A 45-year-old man with newly diagnosed Philadelphia chromosome-negative B-cell acute lymphoblastic leukemia (Ph-negative B-ALL) achieves complete remission after induction therapy. Minimal residual disease (MRD) assessment by multiparameter flow cytometry at end-of-induction shows 0.05% leukemic cells. What does MRD positivity at this threshold predict, and how does it alter management?
- A MRD positivity is irrelevant in adult ALL; proceed with consolidation chemotherapy only
- B MRD positivity only matters if the patient is Ph-positive; no change in management here
- C MRD >=0.01% is associated with higher relapse risk; allogeneic hematopoietic stem cell transplant should be considered in first remission ✓
- D MRD must be confirmed by IgH PCR; flow cytometry results are not actionable
Correct answer: C. MRD >=0.01% is associated with higher relapse risk; allogeneic hematopoietic stem cell transplant should be considered in first remission
Explanation
In adult ALL, end-of-induction MRD >=0.01% (10^-4) by flow cytometry or PCR is an independent predictor of relapse and inferior survival, irrespective of Ph status. MRD-positive patients benefit from allogeneic transplant in first remission. MRD has superseded many traditional risk factors in adult ALL treatment algorithms. Blinatumomab is also approved for MRD-positive ALL.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.