What you need to know about skin cancer and how to prevent it, according to a doctor

Get inspired by a weekly roundup on living well, made simple. Sign up for CNN’s Life, But Better newsletter for information and tools designed to improve your well-being.

CNN
 — 

Skin cancer is by far the most common form of cancer in the United States, according to the American Cancer Society.

With summer coming in the Northern Hemisphere, it’s time to check in with CNN wellness expert and emergency physician Dr. Leana Wen about the dangers of skin cancer and the need for safe sun exposure.

As we head into summer, what do we need to know about the chance of developing skin cancer? And how can someone know if a mole or skin discoloration needs to be checked out? Which health care provider should be contacted if there is a concern? Should people get full-body skin cancer screening exams? Are self-exams useful?

Wen has some answers for us, as well as steps everyone can take to reduce the risk of developing skin cancer. An emergency physician and adjunct associate professor at George Washington University, she previously was Baltimore’s health commissioner.

CNN: I was surprised to learn that skin cancer is so common. What are the major forms of skin cancer?

Dr. Leana Wen: There are three main forms of skin cancer. The most common type is called basal cell carcinoma. These cancers can look like an elevated transparent bump on the skin and most frequently occur on the head, neck and other areas most exposed to the sun. Although these cancers generally develop slowly, they can grow deep and damage nerves and bones.

Squamous cell carcinoma is the second most common type of skin cancer. These often resemble a red bump and may manifest as a sore or wound that heals and then opens up again. These, too, tend to appear in areas with frequent sun exposure and can also appear on the lip and ear. They can grow deep and spread to other parts of the body.

Melanoma is the third type that is critical to know. That’s because while it only accounts for 1% of total cancers, it is the cause of the majority of deaths from skin cancer. In the United States in 2024, more than 8,000 people will die annually from this cancer.

Melanoma can develop within a mole that already exists or as a new dark spot on the skin. There is also an association with sun exposure and melanoma. According to the American Cancer Society, though melanoma risk increases with age, it is one of the most common cancers in young adults.

CNN: How can someone know if a mole or skin discoloration should be checked out by a medical professional?

Wen: There is an “ABCDE” rule that describes warning features that could signify a melanoma. A is for asymmetry, if the shape of one half of the mole does not match the other. B is for border. A mole with blurred, irregular edges could be concerning. C is for color, meaning a mole that has multiple colors and shades. D is for diameter. Some melanomas can be very small, but most are over 6 millimeters, about ¼ inch, wide. E is for evolving, meaning that the mole has changed over the past weeks or months.

Anyone who notices these features of a mole should get it checked out. In addition, people who notice a new growth, a spot or bump that is increasing in size over time, a skin discoloration that is causing discomfort or a sore that doesn’t get better should also seek medical attention.

CNN: Should people make an appointment with a dermatologist? What if they don’t have one?

Wen: Those who have a dermatologist should contact that person first. Sometimes, a referral from a primary care provider may be necessary.

People who have concerning signs that could point to melanoma should clearly state this as a reason — that they have a change in size or color of a mole, for example, and they are concerned about skin cancer.

CNN: Is it recommended for everyone to receive regular skin cancer screening tests?

Wen: The influential US Preventive Services Task Force issued a recommendation in 2023 that there is insufficient evidence to assess the benefits versus risks of regular visual skin examination as a method to screen for skin cancer.

It’s important to note that this is the general recommendation for people at average risk for skin cancer who have no suspicious moles or spots. People who do see concerning new skin changes should be sure to contact their physician right away.

In addition, those who are at increased risk for skin cancer should ask a…