Bone marrow transplant can be used as a primary treatment of certain types of cancers or as a way to help treat chemotherapy and radiotherapy patients.
Cancer can be treated different ways, which include radiotherapy and chemotherapy, which may compromise the immune system of the body. Bone marrow transplant can help treat such patients. It can also be used to treat some primary types of cancers.
Bone Marrow Transplantation:
EMT or bone marrow transplantation is a process in which the immature cells that form blood that may have been destroyed due to exposure to radiation therapy or excessive dosages of chemotherapy are restored. These cells may suffer from this fate because certain forms of cancer require a very high dose of anti-cancer medication to eliminate the cancer causing cells and obtain a definite cure. The problem arises with the fact that these anti-cancer drugs not only eliminate all the cancer causing cells in the body, but these methods may also kill the normal stem cells of the body in the process. This is by far the most dangerous complication of chemotherapy because in the absence of white blood cells the body is not capable of combating infections; and, in the absence of platelets, clotting cannot occur after an injury, and the patient could die from excessive bleeding.
The bone marrow transplantation procedures enable the body to initiate the production of new blood forming cells after chemotherapy in order to restore the balance of the cells. This procedure has been used on numerous patients since the 1980’s and has improved the survival statistics of patients significantly, especially of those suffering from myelomas, leukemia and lymphomas. Bone marrow transplantation procedures are also effective against various cancers, most prominently neuroblastoma, which is a form of childhood cancer.
Bone marrow transplantation is a complex multi-step procedure which requires a great deal of coordination and accurate planning at each step. The first step involves the harvesting of stem cells which need to be transplanted. Initially, these stem cells are acquired from the marrow found inside the pelvic bone through an invasive surgical process that requires general anesthesia. However, a much simpler process is being used recently. It involves obtaining stem cells from the patient’s bloodstream rather than the marrow. This process is known as PSCT, or the Peripheral Stem Cell Transplantation. Once harvesting of the stem cells has been done, the patient is subjected to a significant amount of radiation and chemotherapy. Towards the end of the process, the harvested stem cells are then introduced into the patient’s vein in a manner similar to any other blood product. These cells then find their way to the bone marrow. Once they have reached the bone marrow, these stem cells can then multiply and initiate the production of new, healthy cells in order to make up for the compromise.
Types of transplants:
There are two forms of bone marrow transplantations namely autologous and allogenic transplants.
Autologous transplants: In this procedure, the stem cells or the marrow of the patients themselves are harvested prior to chemotherapy and radiation therapy. These cells are then infused back once the treatment has been successfully completed.
Allogenic Transplants: In allogenic transplants the peripheral stem cells or the bone marrow of separate healthy donors are taken and transplanted into the patient. In order to prevent rejection of stem cells and marrow fragments by the body of the recipient, a donor whose white blood cells show genetic structure and makeup similar to that of the recipient is carefully selected. If the structure and cellular makeup of the donor’s white blood cells match that of the recipient, the chance of long term complications and other side effects is much less when compared to cases where the genetic structures do not match.
Generally, most patients have siblings whose white blood cells show similar genetic structure and makeup to the patient’s. Therefore, siblings have become the ideal stem cells donors in transplantation procedures. In case of no siblings, closest white blood cell matches can be located with the help of donor registries found at hospitals. This type of transplant has a lower success rate when compared to sibling donors.
The short and long term side effects of bone marrow transplantations experienced by patients (recipients) are similar to those seen in cases of chemotherapy which is administered for a greater duration and a greater intensity. However, in case of transplantations greater measures have to be taken in order to prevent the risks of infection and excessive bleeding compared to normal chemotherapy.
It has been noted that allogenic transplant patients are at a higher risk of developing a condition known as “graft versus host diseases”, or GVHD. This disease is characterized by the attack of donor stem cells on the recipient’s organs such as the liver, GI tract, skin and lungs. This condition also increases the risks that the patient might develop infection or develop severe damage to different organs of the body. It is possible for the patient to recover significantly from GVHD with the help of medication and other measures, but the long term effects may continue to manifest for a long period of time. The condition can become life threatening.
Carrier, Ewa, and Gracy Ledingham. 2004. / 100 Questions and Answers about Bone Marrow and Stem Cell Transplantation. Boston: Jones and Bartlett. Detailed information about bone marrow and stem cell transplantation is presented in an easy-to-read question-and-answer format. Terms are explained in the sidebar, and the book includes lists of Web sites, organizations, and support resources. This book was co-authored by a physician and a bone marrow transplant survivor.
This site has information about the resources, programs, and sevrices provided by this patient-support organization. The resource center section includes a database of medical articles searchable by topic and keyword. The site also includes an archive of questions to experts, a comprehensive listing of organizations, and a list of transplant centers.
National Marrow Donor Program (NMDP). Access at: www.nmdp.org/
The National Marrow Donor Program® (NMDP), a nonprofit organization, is the global leader in providing bone marrow and umbilical cord blood transplants to patients in need. .The “Donor Resources” section has information for marrow donors and those thinking of joining the registry. “Patient Resources” is for patients and caregivers. The information
is provided for adults and children who are in different stages of treatment: pre-transplant, during transplant, and post-transplant.
This article was originally published on 7/12/2014 and last revision and update of it was 9/14/2015.