Researchers from St. Jude Children's Research Hospital in Memphis, Tennessee, and the Children's Oncology Group (COG) have found that Native American ancestry increases young leukemia patients' risk of disease recurrence.1
To the authors' knowledge, this is the first genome-wide study to demonstrate an inherited basis for racial and ethnic disparities in cancer survival. Researchers also note that the added risk could be eliminated by administering an extra phase of chemotherapy.
The study found that Hispanic patients who have a high percentage of Native American ancestry were more likely to carry a version of the PDE48 gene that also was strongly associated with disease recurrence. These variants also were associated with reduced sensitivity to glucocorticoids, which are used to treat acute lymphoblastic leukemia (ALL).
Senior author Mary Relling, PharmD, of St. Jude, notes that this variant is one example of how ancestry affects recurrence risk and that many other genes are likely involved.
The team used a library of 444,044 common single-nucleotide polymorphisms to search each patient's DNA for evidence linking ancestry and disease recurrence. Cancer was 59% more likely to return in patients whose genetic makeup reflected at least 10% Native American ancestry.
Researchers also found that ALL patients with Native American ancestry who received an extra round of chemotherapy as part of a COG clinical trial benefited more than other children. They note that these findings are important steps toward personalized care for different subgroups of patients.