The difference between no signs of cancer and a “cure”

By Luana Ferreira 

Updated on September 29, 2023

 Medically reviewed by Doru Paul, MD

There is often confusion between the terms "cure" and "remission," but it's important to understand that they don't mean the same thing. Cure means that there are no traces of cancer left after treatment and will never come back, while remission means that signs and symptoms of cancer are partially or entirely gone.1

Oncologists don't normally use the word "cure" because cancer cells may remain in the body for many years even if tests can't detect them after treatment and they can cause the cancer to return later. Therefore, they generally prefer to use the term "remission" to describe a state where there are no signs of cancer.

Verywell / Theresa Chiechi

Definition of Remission

Remission of cancer means a decrease or disappearance of cancer symptoms after different types of treatments such as surgery or chemotherapy.2 The definition can be slightly different depending on the type of cancer in question.

In cases of solid tumors (such as lung cancer or breast cancer), remission means the tumor has shrunk significantly or has completely disappeared. For blood cancers like leukemia, remission means a significant reduction or no evidence of cancer cells. 

 Types of Cancer and How They Differ

There are two types of remissions:

  • Partial remission: The cancer is still detectable, but there was a reduction of at least 50% in a tumor's size (with solid tumor cancers). In cases of blood cancer, it means fewer cancer cells are circulating in the body. At this stage, doctors will often say that the disease is controlled

  • Complete remission: Tests, scans, and exams are unable to detect traces of cancer in the body. Doctors also describe it as no evidence of disease (NED). However, some cancer cells may still be present but are undetected by tests

There are different ways to measure the size of a tumor and the number of cancer cells to establish if there is a remission or not. In solid tumors, doctors may request CT scans, physical exams, and X-rays, depending on the type of cancer. To measure cancer cells, doctors often use X-ray studies, MRI, PET scans, and blood and urine tests.

If remission is not achieved, the condition may be classified as stable disease or progressive disease. Cancers that aren’t changing may be called stable disease.3 When cancer grows, spreads, or gets worse it’s called progressive disease. When cancer comes out of remission, it’s said to have progressed. In the case of chronic cancers, recurrence and progression can mean much the same thing.

Some doctors will reasonably use the word “cure” if complete remission is sustained for five or more years. This is because most cancer recurrences happen within five years.1 Even so, there is no guarantee that cancer won’t return.  

Remission Rates

Remission rate can differ by the type, stage, and grade of cancer as well as the age of the patient and other factors. 

Early-stage cancer (stage I-II) is often highly treatable and have higher chances of remission. Advanced-stage cancer (stage III-IV) tends to be more resistant to treatment. Late-stage cancers is considered incurable, and, as such, doctors don't aim for complete remission but rather a reduction in tumor size followed by a sustained period of progression-free survival. In those situations, doctors often suggest palliative treatments with the goal of relieving symptoms and improve quality of life.

Remission rate may be different depending on the type of treatment as well. For instance, surgery commonly used for curative intent may be avoided in the advanced stages (such as with stage IIIb and stage IV lung cancer) when the risks outweigh the benefits. 

Some cancers have higher complete remission rates than others. For example, people with leukemia tend to have high complete remission rates—up to 90% in some cases.4 Those with pancreatic cancer may have complete remission rates closer to 10%.5

 How Cancer Is Treated

Maintaining Remission

After the initial treatment, doctors can suggest that patients participate in maintenance therapy, even if they have a complete remission. The goal of maintenance therapy is not to cure cancer but to prevent or delay recurrence of the disease in the future. Several types of cancers, such as ovarian cancer and colon cancer, respond well to this therapy.

In the past few years, new drugs with fewer side effects have been released, which means these therapies can be used for extended periods. Besides medication, maintenance therapy may include chemotherapy, hormonal, or targeted therapy. The treatment can last weeks or years, depending on the type of cancer and how the body responds to it. 

Those undergoing maintenance therapy should always keep their doctors updated about the intensity of the side effects they are experiencing. That way, their doctors can help them adjust or change their treatment if necessary.

Risk of Recurrence

Even in cases of complete remission, there is no guarantee that the cancer will not come back. Recurrence can happen in the same place where it started or in another part of the body. Although it is not possible to predict a recurrence, there are some explanations for why it happens:

  • Undetected cancer cells: Some cancer cells can hide for months or years. They are undetectable on tests that are available at the moment, and this is one of the reasons doctors tend not to say a patient is cured even when they have a complete remission

  • Resistant cancer cells: Cancer stem cells are a subset of cancer cells. They are stronger and more resistant to treatments. Some researchers believe it is because they divide more slowly than other cancer cells

  • Second primary cancer: In this case, the recurrence is a new cancer and not related to the initial one that was being treated. It can appear in the same area as the previous cancer or a new region or organ. The risks of a second primary cancer have been increasing over the past few years, especially among people who had the disease during childhood

As a general rule, the longer you are in complete remission, the less likely it is to return. Even so, a small percentage of people with no signs of cancer may suddenly experience a late relapse (defined as recurrence after five years of complete remission). This occurs more commonly with some cancers than others like breast cancer.

Research has found that 10% of people with diffuse large B-cell lymphoma will experience recurrence after 10 years.6 Women with estrogen-receptor-positive breast cancer are also more likely to experience late recurrence than early recurrence.