BRCA1 and osteosarcoma: In low-stage osteosarcomas, tumor stage (OS; P = 0.036, RFS; P = 0.025), histologic grade (OS; P = 0.036, RFS; P = 0.025), γH2AX expression (OS; P = 0.009, RFS; P = 0.006), and BRCA1 expression (OS; P = 0.026, RFS; P = 0.005) was associated with both OS and RFS (Table 3).