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Signs of Skin Cancer & Prevention

Contributor Shadi Kourosh, MD, MPH
10 minute read
Young man applies sunscreen to face

Sunlight offers incredible benefits for mental and physical health — but, like anything, too much can cause harm. Overexposure to ultraviolet (UV) radiation from the sun can cause skin damage and increase your risk of developing skin cancer. So it’s important to protect your skin before and during your time outside.

We’re primed to think about skin protection when we’re enjoying the sunshine during hot summer months. But skin cancer prevention is important all year long.

Shadi Kourosh, MD, MPH, is a Mass General Brigham dermatologist. She is also the director of Dermatology in the Community Health Program at Massachusetts General Hospital. In this article, she discusses important signs of skin cancer to watch for and share skin cancer prevention tips you need to stay safe in all four seasons.

Signs of skin cancer

When it comes to identifying skin cancer, it’s important to understand that skin cancers are not all the same. There are three main types of skin cancer:

  1. Basal cell carcinoma
  2. Squamous cell carcinoma (also known as non-melanoma carcinoma)
  3. Melanoma skin cancer

Although melanoma skin cancer is the least common of the three types, it is the deadliest. And according to Dr. Kourosh, rates of melanoma are on the rise both because of intense exposure to harmful radiation like UV rays, and unhealthy habits like indoor tanning.

When doctors look for signs of melanoma skin cancer, they use the ABCDEs:

  • Asymmetry. Watch for spots that are not symmetrical on your body.
  • Border irregularity. The borders of a mole should be fairly smooth. If they’re jagged, for example, that’s a sign it should be checked.
  • Color irregularity. Examine moles for irregular colors like pink, red, white, blue, or blue-black.
  • Diameter. Healthy moles are usually no larger than 6mm in diameter — about the size of a pencil eraser.
  • Evolution. One of the most crucial factors in evaluating a mole is whether the mole is changing over time. “If a mole is changing in size, color, or appearance in any way, or you’re experiencing symptoms such as pain, itching, crusting, or burning, it’s important to have that evaluated,” says Dr. Kourosh.

Basal cell carcinoma and squamous cell carcinoma may present differently from melanoma:

  • Basal cell carcinoma may appear as a small, fleshy bump or skin tag, an open sore that does not heal, a smooth growth that dimples in the center, or a lump with a waxy or pearly appearance.
  • Squamous cell carcinoma lesions may look like rough, reddish patches on the skin that grow quickly. They may resemble warts.

If a spot on your skin is changing in size, color, or appearance in any way or has symptoms such as pain itching crusting, it’s important to have it checked out. Watch this video to hear more of Dr. Kourosh’s tips for identifying skin cancer.

Is itchy skin a sign of cancer?

Itchy skin can be a warning sign of cancer — but itching isn’t an immediate cause for concern. There are many other reasons you could be experiencing itchy skin, including, but not limited to:

  • Dry skin
  • Skin condition such as eczema, psoriasis, chicken pox, ringworm, or hives (among others)
  • Insect bites
  • Allergic reactions
  • Reaction to medication

If you are concerned about a spot on your skin that is causing you to itch, contact your dermatologist. They can help determine the cause of your itch and help you take steps to stop it.

Are skin tags a sign of cancer?

Skin tags are not a sign of skin cancer; in fact, they are benign growths that mostly form in areas where your skin creases or rubs against itself (such as your armpits, neck, or eyelids). Skin tags are typically quite small. They’re approximately the size of a small pebble, but they can occasionally grow up to a half-inch.

However, if you notice a new growth (or cluster of growths) that look like skin tags, it’s still worth consulting with your doctor. That’s because there are some skin cancers that can cause skin-tag-like tumors. This is especially common in basal cell carcinoma and melanoma. It’s best to get an expert opinion to remove any doubt and discuss any further steps you should take.

We recommend annual skin checks if you’ve had a family history of skin cancer, if you’ve had a lot of sun exposure or sun burns, or particularly if you have a history of using indoor tanning beds.

Shadi Kourosh, MD, MPH
Mass General Brigham

Skin cancer prevention

There’s no sure-fire way to prevent skin cancer. But there are ways you can lower your risk of skin cancer. According to Dr. Kourosh, these are the top three tips for skin care prevention:

  1. Get your skin checked. “I cannot stress this enough,” says Dr. Kourosh. “We recommend annual skin checks if you’ve had a family history of skin cancer, if you’ve had a lot of sun exposure or sun burns, or particularly if you have a history of using indoor tanning beds.”

    But everyone should be making a point to have their skin evaluated by a dermatologist. “I’ve seen skin cancer in patients as young as 20 years old,” says Dr. Kourosh. “Some of my patients have darker skin types and may not be aware that they, too, are at risk of skin cancer — but skin cancer can affect all skin types so we recommend skin checks for everyone.”
  1. Wear sunscreen that will protect you from UV radiation, visible light, and infrared radiation like heat. “To protect yourself from all these rays, sunscreens need to be mineral based — meaning that when you read the active ingredients, they need to contain zinc, titanium, or iron oxide,” says Dr. Kourosh. And remember to reapply your sunscreen every 2 hours. “Fun fact: Sunscreen testing was only done for 2 hours, so we really don’t know how well they hold up after that,” she says.
  1. Protect your face from pollution. “Pollution contains toxic chemicals that can deposit and corrode the top layers of the skin, making it vulnerable to DNA damage,” says Dr. Kourosh. “A good skin care regimen to protect against pollution involves not only a mineral sunscreen but also a cleansing regimen to remove chemicals that may have deposited on the skin, and serums that contain antioxidants to protect your skin against free radicals.”

Does sunscreen prevent skin cancer?

Sunscreen is a key tool in reducing your risk of certain skin cancers — but it’s not guaranteed to completely prevent skin cancer. To ensure you’re getting the most protection possible, it’s crucial that you apply sunscreen with sun protection factor (or SPF) of at least 15 on a daily basis. And be sure to follow Dr. Kourosh’s instructions about reapplying any sunscreen every two hours, and immediately after sweating or swimming.

It’s important to take care of your skin during the summer — but year-round skin protection is critical to skin cancer prevention. If you have questions about skin cancer, or are concerned for yourself or a loved one, please reach out to your doctor for more support.

Headshot of Shadi Kourosh, MD, MPH