Aaron Viny, MD
Every year, about 18,000 people in the U.S. with leukemia, lymphoma, myeloma, and other serious blood disorders need a bone marrow or stem cell transplant to survive. While some patients are fortunate to have a relative who is a suitable match, about 70% must rely on finding a volunteer donor- which can be difficult for certain racial and ethnic backgrounds.
Despite how critical these transplants can be, misunderstandings about the donation process are common, and may influence whether someone's decision to become a donor.
This Blood Cancer Awareness Month, Dr. Aaron Viny, Columbia University Irving Medical Center/Herbert Irving Comprehensive Cancer Center hematologist and oncologist - and personal survivor of leukemia - is shining a light on the lifesaving role of transplants in treating blood cancers and addressing some of the most persistent myths surrounding donation.
Myth #1: All family members are a match
While it is natural to assume that any family member would likely be the perfect genetic match for a bone marrow or stem cell transplant, it is not as simple as a trait such as eye color or blood type that are passed on from a parent. Bone marrow matches are based on human leukocyte antigen (HLA) typing, which are a series of genetic markers that the immune system uses to distinguish your own cells from something foreign in your body.
These markers are inherited, and rather than having "dominant" or "recessive" traits where one parent's genetic information wins out over the other, both are actually used to give a distinct "co-dominant" pattern. This means that your HLA only matches 50% from each parent. While a full sibling has a 25% chance of being a perfect match, the combinations of these HLA patterns are so diverse that even close non-sibling relatives are rarely a match. Only about 30% of all patients find a compatible donor within their family. The others seek out donations from volunteers- who are often identified through registries.
Myth #2: Everyone has the same odds of finding a match from volunteer donors
Patients from the same genetic ancestry are more likely to be an HLA match for donation. Western European white patients have the highest chances of finding a match (around 79-93%) from volunteer bone marrow registries, while donors of AAPI, Latinx, and black backgrounds are underrepresented in these registries resulting in far lower odds in finding a match. This makes it critical to have more donors from all communities and racial and ethnic backgrounds to ensure that every patient who needs a bone marrow transplant has access to a donor.
Myth #3: Bone marrow donation is painful
There are two main ways to donate bone marrow: Peripheral blood stem cell (PBSC) isolation and bone marrow aspiration. The vast majority of donations are made through peripheral blood stem cell (PBSC) collection. It is very similar to donating blood or platelets: blood is drawn from one arm, passed through a machine that collects stem cells, and returned through the other arm. Common side effects of this procedure, including fatigue or mild bone aches from medication that helps move stem cells into the bloodstream, are mild and temporary.
In cases where bone marrow itself is needed, the procedure is done under general anesthesia. Donors don't feel pain during the process, and soreness afterward usually fades within a few days.
Myth #4: Bone marrow and stem cell transplants are only used for blood cancer patients
Although often associated with treating leukemia, lymphoma, and myeloma, bone marrow and stem cell transplants are also critical for other life-threatening conditions such as severe aplastic anemia, sickle cell disease, immune deficiencies, and certain inherited metabolic disorders. In all of these cases, a healthy donor's stem cells can replace the patient's damaged or malfunctioning blood-forming cells, restoring their ability to fight infection and make healthy blood cells.
Myth #5: People with tattoos cannot donate bone marrow and stem cells
This misconception likely comes from confusion with blood donation rules. Having tattoos does not automatically disqualify someone from donating bone marrow or stem cells. The key requirement is that the donors are healthy and meet age guidelines. Some collection centers may ask about the timing of recent tattoos or piercings, but as long as standard infection control precautions were followed, donors with tattoos remain eligible.
Myth #6: You have to donate if you sign up for the national bone marrow registry
The largest bone marrow registry in the U.S. is the National Marrow Donor Program (NMDP/Be The Match), which manages the world's largest registry of donors and connects patients with life-saving stem cell transplants. Signing up to join the registry means that you are willing to be available if you are found to be a match, but it is not a binding contract. If you are contacted, you will receive detailed information about the donation process and can decide at that point whether to move forward.
Myth #7: Donating bone marrow or stem cells can cause long-term complications
For most donors, the recovery process is quick, and they are back to their usual routines within days or weeks. The side effects are generally short-term and they resolve quickly. Studies following thousands of donors show no increased risk of cancer, immune problems, or chronic illness after donation. Donors are carefully screened before the procedure, and their health and safety are a top priority throughout.
Myth #8: You can't be a donor after 40
Age is an important factor in donation since physicians want to make sure patients have the healthiest cells possible. People can join the registry between the ages of 18 and 40, since younger donors tend to provide the healthiest cells which lead to the best outcomes for patients. However, once on the registry, donors remain eligible to donate until age 61. Family members can donate at any age as long as the medical team deems the donor healthy enough to donate.
Myth #9: LGBTQIA+ individuals can't donate
This myth reflects outdated restrictions in blood donation policies. In fact, sexual orientation or gender identity is not a part of the donor questionnaire since it does not prevent someone from donating bone marrow or stem cells. Eligibility is determined by age, health, and medical history, not identity. Expanding awareness of this fact is key to ensuring that more people feel welcome to register.
Myth #10: You need to be a full match for it to work
Doctors prefer the closest possible HLA match, but a "perfect" match isn't always necessary. Half-matches, or haploidentical transplants, are increasingly common and effective thanks to advances in transplant medicine. Mismatch of the donor and the recipient can lead to the new donor immune system to attack not just the cancer cells but also the patient's healthy tissue. Medications can help balance these effects, but doctors will weigh the urgency of treatment against the availability of matches and will recommend the safest and most timely option for each patient.
