A risk score system for stratifying the risk of relapse in B cell acute lymphocytic leukemia patients after allogenic stem cell transplantation
For patients with B cell acute lymphocytic leukemia (B-ALL), allogeneic stem cell transplantation (allo-SCT) is a potentially curative treatment—but relapse remains the leading cause of treatment failure. Now, a study from Peking University offers a simple, evidence-based tool to predict which patients are most likely to relapse after allo-SCT, helping doctors tailor care to reduce risk and improve outcomes.
Why This Matters
B-ALL is a fast-growing cancer of the blood and bone marrow, and while allo-SCT replaces a patient’s diseased immune system with healthy cells from a donor, tiny remnants of leukemia (called minimal residual disease, or MRD) can persist. These cells often lead to relapse, which is fatal for many patients. Until now, predicting who would relapse has been imprecise—but this research identifies three key factors that together create a relapse risk score to guide better care.
The Three Key Risk Factors
The study, published in the Chinese Medical Journal in 2021, analyzed data from 477 B-ALL patients who underwent allo-SCT at Peking University People’s Hospital between 2010 and 2015. Researchers found three factors that strongly predicted relapse and survival:
- Post-transplant MRD: Even small amounts of leukemia cells left after transplant (detected via multiparametric flow cytometry, MFC) significantly raise relapse risk.
- Disease status before transplant: Patients in first complete remission (CR1) (where leukemia is undetectable) have better outcomes than those in later remissions (CR2+).
- Chronic graft-versus-host disease (cGVHD): A common side effect where the donor’s immune cells attack the recipient’s body—but which also has a protective “graft-versus-leukemia” effect. Patients without cGVHD are more likely to relapse.
How the Risk Score Works
By combining these three factors into a score (0 to 3, where each factor adds 1 point), the researchers created a clear hierarchy of risk:
- Score 0: No risk factors (CR1, post-MRD negative, cGVHD positive) → 5-year relapse rate: 6.3%; 5-year overall survival (OS): 85.7%.
- Score 1: One risk factor → 5-year relapse rate: 16.6%; OS: 69.2%.
- Score 2: Two risk factors → 5-year relapse rate: 55.9%; OS: 36.6%.
- Score 3: All three risk factors → 5-year relapse rate: 81.8%; OS: 27.3%.
The higher the score, the greater the chance of relapse and the lower the chance of long-term survival. This pattern held true even when accounting for other variables like age, donor type, or Philadelphia chromosome (Ph) status.
Who Led the Research?
The study was conducted by a team from Peking University People’s Hospital & Peking University Institute of Hematology, a top center for hematologic disease research in China. Lead authors include Le-Qing Cao, Yang Zhou, and Yan-Rong Liu, with senior author Xiao-Jun Huang (affiliated with Peking University, the Peking-Tsinghua Center for Life Sciences, and the Chinese Academy of Medical Sciences). Their expertise in stem cell transplantation and leukemia care adds credibility to the findings.
What This Means for Patients
This risk score is a game-changer for B-ALL care. For example:
- A patient with a score of 0 (low risk) might need less frequent monitoring.
- A patient with a score of 2 or 3 (high risk) could benefit from aggressive interventions—like preemptive donor lymphocyte infusion (DLI), targeted therapies for MRD, or strategies to induce cGVHD safely (to harness its anti-leukemia effect).
The study also found that patients with positive post-MRD who received preemptive treatment had better survival than those who did not—highlighting the value of early action.
Strengths and Limitations
The study’s strengths include its large sample size (477 patients) and focus on B-ALL, which has better outcomes than T cell ALL but still faces high relapse risks. It also includes many patients who underwent haploidentical transplantation (using a half-matched donor), a common practice in China that expands access to allo-SCT.
However, the research has limitations:
- It is a single-center, retrospective study, so results need validation in larger, multi-center trials.
- Post-MRD was measured via MFC, not specific biomarkers (e.g., BCR/ABL) that are critical for some B-ALL subtypes.
- Some patients received treatments when MRD was positive, which may have influenced outcomes.
The Bottom Line
This risk score is a promising step toward personalized medicine for B-ALL patients. By combining three easy-to-measure factors, it gives doctors a clear way to stratify risk, monitor high-risk patients more closely, and intervene early to prevent relapse. For patients and families, it offers hope of more precise, effective care—and a better chance of long-term survival.
Le-Qing Cao et al. “A risk score system for stratifying the risk of relapse in B cell acute lymphocytic leukemia patients after allogenic stem cell transplantation.” Chinese Medical Journal, 2021.
doi.org/10.1097/CM9.0000000000001402
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