Reduced Intensity Transplants Show Promise for Hodgkin’s Lymphoma
A recent study performed in the United Kingdom reports that approximately 40 percent of patients with resistant Hodgkin’s Lymphoma can be successfully treated with a lower intensity stem cell transplant from a related or unrelated donor. These results were recently published in the June issue of The Lancet.
Hodgkin’s lymphoma (HL) is a malignancy in which cancerous cells arise from the cells of the lymphatic system. The lymphatic system is a drainage system within the body, and two of the primary functions of the lymph system are to maintain fluid balance and to produce infection-fighting lymphocyte cells. Lymphomas are divided into two categories: non-Hodgkin’s lymphoma and Hodgkin’s lymphoma. Hodgkin’s lymphoma is characterized by the presence of Reed-Sternberg cells, which can be identified under a microscope. Non-Hodgkin’s lymphoma (NHL) includes a large group of various types of cancers of the lymph and immune system. Current treatment options include surgery, chemotherapy and radiation. Other treatments such as high-dose chemotherapy and radiation with stem cell transplantation are being studied in clinical trials. In some cases, patients with HL may not have a complete response to treatment or their disease may recur soon after treatment-an incidence known as refractory or resistant HL.
Stem cells are immature blood cells taken from the bone marrow or blood that are frozen and stored until the patient has completed high doses of chemotherapy or radiation. Stem cells may be collected from the patient, which is known as an autologous transplant. An allogeneic transplant uses stem cells from a family member or a non-family member whose cells match the patient’s. When these treatments are completed, the stem cells are then given back to the patient through an infusion. These cells are then allowed to grow and mature to restore the patient’s blood cells. These new cells provide the patient with a reenergized immune system to fight HL within the patient.
This research focused on providing stem cell transplants after the patient received a reduced intensity dose of chemotherapy. Reducing the intensity allows the new cells to grow, reduces complications associated with transplantation, and allows older patients with other illness or chronic conditions the possibility of receiving stem cell transplant.
In this recent study, researchers evaluated 49 patients with refractory HL. Of these 49, 44 of the patients had recurrent disease after receiving an autologous stem cell transplant. The average age of this group was 32 years, with the oldest patient being 51. Each of the patients received an allogeneic stem cell transplant after receiving a reduced intensity regimen of chemotherapy. Thirty-one of the patients received transplants from related stem cell donors, and 18 patients received stem cells from unrelated donors. Deaths related to transplant were 7.2 percent among the patients who received donor related stem cells versus 34.1 percent for patients who received unrelated donor stem cells. The projected 4-year survival was 55.7 percent with a disease-free survival of 39 percent.
Researchers concluded that these results are better than expected and support the possible use of reduced intensity regimens with stem cell transplants among patients with a stem cell donor.
Reference: Peggs K, Hunter A, Chopra R, et al. Clinical evidence of a graft versus Hodgkin’s lymphoma effect after reduced intensity allogeneic transplantation. The Lancet 2005; 365: 1934-1941.