Melanoma Risk Factors and Prevention

Most people are aware that melanoma is a skin cancer that can spread earlier and more quickly than the other skin cancers. Our awareness in the public and in the medical community is increasing about how the sun causes skin damage. There are great sites on the internet with an incredible amount of information about all aspects of melanoma. In this article, I will narrow down that information and answer a few basic questions.

Woman undergoing a skin cancer check

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Melanoma is a cancer in melanocytes, or pigment-producing cells, in the skin. There are other types of skin cancer that don't spread, but melanoma is the type that can spread to other areas of the body, or metastasize. It most frequently appears on the trunk in men and on the legs in women, but it can occur anywhere on the body.

Melanoma is the eighth most common cancer in the United States and causes 1-2% of all cancer deaths. The incidence of melanoma has been increasing faster than any other cancer over the past 20 years. The way to decrease your chance of developing melanoma is to recognize if you are at risk and take measures to decrease that risk or be more vigilant.

Risk Factors

The following are risk factors from the highest to lowest risk. Also, the more risk factors you have, the higher your chances are of getting melanoma.

  • A mole that is changing
  • Atypical nevus syndrome
  • Having a mole that is >15cm in diameter and has been present since birth
  • White race
  • A prior skin cancer
  • A close family member with melanoma
  • Using a tanning bed ten times a year or more before age 30
  • More than 50 moles on your body
  • Suppression of the immune system
  • The tendency to burn and freckle instead of tan


The best prevention is to recognize any risk factors you may have and take steps to prevent sun damage. Use a sunscreen that has at least an SPF of 15 anytime you go out in the sun. If you have several risk factors you should probably use a sunscreen all the time with an SPF of 30. There are several moisturizers you can buy that already have sunscreen added to them.

Recognizing Suspicious Moles

The common rule of thumb is to apply the ABCDs.

  • Asymmetry - Draw a line through the middle of the mole. If the halves don't match, the mole is asymmetric and more likely to be abnormal.
  • Border - The borders of atypical moles are not well defined or can look scalloped with notches between the scallops.
  • Color - An uneven color throughout the mole is more likely a sign of abnormality. This is especially true if all the other moles on your body are a uniform color. On the other hand, some people normally have moles that have different colors in them. The colors red, white, and blue may be patriotic, but they also are signs of abnormality.
  • Diameter - Most melanomas spread horizontally before they start to spread vertically. Therefore look for moles that are enlarging in diameter greater than 6 mm or 1/4 inch. This is about the size of a pencil eraser.


If you are concerned about a mole, you should ask your provider about it. Treatment of melanoma starts with excision of the lesion also taking at least a 1 cm border of healthy tissue around it. The stage of the cancer is determined by how many millimeters thick the cancerous tissue is. To make sure the cancer hasn't spread to other areas of the body, a chest X-ray is taken and a lab test checking the liver is also done. Depending on several factors, sometimes lymph nodes in the area are removed and examined to see if they contain cancerous cells. If the cancer has spread to other areas of the body, the best treatment is to remove the cancerous tissue if possible. Sometimes, chemotherapy is used along with removal. Radiation therapy is generally not helpful. Finally, there are controversial treatments involving interferon and vaccines.

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