3.1. Patient characteristics
The clinical characteristics of 154 patients enrolled in EpSSG RMS2005 and 85 patients enrolled in COG ARST0531 are presented in Table 1.
Adverse prognostic factors including tumor size > 5 cm, advanced IRS Group and tumor location at unfavorable sites, predominated in both cohorts. Large tumors (>5 cm) were more frequent in EpSSG than in COG patients: 71% vs 53%, respectively, (p-value 0.0029). IRS Group III tumors were also more frequent in the EpSSG than in the COG cohort: 93% vs 80%, respectively, (p-value 0.0027). Tumor location at unfavorable sites (parameningeal, limbs, bladder-prostate, other sites) (79% in EpSSG and 84% in COG) and invasiveness (T-stage 2, 60% in EpSSG and 65% in COG), were similar in both cohorts.
Fusion status of tumors, determined by the presence of FOXO1translocation (regardless of the PAX fusion partner), was analyzed in 81% of patients in EpSSG and in 93% in COG. FOXO1translocation, when FOXO1 fusion status was known (76% in EpSSG and 79% in COG), was similar in both series.
Histological analysis of nodal involvement was performed less frequently (50%) in patients enrolled in EpSSG (nodal biopsy was not mandatory in RMS2005, except for tumors arising in extremities), as compared to COG (81%) (p-value 0.0035).