Melanoma Risk Factors, Types, and Stages
Melanoma is a type of skin cancer. It affects melanocytes, which are cells in the skin's outer layer (epidermis).
Melanocytes make melanin, the pigment that gives skin color and helps protect it from the sun's UV rays. Melanomas form when melanocytes grow in abnormal ways.
Melanoma cases in the U.S. doubled between 1982 and 2011.
During the last 10 years, incidence rates of melanoma have:
- Declined in people under 30.
- Increased in people 80 and older.
Death rates from melanoma declined by 4% between 2014 and 2019. New treatments for advanced melanoma — such as immunotherapy — have helped lead to this decline.
When to Talk to Your Doctor About Melanoma
Melanoma is an aggressive cancer that can often spread to other parts of the body when left untreated. Early detection and treatment are crucial to preventing the spread.
Check your skin often so you know what's normal for you. This will help you spot any changes.
Tell your doctor about:
- Moles or patches with uneven edges (borders) or shapes that aren't round or oval (asymmetrical).
- Black, brown, pink, tan, or white moles that have different shades of color within the same mole.
- Large moles that are bigger than a pencil's eraser.
- Moles or spots that change (evolve).
- Moles or spots that bleed, itch, or form a crust.
UPMC Hillman Cancer Center offers free monthly skin cancer screenings. To make an appointment, call 412-692-4724.
Melanoma Risk Factors
Some people are at higher risk of getting melanoma.
It's vital to know common melanoma risk factors.
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.
Types of Melanoma
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.
If you have melanoma, your doctor will find out if it has spread and, if so — how far (stages the disease). Your doctor will then decide the best course of treatment based on its stage.
To stage melanoma, doctors remove part — or all — of the tumor during a biopsy.
They then study the tissue to learn the:
- Tumor depth (thickness). Doctors measure how deep (in millimeters) the tumor extends into the skin.
- Tumor ulceration. Doctors check to see if the skin on top of the melanoma has broken open, forming an ulcer. Melanomas with ulcers are more likely to spread.
- Mitotic rate. Doctors measure how fast the melanoma cells are dividing and growing. When a melanoma has a high mitotic rate, it may be more likely to spread.
After doctors assess the melanoma tissue, they assign a stage — 0 through VI.
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:
Contact Us About Melanoma and Skin Cancer Care
To learn more about melanoma and skin cancer care or to make an appointment, you can:
- Call 412-647-2811.
- Contact a UPMC Hillman Cancer Center near you.
- Call 1-800-533-8762 for a cancer screening.