Interdigitating and follicular dendritic cell sarcomas: A SEER analysis

OBJECTIVES: Follicular dendritic cell sarcoma (FDCS) and interdigitating dendritic cell sarcoma (IDCS) are rare neoplasms of dendritic cell origin. Because of the rarity of these diagnoses, optimal management is unclear. METHODS: In this study, we reviewed the data on FDCS and IDCS available in the Surveillance, Epidemiology, and End Results database. Fifty-four patients with FDCS and 20 with IDCSs were identified between the years 2001 and 2008. RESULTS: Median follow-up was 28 months. Sixty-one percent of FDCS patients and 55% of IDCS patients presented with localized disease. Of the FDCS patients with localized disease, 31/33 (94%) underwent surgical resection. Fifty-five percent (6/11) of localized IDCS patients underwent surgical resection. Radiation therapy was given to 30% of patients. Overall survival was significantly better for patient with FDCS compared to those with IDCS. Median survival was 35 months in patients with IDCS and was not reached in patients with FDCS. There was a trend toward improved overall survival in FDCS patients with localized disease. IDCS patients with localized disease had a significantly improved overall survival compared with those with distant disease with 2-year overall survival of 72% versus 33%, respectively (P=0.05). CONCLUSIONS: These data demonstrate that most patients with localized disease are treated similar to a soft tissue sarcoma with primary surgical resection with or without radiation. No chemotherapy data were available in the Surveillance, Epidemiology, and End Results database. The role of chemotherapy and radiation therapy remains unclear.