Reader's Question: My mother and father had skin cancer. Does this mean I will inherit skin cancer from my parents?
Dr. Berman's Response: This is a common question we hear as skin cancer is so common and many people become aware of their risk as they see their parents treated for various skin cancers. While this question seems simple enough, it is really very complicated and there is no exact answer. While some families seem to have multiple members with skin cancer, other families have no skin cancer history despite excessive sun exposure. Is this coincidence or is there good reason behind this?
For the most part, skin cancers are acquired through sun exposure so are more environmental rather than genetic. However, we do inherit our skin type from our parents so there is an indirect inherited predisposition to cancer. For example, a person whose skin is very white and fair is more likely to accumulate sun damage rather than a person whose skin is darker and has more inherent sun protection.
So it does make sense that skin cancer is more common among Caucasians over African-Americans. Of course, a person with very fair skin who is prone to sunburn may be more likely to properly apply sunscreen so they may compensate for their fair skin by using applied protection from the sun.
And we also learn our behavior from our parents so at a young age, we follow the role of our parents in sun exposure behavior. If parents are outdoors a lot without sunscreen, they will tend to raise kids who spend a lot of time outdoors without sun protection. So while this behavior is not inherited from parents, it is learned at a young age.
That being said, there are certain rare genetic mutations which make one more susceptible to skin cancer, and certain skin cancers may be inherited. For example, a genetic mutation has been identified that is linked to melanoma and pancreatic cancer. Thus, family members carrying this mutation may indeed have an inherited melanoma.
Recently, a commercially available test for this genetic mutation has become utilized in families with abnormally high rates of melanoma and/or pancreatic cancer. Fortunately, this mutation is rare although it is not known if other genes will be identified as "cancer" genes. More commonly, there are families in which having many atypical or "dysplastic" moles is an inherited trait and for these individuals, they are at higher risk of developing melanoma even if they practice strict sun protection. These people have many moles, especially on the chest and back, that appear highly suspicious for melanoma.
There is another genetic mutation linked to multiple basal cell carcinomas but this is usually suspected at a young age as there are other findings suggesting this syndrome before the first skin cancer is diagnosed, which is usually during the late teen years. For these people, it is not uncommon to have several basal cell carcinomas treated before being old enough to legally drink alcohol
One very extreme, and fortunately very rare, condition is called "xeroderma pigmentosa" and people with this inherited condition are extremely sensitive to the sun and cannot be outside during daylight hours for very long. While they are not "allergic" to the sun, they are so sensitive to sun damage that skin cancers arise before the teenage years as their skin cells cannot repair even minor damage caused by the sun. This is a rare and very extreme case of "inheriting" skin cancer.
We all inherit many traits from our parents and while the role of genetics is not clear for skin cancer, several themes have emerged. First, sun protection is a necessity even if no close relatives have been diagnosed with skin cancer. Second, if you have inherited fair skin or have many moles, be especially careful. Third, we all eventually turn into our parents to an extent so if your parents have skin cancer, see a dermatologist yearly to have a full body skin exam.