Assessment of Clinical Time Intervals Along the Patient Journey with Overall Survival in Localized Osteosarcoma and Ewing Sarcoma: A 20-Year Tertiary Sarcoma Centre Experience

Background: The impact of healthcare-related time intervals on outcomes in bone sarcomas remains controversial. We evaluated the impact of clinically defined post-referral, in-hospital care intervals on overall survival (OS) and their variation over two decades, in patients treated at a tertiary sarcoma centre. Methods: We retrospectively analysed 506 patients with localized osteosarcoma (n = 319) or Ewing's sarcoma (n = 187) treated between 2002 and 2021. We defined three in-hospital time intervals: time to diagnosis (TToD; first specialist evaluation to diagnostic biopsy), time to treatment (TToT; biopsy to treatment initiation), and total post-referral patient journey time (PJT; first specialist evaluation to treatment). Multivariable Cox models adjusted for age, sex, tumour location, and surgical factors evaluated associations with OS. Results: Median PJT was longer in Ewing's sarcoma than in osteosarcoma (17 vs. 14 days; p < 0.001), mainly because of a longer TToT. Over time, median PJT increased from 12 to 19 days (p < 0.001), driven by longer TToT, while TToD remained stable. Neither PJT nor TToD was associated with OS. Although longer TToT was associated with lower mortality risk, this was not confirmed after stratification by diagnostic period. Worse OS was independently associated with amputation, upper-extremity tumours, and intralesional margins. Conclusions: Within the specialized tertiary centre setting, longer in-hospital care timelines were not associated with poorer overall survival despite increasing over time, a finding that may reflect the growing complexity of multidisciplinary management exclusively during the post-referral phase.