You have been diagnosis with cancer. Perhaps you are the first in your family or maybe there are several family members who have had different kinds of cancer through the years. As you traverse the stages of shock, denial, anger, and finally acceptance you find yourself asking “Did I inherit my cancer from my parents?”
Genes make up the template that makes each of us who we are from the color of ours eyes, hair, and skin to our height and everything in between. Genes also control whether you are susceptible to certain diseases, like cancer. An abnormal change in a gene is a mutation. Cancer is a disease of abnormal genes. An inherited gene mutation is passed from parent to child and is present in every cell of the child. What is inherited is an abnormal gene that can lead to cancer, not the cancer itself. The chance of one mutation leading to cancer is rare. It usually takes multiple mutations over a lifetime to produce a cancer. Only 5 to 10% of all cancers are “inherited”. These individuals start out with a mutation from the get go, making it easier and quicker for other mutations to occur. This is why hereditary cancers are found in younger patients. There are many different Family Cancer Syndromes and each one is associated with certain traits and cancers.
Most cancers are caused by mutations you acquire during the course of your lifetime. This is why cancer is more common as we grow older. These mutations are caused by the things we do to our bodies and what we are exposed to, like cigarettes, alcohol, sunshine, and diet to name a few.
So what do we look for when trying to determine if your family has a mutated gene which might make you more likely to develop certain cancers? These families will have rare types of cancers. Cancers will tend to occur in individuals who are younger than what is normally expected for that cancer. Family members will have more than one cancer and they may have cancer on both sides, like breast cancer in both breasts. There maybe two or more close relatives with the same type of cancer or a greater number of relatives with cancer than would be expected to occur sporadically(normally).
Geneticists are the doctors that take a special interest in genes and disease. In families suspected of having a Family Cancer Syndrome the geneticist would construct a detailed family tree with the age of each person and the type of cancer they developed. This helps the geneticist determine the syndrome and make recommendations for testing, if testing is available.
It’s a lot more than just thinking there are too many people in your family with cancer. Cancer and genetics is complicated and we are just scratching the surface.
Dr. Kris Gast is a Board Certified Radiation Oncologist who has been in practice 21 years, the last 13 years at Fort Smith Radiation Oncology.