Event-free survival according to rhodamine 123 (Rh123) efflux. Of 160 studied patients, 54 demonstrated Rh123 efflux, of whom 29 were randomized in the quinine arm, and 106 were scored Rh123 negative, of whom 53 received quinine. The differences in EFS observed in the absence of quinine (without quinine: Rh123+, n = 25; Rh123–,n = 53) do not reach statistical significance.