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PubMed This is a summary of 30 peer-reviewed journal articles Updated
Hematology · Chronic Myeloid Leukemia

How Common Is Ph+ CML and What Age Is It Diagnosed?

At a Glance

Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML) is uncommon, affecting about 1 to 2 adults per 100,000 each year. It is usually diagnosed in later adulthood, but it can occur at any age and often responds well to modern targeted treatment.

In this answer

4 sections

01

How Common is Ph+ CML?

02

Typical Age at Diagnosis

03

How CML Compares to Acute Leukemias

04

Factors That Shape Your Care

Being diagnosed with leukemia can be overwhelming, but modern targeted therapies have transformed Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML) into a manageable condition for many. Ph+ CML is a relatively uncommon cancer. About 1 to 2 adults per 100,000 are diagnosed with the condition each year [1][2][3]. While it can occur at almost any age, it is most often diagnosed in later adulthood. The median age at diagnosis varies by region; for instance, European registries report a median age around 56 to 57 years [1][4], while U.S. data often skew older, into the mid-60s. “Median” means half of the people diagnosed are older than this age, and half are younger.

How Common is Ph+ CML?

CML accounts for approximately 15% of all newly diagnosed leukemias in adults [5][3][6]. The disease is driven by the BCR::ABL1 fusion gene, which is created by a genetic swap between two chromosomes. About 90% to 95% of cases have a visibly detectable version of this swap called the Philadelphia chromosome, and nearly all CML is BCR::ABL1-positive [7][8][9].

Because highly effective treatments allow many people with CML to live long lives, the number of people living with the disease (prevalence) is much higher than the number of new cases each year. A contemporary review estimated that roughly 150,000 people are currently living with CML in the United States [2].

Typical Age at Diagnosis

The likelihood of developing CML increases as people get older. For example, incidence is about 0.39 cases per 100,000 people per year in their 20s, but rises to over 1.5 cases per 100,000 per year in people over the age of 70 [1].

While the median age at diagnosis is in later adulthood, young adults can and do get CML [1][4]. However, it is exceedingly rare in children, occurring in only about 1 per million children per year [10]. It is important to know that age alone does not determine a person’s prognosis. With modern therapies, older adults can achieve excellent responses to treatment [11][12].

How CML Compares to Acute Leukemias

Leukemias are generally categorized by how quickly they progress (chronic vs. acute) and the type of blood cell involved (myeloid vs. lymphoid).

  • The Tempo: CML is usually diagnosed in the chronic phase. This means it generally has a slower course, though it can and will progress without treatment [13][14]. In contrast, acute leukemias—like Acute Myeloid Leukemia (AML) and Acute Lymphoblastic Leukemia (ALL)—can worsen rapidly and require prompt, intensive treatment [15][16][17].
  • The Frequency: AML is generally more common than CML in older adults, with a median diagnosis age of 68 [18]. ALL, on the other hand, is most commonly diagnosed in childhood [19][20].

Without effective treatment, CML can eventually speed up and progress into a “blast phase,” which acts very much like an acute leukemia [13][14]. Fortunately, current treatments prevent this progression in the vast majority of patients.

Factors That Shape Your Care

Because CML is a long-term condition, several personal factors will influence your care plan:

  • Age, Health, and Medication: The primary treatment for Ph+ CML is a class of oral drugs called Tyrosine Kinase Inhibitors (TKIs), which specifically target the cancer-causing protein. There are several TKIs available, and they carry different risks. For example, dasatinib is associated with fluid around the lungs (pleural effusion), while nilotinib is associated with cardiovascular risks [2][21]. Your doctor will carefully consider your age and other medical conditions to select the safest drug [22][23][24]. You should report any new shortness of breath, chest pain, or rapid swelling immediately. Also, check with your doctor before starting any new medications or supplements to avoid dangerous drug interactions.
  • Disease Phase and Prognosis: Most patients are diagnosed in the chronic phase and treated with TKIs. Many people diagnosed in chronic phase who respond well to treatment can have a life expectancy approaching that of the general population [13][25]. However, treatment must not be stopped without specialist supervision. If the disease advances to the accelerated or blast phase, treatment is individualized; it often includes acute-leukemia-type therapy combined with a TKI, and an allogeneic stem cell transplant may be considered for eligible patients [26][27][28].
  • Treatment Response: Your doctor will regularly monitor your blood using a Polymerase Chain Reaction (PCR) test. This test measures BCR::ABL1 transcript levels as a standardized estimate of your leukemia burden [29][30]. Standard milestones often look for the BCR::ABL1 level to drop to 10% or less at 3 months, 1% or less at 6 months, and 0.1% or less at 12 months [25][30]. However, a single high result does not automatically mean treatment failure; your doctor will look at trends over time. If milestones are truly missed or side effects are unmanageable, your doctor may adjust your dose or switch you to a different TKI [24][5].

Common questions in this guide

How common is Philadelphia chromosome-positive CML?
CML accounts for about 15% of new adult leukemia diagnoses, and roughly 1 to 2 adults per 100,000 are diagnosed with CML each year. About 90% to 95% of CML cases have a detectable Philadelphia chromosome, and nearly all are BCR::ABL1-positive.
What is the usual age when CML is diagnosed?
CML is most often diagnosed in later adulthood. The median age is about 56 to 57 years in European registries and is generally in the mid-60s in U.S. data, although young adults can also develop CML.
Can children or young adults develop Ph+ CML?
Yes, CML can occur at any age. It is very rare in children, occurring in about 1 case per million children each year, but it can occur in young adults.
Does being older make CML treatment less effective?
Age alone does not determine prognosis. Older adults can have excellent responses to modern treatments, although other health conditions and medication risks help doctors choose the safest tyrosine kinase inhibitor.
What treatment is usually used for chronic-phase Ph+ CML?
Most people diagnosed in chronic phase receive an oral tyrosine kinase inhibitor that targets the BCR::ABL1 protein. Doctors choose among these medicines based on disease phase, treatment response, age, other health conditions, side-effect risks, and possible drug interactions.
How do doctors monitor whether CML treatment is working?
Doctors use regular blood PCR tests to measure BCR::ABL1 levels. Common response milestones are 10% or less at 3 months, 1% or less at 6 months, and 0.1% or less at 12 months, but doctors also consider trends and individual circumstances.

Related questions

What Happens If CML Misses 3-, 6-, or 12-Month Milestones? What Lifestyle Advice Applies During CML TKI Treatment? What Does an Undetectable BCR::ABL1 PCR Result Mean? What Are the WHO, ICC, and ELN CML Phase Definitions? What Drug and Food Interactions Affect CML TKI Treatment?
Show more
How Often Are CML PCR and CBC Tests Done After a TKI? How Do BCR::ABL1 Transcripts Affect CML Monitoring? How Does CML Progress from Chronic to Blast Phase? How Is Ph-Positive CML Different From Other Blood Cancers? What Does the ELTS Risk Score Mean in Ph+ CML Patients? What Is Life Expectancy for Adults With Ph+ CML Today? What Tests Confirm Philadelphia-Positive CML and Its Phase? How Do Health Conditions Affect First-Line CML TKI Choice? Why Do My CML PCR Results Change When I Feel Fine? Can Ph-Positive CML Cause Leukostasis Without Symptoms? How Is a Rising BCR::ABL1 in CML Checked for TKI Resistance? How Do Doctors Distinguish Ph+ CML From Ph+ ALL and MPNs? What Does 10% to 19% Blasts Mean for Ph+ CML Patients? What Should I Do About a Rising BCR::ABL1 PCR in CML?

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References

References (30)
  1. 1

    The EUTOS population-based registry: incidence and clinical characteristics of 2904 CML patients in 20 European Countries.

    Hoffmann VS, Baccarani M, Hasford J, et al.

    Leukemia 2015; (29(6)):1336-43 doi:10.1038/leu.2015.73.

    PMID: 25783795
  2. 2

    Chronic Myeloid Leukemia: A Review.

    Jabbour E, Kantarjian H

    JAMA 2025; (333(18)):1618-1629 doi:10.1001/jama.2025.0220.

    PMID: 40094679
  3. 3

    Chronic myeloid leukemia: 2016 update on diagnosis, therapy, and monitoring.

    Jabbour E, Kantarjian H

    American journal of hematology 2016; (91(2)):252-65 doi:10.1002/ajh.24275.

    PMID: 26799612
  4. 4

    Real-life data of patients with chronic myeloid leukemia in Amazonas.

    Abreu RS, Maior KS, Souza IML, et al.

    BMC cancer 2026; (26(1)).

    PMID: 41877029
  5. 5

    Chronic myeloid leukemia: 2025 update on diagnosis, therapy, and monitoring.

    Jabbour E, Kantarjian H

    American journal of hematology 2024; (99(11)):2191-2212 doi:10.1002/ajh.27443.

    PMID: 39093014
  6. 6

    Chronic myeloid leukemia: 2022 update on diagnosis, therapy, and monitoring.

    Jabbour E, Kantarjian H

    American journal of hematology 2022; (97(9)):1236-1256 doi:10.1002/ajh.26642.

    PMID: 35751859
  7. 7

    Chronic myeloid leukemia with variation of translocation at (Ph) [ins (22;9) (q11;q21q34)]: a case report.

    Wang Z, Zen W, Meng F, et al.

    International journal of clinical and experimental pathology 2015; (8(10)):13707-10.

    PMID: 26722598
  8. 8

    Philadelphia-positive case negative for JAK2 V617F mutation with hyperdiploidic karyotype: A case report.

    Nikolova D, Damyanova V, Hrischev V, et al.

    Molecular and clinical oncology 2019; (11(6)):607-611 doi:10.3892/mco.2019.1933.

    PMID: 31693726
  9. 9

    Additional chromosomal abnormalities in Philadelphia positive chronic myeloid leukemia.

    Tashfeen S, Mahmood R, Khan SA, Khadim T

    Pakistan journal of medical sciences 2020; (36(2)):208-212 doi:10.12669/pjms.36.2.1384.

    PMID: 32063961
  10. 10

    Definition, Epidemiology, Pathophysiology, and Essential Criteria for Diagnosis of Pediatric Chronic Myeloid Leukemia.

    Suttorp M, Millot F, Sembill S, et al.

    Cancers 2021; (13(4)) doi:10.3390/cancers13040798.

    PMID: 33672937
  11. 11

    Clinical outcomes of second-generation tyrosine kinase inhibitors versus imatinib in older patients with CML.

    Ono T, Takahashi N, Kizaki M, et al.

    Cancer science 2023; (114(3)):995-1006 doi:10.1111/cas.15642.

    PMID: 36336963
  12. 12

    Chronic myeloid leukemia without major molecular response after 2 years of treatment with tyrosine kinase inhibitor.

    Bidikian A, Jabbour E, Issa GC, et al.

    American journal of hematology 2023; (98(4)):639-644 doi:10.1002/ajh.26836.

    PMID: 36606715
  13. 13

    Chronic Myeloid Leukemia, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology.

    Deininger MW, Shah NP, Altman JK, et al.

    Journal of the National Comprehensive Cancer Network : JNCCN 2020; (18(10)):1385-1415.

    PMID: 33022644
  14. 14

    Chronic Myeloid Leukemia: Modern therapies, current challenges and future directions.

    Osman AEG, Deininger MW

    Blood reviews 2021; (49()):100825 doi:10.1016/j.blre.2021.100825.

    PMID: 33773846
  15. 15

    The Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of acute leukemia.

    Boyiadzis MM, Aksentijevich I, Arber DA, et al.

    Journal for immunotherapy of cancer 2020; (8(2)) doi:10.1136/jitc-2020-000810.

    PMID: 33077513
  16. 16

    Diagnosis of acute myeloid leukemia in a dental hospital; report of a case with severe gingival hypertrophy.

    Misirlioglu M, Adisen MZ, Yilmaz S

    Nigerian journal of clinical practice 2015; (18(4)):573-6 doi:10.4103/1119-3077.151803.

    PMID: 25966736
  17. 17

    Treatment outcomes of pediatrics acute myeloid leukemia (AML) and associated factors in the country's tertiary referral hospital, Ethiopia.

    Mamo W, Moges A, Yesuf SA, et al.

    BMC cancer 2024; (24(1)):640 doi:10.1186/s12885-024-12404-5.

    PMID: 38789952
  18. 18

    Epidemiology of acute myeloid leukemia: Recent progress and enduring challenges.

    Shallis RM, Wang R, Davidoff A, et al.

    Blood reviews 2019; (36()):70-87 doi:10.1016/j.blre.2019.04.005.

    PMID: 31101526
  19. 19

    The Global Burden of Leukemia and Its Attributable Factors in 204 Countries and Territories: Findings from the Global Burden of Disease 2019 Study and Projections to 2030.

    Du M, Chen W, Liu K, et al.

    Journal of oncology 2022; (2022()):1612702 doi:10.1155/2022/1612702.

    PMID: 35509847
  20. 20

    Global, regional, and national burden of leukemia: Epidemiological trends analysis from 1990 to 2021.

    Hu C, Chen W, Zhang P, et al.

    PloS one 2025; (20(6)):e0325937 doi:10.1371/journal.pone.0325937.

    PMID: 40569983
  21. 21

    Flumatinib versus Imatinib for Newly Diagnosed Chronic Phase Chronic Myeloid Leukemia: A Phase III, Randomized, Open-label, Multi-center FESTnd Study.

    Zhang L, Meng L, Liu B, et al.

    Clinical cancer research : an official journal of the American Association for Cancer Research 2021; (27(1)):70-77 doi:10.1158/1078-0432.CCR-20-1600.

    PMID: 32928796
  22. 22

    Long-term safety review of tyrosine kinase inhibitors in chronic myeloid leukemia - What to look for when treatment-free remission is not an option.

    Lipton JH, Brümmendorf TH, Gambacorti-Passerini C, et al.

    Blood reviews 2022; (56()):100968 doi:10.1016/j.blre.2022.100968.

    PMID: 35570071
  23. 23

    SOHO State of the Art Updates and Next Questions | Choosing the Best Frontline BCR::ABL1 Tyrosine Kinase Inhibitor in Chronic Myeloid Leukemia-How to Define the Treatment Value?

    Haddad FG, Jabbour E, Breccia M, et al.

    Clinical lymphoma, myeloma & leukemia 2026; (26(2)):57-65 doi:10.1016/j.clml.2025.10.001.

    PMID: 41139562
  24. 24

    Is there a best TKI for chronic phase CML?

    Larson RA

    Blood 2015; (126(21)):2370-5 doi:10.1182/blood-2015-06-641043.

    PMID: 26585806
  25. 25

    European LeukemiaNet 2020 recommendations for treating chronic myeloid leukemia.

    Hochhaus A, Baccarani M, Silver RT, et al.

    Leukemia 2020; (34(4)):966-984 doi:10.1038/s41375-020-0776-2.

    PMID: 32127639
  26. 26

    Pathogenesis and management of accelerated and blast phases of chronic myeloid leukemia.

    Senapati J, Jabbour E, Kantarjian H, Short NJ

    Leukemia 2023; (37(1)):5-17 doi:10.1038/s41375-022-01736-5.

    PMID: 36309558
  27. 27

    Blast and accelerated phase CML: room for improvement.

    How J, Venkataraman V, Hobbs GS

    Hematology. American Society of Hematology. Education Program 2021; (2021(1)):122-128 doi:10.1182/hematology.2021000240.

    PMID: 34889372
  28. 28

    Management and outcome of patients with chronic myeloid leukemia in blast phase in the tyrosine kinase inhibitor era - analysis of the European LeukemiaNet Blast Phase Registry.

    Brioli A, Lomaia E, Fabisch C, et al.

    Leukemia 2024; (38(5)):1072-1080 doi:10.1038/s41375-024-02204-y.

    PMID: 38548962
  29. 29

    Final 5-Year Study Results of DASISION: The Dasatinib Versus Imatinib Study in Treatment-Naïve Chronic Myeloid Leukemia Patients Trial.

    Cortes JE, Saglio G, Kantarjian HM, et al.

    Journal of clinical oncology : official journal of the American Society of Clinical Oncology 2016; (34(20)):2333-40 doi:10.1200/JCO.2015.64.8899.

    PMID: 27217448
  30. 30

    Transplantation in CML in the TKI era: who, when, and how?

    Niederwieser C, Kröger N

    Hematology. American Society of Hematology. Education Program 2022; (2022(1)):114-122 doi:10.1182/hematology.2022000329.

    PMID: 36485123

This page is for informational purposes only and does not constitute medical advice. Your hematology team can explain how population statistics and treatment considerations apply to your situation.