Cumulative incidence of local progression was 41 % ( 22-70 ) in the STAS group , 61 % ( 37-95 ) in the STAS plus zoledronic acid group , 15 % ( 05-37 ) in the ITAS group , and 34 % ( 17-61 ) in the ITAS plus zoledronic acid group ; no differences were noted between groups .