WHAT IS HEREDITARY CANCER?
Experts estimate that roughly 41% of Americans will develop cancer at some point in their lifetime. Given those startling numbers, it's not surprising that many families have at least a few members who have had some form of cancer. In some of these families, specific types of cancer may seem to occur more frequently. In most cases, these familial histories of cancer are simply reflective of overall cancer rates and the result of unknown and non-hereditary causes. In some cases they may also be due to shared risk factors such as dietary choices, smoking, or other environmental variables.
In other cases, however, these familial patterns of cancer are caused by specific genetic changes (mutations) that are being passed along from generation to generation, increasing the risk for certain cancers. This is often referred to as hereditary cancer, although what is inherited is not the cancer itself, but the abnormal gene that can lead to an increased risk for cancer. As many as 10% of all cancers are believed to be the result of these inherited genetic mutations.