MKI67 and synovial sarcoma: In the univariable analysis, there were no significant differences in PFS regarding sex (male vs. female), age (< 40 vs. ≥40 years), ECOG performance status (0 vs. 1), histological subtype (undifferentiated pleomorphic sarcoma, leiomyosarcoma, synovial sarcoma, or other), histological tumor differentiation (score 3 vs. 2), tumor necrosis (score 1 or 2 vs. 0), and mitosis (score 2 or 3 vs. 1), histological grade evaluated by FNCLCC system (grade 3 vs. 2) and Ki-67 system (grade 3 vs. 2).