If you have chronic myeloid leukemia, there are several treatment options available. These include targeted therapies, chemotherapy, and bone marrow transplant.

About chronic myeloid leukemia

Chronic myeloid leukemia is sometimes known as chronic myelogenous leukemia, or simply CML. This is a specific kind of cancer that begins in the blood-forming cells in the bone marrow. It is thought to be caused by a gene that makes too much of an enzyme called tyrosine kinase. Symptoms develop slowly, so many people do not know they have CML for a long time. It’s often diagnosed during blood tests done for other reasons.

Phases of CML

CML has three phases. These phases are based on how many cancer cells are present:

  • The chronic phase is the first phase of CML, when there are fewer cancer cells and they are growing slowly.
  • CML progresses to the accelerated phase if treatment is not sought or is unsuccessful. During this phase, there are more cancer cells and they are growing more quickly.
  • In the blastic phase, the cancer cells are growing rapidly. This leaves little room for healthy cells, which is why it is considered the most dangerous phase.

Treatment options

Treatment depends on the phase of cancer, and other factors like age and overall health. The standard course of treatment begins with targeted therapy, which involves oral medications called tyrosine kinase inhibitors or TKIs. These drugs specifically target tyrosine kinase and block its action. This slows or stops the growth of cancer cells.

Common TKIs for CML include:

These drugs are highly effective, and many people go into remission for years on this type of therapy. Side effects are usually mild and are far outweighed by their benefits. Side effects may include:

  • fatigue
  • nausea
  • diarrhea
  • fluid buildup
  • lowered white blood cell and/or platelet count

In some cases, chemotherapy may be prescribed along with a TKI. This may help lower the white blood cell count, killing off many of the diseased cells. As the TKI stops the cancer cells from coming back, room is left for healthy cells to grow.

If one type of TKI fails to work, or stops being effective, then another can be prescribed. If none of the TKIs are effective, then the cancer progresses to one of the two later phases: accelerated or blastic. A bone marrow transplant is likely necessary if this occurs. If possible, during the blastic phase, TKIs and/or chemotherapy will be used to bring the cancer back to the chronic phase before the transplant.

In a transplant, the bone marrow that contains leukemia is replaced by hematopoietic stem cells. These develop into health bone marrow. The person’s immune system cells are also replaced by the donor’s, which prevents new cancer cells from growing. This is the only treatment that can result in a cure for CML. About 70 percent of patients who receive a transplant are cured. Success rates are higher when the donor is a sibling or other close relative. Because more parents are choosing to store umbilical cord blood, some people may be able to receive transplants of their own stem cells. This is even better than using a donor who is a relative because the cells are an exact match.

Although transplants can result in a complete cure, they aren’t the first course of treatment. Transplants are demanding for the body, have risks, and can result in serious complications.

Prognosis

Overall prognosis for those with CML is good, and it’s only getting better as new and improved treatments are being developed. Large-scale research studies are finding new and effective TKIs, while websites are helping connect potential donors with those who need bone marrow transplants.