Bone Marrow Transplant Risks and Survival Rate

Pictured is an illustration of a healthy bone marrow cell -- the kind doctors harvest from donors to use in bone marrow transplantation.

The life expectancy, survival rate and quality of life after a bone marrow transplant have improved considerably with more accurate genetic matching with donors, following up transplantation with an antibiotic regimen to control infections, and improved post-transplant care, in general.

Cancer and other diseases of the blood and bone marrow, which is responsible for manufacturing blood cells, may require a bone marrow transplant from a healthy, genetically compatible donor. Ideally, the donor marrow replaces diseased cells to allow the body to maintain healthy levels of red blood cells, white blood cells, and platelets.

Understandably, transplants for patients with nonmalignant diseases have a much better success rate with 70% to 90 % survival with a matched sibling donor and 36% to 65% with unrelated donors.

The survival rates after transplant for patients with acute leukemia in remission are 55% to 68% with related donors and 26% to 50% if the donor is unrelated.

Transplanting the patient’s own bone marrow from an unaffected bone to a diseased one (autologous bone marrow transplant) along with chemotherapy has improved survival rates with certain cancers such as:

• Ewing sarcoma
• Wilms tumor
• germ cell tumor
• neuroblastoma

Autologous transplants have not enhanced the survival rates with other pediatric malignant cancers, with metastatic alveolar rhabdomyosarcoma, or with metastatic Ewing sarcoma.

Patients in remission or with stabilized disease generally have a much better result than those with the disease in later stages or relapse.

Transplants of younger patients have a higher chance of success.

Additionally, when both the donor and recipient are cytomegalovirus (CMV) negative, survival rates are higher.

Prevention of viral infections and management of graft-versus-host disease (or GVHD, in which immune cells in donor tissue attack the transplant patient’s own tissues), and reimmunization through vaccination are important for optimal survival.

Testing positive for small amounts of cancer cells after treatment (minimal residual disease or MRD) in children with acute lymphoblastic leukemia was a risk factor for relapse. The life expectancy increased markedly in those who tested negative for bone marrow MRD before their allogeneic transplant. The MRD-negative patients had a leukemia-free survival rate of 83% and overall survival rate of 92% – much higher when compared with patients with persistent MRD.

Patients with persistent MRD pre-transplant had survival rates of 41% leukemia-free and 64% overall. In patients with MRD measured after the transplant, the survival rate dropped to 35% leukemia-free and 55% overall.

Another study on adult survivors of bone marrow transplant revealed lower patient quality of life when any of the following conditions are present:

• severe, chronic GVHD
• lower performance
• permanent disability
• resulting mental distress

Currently, the success of bone marrow transplantation in treatment of many cancers – including some brain tumors – has fallen short of expectations. Researchers continue to improve transplant techniques, however, including improvements in matching donors and recipients, as well as better post-transplant care.