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After treatment and remission

What is a relapse

A relapse is leukaemia coming back after remission. This topic explains calmly and clearly what a relapse is, why it happens, where it can occur and how it is confirmed.

Last updated: ~3 min read
A small distant wave on a calm sea.
Figure 1.A calm explanation of relapse.

01Short answer

Remission means that tests find no signs of leukaemia. But sometimes a small number of leukaemia cells that ordinary tests cannot see remain in the body, and over time they can multiply again. This is called a relapse. A relapse is not your fault or your family’s — it is linked to the biology of the illness. The risk of relapse depends on the type of leukaemia (ALL, AML, CML, CLL), genetic features, the first response to treatment and MRD results (topic “Monitoring with the CBC”). The risk is highest in the first years after treatment and falls over time. Where a relapse can occur: most often in the bone marrow; sometimes in the central nervous system (the brain and spinal fluid), in the testes (in boys with ALL) or in other organs. Sometimes it shows only on an MRD test — before any symptoms; this is called a molecular relapse. In CML it often shows as a rising BCR-ABL level; in CLL the idea of “relapse” is different — treatment starts only when symptoms appear. If a relapse is suspected, a blood test, a bone marrow test and, if needed, a spinal fluid test and genetic tests are done. These tests both confirm the relapse and help choose new treatment. A relapse is hard news, but it does not mean treatment has run out: there are other chemotherapy regimens, targeted drugs, immunotherapy (such as CAR-T cells) and stem cell transplantation. Your haematologist will explain which option suits you.

02Simple explanation

A relapse is leukaemia returning after remission.

It is not your fault.

The risk is highest in the first years.

Most often in the bone marrow.

Treatment options exist.

03Scientific explanation

Definition: the NCI describes recurrence as cancer coming back after a period when it could not be detected, because undetected cells remained.

Site: according to the NCI PDQ, relapse in ALL most often occurs in the bone marrow, and sometimes in the central nervous system or testes.

Risk: the ACS notes that the risk of recurrence depends on the type of illness and the response to treatment, and falls over time.

Treatment: the NCI PDQ lists chemotherapy, targeted therapy, immunotherapy and transplantation as possible options for relapsed ALL and AML.

04What happens in the body?

Why does relapse happen?

Sometimes a small number of cells that tests cannot see remain and multiply over time.

Does it mean someone made a mistake?

No. Relapse is linked to the biology of the illness, not to lifestyle or anything the family did.

Where can it occur?

Most often in the bone marrow; sometimes in the central nervous system, testes or other organs. Sometimes only on an MRD test.

How is it confirmed?

A blood test, a bone marrow test and, if needed, spinal fluid and genetic tests.

What happens next?

A new treatment plan: different chemotherapy, targeted drugs, immunotherapy or a transplant.

A crossroads of paths of light.
Figure 2.Options after relapse.

When to call your doctor

Worrying signs — fever, bleeding, new pain, breathlessness — should be reported to your doctor between visits too. Getting in touch early is always better than waiting.

05During a relapse

Steps.

What — What a relapse is.1WhatWhat a relapse is.
Where — Where it can occur.2WhereWhere it can occur.
Confirm — Confirmed by tests.3ConfirmConfirmed by tests.
Plan — A new treatment plan.4PlanA new treatment plan.
ConfirmationThe relapse is clarified.
PlanA new treatment plan is made.
SupportYou are not alone.

06Types of relapse (simplified)

TypeWhat it means
Bone marrow relapseLeukaemia cells in the bone marrow
CNS relapseCells in the spinal fluid
Testicular relapseIn the testes (ALL, boys)
Molecular relapseOnly on MRD or BCR-ABL tests
Early and late relapseHow long after remission

* The type and timing affect the choice of treatment.

07Key terms

Relapse
Leukaemia coming back.
Remission
No signs of leukaemia found.
MRD
Measurable residual disease.
Molecular relapse
A relapse seen only with a sensitive test.
CAR-T
Treatment with the patient’s own modified immune cells.
Refractory
Illness that does not respond to treatment.

08Key points

  • A relapse is not your fault.
  • Don’t miss check-ups.
  • Tell your doctor about symptoms.
  • Ask about test results.
  • Discuss treatment options.
  • Ask for support.

09Frequently asked questions

Is there still hope after a relapse?

Yes, in many cases there are treatment options; your doctor will explain your situation.

How can relapse be prevented?

Following treatment and follow-up exactly matters most.

Can I get a second opinion?

Yes, that is normal.

How can I cope?

Your team, family and a psychologist — don’t stay alone.

Does this information replace medical advice?

No. This is general education; only your treating doctor can assess your situation.

10Questions for your doctor

Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.

  1. Is there still hope after a relapse?

  2. How can relapse be prevented?

  3. Can I get a second opinion?

  4. How can I cope?

  5. Does this information replace medical advice?

My questions

12Sources

  1. National Cancer Institute. Recurrent Cancer: When Cancer Comes Back
  2. American Cancer Society. Cancer Recurrence
  3. National Cancer Institute. Childhood Acute Lymphoblastic Leukemia Treatment (PDQ®)
  4. National Cancer Institute. Adult Acute Myeloid Leukemia Treatment (PDQ®)
  5. National Cancer Institute. Adult Acute Lymphoblastic Leukemia Treatment (PDQ®)
  6. National Cancer Institute (NCI). Follow-Up Medical Care
  7. National Cancer Institute (NCI). Cancer Survivorship
  8. Cancer.Net (ASCO). Follow-Up Care After Cancer Treatment
  9. Leukemia & Lymphoma Society (LLS). Long-Term and Late Effects of Treatment
  10. National Cancer Institute. Facing Forward: Life After Cancer Treatment
Medical disclaimerThis information is for educational purposes only and does not replace medical advice.
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