Melanoma Risk Factors, Types, and Stages

Moles form when melanocytes cluster together.

If you have more than 50 moles, you may be at increased risk for melanoma. That's because people may get many moles from sun damage or certain genetic changes that increase their risk.

If you have moles, it's vital to know what a typical one looks like for you. New moles that don't look like the others, or changes to existing ones, can be a sign of melanoma.

Check your skin often to see if your moles show any concerning signs and symptoms of melanoma.

UV radiation from the sun damages DNA inside your skin cells.

This damage occurs when you get a sunburn. Even sunburns that happened long ago can increase your risk of melanoma.

Tanning beds also expose your skin to UV radiation that can damage cells and increase your cancer risk.

Certain physical features or other factors that may increase your melanoma risk include:

• Having fair skin and light eyes. You have less melanin to protect you from the sun and may be more likely to get sunburns. A sunburn can increase your melanoma risk.
• Age. Your cancer risk increases as you age. The average age of melanoma diagnosis is around 65. But it remains common in people younger than 30, so it's important for people of all ages to check their skin.
• Suppressed immune system. If your immune system is weak due to disease or organ transplant, your body may not be able to fight cancer cells. A suppressed immune system can allow cancer to grow unchecked.

If someone in your family has had skin cancer, you might have inherited genes that could increase your own risk.

You might also be more likely to form a new melanoma if you've had it in the past.

Early detection and treatment help prevent melanoma from spreading and becoming more serious.

When doctors diagnose and treat melanoma before it spreads to lymph nodes or other organs, it has a 99% five-year survival rate.

The most important thing you can do to protect yourself from melanoma is to check your skin routinely. Be sure to check areas not exposed to sunlight too, like the soles of your feet.

Ask a partner or friend to check your back and the back of your neck and ears.

This is the most common type making up 70% of all melanomas.

These melanomas are mostly flat and vary in shape and color. They tend to spread across the outer layer at the skin's surface.

Between 5% and 15% of melanomas are this type.

These large flat melanomas are tan or brown. They often occur where the skin has sun damage.

This type makes up between 10% and 15% of all melanomas.

These aggressive, often raised melanomas may be dark in color. They can grow deep into the layer of the skin called the dermis.

Just 5% of melanomas are this type, but they're the most commonly diagnosed type in people of color.

They often form on skin not typically exposed to sun, such as the soles of the feet or under the nails.

In the earliest stage of melanoma, cancer has not spread.

The tumor is in the epidermis and is noninvasive.

Melanomas at stage I have begun to grow into the next layer of skin but haven't spread to lymph nodes.

They're under 2 millimeters in thickness.

There may or may not be tumor ulceration.

Stage II has a higher mitotic rate than in stage I, but tumors haven't spread to lymph nodes or other organs.

They're at least 1 millimeter thick and could be thicker than 4 millimeters.

These tumors may have ulcers.

Stage III melanomas have begun to spread to lymph nodes. Your doctor may perform a lymph node biopsy to confirm cancer's spread.

Tumor thickness is at least 2 millimeters, and there may be ulceration.

Doctors assign a letter — A, B, C, or D— to stage III melanomas. The letter tells the tumor thickness and how far it has spread into nearby lymph nodes.

Stage III-D is the most advanced.

Stage IV is the most advanced melanoma.

Cancer has spread to lymph nodes or to distant organs, such as the:

• Brain
• Liver
• Lungs