Stem cells are unique cells located in bone marrow or peripheral blood that can develop into red blood cells, white blood cells, and platelets. The goal of cancer treatments such as radiation therapy and chemotherapy is to destroy cancer cells. Unfortunately bone marrow and other healthy cells are damaged in the process.
In an autologous stem cell transplant, bone marrow stem cells are removed from the patient’s own body prior to cancer treatment in order to protect them. Stem cells can be collected in two ways. The primary method involves collection of stem cells from the peripheral blood. For this procedure, medication is given a few days prior to collection to encourage stem cells to leave the bone marrow and enter the blood. Blood is then withdrawn from one arm and circulated through an apheresis machine, or a “cell separator,” where the stem cells are removed. The remaining blood components are returned through the catheter in the other arm. If this method does not provide enough stem cells, they may be taken directly from bone marrow. To harvest stem cells from bone marrow, the physician will use a special syringe to retrieve the bone marrow from the hip bone. Once removed, the bone marrow is processed to remove the stem cells.
After being removed from the blood, stem cells are frozen. Following cancer treatment, the stem cells are thawed and then drawn into a syringe so they can be returned or “transplanted” back into the body through a central line. In the first two weeks following the procedure, the immune system will be compromised and transfusions of platelets and red blood cells will be necessary. During this time, the stem cells begin producing new blood cells and restoring bone marrow. Close monitoring is necessary to ensure the bone marrow and immune system are functioning effectively.