(P 02) CLINICAL CHARACTERISTICS AND OUTCOME OF ADOLESCENT AND YOUNG ADULTS SOFT TISSUE AND BONE SARCOMAS AT AN ADULT CANCER CENTER: THE BENEFITS OF A DEDICATED, MULTIDISCIPLINARY MANAGEMENT

Objective: The aim of this retrospective mono-center analysis was to investigate the clinical and pathological characteristics of Adolescent and Young Adult (AYA) sarcomas and to underline the benefits of multidisciplinary management of this particular category of patients (pts).

Methods: We retrospectively collected demographic, clinical and pathological data on the diagnosis, treatment and follow-up of all sarcoma pts aged 15-39 years (ys), which were seen at our Institute between January 2010 and December 2021. As AYA referral center, we also reported the diagnostic delay (TTD - time to diagnosis, from the symptoms onset to pathological diagnosis), the treatment delay (TTT - time to treatment, from diagnosis to the disease management) and the incidence of significant late effects of the treatments. We also evaluated clinical outcomes in terms of Progression-Free Survival (PFS) and Overall Survival (OS).

Results: We identified 228 AYA pts with median age 30 ys, 29% ≤ 25 ys, 57% males. Out of 188 evaluable pts, 35% were smokers. While out of 190, the median Body Mass Index (BMI) at the diagnosis was 23.05 (range 12.42-46.81). Among 228, 200 (88%) were Soft Tissue Sarcoma (STSs) and 28 (12%) bone sarcomas (BS). Among STSs, 26/200 (13%) were small cells tumors (21 extraskeletal Ewing’s sarcomas) and 104/200 (52%) intermediate-high grade (including 18 synovial sarcomas, 18 liposarcomas, 15 leiomyosarcomas, 9 angiosarcomas, 8 MPNST, 3 clear cell sarcomas, 7 epithelioid sarcomas and 3 alveolar soft part sarcomas). We also identified 48/200 (24%) low grade STSs, 16/200 (8%) desmoid fibromatosis and 6/200 (3%) GIST.
Among BS (28/200, 14%), 9/28 (32%) were high-grade (4 were osteosarcomas) and 19/28 (68%) low-grade (11 giant cells tumors).
TTD of 195/228 (86%) pts was available and the median TTD was 120 days (range 0-8255). TTT was available for the whole population and the median was 12 days (range 0-237). Surgery was performed in 190/228 (83%), radiotherapy in 66/228 (29%) and systemic therapy in 62/228 (27%) pts.
In the whole study population, with a median follow-up from diagnosis of 72.9 months (range 1.6 - 145), 5-ys and 10-ys OS were 78.5 % and 62% respectively (median 140.9). We reported a better OS for females vs males (5-ys OS 82.9% vs 74.9%, p 0.16) with no difference in PFS. According to an age cut off 25 ys, 5-ys OS was 69.8% vs 82.2 % for ≤25 ys vs > 25 ys respectively (p 0.047), difference overcome excluding small cell sarcomas. No significant impact on PFS and OS was reported for BMI and smoking. Kaplan-Meyer analysis showed unexpectedly a significantly better 5-ys OS for pts with > 92 days of TTD (85.7% vs 66.7%, p 0.001), also confirmed in intermediate-high grade sarcomas cohort. We also reported a significant better 5ys-PFS in pts with a TTD > 92 days (50.2% vs 24.9%, p 0.009).
No secondary tumors or anthracycline-associated cardiac failure were reported.

Conclusion: Our analysis confirmed previously published data on epidemiology and prognostic characteristics of sarcoma AYA pts. The results in terms of outcomes highlighted the crucial role of sarcoma referral center in the management of this peculiar subgroup of pts.