Relapsed or Refractory Leukemia

This content has been reviewed and approved by

Hagop M. Kantarjian, MD
Chairman & Professor, Leukemia Department
MD Anderson Cancer Center
University of Texas

Patients failing treatment can be divided into two groups. Those whose cancer does not disappear after a complete course of remission induction chemotherapy treatment are called "induction failures." Those who achieve a complete remission, and then experience a cancer recurrence, are said to have "relapsed leukemia." Relapse of leukemia may occur months or years after remission, but most relapses happen within 2 years of initial treatment.

Patients who fail induction treatment or who relapse have two basic choices of therapy. Further treatment with chemotherapy rarely cures the disease. Some patients choose palliative treatment. This is therapy designed to control the disease as long as possible, while giving a good quality of life. Lower doses of drugs are used, which give fewer side effects.

The alternative approach is to receive more intensive treatment or participate in clinical studies in an attempt to produce a complete remission. For some patients, a stem cell transplant offers a possibility for control or cure of the leukemia. Other patients may choose to participate in clinical trials of new treatments.

A stem cell transplant is a procedure that is performed to repair the damage caused by high-dose chemotherapy (HDC). HDC kills more cancer cells than lower-dose conventional chemotherapy. Unfortunately, HDC also kills more normal cells, especially the blood-producing stem cells in the bone marrow. Stem cells are immature cells produced in the bone marrow. They develop into red blood cells, which provide oxygen to tissues; white blood cells, which fight infection; or platelets, which aid in blood clotting.

Stem cell transplant is intended to restore the blood-producing stem cells after HDC has reduced them to dangerously low levels. When stem cells reach critically low levels from HDC, complications such as anemia, infection, and bleeding can occur. Thus, it is essential to restore stem cell levels as quickly as possible. An autologous stem cell transplant involves the collection of a patient's own stem cells before  chemotherapy treatment. These stem cells are frozen and then infused back into the patients after treatment to "rescue" the bone marrow. An allogeneic stem cell transplant uses stem cells collected from a related or unrelated donor.

Treatment of Patients Failing Induction

The best treatment for patients failing induction treatment is an allogeneic stem cell transplant. Adults and children who fail remission induction should undergo an allogeneic stem cell transplant as soon as a donor can be found. Reinduction therapy with standard chemotherapy drugs has been effective in producing remissions in some patients, but there are no cures without an allogeneic stem cell transplant.

Currently, 15 percent to 30 percent of children and adults failing induction can be cured with an allogeneic stem cell transplant. Allogeneic stem cell transplantation offers the only prospect of long-term, disease-free survival. If a compatible family member donor is not available, there should be a search for an unrelated donor or an umbilical cord source of stem cells.

Treatment of Patients Relapsing After an Initial Remission

Patients who relapse after an initial complete remission may be cured with standard chemotherapy, autologous stem cell transplant, or allogeneic stem cell transplant. Patients who get a leukemia recurrence in the testicles alone can be cured two-thirds of the time with additional chemotherapy and radiation. Children with recurrent leukemia can be cured with either standard chemotherapy or an allogeneic stem cell transplant.

The timing of the relapse is important. If you relapse while receiving chemotherapy, or soon afterwards, it is unlikely that the leukemia will be cured with further chemotherapy. However, if the relapse occurs many months or years after chemotherapy ends, you may be cured with more chemotherapy.

Research is in progress to refine existing treatments and develop new ones. For information on some of the techniques currently under investigation, see Strategies to Improve Treatment.