Why Bone Marrow Transplants are done:
One reason BMT is used in cancer treatment is that it is possible for patients to receive very high doses of chemotherapy and/or radiation therapy (RT) which have a greater chance of ablating disease.
These are both types of BMT which serve many purposes including:
- Curative therapy for malignant diseases (e.g. ALL, AML)
- Most commonly used in the treatment of leukemia and lymphoma (most effective when these disease are in remission)
- Replacement of:
- A dysfunctional immune system with a new immune system (e.g. Severe Combined Immunodeficiency Syndromes)
- Single enzymes that are genetically missing (e.g. Hurler Syndrome)
- One’s own hematopoietic stem cells following myeloablative chemotherapy (e.g. autologous transplant for solid tumors)
- Abnormal red blood cells with normal red blood cells (e.g. Beta Thalassemia).
- Entire hematopoietic system in marrow failure syndromes (e.g. Severe Aplastic Anemia).
For some types of leukemia the graft versus tumor (GVT) effect that occurs after allogeneic BMT and PBSCT is critical to the effectiveness of the treatment. GVT occurs when white blood cells (WBC) from the donor (the graft) identify the remaining cancer cells after chemotherapy and RT as foreign and attack them. WBC from the donor may also attack normal host tissues leading to graft versus host disease (GVHD) which may be a serious complication of BMT.