Researchers Identify Cancer Stem Cells That May Cause Relapse In MDS Patients With Chromosome 5 Deletion
Published: Feb 9, 2011 12:28 pm
A recent study found that myelodysplastic syndromes patients with a deletion in chromosome 5 have malignant stem cells that persist through Revlimid-induced remission and may cause relapse.
The study authors therefore suggested that strategies to complement Revlimid therapy should be developed to target the malignant stem cells.
Myelodysplastic syndromes (MDS) patients who have missing genetic material from the ‘q’ arm of chromosome 5 frequently reach remission in response to treatment with the drug Revlimid (lenalidomide). Revlimid has been approved for use in lower risk MDS patients with that chromosomal mutation. However, 50 percent of these patients who reach remission relapse within three years.
Previous research identified a distinct group of malignant stem cells in the bone marrow of MDS patients with deletion 5q. Researchers hypothesized that these stem cells may be particularly resistant to treatment with Revlimid.
In this study, researchers investigated this hypothesis by examining the bone marrow from seven low-risk or intermediate-risk MDS patients with deletion 5q. Each patient had been treated with Revlimid and became transfusion-independent.
Researchers looked for the presence of the distinct stem cells and other cells with deletion 5q in each patient’s bone marrow before and during treatment with Revlimid.
The researchers found that the Revlimid-resistant stem cells were present before treatment, and most of these cells had the deletion 5q mutation. After the patients achieved transfusion independence, many cells with deletion 5q were reduced or even eliminated.
However, the researchers also found that despite Revlimid treatment, a small portion of the resistant group of stem cells persisted.
The researchers noticed that the majority of patients eventually experienced an increase in the portion of treatment-resistant stem cells. Four of the patients progressed from transfusion independence to transfusion dependence.
The researchers explained that because most of the malignant cells in the marrow are eliminated, normal stem cells can grow following treatment and can restore normal blood cell formation. However, when the malignant stem cells are allowed to persist, relapse is possible.
For additional information, please see the article in The New England Journal of Medicine (abstract).
- Researchers Identify Prognostic Factors For MDS Patients With Chromosome 5 Deletion (EHA 2011)
- Discontinuation Of Revlimid May Be Possible In Certain MDS Patients
- Researchers Link Revlimid Dosage To Transfusion Independence In MDS Patients With A Deletion In Chromosome 5 (ASCO 2011)
- Revlimid Does Not Increase The Risk Of AML Progression In Myelodysplastic Syndromes Patients (ASH 2010)
- Re-Treatment With Revlimid Following A Short Treatment-Free Period May Result In A Second Response In Relapsed MDS Patients (ASH 2010)