Skin Cancer and Heredity

It’s Labor Day weekend and your family is finally all together from different parts of the country for the first time in ages. It’s the dreaded “family reunion." These are things you do and don’t want to hear at your family reunion as you sit by the pool.

You want to hear these:

• You have your mom’s eyes. They are lovely
• You have your dad’s smile. He’s so handsome
• Glad you got your mom’s athleticism. She was a heptathlete

You are not sure that you want to hear these:

• You have your dad’s hips (?)
• You are aging well, all things considered(?)
• Your personality is not like anyone’s in the family(?)

You don’t really want to hear these:

• You are balding like your grandfather
• You have your dad’s skin with all those moles

Heredity and skin cancer

All kidding aside, genetics makes a difference in the way we behave, feel, look, etc. One thing I have heard is that skin cancer can run in the family. I have read that genetics play a significant role in skin cancer incidence. I never really studied these claims, but they seemed correct intuitively and anecdotally. It makes sense that people with the same genes would have the same predisposition toward skin cancers like melanoma. If true though, then how much of a factor is it? I wanted some answers.

The research shows...

I read a fairly recent article from cancer.net on the topic of “familial malignant melanoma”¹, which clearly addressed some of these questions.

What is "familial malignant melanoma?

This phrase refers to families where at least two, first-degree family members have melanoma. First-degree kin would mean a parent, child, or sibling. According to the article, about 8% of those diagnosed with melanoma have had one first-degree family member with the same diagnosis.

Can we pinpoint a gene?

Familial melanoma can be linked to two genes, which may be passed from generation to generation. CDKNA2A and CDK4 have been identified as genes that can mutate leading to melanoma, although this accounts for only a small percentage of familial melanoma. Other genetic factors play a role in the risk of mutation, specifically MC1R, which regulates skin pigment and hair color. Genetic testing may be done to determine these mutations, though this is not common. The article asserts that families with a strong history of melanoma should be routinely screened for the disease whether hereditary factors are studied or not because they are at a higher risk.

How much is genetically inherited, and how much is it behaviorally "inherited?"

Questions came to mind as I read this. Could the added risk for melanoma found in first-degree family members be rooted in similar lifestyles as well? Do siblings and their parents share common behaviors that may lead to melanoma apart from a genetic predisposition? To my knowledge, my parents have not had melanoma. I grew up in Southern California and they grew up in the Midwest. Even though we all went to the beach when I was a child, they were not exposed as much during their formative years. Possibly, the cumulative sun exposure was a factor for me. More studies are needed.

No matter the cause, we need to take the same protections

Whether melanoma is primarily caused by nature (genetic) or by nurture (lifestyle choices) or some combination of both, it really doesn’t make a difference to me. I still need to be about making good skin care choices and getting checked out by a medical professional regularly or when I notice something suspicious. So, now when Uncle Louie makes a smart remark about my skin, I can respond by smiling and tossing him a bottle of SPF50 sunscreen and a floppy hat.

Has anyone else in your family had skin cancer?