Alveolar soft-part sarcoma: Primary metastatic disease and metastatic relapse occurring during long-term follow-up: Treatment results of four Cooperative Weichteilsarkom Studiengruppe (CWS) trials and one registry

BACKGROUND Patients with metastatic alveolar soft-part sarcoma (ASPS) are known to have a very poor prognosis. Little is known about best treatment of primary metastatic disease (MD) or relapsed metastatic disease (rMD). PATIENTS AND METHODS Patients with localized disease (LD), primary MD, and metastatic recurrence after complete remission (CR) treated within the CWS-86, -91, -96, -2002P trials and the recent registry SoTiSaR (1985-2016) were analyzed. RESULTS Fifteen of 61 patients had primary metastases at initial diagnosis at the age of 14.6 years (range, 7.8-19.7). Nine of 46 patients with initial LD suffered of rMD at a median age of 9.9 years (range, 3.5-30), 3.75 years (0.75-21) after CR of primary disease. Complete resection (microscopically or macroscopically) was possible in 2 of 15 patients with MD and in 5 of 9 with rMD. RT was administered in 4 of 15 MD and 1 of 9 rMD. Chemotherapy was administered to 11 of 15 MD and 3 of 9 rMD, targeted therapy to 3 of 15 MD and 1 of 9 rMD. Median time to progression of patients treated with targeted therapy (n = 4), CHT (n = 14), and resection only (n = 6) was 56, 17, and 23 months, respectively. The 5-year event-free survival and overall survival (OS) rates were 19.8% and 61%, respectively, for patients with MD compared with 79% and 98% for patients with LD. The 5-year progression-free survival and OS were 67% and 100% for patients with rMD. CONCLUSIONS Complete tumor resection correlates with long-term survival in patients with primary and relapsed MD.