What Kareem Abdul-Jabbar's Story Can Teach Us About Chronic Myeloid Leukemia

What he said in 2009

Kareem Abdul-Jabbar told ABC News in November 2009 that he had been diagnosed the previous December with Philadelphia chromosome-positive chronic myeloid leukemia. What sent him to a doctor was ordinary and easy to dismiss.

"I had noticed I was having hot flashes and sweats," he said. "I'm not going through menopause." A blood test showed a high white blood cell count.

He was blunt about his first reaction. "I heard the word 'leukemia,' and I thought this was definitely a death sentence." He then described a different understanding: "If I can do this as I'm told to do it, I can manage this."

That is the record of what he chose to share. This article does not go past it. The rest is about the disease, which is one of the most instructive in all of oncology.

One broken join in the genome

Chronic myeloid leukemia has a single, known cause at the cellular level, which is rare.

Two chromosomes swap pieces. The National Cancer Institute describes it as a reciprocal translocation between the long arms of chromosome 9 and chromosome 22. The shortened chromosome 22 that results is called the Philadelphia chromosome.

The swap fuses two genes, BCR and ABL1, into one. That fused gene makes an abnormal tyrosine kinase, an enzyme that acts like a stuck accelerator on cell growth. White blood cells of the myeloid line keep multiplying because nothing tells them to stop.

Everything about modern CML treatment follows from knowing that one fact.

How it usually shows up

CML often causes nothing at all early on, and is found when a routine blood count comes back strange. When there are symptoms, NCI lists fatigue, weight loss, night sweats, and fever.

The most common finding a doctor detects on examination is splenomegaly, meaning an enlarged spleen. The spleen filters blood, and it swells when it is asked to handle a huge excess of white cells. That is why some people notice fullness or aching under the left ribs, or feel full after only a few bites of a meal.

When to get checked

There is no screening test for leukemia in healthy adults, so this rests entirely on symptoms and on paying attention to lab results you already have.

• Drenching night sweats that soak your nightclothes or sheets, continuing for more than two weeks with no fever or infection to explain them.
• Weight loss you did not intend.
• Fatigue that does not improve with rest and has lasted a month or more.
• Fullness, aching, or a mass under the left rib cage, or feeling full after a few mouthfuls.
• Fevers without an obvious infection.
• A white blood cell count that is high on a routine test and stays high on a repeat. This is the single most common way CML is found. A persistently elevated white count is a question, not a footnote, and it deserves an answer rather than another six-month wait.

None of these symptoms are specific. Night sweats have many causes, most of them not cancer. The point is that a cluster of them, or one that persists, should end with a blood test rather than a shrug.

Naming it precisely

NCI lists the tests. A complete blood count with differential shows how many of each cell type are present. Cytogenetic analysis looks at chromosomes under a microscope and can show the Philadelphia chromosome directly.

FISH, short for fluorescence in situ hybridization, uses fluorescent probes to light up the BCR::ABL1 fusion. Reverse transcription polymerase chain reaction, or RT-PCR, measures how much BCR::ABL1 message the cells are producing. That last test becomes the running scorecard for years afterward.

Three phases, defined by a percentage

CML is graded by the proportion of blasts, meaning immature blood cells, in blood or marrow. NCI gives the thresholds:

• Chronic phase: fewer than 10% blasts and promyelocytes in blood and marrow. Most people are diagnosed here.
• Blastic phase: 20% or more blasts in blood or marrow.
• Accelerated phase: the ground in between, where counts and symptoms are worsening but the blast count has not reached 20%.

Movement between phases is what treatment is designed to prevent.

Treatment that arrives as a pill

CML was the first cancer to get a targeted drug aimed at its specific molecular defect. Tyrosine kinase inhibitors, or TKIs, block the abnormal enzyme the fusion gene builds.

NCI lists first-line options: asciminib, nilotinib, dasatinib, bosutinib, and imatinib. These are taken by mouth, usually daily, usually indefinitely. They are not conventional chemotherapy, and they do not typically cause hair loss or the pattern of side effects people picture. They have their own side effects, which is a real conversation to have with a hematologist.

Two things make or break this approach. One is taking the drug consistently. The other is monitoring.

The numbers that get checked, and what they mean

Progress in CML is measured in the amount of BCR::ABL1 left in the blood, using that RT-PCR test. NCI defines the milestones:

• Major molecular response, or MMR, means BCR::ABL1 at 0.1% or less.
• Deep molecular response, or DMR, means 0.01% or less.

These are not vague terms. They are ratios reported on a lab sheet, tracked over months and years. A response that stalls or reverses prompts a change of drug or a look for resistance mutations.

What the survival picture actually shows

Two federal sources give figures that look different, and both are correct.

SEER, the federal cancer statistics program, reported five-year relative survival of 71.1% for chronic myeloid leukemia among people diagnosed between 2016 and 2022, and alongside it lists an American Cancer Society projection of 9,650 new cases and 1,170 deaths in the United States in 2026. That figure covers everyone, including people diagnosed at older ages, with other illnesses, or in advanced phases.

NCI's guidance for clinicians describes what happens in chronic phase on modern TKI therapy: 10-year event-free and overall survival rates exceeding 90%, with median survival projected to approach normal life expectancy for most patients. The American Cancer Society's 2025 estimate, which that summary reproduces, is 9,560 new cases and 1,290 deaths.

Both are group statistics. Neither describes a particular person, and neither is a promise. But the gap between them is the story of the last twenty-five years of cancer research, compressed into two numbers.

Sources

• NCI: Chronic Myeloid Leukemia Treatment (PDQ) — Health Professional Version
• SEER Cancer Stat Facts: Chronic Myeloid Leukemia
• American Cancer Society: Cancer Facts & Figures
• ABC News: NBA Great Kareem Abdul-Jabbar Diagnosed With Leukemia