Chronic Myeloid Leukaemia (in Remission)

Chronic myeloid leukaemia can now be controlled so effectively that many patients can achieve deep remission and, in some cases, even stop their treatment while maintaining that remission with careful monitoring.

Table of contents

• Understanding Remission in Chronic Myeloid Leukaemia
• Treatment-Free Remission: A Realistic Goal
• Who Can Consider Stopping Treatment?
• The Process of Stopping Treatment
• Monitoring During and After Treatment Breaks
• What Happens If the Leukaemia Returns?
• Living with Chronic Myeloid Leukaemia in Remission

Understanding Remission in Chronic Myeloid Leukaemia

Chronic myeloid leukaemia (CML) is a type of blood cancer that affects the bone marrow and white blood cells. It is caused by a genetic change called the Philadelphia chromosome, which creates an abnormal gene called BCR-ABL. This gene produces a protein that causes certain blood cells to grow out of control^[1][2].

The outlook for people with CML has improved dramatically over the past few decades. In the 1970s, only 22% of people with CML survived five years after diagnosis. By 2017, that number had increased to 71%^[1]. This transformation came about thanks to drugs called tyrosine kinase inhibitors (TKIs), which block the abnormal protein that causes CML^[2].

When someone with CML responds well to treatment, tests may no longer detect any signs of the leukaemia in their blood or bone marrow. This state is called molecular remission^[6]. In molecular remission, the BCR-ABL gene cannot be found through standard testing methods. However, this does not necessarily mean every cancer cell has been eliminated from the body.

Treatment-Free Remission: A Realistic Goal

One of the most significant advances in CML care is the concept of treatment-free remission (TFR). This means the ability to maintain a molecular response after stopping therapy^[4]. Clinical trials beginning around 2007 started exploring whether it might be safe for some patients to stop taking their TKI medication^[5].

The results have been encouraging. Studies show that some patients with CML in the chronic phase who achieve sustained deep molecular responses can safely suspend therapy with no evidence of relapse^[4]. With longer follow-up periods and increasing numbers of eligible patients, treatment-free remission has become a validated concept and an important goal in CML management.

Not all patients who meet the criteria for stopping treatment choose to do so. However, many welcome the opportunity to live their lives without the daily burden of medication and its side effects^[5]. This option represents an important quality of life consideration for people living with CML.

Who Can Consider Stopping Treatment?

Stopping TKI treatment is not appropriate for everyone with CML. Your doctor might suggest you consider a treatment break if you meet certain criteria^[3][6]:

• You have been taking TKIs for at least three to five years
• You are in a low-risk category
• You have not experienced accelerated or blast phase leukaemia
• You have had a very good response to treatment that has lasted for at least two years (a deep molecular response)
• You do not have any extra chromosomal abnormalities
• Your hospital has a laboratory that can provide the necessary blood tests
• You understand what stopping treatment involves and are willing to have regular blood tests to monitor your CML

Patients considered for treatment-free remission typically include those who have taken one kind of medication during their treatment course and are in molecular remission for at least two years^[6]. Molecular remission means the gene that causes CML cannot be found in blood or bone marrow testing.

Your doctor will discuss these criteria with you and help determine whether attempting a treatment break is a suitable option in your individual case.

The Process of Stopping Treatment

If you and your doctor decide to try stopping treatment, there are different approaches. Your doctor might suggest gradually reducing your dose of TKI for around 12 months before stopping completely. Alternatively, you might stop taking the TKI straight away^[3].

Some people experience side effects when they stop taking TKIs. Doctors call this withdrawal syndrome^[3]. Side effects can include:

• Aching muscles and joints
• Feeling unwell

These symptoms are usually mild and pass quickly. Your doctor might suggest you take non-steroidal anti-inflammatory drugs to help manage them. Rarely, you might need to restart taking TKIs if symptoms are severe^[3].

Monitoring During and After Treatment Breaks

Regular monitoring is essential when you stop treatment. Your doctor will continue to look for signs of leukaemia in your blood through a test called PCR (polymerase chain reaction), which looks for the BCR-ABL1 gene^[3].

The frequency of testing is typically^[3][6]:

• Monthly for the first six months
• Every six weeks to two months for the next six months
• Every two to three months after that, progressing to every six months

This monitoring schedule may vary depending on your individual situation and your doctor’s recommendations. Even patients in treatment-free remission must be monitored regularly for life and work closely with a haematologist (a doctor who specializes in blood disorders) or oncologist^[6].

If your CML returns, it is most likely to come back in the first six months after you stop treatment. The rest of the people who need to restart treatment usually do so within the first two years. It is less common to need to restart after two years, although this can happen^[3].

What Happens If the Leukaemia Returns?

Your doctor will recommend you start treatment again if tests begin to detect the BCR-ABL1 gene. This indicates that your CML is coming back^[3].

If you need to restart TKI treatment, you usually restart the same drug you were taking before the treatment break. Alternatively, you might be given a different drug if you experienced side effects with the previous medication. Your doctor will perform blood tests every four weeks to look for signs of leukaemia until you go back into remission^[3].

The good news is that the vast majority of people have a very good response when they restart treatment. Studies over the past 10 to 15 years have shown that when medication is restarted early, the chance of achieving remission is almost 100%^[6]. This means that after taking the TKI treatment again, tests no longer show any signs of leukaemia.

If the disease is discovered early through regular monitoring and treatment is resumed promptly, restarting with no added risk is possible^[6]. This excellent response rate provides reassurance to both patients and doctors considering treatment-free remission.

Living with Chronic Myeloid Leukaemia in Remission

Life with CML in remission can be different from other types of cancer. Unlike some cancers that go away completely when treatment ends, CML is often managed as a chronic condition. Even with excellent treatment responses, CML will likely always be part of your life^[20].

Although some people can eventually stop treatment, for many there is not an end to treatment or testing. You cannot plan for a life completely free from cancer concerns. This can be difficult to adjust to, and many people face ongoing uncertainty and worry about how well treatment is working^[20].

With time and support, many people manage to adjust to life with CML. Important aspects of living well with CML in remission include:

Attending regular appointments: Even in remission, regular blood tests and hospital visits remain necessary. This ongoing monitoring is essential for detecting any signs of the leukaemia returning early.

Managing emotions: You might experience a range of emotions including anxiety, uncertainty, or relief. These feelings are normal. Many people find it helpful to talk to friends, family, or healthcare professionals about what they are experiencing^[20].

Seeking support: Help and support are available from various sources. Your healthcare team can provide guidance and address concerns. Support groups and organizations specializing in blood cancers can also offer valuable information and connection with others who understand your experience.

Looking after yourself: Maintaining a healthy lifestyle, staying active where possible, and managing side effects can all contribute to your wellbeing.

The ability to achieve and maintain remission, and in some cases stop treatment altogether while remaining disease-free, represents a remarkable achievement in CML care. With proper monitoring and support, many people with CML can live full, active lives.