Objective: To evaluate the impact of kinetics of molecular remission via retro-transcriptase polymerase chain reaction (RT-PCR) assay on the long-term survival in patients with acute promyelocytic leukemia (APL).
Methods: Seventy patients with newly-diagnosed APL in remission were involved in this study. Monitoring of minimal residual disease (MRD) was performed regularly by RT-PCR assay for PML-RAR alpha during consolidation.
Results: A 5-year relapse-free survival (RFS) and overall-survival (OS) were estimated as 46.8% +/- 8.4% and 69.9% +/- 9.4% for the whole group. Fifty-two (74.3%) patients got negative RT-PCR result at least once. Serial monitoring of RT-PCR was available in 38 cases and 24 (63.2%) patients presented with persistent negative PCR results. The achievement and continuous negative RT-PCR result was significantly related to the RFS.
Conclusions: Achievement of negative RT-PCR in remission is associated with favorable RFS and OS. Continuous negative RT-PCR results are associated with long-term relapse-free survival and may be considered as potentially curative. RT-PCR assay for detection of MRD should be performed regularly during post-remission period as an important prognostic factor.