OBJECTIVE Osteosarcoma is rare disease and there is a strong controversy about the potential impact of symptom interval on the stage of disease and patients' outcomes . We want to assess whether increased symptom interval (SI) is associated with advanced tumor stage and poor prognosis for patients with osteosarcoma .
METHODS We analyzed prospectively collected data of 220 patients younger than 40 years who had osteosarcoma around the knee . Symptom interval was analyzed to evaluate its impact on metastases at diagnosis, tumor volume, chemotherapy response and overall survival .
RESULTS The median of SI was 64.5 (Q1-Q3 : 42-88) days . The 5-year overall survival rate for patients with different length of symptom interval (< 42 days , 42-64 days , 65-87 days ,> = 88 days) were 0.78 (95% CI : 0.67-0.89), 0.49 (95% CI : 0.35-0.63), 0.52 (95% CI:0.39-0.65), and 0.65 (95% CI:0.53-0.77) respectively (p = 0.013). Nonparametric test showed increased SI was associated with metastases at diagnosis (p = 0.008), but not associated with large tumor volume or poor chemotherapy response . Cox regression mode test showed that patient with increased SI had higher hazard ratio (42-64 days HR : 2.586 (95% CI:1.360-4.915); 65-87 days, HR : 2.225 (95% CI:1.170-4.233) ) for poor outcomes compared to short SI (< 42 days), though it was not significant in multivariate analysis (p = 0.182).
CONCLUSION Increased SI but not the longest SI is associated with higher incidence of metastases at diagnosis; patients can benefit from an earlier diagnosis in terms of survival.