Abstract
Objective: To evaluate the prognostic significance of minimal residual disease (MRD) monitoring by 10-color flow cytometry in multiple myeloma (MM) patients after treatment. Methods: 150 patients with MM who were admitted to the First Affiliated Hospital of Soochow University from July 2015 to July 2017 were retrospectively analyzed. Clinical data, MRD data monitoring by 10-color flow cytometry and prognosis were analyzed. Results: 39.1% (34/87) patients were MRD negative after induction chemotherapy, and 49.3% (34/69) patients were MRD negative within 1 year after autologous hematopoietic stem cell transplantation (ASCT) . MRD-negative patients after induction chemotherapy or after transplantation have better progress-free survival (PFS) than MRD-positive patients (P=0.022 and P<0.001) . According to the changes of MRD pre-ASCT and after ASCT, the patients were divided into 4 groups: patients with MRD continued negativity,improved from MRD positive to MRD negative, MRD continued positivity, transformed from MRD negative to MRD positive. The two-year PFS of the four groups were 83%, 82%, 44%, 0, respectively, (P=0.002) . Multivariate analysis showed that the level of MRD after induction chemotherapy was an independent factor for PFS (P=0.002) , HR=4.808 (95%CI 1.818-12.718) . Conclusion: Patients with MRD negative after treatment is a better prognosis marker than complete remission or even the best marker, which can evaluate prognosis by combining R-ISS and cytogenetic changes.