When doctors are considering stem cell transplant as a treatment option, they do an assessment to find out if the person with cancer (recipient) is a suitable candidate for the procedure. Doctors may do several examinations and diagnostic tests to determine if candidates are physically and mentally prepared for the procedure. The recipient may also need other procedures to prepare for the stem cell transplant.
The doctor may do the following tests to determine if a person is a suitable candidate for stem cell transplant:
Members of the healthcare team teach the person with cancer and the family about the procedure and what to expect. They discuss the risks and benefits of stem cell transplants. They will also arrange:
Once recipients have been fully informed about all procedures and agree to have a stem cell transplant, they sign a consent form (informed consentinformed consentThe process by which a person learns the important facts about a procedure, treatment, clinical trial or test before deciding to participate.).
A central venous catheter (CVC) is a thin, flexible tube. It is placed into the large vein above the heart, usually through a vein in the neck, chest or arm. It is also called central venous line or central line.
For allogeneic stem cell transplants, the recipient’s transplant doctor identifies potential matches and arranges donor testing.
To increase the chance of a successful transplant and to reduce complications, the transplanted stem cells must match the recipient’s as closely as possible. Most matches are between close family members (related donor), so the search for a donor starts with the recipient’s brothers and sisters. The closest match is an identical twin because identical twins have the same HLAs.
If a sibling match is not found, parents or extended family members, such as aunts, uncles and cousins, may be tested. Parents and children of recipients are unlikely to be perfect matches because they pass on or receive only 3 of the 6 genes needed for a perfect match. According to Canadian Blood Services, less than 30% of people have an HLA-matched donor in their family.
If a match is not found within the family (and often only brothers and sisters are tested), the search starts for an unrelated donor in the general public through the OneMatch Stem Cell and Marrow Network. This registry has access to over 10 million volunteers worldwide.
Donors are checked to make sure that they are in good health and physically able to donate stem cells. Tests may include:
Once donors are informed about the donation process and agree to proceed, they sign a consent form (informed consent).
When children are stem cell donors, a social worker or child-life specialist may be able to help them cope with the medical procedure. Donors who give bone marrow or stem cells to help their brother or sister often feel a lot of pressure. They are often told that they are helping save their brother’s or sister’s life. If the transplant does not go well, they may feel responsible, guilty and depressed. If other siblings in the family are not chosen as the donor, make sure they understand that a tissue match is random and not a measure of how important they are in the family.
The process of collecting the stem cells is called harvesting. Harvesting differs based on where the stem cells are collected from. Stem cells may be collected from bone marrow, peripheral blood or umbilical cord blood.
Stem cells may be harvested or treated differently for different types of stem cell transplants (allogeneic, syngeneic or autologous stem cell transplants).
For some allogeneic and syngeneic transplants, the stem cells may be given to the recipient within several hours of being harvested from the donor. In other transplants, stem cells are harvested and mixed with a preservative so that they can be stored by a special freezing process. This is called cryopreservation. This process helps keep stem cells alive until it is time for the transplant.
Stem cells may be collected from the umbilical cord shortly after a baby is born. They are processed from the cord blood, frozen and stored until they are needed.
The Canadian Cancer Society’s Cancer Information Service (CIS) is Canada’s only national, bilingual, toll-free service that offers personalized comprehensive cancer information in over 100 languages.