CHICAGO, Sept. 13 (Xinhua) -- A DNA-based analysis of blood cells soon after a stem cell transplant can predict the likelihood of disease recurrence in patients with myelodysplastic syndrome (MDS), according to a study at Washington University School of Medicine in St. Louis.
In the study, published Thursday in the New England Journal of Medicine, the researchers performed DNA sequencing to identify mutations in the cancerous cells before stem cell transplantation in 86 patients with MDS, a group of cancerous disorders characterized by dysfunctional blood cells.
Of these patients, 35 experienced disease recurrence at a median of 141 days after transplant, and 51 did not develop a recurrence within a median follow-up of about one year.
Mutations found before the transplant established a genetic "fingerprint" of each patient's cancer. About one month after a stem cell transplant, the researchers sequenced each patient's blood cells again to see if they could still detect the cancer's fingerprint.
The patients whose cancer fingerprints could be detected 30 days after the transplants had about four times the risk of disease recurrence in the first year after their transplant, compared with patients with no genetic sign of cancer cells, which are 53 percent and 13 percent, respectively, according to the researchers.
To identify cancer fingerprints, the researchers first used a broad sequencing approach to detect mutations in over 20,000 genes, then narrowed their analysis to include only 40 genes.
Though the 40-gene test was not able to identify a cancer fingerprint in as many patients as looking at all genes, it still identified most high-risk patients and demonstrated that a similar test could be practical for future use in patients.
MDS is difficult to diagnose. Symptoms often are related to low blood cell counts. Many people with the disease may never know they have it because they may experience only nonspecific symptoms such as fatigue or shortness of breath.
But others may have a more aggressive form that is eventually fatal. About one-third of MDS patients progress to acute myeloid leukemia, a fast-growing blood cancer that also can be fatal.
"A genetic analysis is a much more precise method of measuring how many blood cells are cancerous. It also lets us find abnormal cells at earlier time points after a stem cell transplant, when there are fewer cancerous cells to find. The earlier we can detect that the cancer is coming back, the more time we may have to intervene," said senior author Matthew J. Walter, a professor of medicine at the university.
The practice is also expected to help guide treatment decisions.