Localised Synovial Sarcoma in Adolescents and Young Adults Versus Adults - Is There a Difference in Outcome?

Synovial sarcomas are a rare subgroup of soft-tissue sarcoma arising in adolescents and young adults (AYA) and in adult patients. The objective of our analysis was to investigate the outcomes and potential differences of AYA versus adult patients with initially localised disease.

In total, 51 patients (25 AYA and 26 adult) were identified and evaluated in this retrospective single centre analysis. Baseline characteristics, treatment and outcome were assessed.

The predominant subtype in both groups was monophasic synovial sarcoma (17 AYA and 21 adult) and the most common site was the extremities (14 and 19 patients) with deep tumour location in both groups (33 and 24 patients). More AYA patients had tumours >5 cm (13/25 patients) when compared with adults (10/26 patients, P = n.s.). Primary wide resection was carried out in 15 AYAs and in 18 adults. Postoperative radiation therapy was the only statistical difference between AYA (n = 19) and adult patients (n = 12; P = 0.029). Nineteen and 17 patients, respectively, received adjuvant chemotherapy with no evidence of disease after six cycles. Nine and 11 patients relapsed after initial therapy and the most common metastatic site was the lung (eight versus nine patients). Five-year overall survival rates were 85% and 75%. Female gender, tumour size ≤5 cm and absence of progressive disease showed a significant association with overall survival in AYA patients (P = 0.013, P = 0.04 and P < 0.001), whereas non-extremity tumours and progression after initial therapy were significant for worse overall survival in adult patients (P = 0.012 and P < 0.001). No difference in overall survival between AYA and adult patients was observed (P = 0.899).

AYA and adult patients showed no significant difference in terms of overall survival. Male gender, tumour size >5 cm and progressive disease were prognostic markers for worse outcome, whereas tumour location (non-extremity) and progression after initial therapy were markers for worse outcome in adult patients.