Chronic Myeloid Leukemia Treatment and Survival Rate

April 19, 2024 
This page was reviewed under our medical and editorial policy by Guido Marcucci, M.D., Chair, Department of Hematologic Malignancies Translational Science, City of Hope Duarte

People who have been diagnosed with chronic myeloid leukemia (CML) have several advanced treatment options to help treat the disease. The care team will work with patients and their loved ones to customize a CML treatment plan based on:

• The cancer’s phase — chronic, accelerated or blast
• Any existing health conditions
• The patient’s age
• Potential side effects
• Donor availability for stem cell transplant
• Personal preferences of the patient

CML Treatment Options

The goals for each phase of CML may differ based on such factors as how far the cancer has spread and how well it responds to treatment.

Targeted Drug Therapy

The mutated gene responsible for CML makes an enzyme (protein) that causes white blood cells to grow out of control. This protein is categorized as a tyrosine kinase, and the drugs targeted to block it are called tyrosine kinase inhibitors (TKIs). These drugs are taken by mouth at home, and they are the first and main CML treatment given during the chronic phase due to their success rate. The drugs have been shown to trigger a complete cytogenetic response within the first year in about 70% or more of patients.

These targeted therapy drugs are also standard treatments for patients in accelerated and blast phase CML, although they may not be as successful in these phases.

Interferon Immunotherapy

Interferon alpha is a drug that mimics the defense response of the patient’s immune system to help reduce leukemia cell growth and division.

Before the more effective TKIs were introduced, it was a first line of defense against CML. If TKIs are unable to be taken due to side effects or other health reasons, or if they are not working, interferon treatment may be used in all three phases of CML.

Chemotherapy

This is a drug treatment that is harmful to leukemia cells and quickly destroys them. Chemotherapy may be taken as a pill or by infusion or injection into a vein. It is more commonly used in the accelerated and blast phases and may help trigger a response when combined with TKIs. Chemotherapy may also be used to help control leukemia cells before procedures such as a stem cell transplant.

Radiation Therapy

Like chemotherapy, radiation therapy is used to destroy leukemia cells. The therapy sends beams of high-energy particles onto the affected areas. It’s most often used in the blast phase of cancer to reduce the size of the spleen. It may also be deployed in any phase of CML before stem cell transplants to help improve outcomes.

Allogeneic Stem Cell Transplant

In an allogeneic transplant, healthy stem cells are transplanted into the patient from a donor. The procedure may have serious side effects, and it’s typically only performed on people in accelerated or blast phase CML who are unable to tolerate TKIs or resistant to two or more TKI drugs. A stem cell transplant may also be recommended for people in the chronic phase of CML who don’t respond to other therapies, especially younger patients who have a matching donor.

Surgery

While surgery isn’t used to treat CML itself, it may be needed to remove an enlarged spleen, which is one symptom of CML. This procedure is known as a splenectomy.

Supportive Care

The care team consults with the patient to ensure that treatments focus on pain management and overall comfort, also known as palliative care, especially during the blast phase. Chemotherapy medications such as hydroxyurea may be given for pain, along with radiation therapy for painful bone damage or to treat an enlarged spleen.

Monitoring Treatment Success

When monitoring whether CML treatment is working, experts consider three to six months a response time tied to improved outcomes.

Treatment focuses on returning white blood cell and platelet counts to normal levels. Because CML is caused by a mutated gene (BCR-ABL1) that forms a chromosome called the Philadelphia chromosome, treatment success also includes reducing levels of cells with this chromosome and the mutated genes in the blood and bone marrow.

The levels listed below may also help the care team determine how well treatments are working.

Complete hematologic response: White blood cell and platelet counts return to normal levels and the spleen returns to normal size if it was enlarged. The blood is also free of immature cells.

Major cytogenetic response: The Philadelphia chromosome is found in 35% or less of bone marrow cells. If less than 1%t of these cells contain this chromosome, it’s considered a complete cytogenetic response. If between 1% and 35% of these cells contain this chromosome, it’s considered a partial cytogenetic response.

Other cytogenetic responses: In a minor cytogenetic response, between 36% and 65% of the bone marrow cells contain the Philadelphia chromosome.

In a minimal cytogenetic response, 66% to 95% of these cells contain this chromosome.

Major molecular response: Patients have significantly reduced levels of the BCR-ABL 1 gene in the blood or bone marrow. Tests show the gene level is 1/1000th (1,000 times fewer) or less of levels found in patients with untreated CML at the time of diagnosis.

Complete molecular response: Tests show that the BCR-ABL1 gene is completely absent from the bone or blood marrow.

The wide array of treatments provides a multifaceted approach to CML treatment aimed at helping promote successful responses with a variety of cancer drugs, medicines and therapies.

Some people have significantly higher-than-normal white blood cell counts when they’re first diagnosed with CML, which may impair blood flow to vital tissues and organs. A chemotherapy drug called Hydrea^® (hydroxyurea) may be given in capsule form to help lower white blood cell numbers.

Leukapheresis is another treatment used, which removes white cells from the blood using a machine.

Chronic Myeloid Leukemia Survival Rate

The overall five-year relative survival rate for chronic myeloid leukemia is 70.6%, according to the National Cancer Institute. This varies considerably between younger people and older people. The five-year relative survival rate for 2013-2019, the most recent timeframe for which the Institute shows data, reflects the following information:

• 90.6% for patients under age 50
• 81.2% for patients ages 50 to 64
• 50.3% for patients ages 65 and older

The CML survival rate also differed between men and women, although only slightly. The five-year relative survival rates were 72.4% for females and 69.4% for males, according to the Institute.

Overall, the CML survival rate more than tripled between the 1970s and the period between 2012 and 2018, due in large part to advances in treatments, such as targeted drug therapies.

At City of Hope^®, patients find an innovative portfolio of cancer-fighting drugs and one of the world’s largest bone marrow and stem cell transplant centers, plus on-site pharmacists, hematologists (blood disorder experts), pathologists, oncologists and a care team that focuses on creating a personalized treatment plan for every patient.