What is the recurrence rate of Acute Myeloid Leukemia (AML) after a stem cell transplant in a 64-year-old male?

Recurrence Rate of AML After Stem Cell Transplant in a 64-Year-Old Male

The recurrence rate of AML after stem cell transplantation in a 64-year-old male ranges from 30-38%, with higher rates in those with FLT3 mutations (38%) compared to wild-type (28%). 1

Risk Factors for Relapse

Several factors influence the likelihood of AML recurrence after transplantation:

• Time to transplant: Patients transplanted in first complete remission (CR1) have significantly lower relapse rates compared to those transplanted in CR2 or beyond 1
• Genetic factors:
  • Presence of FLT3-ITD mutations increases relapse risk (38% vs 28% in wild-type) 1
  • NPM1 mutations are associated with better outcomes and lower relapse rates 1
  • Adverse cytogenetics significantly worsen prognosis 1
• Pre-transplant disease status:
  • Minimal residual disease (MRD) positivity before transplant increases relapse risk 1
  • Need for more than one induction treatment to achieve remission negatively affects outcomes 1

Timing of Relapse

The timing of relapse is critical for prognosis:

• Median time to relapse after transplantation is approximately 6.5 months 2
• Early relapse (within 6 months) carries a particularly poor prognosis 2
• FLT3-mutated AML is associated with higher risk of early relapse (30-59%) compared to FLT3-wildtype AML 1

Age Considerations

Despite the patient's age of 64, evidence suggests that age alone should not be considered a contraindication to transplant or affect post-transplant outcomes:

• A study of patients ≥60 years showed that age did not adversely affect non-relapse mortality, relapse rate, relapse-free survival, or overall survival 3
• The 1-year relapse rate in patients ≥60 years was 21.4% 3
• Disease risk index was more predictive of outcomes than age 3

Post-Transplant Monitoring and Prevention

To improve outcomes, the following monitoring and prevention strategies are recommended:

• Regular MRD monitoring using RT-qPCR or multiparameter flow cytometry to detect impending relapse 1
• Chimerism studies to assess donor cell engraftment 4
• Maintenance therapy considerations:
  • For patients with FLT3 mutations, post-transplant maintenance with sorafenib significantly reduced relapse incidence (HR=0.39) 1
  • Midostaurin maintenance showed promising results with estimated relapse rates at 18 months of 11% vs 24% in standard care 1

Management of Relapse

If relapse occurs despite preventive measures:

• Prognosis is generally poor with median overall survival of 3-6 months 5, 2
• Factors influencing survival after relapse include:
  • Time to relapse after transplant (longer is better) 5
  • Performance status at relapse 5
  • Disease burden (patients with <5% bone marrow blasts have better outcomes) 2
• Treatment options include:
  • Intensive salvage chemotherapy (can achieve CR in up to 71% of selected patients) 5
  • Second cellular therapy (second transplant or donor lymphocyte infusion) 2
  • Clinical trials with novel agents 1

Summary of Relapse Rates

Based on the most recent and highest quality evidence:

• Overall relapse rate after stem cell transplant: 30-38% 1
• In FLT3-mutated AML: 38% 1
• In FLT3-wildtype AML: 28% 1
• In patients ≥60 years: 21.4% at 1 year 3

The patient's specific risk factors should be evaluated to determine if they fall into a higher or lower risk category within these ranges.