Non-Hodgkin's Lymphoma - Transplantation

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The Blood Stem Cell Collection Procedure.

• The donor is usually given a drug called granulocyte colony-stimulating factor, or G-CSF (filgrastim, lenograstim, pegfilgrastim) to stimulate stem cell growth.
• The patient (or donor in an allogeneic 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 With this process the blood is withdrawn from one of the patient's veins, then passes through a machine that filters out the white cells and platelets, which contain the stem cells.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 - 4 hours but needs to be repeated several times.
• The stem cells are treated to remove contaminants and then are frozen to keep them alive until the patient is ready to receive them back.

The Transplantation Procedure

• Allogeneic transplants are preceded by chemotherapy treatment known as conditioning. The point of this treatment is to inactivate the immune system and to kill any residual malignant cells. It is extremely toxic since it also destroys non-malignant marrow cells. Drugs used are typically cyclophosphamide, carmustine, and etoposide. Alternative conditioning to reduce toxicity includes total-body radiation plus drugs. Monoclonal antibodies, such as rituximab, are promising drugs, since they have low toxicity and may add benefits for all stages of transplantation.
• A few days after treatment, the patient given the stored stem cells, which are administered through a vein. This may take several hours. Patients may have a fever, chills, hives, shortness of breath, or a fall in blood pressure during the procedure.
• The patient may be treated with granulocyte colony-stimulating factor after chemotherapy. The goal is to stimulate the growth of infection-fighting white blood cells. Adding thrombopoietin may help enhance stem cell production.
• The patient is kept in a protected environment to minimize infection. Patients who have received an allogeneic transplant may need blood cell replacement, nutritional support, and drugs to treat graft-versus host disease. They usually can leave the hospital within 3 - 5 weeks.

Candidates and Success Rates

Candidates. These procedures are typically used for patients with relapsed aggressive lymphoma who are still sensitive to the effects of chemotherapy. The procedures do not work for patients whose tumors are not responsive to drugs. Some evidence suggests that certain primary (non-relapsed) lymphomas initially unresponsive to a first round of chemotherapy but who respond to a second round may benefit from combination of high-dose chemotherapy and radiation followed by transplantation. Transplantation is also being investigated as first-line therapy for patients with aggressive lymphomas, although at this time evidence does not support its use.

Success Rates. Success rates vary depending on many factors. The following are survival rates reported by a few 2000 and 2001 studies of patients with different lymphomas: