Biomedicines. 2022 Jun 28. pii: 1530. [Epub ahead of print]10(7):
Maddalena Benetton,
Pietro Merli,
Christiane Walter,
Maria Hansen,
Ambra Da Ros,
Katia Polato,
Claudia Tregnago,
Jonas Abrahamsson,
Luisa Strocchio,
Edwin Sonneveld,
Linda Fogelstrand,
Nils Von Neuhoff,
Dirk Reinhardt,
Henrik Hasle,
Martina Pigazzi,
Franco Locatelli.
Hematopoietic stem cell transplantation (HSCT) is a curative post-remission treatment in patients with acute myeloid leukemia (AML), but relapse after transplant is still a challenging event. In recent year, several studies have investigated the molecular minimal residual disease (qPCR-MRD) as a predictor of relapse, but the lack of standardized protocols, cut-offs, and timepoints, especially in the pediatric setting, has prevented its use in several settings, including before HSCT. Here, we propose the first collaborative retrospective I-BFM-AML study assessing qPCR-MRD values in pretransplant bone marrow samples of 112 patients with a diagnosis of AML harboring t(8;21)(q22; q22)RUNX1::RUNX1T1, or inv(16)(p13q22)CBFB::MYH11, or t(9;11)(p21;q23)KMT2A::MLLT3, or FLT3-ITD genetic markers. We calculated an ROC cut-off of 2.1 × 10-4 that revealed significantly increased OS (83.7% versus 57.1%) and EFS (80.2% versus 52.9%) for those patients with lower qPCR-MRD values. Then, we partitioned patients into three qPCR-MRD groups by combining two different thresholds, 2.1 × 10-4 and one lower cut-off of 1 × 10-2, and stratified patients into low-, intermediate-, and high-risk groups. We found that the 5-year OS (83.7%, 68.6%, and 39.2%, respectively) and relapse-free survival (89.2%, 73.9%, and 67.9%, respectively) were significantly different independent of the genetic lesion, conditioning regimen, donor, and stem cell source. These data support the PCR-based approach playing a clinical relevance in AML transplant management.
Keywords: AML; HSCT; MRD; molecular genetics; q-PCR