Chronic Myeloid Leukemia (CML)

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Chronic Myeloid Leukemia (CML): Fast Facts

• Chronic myeloid leukemia (CML)—also known as chronic granulocytic, chronic myelocytic or chronic myelogenous leukemia—is a rare type of blood cancer that typically grows worse slowly.
• Unlike other cancers, chronic myeloid leukemia originates from the presence of a genetic abnormality in blood cells called the Philadelphia chromosome and progresses through distinct phases.
• In a healthy person, bone marrow makes the blood stem cells that mature into infection-fighting white blood cells, oxygen-carrying red blood cells and blood-clotting platelets. When a person has CML, too many blood stem cells develop into a type of white blood cell called granulocytes, which are abnormal and never become healthy white blood cells.
• In the first stages of CML, known as the chronic phase, patients show few signs of illness. In the end, however, millions of abnormal, useless white blood cells accumulate, preventing production of normal blood cells and blood-clotting platelets. Patients suffer from infections, anemia, uncontrolled bleeding and other complications that lead to death.
• CML usually occurs during or after middle age and rarely develops in children. Bone-marrow or stem-cell transplantation is the only known cure for the disease.

Read more about leukemia treatment at the Seattle Cancer Care Alliance. »

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Chronic Myeloid Leukemia (CML): Some of Our Key Research

Hutchinson Center researchers published a study in 1998 showing that chronic myeloid leukemia (CML) patients who received a bone-marrow transplant from an unrelated donor with matching tissue could expect about the same five-year survival rate as patients with matched related donors. Since then, our researchers have led the way in improving the treatment of CML.

Pioneering bone-marrow transplantation
One of the Hutchinson Center's founders, Dr. E. Donnall Thomas, won the Nobel Prize in 1990 for his groundbreaking work in bone-marrow transplantation, one of the greatest success stories in cancer treatment.

Since then, Center investigators have trained physicians around the world in this procedure, and many new advances have occurred.

Read more about the Hutchinson Center's transplantation work. »

Making transplantation less toxic

• In the late 1990s, Dr. Rainer Storb and colleagues pioneered the development of a radically different approach to bone-marrow transplantation that offers hope for older or otherwise medically unfit blood-cancer patients whose bodies cannot withstand the rigors of a conventional transplant.
  
  Unlike traditional bone-marrow transplantation, this treatment—called the non-myeloablative stem-cell transplant or "mini" transplant—does not wipe out bone marrow and involves minimal doses of radiation. That means patients do not lose their hair or experience severe nausea or other side effects, and the procedure typically can be performed without a hospital stay. Learn more. »

Listen to a Webcast with Dr. Rainer Storb. »

• Since then, a significant 2007 study by Dr. Marco Mielcarek and colleagues found that lymphoma, leukemia and other blood-cancer patients who underwent these lower-intensity transplants experienced similar outcomes regardless of whether they received stem cells from a tissue-matched relative or an unrelated donor. The finding was significant because historically, researchers had observed a link between conventional bone-marrow transplants from unrelated donors and decreased overall survival rates for those patients. Learn more. »

Exploring the effectiveness of anticancer drugs
The Hutchinson Center has participated in clinical trials that led to the FDA approval of the "leukemia pill," Gleevec® (also known as STI-571). As doctors obtain greater experience using the drug, they have observed that some patients fail to respond to the drug, while others relapse.

Center investigators continue to study the long-term effectiveness of Gleevec to determine which CML patients are best treated with the drug and which other treatments may work effectively in conjunction with the drug. Other chemotherapy drugs under investigation by Center researchers, as part of the conditioning regimen before a stem-cell transplant, include Campath® (alemtuzumab) and fludarabine.

Investigating new sources of transplantation cells
About one-third of all blood-cancer patients whose best curative treatment option is bone-marrow transplantation are unable to find a tissue-matched donor. One alternative is receiving a transplant that uses umbilical cord blood, which is rich in blood stem cells and can be collected without risk from the umbilical cord after birth of a child.

A major advantage of this source of cells for bone-marrow transplantation is that it does not need to be as well tissue-matched, allowing those patients who can not find a conventional donor to undergo transplantation. The major disadvantage is the small number of cells available from the cord blood. Learn more. »

Listen to a Webcast with Dr. Colleen Delaney. »

Fortifying the body against leukemia
Dr. Stanley Riddell and colleagues have been investigating use of a treatment technique for leukemia called immunotherapy—that is, harnessing the body's own infection-fighting T-cells against the disease. T-cells, however, typically die quickly, resulting in an interruption in immune response that could cause cancer to return. Through advanced testing, Riddell and colleagues found that one type of T-cell—central memory cells—had the staying power they were seeking. The approach holds promise for treating several types of cancer, including chemotherapy-resistant ALL in children. Learn more. »

Charting CML's course in patients
One major obstacle to treating cancer successfully is the inability to precisely predict whether a patient would fare better with one type of therapy over another. A study by Dr. Jerry Radich and colleagues has formed the groundwork for a test to predict outcomes for patients with CML. This work could enable doctors to customize their patients' treatments precisely to their individual condition and to improve their chances of survival.

In their study, the researchers created a timeline of sorts that charts the sets of genes that are turned on or off as the disease advances from early to more aggressive phases. The scientists found reproducible genetic "signatures" that could form the basis for tests to predict prognosis and match patients with the best treatment for their illness. The study also identified genes that may be promising targets for new drugs that could benefit patients whose disease is advanced and incurable with existing therapies. Learn more. »

Measuring and detecting remission
An international research group including Dr. Jerry Radich and colleagues was the first to develop a molecular test that is sensitive enough to detect one blood-cancer cell among a million normal cells—an accomplishment that saves lives. Used to monitor the disease status of CML patients after treatment with a bone-marrow or stem-cell transplant, this test enables doctors to respond quickly at the first sign of relapse. Learn more. »

Determining quality of life after transplantation

• Many patients who undergo bone-marrow or stem-cell transplantation face a decline in mental skill and physical coordination after treatment, but a 2004 study by Dr. Karen Syrjala and colleagues has shown that these effects are largely temporary and that most patients can expect a return to normal function within a year of their transplant. A more recent analysis showed that most patients show even further improvement in brain function between one and five years after transplant. Learn more. »

• Another study led by Syrjala found that survivors of stem-cell transplantation for blood cancers can expect to be just about as healthy 10 years later as adults who have never had a transplant. The study found that transplant survivors and people who hadn’t had transplants reported similar rates of hospitalization and outpatient medical visits. They also had similar rates of diseases and conditions such as asthma, diabetes, high blood pressure, high cholesterol, osteoporosis and hypothyroidism, along with similar psychological health, marital satisfaction and employment. It is, however, very important for transplant survivors to get regular primary care and health monitoring in the years after transplant. Learn more. »

Listen to a Webcast with Dr. Karen Syrjala. »

Find out more about our leukemia investigators:
Fred Appelbaum » William Bensinger » Irwin Bernstein » Paul Carpenter » Joachim Deeg » Colleen Delaney » John Hansen » Kenneth Kopecky » Paul Martin »	Marco Mielcarek » John Pagel » Stephen Petersdorf » Oliver Press » Jerald Radich » Brenda Sandmaier » Andrei Shustov » Karen Syrjala » Edus "Hootie" Warren »

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Chronic Myeloid Leukemia (CML): More Resources

• Every advance in cancer treatment in recent years has come out of clinical trials that test innovative medical approaches on patients.Find out more about clinical trials on chronic myeloid leukemia. »

• The Hutchinson Center also conducts ongoing cancer-prevention studies that depend on participation of healthy volunteers. Learn more about getting involved in research studies. » 

• In need of medical attention for chronic myeloid leukemia? Visit the Seattle Cancer Care Alliance to get help. »

• The Hutchinson Center is on a mission to eliminate cancer and related diseases as causes of human suffering and death, and you can help. Make a gift today. »

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