Does Skin Cancer Run in Families?
If one or more of your family members has been diagnosed with any type of skin cancer, it is a common worry that you may also develop skin cancer at some point. You may also worry about siblings and children if you have been diagnosed with skin cancer. Is there cause for concern? The answer is still uncertain at this point in time. It seems that most skin cancers are caused by environmental factors such as long term sun damage but new research is showing that there can be some genetic factors involved in who is more at risk for developing certain types of skin cancer.
In this post we are going to discuss what we currently know about the genetics of melanoma, squamous cell, and basal cell skin cancers.
**What do we know about the risk factors of developing skin cancer? **
- There are certain factors associated with a higher risk of developing skin cancer such as having red or blonde hair, having light skin, and having the tendency to burn easily in the sun.
- Another risk factor increasing your odds for being diagnosed with skin cancer is having a large number of moles.
- If you live in a geographic area where you are more likely to get high levels of ultraviolet (UV) radiation you are more at risk for developing melanoma or other types of skin cancer. People who live in Australia, for example, have a high incidence of skin cancer for their population.
These risk factors make it difficult to sort out the genetic vs. environmental factors because your family members are likely to live in the same geographic area, you may share the same behaviors as far as protecting your skin or not, and you may have the same skin type. It makes sense that family members may share some of the same risk factors for acquiring skin cancer but the main cause is usually UV radiation from the sun or from tanning booths.
What do we know about inheriting basal cell carcinoma?
- There is a medical condition called basal cell nevus syndrome, also called Gorlin’s syndrome, which can be inherited. This is a rare genetic condition which may be passed on by a parent. Gorlin’s syndrome affects the skin, nervous system, eyes, endocrine glands, and bones. It is characterized by a much higher risk of developing multiple basal cell skin cancers, often at an early age such as puberty.
- The National Cancer Institute reports that people with basal cell lesions have more family members who have this type of skin cancer than people who have never been diagnosed with BCC. They warn that a family history of any type of skin cancer is a strong predictor that you may be more at risk for developing basal cell carcinoma.
**What do we know about the genetics of squamous cell carcinoma? ** The National Cancer Institute cites research which shows that a family history of squamous cell cancer (SCC) may increase the risk of developing this type of skin cancer in first-degree relatives. First degree relatives include parents, siblings and offspring. One Swedish study found that people with a sibling or parent diagnosed with squamous cell carcinoma, Bowen’s disease, or pre-cancerous lesions called actinic keratosis were two to three times as likely to develop SCC as compared to the general population.
Is there any research on the genetic factors of developing melanoma skin cancer?
Since melanoma is the most deadly type of skin cancer, most people want to know about the genetic factors associated with it. In recent years there has been research to show that in fact, there is a genetic link.
- A 2009 study published in the journal Nature Genetics, found a clear link between specific genes on chromosomes 9 and 22 and increased risk of melanoma. The researchers determined that there are at least five genes which influence the risk of melanoma. An individual who carries all the variants associated with this increased risk is about 8 times more likely to develop melanoma than people who have none.
- The National Human Genome Research Institute also cites research which implicates certain gene mutations are responsible for a greater risk for developing melanoma. Specifically a mutation in the CDKN2 gene on chromosome 9 may be a factor in melanoma development. They also report that genes on chromosomes 1 and 12 may play a role in familial melanoma.
- The National Cancer Institute warns that: "Having two or more close relatives who have had melanoma is a risk factor. About 10 percent of all patients with melanoma have a family member with this disease."
So what can one make of all this? If you have one or more family members who have been diagnosed with melanoma or any type of skin cancer you may be at more risk for developing skin cancer than the general population and especially if they are first degree relatives. But it is important to note that just because you have more risk factors or a family history of skin cancer, this doesn’t mean you will automatically get it yourself. It simply means that you have to be more careful about sun safety and to be vigilant about using skin cancer prevention strategies.
It would also be wise to tell your doctor or dermatologist of your family history so that they are aware of your greater risk for skin cancer. They may want to check your skin more regularly for any suspicious moles or lesions.
For more information about this topic please refer to the following SkinCancerConnection articles: