Study: Most People Who Get Melanoma Had Few Moles

People with a lot of moles on their body are thought to be at greater risk for melanoma skin cancer than people with fewer moles or none at all. But according to a study published March 2, 2016 in JAMA Dermatology, most people who get melanoma have few or no moles, so it’s important to pay attention to your skin and perform skin self-exams.

According to study author Alan C. Geller, MPH, RN, a senior lecturer at the Harvard TH Chan School of Public Health in Boston, people at highest risk for melanoma include all people with light skin, but especially white men age 50 or older and people who use indoor tanning – regardless of whether they have a lot of moles.

“We’ve been led to believe that one is at greater risk of melanoma by being very moley – and we are not dismissing that. We are not telling people to stop screening yourself if you have lots of moles. But we are finding that number of moles is not always the decisive factor. Every American adult of light and olive complexion should be getting a baseline skin exam and should be learning how to do a skin self-examination,” said Geller.

Geller and his colleagues studied 566 people diagnosed with melanoma in Michigan and California. Dermatologists performed skin cancer exams on the participants, counting their moles and classifying them as typical (normal) or atypical (those that look a little like normal moles but also have some features of melanoma). Overall, two-thirds (66%) of the people with melanoma had fewer than 20 moles or none at all, and about three-fourths (77%) had no atypical moles. However, people who had 5 or more atypical moles were more likely to have melanoma with a worse prognosis because it was thicker or deeper in the skin.

Risk factors

Geller recommends everyone make it a habit to check their own skin once a month, and if they notice anything suspicious, get it checked out by a doctor. He says that while a family history of melanoma and a personal history of sunburns are risk factors for melanoma, his study did not show them to be as important as some other risk factors, including:

  • Age and gender. According to Geller, 50% of melanoma deaths are in white men 50 years of age and above. He says it’s especially important for these men to have any new moles checked by a doctor.
  • Indoor tanning. A study published January 27, 2016 in JAMA Dermatology found that women younger than 30 were 6 times more likely to develop melanoma if they were users of indoor tanning.
  • Skin color. Anyone can get skin cancer, but the risk is much higher for whites than for African Americans. Whites with red or blond hair, blue or green eyes, or fair skin that freckles or burns easily are at increased risk.
  • Adult survivors of childhood cancer. Geller says exposure to radiation during treatment puts people who’ve had childhood cancer at greater risk for all types of skin cancer, not just melanoma.

How to do a skin self-exam

It’s important to check your skin about once a month and report anything that doesn’t look right to your doctor. Look at your skin in a well-lit room in front of a full-length mirror. Use a hand-held mirror to look at areas that are hard to see.

Use the “ABCDE rule” to look for some of the common signs of melanoma:

  • Asymmetry: One part of a mole or birthmark doesn’t match the other.
  • Border: The edges are irregular, ragged, notched, or blurred.
  • Color: The color is not the same all over and may include shades of brown or black, sometimes with patches of pink, red, white, or blue.
  • Diameter: The spot is larger than ¼ inch across – about the size of a pencil eraser.
  • Evolving: The mole is changing in size, shape, or color.

Not all melanomas look like this, though, so point out anything you’re concerned about to your doctor. That would include:

  • Any new spots
  • Any spot that doesn’t look like others on your body
  • Any sore that doesn’t heal
  • Redness or new swelling beyond the border of the mole
  • Itching, pain, or tenderness
  • Oozing, scaliness, or bleeding

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Total Nevi, Atypical Nevi, and Melanoma Thickness An Analysis of 566 Patients at 2 US Centers. Published March 2, 2016 in JAMA Dermatology. First author Alan C. Geller, MPH, RN, Harvard TH Chan School of Public Health, Boston, Mass.

Association Between Indoor Tanning and Melanoma in Younger Men and Women. Published January 27, 2016 in JAMA Dermatology. First author DeAnn Lazovich, PhD, University of Minnesota, Minneapolis.

American Cancer Society news stories are copyrighted material and are not intended to be used as press releases. For reprint requests, please see our Content Usage Policy.