.7 months, and the median disease-free survival was 15.5 months. The factors predictive of 3-year overall survival were the absence of EPM, complete surgical resection, postoperative WAP RT, and postoperative chemotherapy. The intraperitoneal chemotherapy had no impact on overall survival.
CONCLUSIONS: DSRCT is a rare and aggressive disease. In patients without EPM, a multimodal treatment combining systemic chemotherapy, complete macroscopic resection, and postoperative WAP RT could enable prolonged survival. No benefit of surgery was demonstrated for patients with EPM. The value of associated hyperthermic intraperitoneal chemotherapy remains unproven.