Salvage rates and prognostic factors after relapse in children and adolescents with initially localised synovial sarcoma.

BACKGROUND: Previous studies have reported a poor outcome for synovial sarcoma patients whose tumours relapse.
METHODS: This study analysed 44 relapsing cases in a series of 118 consecutive patients <21 yr of age with non-metastatic synovial sarcoma prospectively enrolled in Italian paediatric protocols between 1979 and 2006. In an effort to identify a possible risk-adapted stratification enabling a better planning of second-line treatment, the relapsing patients' outcome was analysed vis-à-vis their clinical picture at onset, first-line treatments, clinical findings at the time of first relapse and second-line treatment modalities.
RESULTS: The first event was a local recurrence in only 15 cases, and metastatic in 29 (associated with local relapse too in 7 cases). The time to relapse ranged from 4 to 108 months (median 20 months). Overall survival was 29.7% and 21.0% five and ten years after relapsing, respectively. The variables influencing survival were the timing and type of relapse (combined) and the chances of a secondary remission, which correlated strongly with the feasibility of complete surgery.
CONCLUSIONS: Our study confirmed a largely unsatisfactory prognosis after recurrences in children and adolescents with synovial sarcoma: the chances of survival can be estimated on the basis of several variables for the purposes of planning risk-adapted salvage protocols. An aggressive surgical approach should be recommended. New effective systemic agents are warranted, and experimental therapies can be offered to patients with little chance of salvage.