AbstractIntroductionThe aim of this retrospective study was to investigate the clinicopathological characteristics of AYA sarcomas and their clinical outcomes at a high‐volume single center.MethodsDemographic, clinicopathological data on the diagnosis, treatment and follow‐up of all sarcoma patients aged 16–39 years (ys) observed at our Institute between January 2010 and December 2021 were retrospectively collected, including diagnostic (TTD) and treatment delay(TTT), clinical outcomes (OS and PFS), and late‐treatment effects.ResultsWe identified 228 AYA patients, median age 30 years, 29% ≤ 25 years, 57% males, 88% soft tissue sarcomas (STS), and 12% bone sarcomas (BS). Among STSs, 13% were small round cell tumors (SRCT), 52% intermediate–high‐grade, 24% low‐grade STSs. Among BS, 32% were high‐grade. Median TTD and TTT were 120 (0–8255) and 7 days (0–83), respectively. Surgery was performed in 83%, radiotherapy in 29%, and systemic therapy in 27%. Median follow‐up was 72.9 months(1.6–145), 5‐year and 10‐year OS were 78.5% and 62%, respectively. Kaplan–Meyer analysis showed a significantly better 5‐year OS and PFS for patients with >92 days of TTD (OS 85.7% vs. 66.7%, p = 0.001, PFS 50.2% vs. 24.9%, p = 0.009). According to age (≤25 years vs. > 25 years), 5‐year OS was 69.8% versus 82.2%, respectively (p = 0.047).ConclusionOur analysis confirmed previous data on sarcoma AYA patients followed in a referral center. Unexpectedly, diagnostic delay was not associated with poor OS and PFS. Patients <25 years showed a poorer prognosis due to the higher incidence of SRCT.