American Indian heritage may increase odds leukemia patients will relapse, new research from St. Jude Children's Research Hospital and the Children's Oncology Group (COG) indicates, recently published in the scientific journal Nature Genetics.
A genetic variation, PDE4B, specific to Indian ancestry was linked to a higher risk factor of leukemia recurring in youth and young adults. Cancer was 59 percent more likely to return in patients with at least 10 percent Native American ancestry in their genetic makeup, the study found. About 25 percent of the 2,534 patients, children and adolescents battling acute lymphoblastic leukemia (ALL), in the study met the 10 percent point, states a St. Jude's press release.
The presence of PDE4B variants is also linked to patients who respond with less sensitivity to glucocorticoids, vital medications in treatment of ALL, which is the most common childhood cancer, according to the National Cancer Institute.
The find marks the first study using genomics to define ancestry, rather than self-declared status, shedding new light on the ability of an inherited genetic trait to actually influence one’s likelihood of overcoming cancer and remaining healthy.
Investigators discovered a strategy that may increase survival—an additional chemotherapy treatment may increase the likelihood of maintaining remission.
While cure rate of ALL has risen from 15 percent to 85 percent in the past four decades—“one of the leading success stories in all of cancer research,” according to the Cure Search for Children’s Cancer website, and the rate at St. Jude is 94 percent, according to its website, racial and ethnic disparities remain.
"To overcome racial disparity you have to understand the reasons behind it," said Jun Yang, Ph.D., St. Jude Department of Pharmaceutical Sciences assistant member and the study's first author, in the news release. "While genetic ancestry may not completely explain the racial differences in relapse risk or response to treatment, this study clearly shows for the first time that it is a very important contributing factor."
Knowing ALL patients with Native American ancestry can benefit from an extra chemotherapy treatment can help doctors adapt recovery strategies for some ethnic and racial communities.
"These are important steps on the way to personalized cancer care, whereby treatment can be tailored to provide maximal benefit to patient subgroups, and someday, individual patients," said co-author Stephen Hunger, M.D., University of Colorado professor of pediatrics and chair of COG's ALL committee, in the St. Jude's news release.