The past decade has experienced rapid expansion of genetic tests. 

It includes new instruments to detect patients having breast cancer and tells them about the risk of recurrence and to guide their treatment. 

The clinical importance of many inherited mutations remain unclear and experts are torn on when and how to deploy new tests. 

Patients are sometimes left paying out-of-pocket for exams that are not yet the standard of care .

Most oncologists are unaware of how to implement the new technologies into standard treatment protocols. 

Testing for BRCA1 and BRCA2 genes used to cost thousands of dollars. Now, doctors can use multi gene test panels for few hundred dollars. 

Some breastcancer experts are concerned that widespread testing can identify genetic mutations. 

However, the impact is unclear and might create anxiety, leading to further testing and also rise in the cost. 

For people diagnosed with breast cancer, most professionals recommend limited testing to certain people. 

Mutations on other genes that are associated with breast cancer are much less common. 

Less common than BRCA1 and BRCA2 mutations and generally don't increase the risk of developing breast cancer as much.

The cancer causing impact of these genes are less clear than that of the BRCA genes.

There is both underuse of tests that science says are relevant and overuse of tests that experts say provide information that can't be interpreted with any scientific certainty.