After a median follow-up of 104 years ( IQR 78-131 ) , 10-year overall survival was 494 % ( 95 % CI 446-541 ) for the preoperative radiotherapy group and 507 % ( 459-552 ) for the preoperative radiotherapy and chemotherapy group ( HR 099 , 95 % CI 083-118 ; p = 091 ) .