Survival analysis
Median follow-up was 5 years, and five-year estimated PFS and OS for the entire population was 58.4% (95% CI: 49.4 – 69.1%) and 59,1% (95% CI: 50.5 – 69.3%), respectively (FIG.1). There were no differences observed between males and females in either PFS (53.8% vs 60.1%; p=0.58) or OS (58.3% vs 60.2%; p=0.49). Patients with localized disease [71.0% (95% CI: 60.3 – 83.7%)] had better OS compared to those with metastatic disease [52.9% (95% CI: 38.7 – 72.4%); p=0.019]. SR patients (5-year OS: 69.4%) were observed to have higher OS than HR patients (5-year OS: 53.8%), although this difference was not statistically significant (p=0.063) (FIG.2). Patients that lived >40km from INCA (5-year OS: 68,2%) fared better than those who lived closer (5-year OS 52%; p=0.032) (FIG.3).
Patients treated as per COGA9961 Protocol had better OS (5-year OS: 70.6%) compared to those treated with pre irradiation chemotherapy regimen (5-year OS: 41.7%), however this difference did not reach statistical significance (p=0.16). Sixteen patients initially stratified as SR were treated with higher doses of radiation therapy as per HR regimen because of the delay in starting raditation therapy. The survival outcomes were better, but not statistically significant, than those treated as SR (79.4% vs 67.7%; p=0.22).