Acute Lymphocytic Leukemia - Treatment After Relapse

Donor or Patient Cells. The sources of marrow or blood cells can be taken from the patient or a donor:

If the bone marrow or stem cells are taken from a donor, the transplant is referred to as allogeneic. Allogeneic transplants from genetically matched sibling donors offer the best results in ALL. With new techniques, donor bone marrow from unrelated but immunologically similar donors is proving to be as effective as those from matched siblings. This approach is still reserved for patients in second remission or beyond.
If the marrow or blood cells are taken from an identical twin, the transplant is called syngeneic.
If the marrow or blood cells used are the patient's own, the transplant is called autologous. Autologous transplants in patients with ALL are generally not beneficial, since there is some danger that the cells used may contain tumor cells and the cancer can regrow. Treatment advances that reduce this risk, however, may make autologous transplantation feasible in patients without family donors.

The Blood Stem Cell Collection Procedure

The donor is usually given a drug called granulocyte colony-stimulating factor, or G-CSF (filgrastim, lenograstim) to stimulate stem cell growth.
The donor (or patient in an autologous procedure) then undergoes apheresis. With this process the blood is withdrawn from one of the patient's veins, then passes through a machine that filters out the white cells and platelets, which contain the stem cells. The blood is returned through another vein. The entire procedure takes 3 to 4 hours but needs to be repeated several times.
The stem cells are then frozen.

The Transplant Procedure

The patient is given high-dose chemotherapy with or without radiation- a treatment known as conditioning. The point is to inactivate the immune system and to kill any residual malignant cells. Drugs used are typically cyclophosphamide, carmustine, and etoposide. Alternative conditioning includes radiation with drugs.
A few days after treatment, the patient is rescued using the stored stem cells, which are administered through a vein. This may take several hours. Patients may experience fever, chills, hives, shortness of breath, or a fall in blood pressure during the procedure.
The patient is kept in a protected environment to minimize infection and he or she usually needs blood cell replacement and nutritional support.

Success Rates

Two- to 5-year survival rates after transplantation plus chemotherapy range from 40 - 80%. Certain patients with the Philadelphia chromosome, which carries a poor prognosis, may achieve significant success with an allogeneic bone marrow transplant from a closely matched related donor.