Patients are not being informed about changes to their genetic risk factors for cancer, a new study shows.

If an individual has a family history of a type of cancer, they can get a genetic test to identify their own cancer risk. Identifying a genetic risk means that person can get regular check-ups and be monitored for signs of the disease. In the event of a diagnosis, they can get treated quickly which will likely improve their outcome

Certain genetic variants that are known to be linked to certain disease are classified as “pathogenic”. Other variants are classified as “benign”, meaning they do not contribute to disease risk. However, a sizeable proportion of variants are of “unknown significance”, as researchers do not know if the gene affects the onset of any disease.

The initial classification of variants depends on all available scientific information. However, as the genetic sciences are advancing so quickly a gene variant once thought to be of no consequence can be reclassified in light of new research.

A 12-year study of 1.46 million individuals who underwent genetic testing for cancer risk showed that 6.4% of all genetic variants had their risk factor reclassified in this period. This included 24.9% of all variants of unknown significance, with 8.7% upgraded to pathogenic. 0.2% of benign variants and 0.7% of pathogenic variants were also reclassified. There was serious concern that this information was not communicated to patients and doctors.

Some labs only offer one-time results from genetic testing, meaning that even if the risk for a particular genetic variant is changed the patient is not informed. This has severe clinical consequences. For example, a person could have invasive and costly tests even if the disease risk is low. It also puts an unnecessary strain on mental health. People who are at risk could also miss out on the vital monitoring that would give them an early diagnosis.

There have also been genetic variants that have been reclassified by one lab and not another, creating confusion for both doctors and patients.

A system needs to be put in place for all labs to inform patients in the event of a genetic variant reclassification. As healthcare systems rely more on universal electronic patient records, this will most likely be easier in the future.