Family Cancer Syndromes

Cancer is a common disease, so it’s no surprise that many families have at least a few members who have had cancer.

Sometimes, certain types of cancer seem to run in some families. In some cases, this might be because family members share certain behaviors or exposures that increase cancer risk, such as such as smoking. Cancer risk might also be affected by other factors, like obesity, that tend to run in some families.

But in some cases the cancer is caused by an abnormal gene that is being passed along from generation to generation. Although this is often referred to as inherited cancer, what is inherited is the abnormal gene that can lead to cancer, not the cancer itself. Only about 5% to 10% of all cancers result directly from gene defects (called mutations) inherited from a parent. This information is about those cancers.