It is possible for leukemia to relapse after 20 years. However, it is much more likely for leukemia to relapse in the first few years after the initial diagnosis or remission.

Some research reports leukemia relapses after 10 years or more following the first diagnosis or remission.

In some cases, there are reports of relapses after 20 years or more, although this appears to be less common.

This article looks at how common a leukemia relapse after 20 years may be, symptoms to look for, and when to contact a doctor.

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It may be possible for leukemia to relapse after 20 years or more, although it is unclear how likely this may be.

Research suggests a leukemia relapse is more likely within the first few years after the initial diagnosis, but it is possible 10 years or later.

Relapse rates may vary depending on various factors, such as the type of leukemia and treatments.

A 2018 case study reports a female who had a relapse of chronic myeloid leukemia (CML) 25 years after having an allogeneic stem cell transplantation.

The case report notes that there is a risk of relapse years after receiving transplantation. In this case, treatment with imatinib (Gleevec) was successful. Researchers note the importance of long-term follow-up to monitor for signs of relapse.

According to a 2023 study, late relapse of acute leukemia occurring more than 2 years after allogeneic hematopoietic stem cell transplantation (HSCT) is rare, occurring in 4.5% of cases.

According to a 2020 trial, late relapse of acute lymphoblastic leukemia (ALL), which is more than 3 years after complete remission, is uncommon. Out of 1,752 people who had complete remission, 21 people had a relapse after 5 years, which researchers consider a very late relapse.

A 2021 study looking at late relapse rates of ALL suggests it is more common for ALL to relapse within the first 2 years following diagnosis. Late relapse, of 5 years or more, is uncommon.

Some researchers consider very late relapse to be more than 10 years after complete remission. The study cites older research, which reported 12 cases of very late relapse out of 1,134 children.

The 2021 study included 1,280 people with ALL receiving treatment between 2000 and 2020. Out of 36 cases of late or very late relapse, 12 people had a first relapse 10 years or later following the initial diagnosis.

According to a 2019 study, a late relapse of acute myeloid leukemia (AML) occurs after a minimum of 5 years of remission. This is rare and only occurs in 1% to 3% of people. The average time of late relapse in the study was 7 years.

The symptoms of a leukemia relapse may be similar to initial leukemia symptoms, such as:

If people notice any leukemia symptoms after having treatment for leukemia, they should speak with a doctor as soon as possible.

People can also speak with their doctor about their specific risk for leukemia relapse, as relapse may depend on factors such as:

  • characteristics of the cancer
  • individual risk factors
  • type of treatment

A person can also discuss what signs to look out for and what follow-up checks they require.

What is the survival rate for a second-time leukemia patient?

According to a 2019 study, survival rates after ALL relapse may be less favorable but can be longer for later relapses. Recent advances in treatments may have affected these rates.

In people with relapsed AML after HSCT, the 3-year survival rate is approximately 20% to 30%.

Survival rates represent the amount of people from a specific group who are still alive after a certain period following diagnosis or treatment. Survival rates cannot accurately predict an individual’s life expectancy, but may help to give an idea.

Can leukemia come back after a bone marrow transplant?

It is possible for leukemia to come back after a bone marrow transplant. Research from 2023 suggests the rate of acute leukemia returning more than 2 years after allogeneic HSCT is 4.2%.

Relapse of AML after allogeneic HSCT may occur in 30% to 40% of cases.

How long can someone live with leukemia without knowing?

Symptoms of acute leukemia can develop suddenly, while symptoms of chronic leukemia can develop gradually over months to years.

Leukemia may return after 20 years, but it is unclear how common this is. Relapse may depend on the type of leukemia and treatment.

It may be more common for leukemia to relapse within the first few years after the initial diagnosis or complete remission. It is possible for leukemia to return after 10 years or more, but research suggests this is less common.

It is important to attend any follow-ups with a healthcare team after leukemia treatment and to contact a doctor as soon as possible if people notice symptoms of leukemia relapse.