How do stem cell transplants affect the risk of second cancers?

Stem cell transplants involve treatment with high doses of chemotherapy, sometimes with radiation, followed by an infusion of blood stem cells to restore the bone marrow. The stem cells can be from a donor (called an allogeneic transplant) or the patient’s own cells that were collected earlier (an autologous transplant). Because the donor cells could see the patient’s cells as foreign and attack them, patients who get allogeneic transplants need to be treated with drugs to suppress the immune system.

Any kind of stem cell transplant is linked to an increased risk of second cancers from the chemotherapy and radiation used.

Patients who get allogeneic transplants also have a risk of developing a post-transplant lymphoproliferative disorder (PTLD), an out-of-control growth of lymph cells. PTLD is often linked to a malfunction of one type of lymph cell, the T-cell, and the presence of Epstein-Barr virus (EBV) in another type of lymph cell called the B-cell. When the T-cells aren’t working well, EBV-infected B-cells can grow and multiply. This disorder can range from a benign increase in lymphocytes in lymph nodes and bone marrow to lymphoma. More information about PTLD can be found in Stem Cell Transplant for Cancer.

Graft-versus-host disease (GVHD) can happen in allogeneic transplants when the immune cells from the donor see the recipient’s body as foreign. The donor immune cells may attack certain organs, most often the skin, gastrointestinal (GI) tract, and liver. Patients with chronic GVHD have an increased risk of squamous cell cancers of the skin and head and neck.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: December 11, 2014 Last Revised: December 11, 2014

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