German Study Emphasizes Importance Of Multiple Tests For MDS Diagnosis
Published: Jul 17, 2009 3:04 pm
In a recent report from the Munich Leukemia Laboratory, German researchers indicated the importance of using multiple tests to correctly diagnose suspected cases of myelodysplastic syndromes (MDS). Results showed that no test on its own could diagnose every MDS case. A combined approach was the most accurate in distinguishing MDS from other conditions and determining its severity.
To perform the study, researchers applied four tests to almost 2000 suspected early cases of MDS. The two main tests were cytomorphology, or studying cell structure, and immunophenotyping, or a technique to identify cells based on certain markers on the cell surface. The researchers followed these tests with cytogenetics, or the study of chromosomes, and molecular genetics, which involves examining genes and mutations.
Current practice relies on cytomorphology as a main indication of MDS. Results showed that although cytomorphology was the most accurate test of the four, 14 percent of MDS cases were identified by immunophenotyping and not by cytomorphology. When used together, the two tests identified one or more of the following in 46 percent of patients: blood or non-blood cancer cells, other non-cancerous diseases, advanced MDS, or chronic myelomonocytic leukemia, a disease in which the bone marrow overproduces immature white blood cells. Thus, performing both tests helped to distinguish cases of other diseases and cases of severe MDS from more minor or early MDS.
Results from the cytogenetics test showed a higher presence of irregular chromosomes in patients for whom both the main tests confirmed MDS. Additionally, in five percent of cases where neither cytomorphology nor immunophenotyping identified MDS, the cytogenetics test revealed irregular chromosomes. This could indicate MDS or another disease, so cytogenetics proved valuable as a supplemental test.
Researchers determined that a molecular genetics test could also be used as a supplement but may not produce significant results in confirming MDS. This test examines mutations in several genes. The mutation observed the most, in 15 percent of the suspected MDS cases, involved a gene called RUNX1 which is thought to play a role in forming blood cellular components. Mutations in other genes did not have a significant observable relationship with confirmed MDS. These findings agreed with past studies.
MDS can be difficult to diagnose due to shared characteristics with other conditions and variations in the disease’s severity among patients. Using certain tests together could result in more accurate diagnoses.
For more information, please see the article in the journal Cancer (abstract).
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