TP53 Mutations in Blood Cancers

Section Editor: Kamran Mirza MBBS PhD FCAP
September 7, 2026

If your blood, bone marrow, or molecular test report mentions a TP53 mutation or a 17p deletion, both findings relate to the same gene. TP53 produces one of the body’s most important proteins for preventing cancer, and when it stops working, cancer cells become harder to kill with treatments that rely on it. These changes are found across many blood cancers, including chronic lymphocytic leukemia, acute myeloid leukemia, myelodysplastic syndrome, multiple myeloma, and mantle cell lymphoma.

What the finding means differs greatly between diseases, which is why this article is organized by diagnosis. In some, knowing about a TP53 change makes better treatment possible. It steers care away from chemotherapy toward drugs that work without needing TP53 at all. As a result, outcomes in chronic lymphocytic leukemia and mantle cell lymphoma have improved substantially. In others, particularly acute myeloid leukemia and myelodysplastic syndrome, effective options remain limited, and this is an area of intense research. This article explains what TP53 does, how it is tested, and what a positive result means in each setting.

What TP53 does, and how it is lost

Every cell contains two copies of the TP53 gene, one inherited from each parent. TP53 makes a protein called p53, which acts as a guardian inside the cell. Its job is to detect damaged DNA, whatever the cause, and decide what to do.

When p53 finds serious damage, it does one of two things. It either pauses the cell’s growth to allow repair before the cell divides again. Or, when the damage is beyond repair, it triggers the cell to destroy itself in a controlled process called programmed cell death. Without working p53, damaged cells that should be destroyed keep dividing instead, passing their damaged DNA to daughter cells and accumulating the errors that drive cancer.

In blood cancers, TP53 is inactivated in two ways, and different tests detect each.

TP53 mutation. A mutation is a change in the gene’s code. Most TP53 mutations in blood cancers produce a faulty protein rather than none at all. A defective version of p53 is still present in the cell, but it can no longer respond to DNA damage.
17p deletion. The TP53 gene sits on the short arm of chromosome 17, in a region called 17p. When that piece of the chromosome is lost, the copy of TP53 it carried is lost with it. A 17p deletion therefore removes one of the cell’s two copies of the gene entirely.

Both changes reduce p53 function, and in many cancers both are present in the same cell, with a mutation disabling one copy while a deletion removes the other. When both copies are affected, the cell has no working p53 at all. This is called biallelic loss, meaning both copies of the gene are involved, and it carries the greatest resistance to treatment. Working out whether one copy or both are affected is now a standard part of assessing several blood cancers, and in myelodysplastic syndrome it defines a specific diagnosis.

Why is the test done?

TP53 testing in blood cancers is done because the result changes treatment. Losing TP53 function does more than make a cancer harder to control. It makes the cancer resistant to a particular category of treatment, and knowing that in advance lets the care team choose something else.

Many chemotherapy drugs work by damaging the DNA of cancer cells and relying on p53 to recognize that damage and trigger the cell to die. When p53 is missing or broken, that final step cannot happen. The drug still delivers the hit, but the cell does not respond to it and keeps dividing. This is why TP53-mutated and 17p-deleted blood cancers often fail to respond to chemotherapy as expected.

The practical consequence differs by disease. In chronic lymphocytic leukemia and mantle cell lymphoma, it shifts treatment decisively toward drugs that bypass p53 entirely, and those drugs work well. In acute myeloid leukemia and myelodysplastic syndrome,e the same resistance applies, but the alternatives are fewer.

How is the test performed?

Two different tests assess TP53 status in blood cancers, and they look for different things. Both are often done together, because either one alone misses half the picture.

Fluorescence in situ hybridization, or FISH, uses fluorescently labeled DNA probes that bind to a specific region of a chromosome. For this purpose, the probe binds to the 17p region where TP53 sits. A normal cell shows two signals, one for each copy of chromosome 17. A cell with a 17p deletion shows only one. FISH finds deletions but cannot find mutations, so a FISH result showing no deletion does not rule out a TP53 problem. Next-generation sequencing reads the TP53 gene in detail and identifies mutations that alter or destroy the protein. It finds mutations but not deletions. A cancer cell can have a normal-looking sequence in the copy that remains while having lost the other copy entirely, which is exactly why the two tests complement each other. Most centers now run both as part of standard molecular profiling, and the two results together give the complete picture.

How are results reported?

A TP53 result may appear in your report in several forms, depending on which tests were done.

17p deletion detected by FISH. The report gives the percentage of cancer cells in which one copy of the 17p region was absent. Laboratories apply a threshold below which they do not consider the finding significant. In chronic lymphocytic leukemia, this is commonly 10 percent of cells, and the cutoff varies between centers and diseases.
TP53 mutation detected. The report names the specific change (for example, TP53 p.R175H) and usually gives the variant allele frequency, or VAF. This is the proportion of tested genetic material carrying the mutation. A high VAF means most cancer cells carry it. A low VAF may mean only a subpopulation does, which can still matter.
Biallelic TP53 loss. When a mutation and a deletion are both present, or two separate mutations are found, the report may state that both copies are affected. This carries the strongest implications of any TP53 finding.
Nothing detected. Neither change was found in the cells tested. In most blood cancers,s this is associated with a better response to treatment.

TP53 in chronic lymphocytic leukemia

In chronic lymphocytic leukemia, a 17p deletion or a TP53 mutation is among the most important findings on the report. These changes are present in roughly 5 to 10 percent of people at first diagnosis. They become more common as the disease progresses, reaching roughly 30 to 40 percent by the time of relapse. That pattern reflects how losing p53 gives cancer cells a survival advantage, letting them outgrow cells with intact p53 over time.

The treatment implication is clear-cut. Chemotherapy-based regimens including fludarabine, cyclophosphamide, and chlorambucil do not reliably work when p53 is missing, and are generally avoided. Instead, treatment uses drugs that bypass p53 altogether.

BTK inhibitors. Ibrutinib, acalabrutinib, and zanubrutinib block Bruton’s tyrosine kinase, a signaling protein that leukemia cells depend on for survival. They do not need p53 to work and are a standard first-line treatment when a TP53 change is present. The newer agents acalabrutinib and zanubrutinib are generally preferred over ibrutinib because they cause fewer heart and blood pressure problems.
Venetoclax. Combined with obinutuzumab or rituximab, venetoclax blocks BCL-2, the protein leukemia cells use to avoid programmed cell death. It opens a different route to cell death that does not run through p53. It is effective in this setting as initial treatment or at relapse.
Pirtobrutinib. A newer BTK inhibitor that binds the target differently from the older ones. The FDA approved it in 2023 for chronic lymphocytic leukemia previously treated with a BTK inhibitor and a BCL-2 inhibitor. That is the situation many people with a TP53 change eventually reach.

With these drugs, outcomes for TP53-affected chronic lymphocytic leukemia have improved substantially compared with the chemotherapy era. Responses still tend to be shorter than in people without a TP53 change, and resistance can develop, so monitoring continues. We discuss this in more detail in our article on chromosome 17p deletion and TP53 mutation in chronic lymphocytic leukemia.

TP53 in acute myeloid leukemia and myelodysplastic syndrome

In acute myeloid leukemia and myelodysplastic syndrome, a TP53 mutation is the single most difficult molecular finding to treat. It is found in roughly 5 to 10 percent of acute myeloid leukemia overall. The proportion is much higher, up to 30 to 40 percent, in leukemia that develops after earlier chemotherapy or radiation given for another cancer. In myelodysplastic syndrome, it is found in roughly 1 in 10 people, and more often in higher-risk disease.

TP53 mutations here are strongly associated with a complex karyotype, meaning the cancer cells carry many chromosome abnormalities at once rather than the TP53 change alone. The combination is among the highest-risk presentations in either disease.

The finding now shapes the diagnosis itself, not only the outlook.

A named category in acute myeloid leukemia. The International Consensus Classification of 2022 recognizes AML with mutated TP53 as its own category, applied when the variant allele frequency is 10 percent or more. Your report may use this wording.
A named category in myelodysplastic syndrome. The World Health Organization classification, 5th edition, recognizes MDS with biallelic TP53 inactivation, so the report may specify whether one copy or both are affected.
Adverse risk group. A TP53 mutation places acute myeloid leukemia in the adverse risk group of the European LeukemiaNet system, most recently revised in 2022.

Standard intensive chemotherapy achieves remission less often when TP53 is mutated, and the remissions that are achieved tend to be shorter. Several approaches are used.

Hypomethylating agents. Azacitidine and decitabine are lower-intensity drugs that change how genes are read inside cancer cells rather than directly damaging DNA. They depend less on p53 and are the most commonly used treatment for TP53-mutated myelodysplastic syndrome and for older or less fit people with TP53-mutated acute myeloid leukemia.
Venetoclax with azacitidine. A standard option for older adults with acute myeloid leukemia. Its activity is more limited when TP53 is mutated, with complete remission in roughly 1 in 5, but it is still widely used.
Stem cell transplantation—the only treatment with the potential for long-term remission in this group. The difficulty is reaching a deep enough remission to proceed safely, and outcomes after transplant are also less favorable than in lower-risk disease.
Clinical trials. Because the standard options are limited, enrollment in a trial is often discussed early rather than after other treatments have failed.

You may encounter older information about a drug called eprenetapopt, also known as APR-246, which was designed to refold the faulty p53 protein into a working shape. Its phase 3 trial in TP53-mutated myelodysplastic syndrome was completed and did not meet its main goal, and the drug has since been placed on clinical hold for blood cancers. It is not an available treatment. Other approaches to restoring p53 function are still being studied, but none has yet been approved.

TP53 in multiple myeloma

In multiple myeloma, the most commonly reported TP53 finding is a 17p deletion, which removes one copy of the gene. It is present in roughly 7 to 10 percent of people at diagnosis. Laboratories apply a threshold for the proportion of myeloma cells carrying the deletion before calling it significant, commonly around 20 percent, and the exact cutoff varies between centers.

A 17p deletion is one feature used to classify myeloma as high risk. The system used is the Revised International Staging System, published in 2015 and updated as the R2-ISS in 2022. Its presence, particularly alongside other high-risk chromosome changes, is associated with shorter remissions and shorter overall survival than standard-risk myeloma. TP53 mutations are less common than 17p deletion at diagnosis but become more frequent as the disease relapses, the same pattern seen in chronic lymphocytic leukemia.

Knowing that myeloma carries a 17p deletion or TP53 mutation affects care in three ways. Initial treatment is usually more intensive, often including stem cell transplantation for those eligible, followed by maintenance treatment. Monitoring is more frequent, because the risk of early relapse is higher. At relapse, clinicians weigh TP53 status alongside other factors, and often discuss clinical trials given the limited durability of standard approaches.

TP53 in mantle cell lymphoma

Mantle cell lymphoma is a fast-growing blood cancer that starts in B lymphocytes, the cells that normally make antibodies. TP53 testing is now standard at diagnosis in most specialist centers, because the result changes the treatment recommended from the outset. TP53 mutations are found in roughly 10 to 20 percent of newly diagnosed cases.

As in chronic lymphocytic leukemia, mantle cell lymphoma cells with a TP53 mutation resist chemotherapy-based regimens. The reason is the same: chemoimmunotherapy relies on p53 to trigger cell death after DNA damage. Reported survival varies widely between studies. Trial cohorts treated with intensive chemotherapy have reported median overall survival under two years for TP53-mutated patients. A large retrospective analysis of 645 patients across 19 United States centers, presented in 2024, reported roughly 8.3 years for TP53-mutated patients versus 14.2 years for unmutated patients. The widespread differences reflect differences in who was studied and how they were treated, and the more recent figures are better than older reports.

The preferred approach avoids chemotherapy and combines drugs that work independently of p53.

BTK inhibitors. Ibrutinib, acalabrutinib, and zanubrutinib are active in TP53-mutated mantle cell lymphoma and are a cornerstone of treatment.
Venetoclax. Blocks BCL-2, opening a route to cell death that does not require p53. Combining it with a BTK inhibitor attacks the lymphoma from two independent directions.
The BOVen combination. Zanubrutinib, obinutuzumab, and venetoclax, given without chemotherapy. In a phase 2 study of 25 previously untreated people with TP53-mutated mantle cell lymphoma, 96 percent responded, and 88 percent had a complete response. At two years, 72 percent were progression-free. This is a small study, but the results compare favorably with what chemotherapy achieved in this group.

For mantle cell lymphoma that has relapsed or stopped responding, CAR-T cell therapy is an option. The patient’s own immune cells are modified to recognize and attack the lymphoma. In the trial supporting approval of brexucabtagene autoleucel, 93 percent of people responded, and 67 percent had a complete response. Activity is retained in higher-risk disease,e including TP53-mutated cases, although the numbers studied are small. Real-world reports show that some people progress too quickly to reach CAR-T, which supports considering it earlier in this group.

TP53-mutated mantle cell lymphoma remains among the more challenging lymphoma subtypes, and clinical trials continue to seek better long-term outcomes.

TP53 in other blood cancers

TP53 mutations also occur in other blood cancers, including diffuse large B-cell lymphoma and Richter transformation. Richter transformation is the change that can occur when chronic lymphocytic leukemia converts into a faster-growing lymphoma. In both, losing p53 is associated with a more difficult disease course and reduced sensitivity to standard treatment. The specific implications depend on the diagnosis and will be discussed by your hematologist or oncologist.

Are TP53 mutations inherited?

It is natural to wonder, when you hear that a gene described as a tumor suppressor is mutated, whether the change was inherited and might affect your children or other relatives.

In blood cancers, TP53 mutations are almost always somatic, meaning they developed inside a blood-forming cell during your lifetime and are not present in the rest of your body’s cells. They are not inherited, cannot be passed to children, and carry no hereditary implications for your family.

This is a separate situation from a germline TP53 mutation. That kind is present from birth in every cell of the body and causes a rare inherited condition called Li-Fraumeni syndrome. Germline mutations are identified with a test on normal tissue, usually blood or saliva, which reflects the DNA in all cells rather than only in cancer cells. If you have concerns about inherited risk, your medical team can clarify it and arrange a referral to a genetic counselor.

What happens next?

What follows a TP53 result depends on which blood cancer you have, and in most cases the result is available before the first treatment decision.

In chronic lymphocytic leukemia, a 17p deletion or TP53 mutation means chemotherapy-based treatment is avoided from the outset, and a BTK inhibitor or a venetoclax-based regimen is used instead. We document the result, and it will inform decisions throughout your care, whether you need treatment now or later.

In mantle cell lymphoma, a TP53 mutation means standard chemotherapy is unlikely to be recommended. Your hematologist will discuss a chemotherapy-free combination, usually including a BTK inhibitor and venetoclax, or a clinical trial. If the lymphoma has relapsed, CAR-T cell therapy is one option.

In acute myeloid leukemia or myelodysplastic syndrome, TP53 status is one of several factors determining treatment intensity and whether a stem cell transplant is appropriate. Because standard options are limited, a clinical trial is often part of the conversation from the beginning.

In multiple myeloma, a 17p deletion places you in the high-risk category, which affects the intensity and duration of treatment and how often you are monitored.

If you haven’t had TP53 testing yet, it is reasonable to ask your hematologist whether it is indicated and when the result is expected.

Questions to ask your doctor

Do I have a TP53 mutation, a 17p deletion, or both?
Were both types of testing done, sequencing as well as FISH?
If both a mutation and a deletion were found, does that mean both copies of the gene are affected?
What percentage of cells carried the change, and does that meet the threshold your laboratory uses?
How does this result change my treatment options compared with what they would be without it?
Does my report use a specific diagnostic category based on the TP53 finding?
Should I avoid chemotherapy in my case, and if so, what is recommended instead?
Is a stem cell transplant or CAR-T cell therapy relevant to my situation?
Are there clinical trials open for people with a TP53 change and my diagnosis?
How will my response to treatment be monitored, and how often?
Could this TP53 change be inherited, and should I see a genetic counselor?
Will TP53 status be retested if my disease progresses or comes back?