Genetic testing for cancer

Of all cases of cancer, only 5 to 10 per cent are thought to be strongly related to an inherited gene mutation, the American Cancer Society says.

While most people do not need to have predictive genetic testing, the society says testing is worth considering if you have:

* A number of close relatives — such as parents or siblings — with cancer, especially with the same kind of cancer or stemming from the same genetic mutation.

* A close family member with more than one type of cancer.

* A family member who developed cancer at a younger-than-expected age.