Health awareness

Understanding melanoma: The signs and risk factors

Learn more about how to detect and help prevent melanoma

April 13, 2023

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What is melanoma?

Melanoma is a serious form of skin cancer. Characterized by the uncontrolled growth of pigment-producing cells, melanoma accounts for approximately 1.7% of new cancer cases worldwide.

Melanoma can occur anywhere on the skin, including areas without sun exposure, but it’s more likely to start in certain locations, like the face and neck, legs (most common in women), and chest and back (most common in men).

Melanoma common sites

The risk of melanoma generally increases with age and incidence is greater among older populations. Melanoma is not uncommon, even among patients younger than 30 years, and is one of the most common cancers in young adults, especially young women.

In most areas of the world, melanoma diagnosis rates have been rising over the past few decades

In 2020, it was estimated that there were more than

new melanoma cases worldwide

Signs of cancerous moles

A new spot on the skin or a spot that is changing in size, shape or color, or one that looks different, is an important warning sign of melanoma and should be checked by a doctor. The ABCDE rule outlines the characteristics of moles that may be melanoma and is helpful guidance for monitoring skin changes:

Illustration A is for Asymmetry

A is for Asymmetry

One half of a mole or birthmark does not match the other.

Illustration B is for Border

B is for Border

The edges of the mole are irregular, ragged, notched or blurred.

Illustration C is for Color

C is for Color

The color is not the same all over and may include different shades of brown or black, or sometimes with patches of pink, red, white or blue.

D is for Diameter

The spot is more than 6 millimeters across (about 1/4 inch – the size of a pencil eraser), although melanomas can sometimes be smaller than this.

E is for Evolving

The mole is changing in size, shape or color.

Any of these warning signs should be discussed with a doctor, especially if you feel you are at risk for melanoma.

Risk factors of melanoma

There are many risk factors and causes of melanoma, including:

  • Ultraviolet light on your skin, such as from the sun or a tanning bed (the most common risk factor for melanoma).
  • Age — melanoma is more common in older people, but younger people are also at risk. Melanoma is one of the most common cancers in people younger than 30 years (especially among women).
  • Moles — having atypical moles, many moles and/or large moles.
  • Personal or family history — melanoma can be genetic and having a relative with melanoma can increase your risk.
  • Fair skin or a fair complexion, a lot of freckles and/or light-colored hair and/or eyes.

Ways to lower your risk of melanoma

Melanoma can’t be entirely prevented, but there are ways to lower your risk. The number one way to lower risk is to protect against UV rays, which damage the DNA of skin cells and impact the genes that control skin cell growth. The top source of UV rays is the sun. That’s why it’s important to practice sun safety every time you go outside, even on cloudy days when UV rays can still shine through. Here are a few ways to protect yourself:

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Seek shade

UV exposure is greatest between the hours of 10 a.m. and 4 p.m. If you need to be outside during these hours, seek shade — under a tree, an umbrella or an awning.

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Wear a hat

Try to find a hat with a wide brim — at least 2 or 3 inches wide — to protect your face, top of the head, ears and neck.

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Cover up

Choose clothing with a tight knit or weave, and avoid shirts that you can see through. Remember, if light is getting through, then UV rays are too.

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Use sunscreen

For extended outdoor activity, use a water-resistant, broad spectrum sunscreen with an SPF of 30 or higher.

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Wear sunglasses

Protect your eyes and the sensitive skin around them. Pick a pair of sunglasses that will block as close to 100% of both UVA and UVB rays as possible.