SNPwatch: Genetic Risk for Skin Cancer Isn’t All About Your Skin
Wear sunscreen! Don’t get sunburned! Pay attention to those moles! These are all simple things that we can do to decrease our risk of getting skin cancer, the most common type of cancer in the United States. Although those with fair skin are at greater risk–they lack the pigment cells that help protect our skin from damaging ultraviolet (UV) radiation–anyone can get skin cancer. New research helps explain why: different types of skin cancer can arise for different reasons, and for reasons not necessarily related to skin pigmentation and UV exposure.
There are two main types of skin cancer: non-melanoma and melanoma. Non-melanoma skin cancer, which includes basal cell carcinoma and squamous cell carcinoma, is much more common but is quite treatable in most cases. Melanoma is less common but more serious, accounting for nearly 75% of skin cancer deaths. Both types have been linked to sun/UV exposure as well as genetics, including genetic variants presented in 23andMe’s Health and Traits reports.
(23andMe customers can view their results for related Health and Traits reports. See table at the end of this post.)
A recent study in the journal Pigment Cell and Melanoma Research looked at variants linked to pigmentation (hair color, eye color, skin color), skin sensitivity to sun, and freckling and moles as they related to different types of skin cancer. They found that melanoma is associated with two different kinds of variants: those related to skin pigmentation and sensitivity to sun, and those related to the number and type of moles an individual has. Basal cell carcinoma also seemed to be associated with two separate categories of genetic variants — those linked to skin and pigmentation traits and those that are not. The researchers also identified several regions of the genome associated with one or more types of skin cancer but not with any pigmentation-related traits. These findings suggest multiple pathways leading to development of these two cancers, including some that are completely independent of skin pigmentation and sun sensitivity.
The relationship between pigmentation traits and skin cancer is complex, and it’s still not clear whether variants linked to both pigmentation and skin cancer risk are directly involved in the development of skin cancer or simply predispose to the condition. The results of this study may help guide future research to tease out the different pathways through which skin cancer can develop and the roles that specific genetic variants play in those pathways.
Variants related to pigmentation and/or skin cancer
| Variant | Pigmentation-associated? | Version | Skin cancer risk? | Version | Related 23andMe reports |
|---|---|---|---|---|---|
| rs1805007 | Yes | T (red hair, more freckling, skin more sensitive to sun) | Yes | T (higher odds of melanoma) | Melanoma (Established) Hair Color (Preliminary) Freckling (Preliminary) |
| rs1805008 | Yes | T (red or light hair) | Yes | T (higher odds of melanoma) | Melanoma (Established) |
| rs16891982 | Yes | C (darker hair) | Yes | C (lower odds of melanoma) | Melanoma (Established) |
| rs1408799 | Yes | T (lower odds of blue eyes) | Yes | T (lower odds of melanoma) | Melanoma (Preliminary) |
| rs801114 | No | Yes | G (higher odds of basal cell carcinoma) | Basal Cell Carcinoma (Preliminary) | |
| rs7538876 | No | Yes | A (higher odds of basal cell carcinoma) | Basal Cell Carcinoma (Preliminary) | |
| rs12913832 | Yes | G (higher odds of blue eyes) | No | Eye Color (Established) | |
| rs12896399 | Yes | T (higher odds of blue eyes, if eyes are non-brown) | No | Eye Color (Preliminary) | |
| rs1393350 | Yes | A (higher odds of blue eyes, if eyes are non-brown) | No | Eye Color (Preliminary) |
SNPwatch gives you the latest news about research linking various traits and conditions to individual genetic variations. These studies are exciting because they offer a glimpse into how genetics may affect our bodies and health; but in most cases, more work is needed before this research can provide information of value to individuals. For that reason it is important to remember that like all information we provide, the studies we describe in SNPwatch are for research and educational purposes only. SNPwatch is not intended to be a substitute for professional medical advice; you should always seek the advice of your physician or other appropriate healthcare professional with any questions you may have regarding diagnosis, cure, treatment or prevention of any disease or other medical condition.
