What an actionable mutation means

"Actionable" is one of those pieces of clinic vocabulary that sounds like it must be describing your cancer. It is not. It is describing the pharmacy shelf.

A change in your cancer is called actionable when somebody has already built a treatment that aims at that change. Nothing about the change itself has to be unusual, aggressive or rare for the label to apply. What has to exist is a matching therapy.

Actionable is a fact about medicine, not a fact about your prognosis.

The National Cancer Institute describes what biomarker testing can produce: the results of a biomarker test could show that your cancer has a certain biomarker that is targeted by a known therapy.

That is the whole concept in one sentence. A biomarker, in NCI's framing, is one of the genes, proteins or other substances that can provide information about cancer. When one of them lines up with an existing drug, the report flags it, and clinicians call it actionable.

This surprises people, and it is worth explaining.

Cancer treatments are studied and approved in specific settings. A drug developed and tested against a particular change in one cancer type may not have been studied in another. So the change can be present, and the treatment can exist, and the match can still not be straightforward.

That is one reason two people can hold reports mentioning the same gene and be told different things. It is also a reason to ask directly: is this option approved for my cancer, or would it be through a clinical trial?

Not everything on a report gets acted on, and that is by design.

NCI states it clearly: genetic changes that are thought to be harmless — benign — or whose effects are not known, described as a variant of unknown significance, are not used to make treatment decisions.

If you have read your own report and found a long list of entries, most of them fall into this bucket. They are recorded because the test looked at them, not because they mean something.

This is the outcome nobody wants and many people get. Handled well, it is still useful information.

Some things to do with it:

• Ask whether the testing was complete, or whether limited tissue meant part of the panel could not be run.
• Ask whether a clinical trial is an option, including trials that do not depend on a specific biomarker.
• Ask what the standard treatment path looks like from here, because standard does not mean second-rate.
• Ask whether there is any circumstance in which retesting later would be considered.

None of that requires you to argue with anyone. These are the questions a good team is already thinking about, and asking them out loud simply makes the reasoning visible to you.

A matched treatment is an opportunity, not a guarantee. Some people respond well to a targeted option and some do not, and no report can tell you in advance which you will be.

What the label does buy you is a concrete thing to discuss. It converts a vague sense of "there must be something out there" into a specific named option with specific pros and cons — and that is a much better place to make decisions from.

If someone has used the word actionable about your results, the most useful next sentence you can say is: "Show me which one, and tell me what you would do about it."