Genetic Testing Results: What Positive, Negative, and VUS Mean

The simple versionExplain▾

Genetic testing for inherited cancer risk does not simply say "yes" or "no." The National Cancer Institute describes several possible results: positive, negative (which can be a true negative or an uninformative one), and a variant of uncertain significance.

Knowing what each result means — and does not mean — helps a person understand their risk without reading too much or too little into it.

A result is information to interpret, not a verdict — and its meaning depends on your family history.

A positive resultExplain▾

A positive result means the laboratory found a change associated with increased cancer risk, called a pathogenic or likely pathogenic variant.

A positive result can:

• Confirm, for a person with cancer, that the cancer was likely due to an inherited change, and sometimes guide treatment
• Point to a higher risk of certain cancers in the future, which can guide screening and prevention
• Give blood relatives information to consider their own testing

But a positive result cannot say whether or when cancer will develop. Some people who inherit a harmful change never develop cancer.

A negative result: two meaningsExplain▾

A negative result means no harmful change was found with current technology. What that means depends on the family's history.

• True negative. If a specific change is already known in the family and the tested person does not have it, that is a true negative. Their risk is about the same as the general population. This does not mean zero risk — it means the risk is not raised by that family change.
• Uninformative negative. If there is a strong family history of cancer but no known change has been found in the family, a negative result is uninformative. An undetected change may still be present, and future testing might find it as technology improves.

In both cases, a care team makes sure a person still gets appropriate follow-up based on personal and family history.

A variant of uncertain significanceExplain▾

Sometimes a test finds a change for which there is not yet enough data to know whether it raises cancer risk. This is a variant of uncertain significance, or VUS.

Key points about a VUS:

• Most often, a VUS is later reclassified as benign — meaning it does not raise risk.
• Because it is not known to raise risk, a VUS is typically not used to make health decisions. Care is based on personal and family history instead.
• It is important to stay in touch with the provider who ordered the test, so you learn if the variant is reclassified in the future.

Results and your familyExplain▾

Unlike most medical tests, a genetic test can reveal information about blood relatives, not just the person tested. A positive result may prompt siblings, children, or parents to consider their own testing. This is one reason genetic counseling is helpful before and after testing.

Why a result can change over timeExplain▾

A person's genes do not change, so a specific test usually does not need to be repeated. But the meaning of a result can shift as science advances. The National Cancer Institute notes that after an uninformative negative, future testing may find a harmful change that was unknown at the time, as new genes are discovered and testing technology improves.

A variant of uncertain significance can also be reclassified later — most often as harmless. This is why staying in touch with the provider who ordered the test matters: it is how you would learn if new information changes what your result means.

A calm way to think about itExplain▾

Each result — positive, true negative, uninformative negative, or VUS — carries a specific meaning, and none is a simple certainty. The most useful step is to have the result explained by a genetic counselor or provider trained in cancer genetics, who can connect it to your own history and help plan sensible next steps.