Watch out for these signs of skin cancer, experts say
Corrections & Clarifications: An earlier version of this story misstated an early sign of melanoma. It has since been updated.
Whether it's rapidly growing spot or a red, angry-looking bump that won’t go away, noticing any new or unusual changes on your skin usually raises a few red flags. Is it a pimple, a mole or at worst, skin cancer?
Skin cancer is by far the most common type of cancer; it’s estimated as many as one in five Americans will develop it at some point in their life, according to the American Academy of Dermatology Association. Skin cancer comes in many different forms: “The three main ones that we think about are Basal cell carcinoma, squamous cell carcinoma (and) melanoma,” says Dr. Elizabeth Berry, an associate professor of dermatology at Oregon Health and Science University.
It’s alarming to receive any kind of skin cancer diagnosis, but as most dermatologists will reassure you, most conditions are treatable when caught early. That’s why it’s important to be able to identify the first signs of skin cancer.
What causes skin cancer?
Exposure to ultraviolet rays is the leading cause of skin cancer in the U.S.. The skin is the body’s largest organ, so naturally, it bears the brunt of UV emitted from the sun, says Dr. Alice Zhou, an assistant professor of oncology at Washington University in St Louis.
People with lighter skin tones have a much greater risk of developing skin cancer than people with darker skin tones. However, there’s a misconception that people with darker skin tones can’t experience skin cancer, and that’s simply not true, says Zhou.
There’s many other risk factors for skin cancer, including but not limited to: A family history of skin cancer, tanning bed use, chronic inflammation, and having a weakened immune function, says Dr. Paul Nghiem, a professor and chair of dermatology at the University of Washington School of Medicine. There are even some rare forms of skin cancer, such as Merkel cell carcinoma and Kaposi sarcoma, that are primarily virus-driven, notes Nghiem.
It’s also important to watch out for moles on the skin.
What does skin cancer look like?
Skin cancers come in all shapes and sizes, but when it comes to identifying Basal cell carcinoma, squamous cell carcinoma and melanoma, here are a few key signs to look out for:
- Basal cell carcinoma (BCC): As the most common type of skin cancer, BCC accounts for 80% of all skin cancer diagnoses in the U.S., per AAD. Typically, BCC looks like a skin-colored, translucent bump that has a bit of shine. It could also present as a small pink patch that bleeds easily, says Zhou. Most BCCs appear on areas of the body that receive regular sun exposure (including the arms, head and neck). It isn’t a particularly aggressive form of skin cancer, and it's usually very treatable, says Berry.
- Squamous cell carcinoma (SCC): The second most common skin cancer, SCC usually develops as a firm red bump that has a bit of crust in the center. They can sometimes resemble a wound, a burn scar or a sore that’s not healing properly, says Berry. It tends to have a scaly texture with bluff, ragged edges, says Zhou.
- Melanoma: Melanoma may only account for 1% of all skin cancers in the U.S., but it’s by far one of the most deadly. The fear with melanoma is that you could have it removed, but if one cancerous cell escapes, it could travel to somewhere else in the body and metastasize years later. Melanoma could easily be confused for just another benign mole, but they can take on a more ugly form as they evolve in size and shape. Very rarely, it could appear as a black or brown streak in the nail. At home, the earliest signs of melanoma can be identified with the “ABCDE” rule, says Nghiem. Per the AAD, see a dermatologist if a spot on your body is exhibiting any of the following signs:
- Asymmetry: One side of the spot is looking suspiciously different to the other.
- Border: The border around the spot has scalloped, irregular or poorly defined edges.
- Color: The spot contains various shades of black, brown, tan, white, red or blue.
- Diameter: The width of the spot is greater than 6 millimeters (approximately the size of a pencil eraser), although melanoma could be diagnosed at smaller sizes.
- Evolution: There are rapid changes to the size, shape or color of a new or existing spot. As melanoma grows, it can also develop itching, bleeding or pain.
Can skin cancer appear in areas not exposed to the sun?
Skin cancer can absolutely appear in areas of the skin that tend to not get much sun exposure.
Acral melanoma, in particular, is a subset of melanoma that grows on the palms and soles. People with darker skin tones are particularly at risk for this type of skin cancer, says Berry. It’s also possible for melanoma to arise in mucosal areas, such as the mouth, eyes and genital skin, Zhou adds.
Tips on skin cancer prevention
Skin cancer prevention starts with sunscreen. Make it part of your daily routine, no matter if it’s summer or winter. You should always wear sunscreen on any part of your body that could potentially be exposed to the sun, and during the winter, you should still be in the habit of applying sunscreen to your face daily, says Nghiem.
Select a broad spectrum sunscreen (ideally mineral-based) that’s at least 30 SPF, and be sure to reapply it every two hours. However, you shouldn’t rely on sunscreen alone to protect yourself, says Zhou. Wear protective clothing, and try to stick to the shade during the midday sun (or whenever the UV is high), she adds.
The bottom line: Skin cancer is treatable if caught early, and it’s always best to take the initiative to try and prevent it from forming full-stop. And of course, always be vigilant about checking if spots or moles are changing color—if you notice any new or unusual changes to your skin, it definitely warrants a check up with your dermatologist, says Berry.