Chronic myeloid leukemia (CML), also known as chronic myelogenous leukemia, often comes with a good prognosis. Both survival rates and life expectancy have improved considerably for people living with CML. Effective treatments for CML can help many people with the condition have positive outcomes and live for years.

To predict your outlook, your doctor will consider prognostic factors — characteristics of your particular condition — that can affect how CML progresses. The treatments that you receive also play a role in your outcome.

Survival Rates

The five-year survival rate for people with CML in the United States is 70 percent. This means that 70 out of 100 people will live for at least five years after being diagnosed with CML. This number is estimated using large groups of people. Although this doesn’t tell you what exactly your own outlook will be, it indicates that on average, people with CML have a good chance of living five years or more. Your healthcare team can help you better understand your potential outcome.

The five-year survival rate for CML has drastically improved in the past several decades. In the 1970s, only about 22 percent of people were alive five years after diagnosis. This means that the survival rate is now more than three times higher than it used to be.

New Treatment Options Have Improved Life Expectancy

One of the main reasons for improved survival among people with CML is that cancer research and clinical trials have led to new drugs that often result in very good outcomes.

In the United States, 70 percent of those diagnosed with CML will still be alive five years after being diagnosed.

The first of these drugs, imatinib (Gleevec), was approved by the U.S. Food and Drug Administration (FDA) in 2001 for people with CML. Imatinib is a type of targeted therapy known as a tyrosine kinase inhibitor (TKI). Since then, other TKIs, such as Asciminib (Scemblix), bosutinib (Bosulif), dasatinib (Sprycel), and nilotinib (Tasigna), have become available and are also very effective at treating CML. There is also a newer formulation of nilotinib called Danziten, which can be taken safely with food. Others must be taken on an empty stomach.

Previously, oncology researchers estimated that only 20 percent of people with CML lived 10 years after being diagnosed. However, new treatments have greatly improved the life expectancy of people living with CML. Researchers now estimate that people with CML can have lifespans that are almost as long as people without the blood cancer. However, it’s important to know that most people will require ongoing TKI therapy to avoid a relapse (return) of active CML. Like all medications, even those sold over the counter, TKIs can cause unwanted side effects.

Factors That May Influence Your Outlook

Certain risk factors — also known as prognostic factors — can influence your outcome. These are details about you and your condition that your doctor may use to estimate your prognosis and determine which treatment options are appropriate for you. Some prognostic factors may be measured with different tests during the diagnosis of CML.

Most people with CML will need to keep taking a tyrosine kinase inhibitor long term to avoid having a relapse of active disease.

CML Phase

When predicting your outlook, your doctor will consider your phase of CML. Your phase is determined by how many cells in your blood and bone marrow (tissue found inside your bones) are blast cells. Blasts are immature white blood cells that crowd out healthy blood cells. There are three CML phases:

• Chronic phase CML — Less than 10 percent of your blood cells are blasts
• Accelerated phase CML — Between 10 percent and 19 percent of your blood cells are blasts
• Blastic phase CML — At least 20 percent of your blood cells are blasts

People with accelerated or blast phase CML have a worse prognosis than people with chronic phase CML.

Age

CML is a type of cancer that often occurs in older adults. The average age at diagnosis is 66 years old. Older people have slightly lower survival rates, according to data from England.

• More than 90 percent of people younger than 60 live for five years after being diagnosed.
• About 80 percent of people aged 60 or older live for five years after being diagnosed.

Biological Sex

Men are more likely than women to develop CML, according to data from the U.S. National Cancer Institute. Additionally, men have a somewhat worse outlook on average. Compared to the general population:

• Approximately 66 percent of men with CML live at least five years after diagnosis.
• About 68 percent of women with CML live five years or more after diagnosis.

Overall Health

If you are in good health, you may be able to tolerate more aggressive treatments, such as chemotherapy combined with TKI therapy, which can kill more leukemia cells. On the other hand, if you have other health problems, you may not be able to tolerate the side effects of stronger treatments. People who are in poorer health often need to use milder treatments.

Doctors evaluate overall health using a measure called performance status. Your performance status is an estimate of how well you can complete daily activities. If you have a hard time performing everyday tasks, you may have a worse CML prognosis.

Numbers of Blood Cells

Doctors use blood tests to determine your levels of different types of blood cells. High or low levels of certain cells can increase your chance of having a worse prognosis. One type of cell that your doctor will look closely at is cancerous blast cells. Having high levels of blasts in the blood is a sign of a worse outcome.

Levels of healthy blood cells also play a role in determining your prognosis. If you have anemia (low red blood cell counts) when you are diagnosed with CML, you have an increased chance of having higher-risk CML. However, with targeted TKI treatment, moderate anemia may not affect your survival rate.

Levels of platelets (cell fragments that make blood clots) also play a role in prognosis. Very low or very high platelet counts may lead to a poor outlook.

Finally, if you have high basophil cell counts, you may have a worse prognosis. Basophils are a type of white blood cell that fights infection. Researchers aren’t yet sure how basophils impact CML, but high levels of basophils are linked to an increase in blast cells.

Levels of LDH Molecules in the Blood

When diagnosing CML, your doctor may perform blood tests to measure your levels of lactate dehydrogenase (LDH). Various tissues in your body make LDH when they become damaged by blood cancers such as lymphoma or leukemia. High LDH levels may increase the risk of CML relapse and resistance to some TKI therapies.

Spleen Size

Splenomegaly (an enlarged spleen) is the most common symptom of CML. More than half of people with CML have splenomegaly. Having an enlarged spleen increases your chances of having a poor outcome.

Gene Changes

CML, like other cancers, develops when cells undergo certain genetic changes. Your doctor can look for these gene changes using a variety of genetic tests. These tests may be performed when you are diagnosed with CML. A test known as bone marrow aspiration, in which a fluid sample is taken from bone marrow, is a test that allows doctors to do a cytogenetic analysis. This can show genetic changes that may indicate a poor prognosis with CML.

BCR-ABL and the Philadelphia Chromosome

Some 95 percent of people with CML have a specific gene change called the Philadelphia chromosome. This gene change happens when part of one chromosome (long piece of DNA) breaks off and attaches to a different chromosome. The Philadelphia chromosome contains an abnormal gene called BCR-ABL.

Your age, overall health, and details about genetic mutations in your leukemia cells are a few factors that can influence your outlook with CML.

People with CML who don’t have the Philadelphia chromosome have a worse outlook. The most effective treatment for most cases of CML is a TKI such as imatinib. TKIs block BCR-ABL and kill leukemia cells. When CML cells don’t have BCR-ABL, TKIs may not be as effective.

Researchers have found that people with CML who don’t have the Philadelphia chromosome have their own set of prognostic factors. Factors that lead to a worse outcome in people without this gene change include:

• Older age
• Anemia
• High levels of white blood cells

BCR-ABL Mutations

Sometimes, the abnormal BCR-ABL gene can undergo additional changes. These changes cause TKI medications to be less effective. One mutation is called T315I — also known as the gatekeeper mutation — and causes resistance to some TKIs, including imatinib.

Other Gene Changes

Some people with CML develop changes in other genes besides BCR-ABL or have other chromosome changes along with the Philadelphia chromosome.

One study found that certain chromosome abnormalities lead to worse outcomes for people with blast phase CML. These include:

• Trisomy 8 (having three copies of chromosome 8 instead of the usual two)
• Trisomy 17
• Trisomy 19
• Changes in chromosome 3
• Changes in chromosome 15

Outcomes With Different CML Treatments

Doctors recommend a few different therapies for the treatment of chronic myeloid leukemia.

Most people with CML have a positive prognosis when they take imatinib. For 70 percent of people with CML, imatinib therapy results in a complete cytogenetic response, which means the BCR-ABL gene is no longer detected. Imatinib also usually reduces other CML symptoms. The 10-year survival rate for people taking imatinib is approximately 83 percent, according to research in the New England Journal of Medicine.

Bone marrow transplants can sometimes cure CML, eliminating all leukemia cells for good. A person’s outcome after a bone marrow transplant depends on their CML phase:

• Eighty percent of people with chronic phase CML do not have leukemia five years after transplant.
• Forty percent to 50 percent of people with accelerated phase CML do not have leukemia five years after transplant.
• Ten percent to 20 percent of people with blast phase CML do not have leukemia five years after transplant.

Talk to your doctor to learn more about what to expect from different treatment options, including potential risks and side effects, which may impact your quality of life. Always follow up with your doctor if you experience side effects from a medication.

Read more about CML treatment options.

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