Human nature likes simple answers and well-defined endings. However, nature often fails to comply. Cancer is one example of this. Upon their initial diagnosis, patients often seek certainty: a single treatment, a clear timeline, and an eventual cure.

Instead, physicians deal with multi-drug resistant mutations, average survival rates, and eventual “remission.” Does this coveted word mean that you are cured?

Unfortunately, reality is slightly more nuanced than that.

Cancer remission: What does this term mean?

When doctors talk about remission, they refer to any cancer treated successfully by any method until it is undetectable. When a patient reaches remission, the signs and symptoms of their cancer are reduced or disappear altogether. In addition, remission entails your cancer cannot be seen via any imaging method – be it X-ray, CT, MRI, or PET scan. 

Remission is often possible through conventional treatments, such as surgery, chemotherapy, or radiotherapy. If a patient stays in remission for 5 years or more, doctors often describe that as being “as good as cured” – although this is not absolute.

Why is remission not the same as a cure?

Even if undetectable and asymptomatic, cancer in remission can technically always come back. All it takes is a single cancer stem cell left for the tumor to start regrowing.

How likely is it to have leftover cancer cells after remission? At just 1 millimetre wide, a tumor would be almost wholly invisible via MRI or PET scan. And yet, even that tiny size represents over a million cells. 

Moreover, conventional treatments are generally less effective against cancer stem cells (also known as cancer-initiating cells). As a result, even after reaching the point of minimally-residual disease, we can have no certainty that a person is fully cancer-free.

How can I ensure I stay in remission indefinitely?

The key to ensuring indefinite remission is to minimize any chance of cancer stem cells. Currently, the most effective method to achieve this is through cancer immunotherapy. This includes experimental and customized treatments, such as Coley’s toxin-based anti cancer vaccines, oncolytic viruses, or targeted cancer killer cells. When applied after a patient has reached remission, these methods can use the patient’s immune system to eliminate any leftover cells around the body.