Synovial sarcoma diagnosis and management in the era of targeted therapies

Synovial sarcomas are a distinct soft tissue sarcoma subtype, with a predilection for young adults. Despite its common translocation, there is substantial heterogeneity in patient outcome. This review discusses recent developments in diagnosis, prognostication, and treatments, together with the role of targeted agents and immunotherapy in patients with synovial sarcoma.

Tumor behavior of synovial sarcomas remains inexplicable and is therefore poorly predictable. Although many variables seem to contribute to and influence patient outcome, no underlying pathophysiology accounting for the variability in behavior has been unraveled. As prognosis remains poor, there is a wistful search for new therapies. In preclinical testing, several receptor tyrosine kinases have been suggested as therapeutic targets with interesting results in vitro or in vivo. However, translating interesting preclinical outcome to clinical results is difficult, to a large extent due to limited patient numbers available to participate in clinical trials.

By defining predictive variables, researchers try to understand the underlying cause of this tumor's biologic behavior and develop new therapeutic targets. Owing to the minimal number of prospective studies usually with small patient numbers, the strength of improving patient outcome will be in collaborative international studies in this rare tumor type.