Lymphoma patients receiving transplant treatment with their own blood stem cells may be at risk of developing another blood cancer, according to a presentation at the 58th annual meeting of the American Society of Hematology Dec. 3-6 in San Diego.
Researchers at the Dana-Farber Cancer Institute argued that the risk comes from blood stem cells carrying acquired mutations.
The team analyzed blood samples from 401 patients with non-Hodgkin lymphoma that were collected when the patients received transplants with their own blood. About 30 percent of the patients were carrying mutations in their blood stem cells, the researchers discovered. They also found that patients older than 60 were more likely to have mutations.
Another finding was that transplant recipients who carried mutations had a 14.4% higher risk of developing another blood cancer in the next decade, compared with 4.4% of patients without mutations. The other cancers were acute myeloid leukemia (AML) and myelodysplastic syndrome.
Patients carrying mutations were also 30.6% less likely to survive the next 10 years than those who did not have mutations. The higher risk of death was not only due to other cancers, but also to the onset of additional health problems, such as heart attacks and strokes.
Most mutations were in the PPM1D gene, which encodes a protein that contributes to DNA damage repair.
Mutations in blood stem cells leads to an age-related condition called clonal hematopoiesis of indeterminate potential, or CHIP. It occurs in 10-15 percent of patients older than 65.
CHIP is characterized by mutations that cause some blood stem cells to divide rapidly and form new cells — and thus, possibly, a new cancer. The mutations may be due to aging or may be triggered by chemotherapy.
CHIP patients do not show symptoms or blood anomalies, but it is possible CHIP may be an early stage of a blood cancer.
The results of the study “suggest the need to specifically study the connection between CHIP and lymphoma more deeply, which could be accomplished by assessing CHIP in patients with newly diagnosed lymphoma prior to the administration of any chemotherapy or mobilizing agents,” the researchers wrote in a news release. “They also suggest the need to consider alternative therapeutic approaches” for lymphoma patients who are being considered for stem cell transplants but are at high risk of developing other cancers.