Presence of residual disease at the end of treatment predicts for long-term PFS and OS independent of prior treatment and cytogenetics. Posttreatment minimal residual disease (MRD) levels were obtained within 6 months after the end of treatment by multiparameter flow cytometry to a sensitivity of 10−4 (0.01%). A patient was considered MRD-negative if the MRD level was below the level of detection (ie, <0.01%). The log-rank P value is displayed, and P < .05 is considered statistically significant. (A) Progression-free survival (PFS) according to the level of detectable disease at the end of treatment. (B) Overall survival (OS) according to the level of detectable disease at the end of treatment. (C) PFS according to prior treatment and the MRD status at the end of treatment. (D) OS according to prior treatment and the MRD status at the end of treatment. (E) PFS according to del(17p) or del(11q) and the MRD status at the end of treatment. (F) OS according to del(17p) or del(11q) and the MRD status at the end of treatment. (E-F) Cytogenetic aberrations were evaluated by fluorescence in situ hybridization. The balance of patients with del(17p) and del(11q), respectively, was comparable between the MRD-negative and MRD-positive groups. In the MRD-negative del(17p/11q) group, 3 of 9 patients (33%) had del(17p), whereas 6 of 9 patients (67%) had del(11q). In the MRD-positive del(17p/11q) group, 6 of 15 patients (40%) had del(17p), whereas 9 of 15 patients (60%) had del(11q). MRD-neg, MRD-negative; MRD-pos, MRD-positive.
