If you become ill with a blood cancer or other disease that requires a stem cell transplant, here’s an uncomfortable fact: Your race matters. Diversity is a strength in much of life, but it’s a curse when finding a stem cell donor match.
For a successful transplant, donor and recipient must have nearly identical genes regulating certain immune cells. These genes evolved in response to the disease threats people faced long ago. “Tell me where your ancestors lived 500 years ago, and I’ll tell you who your potential donors are,” says Jeffrey Chell, an internist who leads the National Marrow Donor Program, also known as Be The Match.
African Americans have the most diverse genetics because their ancestors have been around the longest and because of intermixing with whites, Native Americans and Hispanics since Africans arrived in the Western Hemisphere. When all of humankind’s relevant genes are considered, there are 10 billion possible combinations. That means that “if your ancestors were on two or three continents,” Chell says, “it’s going to be harder to find a match.”
Genetics make the mathematics difficult for people of color. Cultural traditions, mistrust of medicine and ignorance about the need for donors make it worse.
“I didn’t know anything about bone marrow transplants until I learned that I might need one,” says Anthony Thomas, 49, a financial consultant from Randallstown, Md., who has chronic lymphocytic leukemia. Among his African American friends and colleagues, there’s little awareness of the importance of donating, he says, although “you can bet that if Lil Wayne or Beyoncégot leukemia, that would change.”
“People tell me, ‘I’m praying for you,’ ” says Thomas, who spent July 18 on Capitol Hill lobbying against the sequestration of federal funds that have helped Be The Match enroll donors. “I tell them, ‘Prayer is great, but if you want to help me, start a donor drive at your church.’ ”
Thomas may not need a transplant for three to five years, he says. The situation is much more dire for Nina Louie, 33, whose parents are of Chinese descent and who has some Thai ancestors. She is suffering from advanced lymphoma, and chemotherapy is no longer an option.
Sorority sisters mobilize
Ironically, Louie and nine of her sisters in an Asian American sorority joined a stem cell registry 15 years ago as freshmen at Stanford University after learning that cancer patients of Asian descent lacked adequate donor options for transplants. Today, those nine women are battling to save their beloved sorority sister.
In two months, they have helped enlist nearly 8,000 potential donors through a social marketing campaign and ads on 350 billboards across the country. The message: “Save Nina.” The drive, which is aimed particularly at Asians and Asian Americans but asks everyone to register, has located potential donors for three other patients, all of Asian descent. But it has not yet turned up one for Louie. Hospitalized near her home in Los Angeles after 14 rounds of chemotherapy, she is spending as much time as she can with her husband, Matt, and their 2-year-old son, Donovan.
Be The Match, a nonprofit launched in 1986, provides potential access for people such as Thomas and Louie to the healthy cells of 22 million people around the world, about half of them in the United States.
For patients with leukemia, lymphoma and other immune disorders, bone marrow and peripheral blood stem cell (PBSC) transplants help destroy cancerous cells and replace immune cells killed off by chemotherapy. In PBSC, cells are filtered out of the donor’s blood and infused into the patient; in marrow donation, a needle is used to withdraw liquid marrow, which also contains stem cells, from inside the pelvic bone.
The first stem cell transplants were done in the 1950s. Last year, doctors performed more than 50,000 worldwide and the global total reached 1 million transplants. Because of potentially fatal risks, the procedure is performed only on people in dire condition. A recent study in the Journal of Clinical Oncology found that about 90 percent of patients survived at least 100 days after the transfusion, and about 63 percent for a year or more.
Family members are key
About a third of stem cell transplants are from young relatives of the patient, but in Louie’s case no familial match could be found. Doctors have told her she has a 1-in-20,000 chance of finding a match.
In addition to being disadvantaged by their genetic diversity, many minority-group members in the United States have been less likely than other Americans to donate or register for donation, as Louie and her sorority sisters learned years ago.