Compared to treatment with conventional therapy alone, treatment of Hodgkin’s lymphoma with conventional therapy followed by high-dose therapy and autologous stem-cell transplantation does not further increase the risk of second cancers, according to a study published in the Journal of Clinical Oncology .
Hodgkin’s lymphoma is a cancer of the lymph system. It is diagnosed by identifying a characteristic cell under the microscope (the Reed-Sternberg cell). Hodgkin’s lymphoma typically begins in the lymph nodes in one region of the body and then spreads through the lymph system in a predictable manner. It may spread outside the lymph system to other organs such as the lungs, liver, bone, and bone marrow.
For patients with relapsed or refractory Hodgkin’s lymphoma (lymphoma that has returned after conventional treatment or that is resistant to conventional treatment), treatment with high-dose therapy and autologous stem cell transplantation may be a potential cure.
The objective of high-dose therapy is to kill the maximum number of cancer cells. However, high-dose therapy also produces more side effects, particularly to the blood-producing hematopoietic stem cells. Hematopoietic stem cells are immature blood cells produced in the bone marrow that mature into red blood cells (which carry oxygen to tissues), white blood cells (which fight infection), and platelets (which aid in blood clotting).
Procedures such as bone marrow transplantation or peripheral blood stem cell transplantation are used to restore stem cells that were destroyed by high-dose therapy. In an autologous hematopoietic stem cell transplantation (AHSCT), the patient’s own stem cells are collected before therapy and then reinfused afterwards.
Patients with Hodgkin’s lymphoma are known to have an increased risk of second cancers after conventional therapy, but it is uncertain whether patients who received both conventional therapy and high-dose therapy coupled with AHSCT have an even greater risk.
In order to compare risk of second cancers by type of treatment for Hodgkin’s lymphoma, researchers in British Columbia evaluated 1732 patients with Hodgkin’s lymphoma who were treated between 1976 and 2002. Of these 1732, 1530 were treated with conventional therapy alone and 202 were treated with conventional therapy followed by high-dose therapy and autologous stem-cell transplantation. The 202 patients treated with AHSCT all had evidence of relapsed or refractory Hodgkin’s lymphoma. Identification of second cancers occurred during a median of 10 years of follow-up:
- Overall, 9% of patients developed a second cancer during follow-up.
- The most common second cancers were lung (31 cases), breast (18 cases), gastrointestinal (16 cases), and treatment-related acute myeloid leukemia or myelodysplastic syndrome (18 cases).
- Patients who were treated with conventional therapy followed by high-dose therapy and AHSCT had a risk of second cancers (8%) that was similar to the risk among patients treated with conventional therapy alone (10%).
The researchers conclude that although patients with Hodgkin’s lymphoma have an increased risk of developing a second cancer, this risk is not increased further by treatment with high-dose therapy and autologous stem cell transplantation.
Reference: High-Dose Therapy and Autologous Hematopoietic Stem-Cell Transplantation Does Not Increase the Risk of Second Neoplasms for Patients with Hodgkin’s Lymphoma: A Comparison of Conventional Therapy Alone Versus Conventional Therapy Followed by Autologous Hematopoietic Stem-Cell Transplantation. Journal of Clinical Oncology. 2005;23:7994-8002.