Understanding Melanoma

Melanoma is the least common skin cancer but the most important to catch early. It’s almost always curable when found early, but it can become deadly if allowed to spread. Important things to know:

  • Melanoma must be taken seriously. It is more likely than other skin cancers to spread.
  • Exposure to ultraviolet rays, from the sun or tanning beds, is a main cause of melanoma.
  • Oregon has a high rate of melanoma cases compared with other states.
  • Rates have been increasing for the past four decades.
  • Melanoma can strike anyone but is much more common in white people.
  • Melanoma is more common in older people but is also one of the most common cancers among young adults.
Diagram illustrating skin anatomy for understanding melanoma and other skin cancers

What is melanoma?

Melanoma is a type of cancer that arises from pigmented cells called melanocytes. It most often occurs in melanocytes in the skin’s top layer. Less often, melanomas form in other parts of the body, such as the eyes and mouth.

Who gets melanoma?

About 101,000 new skin melanomas are diagnosed in the U.S. every year, according to the National Cancer Institute. Roughly 1.4 million Americans are living with the condition.

Causes and risk factors

Sun exposure: Damage from repeated exposure to ultraviolet rays — from the sun or tanning beds — is a factor in roughly half of melanomas. Ultraviolet rays damage the skin’s DNA, which can lead to cancer.

Family and medical history: About half of melanoma cases are linked to an inherited genetic trait. If a close relative — a parent, brother, sister or child — has had melanoma, you are at a slightly higher risk. Also, if you’ve had melanoma or basal or squamous cell skin cancer, you are at higher risk. OHSU offers expert genetic counseling and testing to learn about your risk and how to manage it.

Region: Oregon is among the top  third of states for melanoma cases. On average, about 1,300 people in Oregon are diagnosed with melanoma every year, according to the National Cancer Institute. That amounts to about 26 cases per 100,000 residents. Within Oregon, Columbia County has the highest incidence, with about 36 cases per 100,000 residents.

Race/ethnicity: Melanoma can strike anyone. It is more common among white people. Those with fair skin and with red or blond hair or blue or green eyes are at increased risk. But although people of color are less likely to get melanoma, they are more likely to die from it, because of delays in detection and diagnosis.

Age: About three in four cases are diagnosed in people age 55 or older. At the same time, melanoma is one of the most common types of cancer among those ages 25 to 39.

Gender: Melanoma is more common in men, but that varies by age. For those younger than 50, women are at higher risk. For those older, men are.

Survival rates

This chart shows that 93.5 percent of people with melanoma survive at least 5 years after diagnosis.
Based on 2013-2019 data from the National Cancer Institute’s Surveillance, Epidemiology and End Results program.

A key concept in understanding survival is five-year relative survival rate. This is the percentage of people who are alive five years after they were first diagnosed, compared with the general population. (It doesn’t count death from other causes.)

The five-year relative survival rate for melanoma is 94%. The rate is 99.6% for patients diagnosed before the cancer spreads.

It’s important to remember that these are averages. Your outlook will vary based on factors specific to you. Five-year relative survival rates also reflect, by definition, treatments that were available five or more years ago.

Melanoma symptoms

Most moles are normal and harmless. But if you notice a mole that seems different, talk to your doctor. It’s important to be familiar with your own skin so you recognize when something looks different.

You can also use the ABCDE guide:

An asymmetrical melanoma

A. Asymmetry: One side is not like the other.

A melanoma with irregular edges

B. Border: The edges are irregular or ragged.

A melanoma with color variations

C. Color: It has color variations, such as shades of brown or black, sometimes with patches of pink, red or white.

An example of a melanoma, which is typically more than 6mm in diameter.

D. Diameter: It’s more than 6 millimeters across (the size of a pencil eraser), though it can be smaller.

An example of a mole that has changed in some way over time.

E. Evolving: The mole may change in size, color or shape.

Other symptoms to watch for:

  • A spot that stands out —  one that's new or looks different from your other moles.
  • A sore that doesn’t heal.
  • Swelling or redness beyond the mole’s border.
  • Itchiness, tenderness or pain at the mole.
  • A mole that is scaly, that oozes or bleeds, or that includes a lump or bump.

Types

  • Superficial spreading melanoma: This type makes up about 70% of cases. It's the most common type in young people. The first symptom is a flat or slightly raised discolored patch with irregular borders. The patch may be tan, brown, black, red, blue or white. It can be anywhere on the body, but it's most likely on the upper back, or on the torso in men and the legs in women. This melanoma grows on the top skin layer for quite a while before invading deeper tissue.
  • Lentigo maligna: This type also stays close to the skin surface for a while. Most often, it appears flat or slightly elevated. It's most often tan, brown or dark brown. This type, which makes up about 10-15% of melanoma cases, is most often found in elderly people.
  • Nodular melanoma: This type is often invasive by the time it is diagnosed. It often appears as a bump that’s usually black but sometimes brown, tan, red, white, blue or gray. It makes up 10-15% of melanoma cases and is the most aggressive type.
  • Acral lentiginous melanoma: This type makes up 2-3% of melanoma cases. It usually appears as a black or brown discoloration under the fingernails or toenails, or on the palms or the soles of the feet. It's most often found in people with darker skin. It's the most common melanoma in Black people and Asian people.
A diagram illustrating Stage II melanomas.

Stages of melanoma

Your treatment depends on the stage of your melanoma. Your care team will determine the stage based on:

  • How deep the cancer is in your skin.
  • Whether there's ulceration (an open sore).
  • Whether cancer has spread to lymph nodes and/or other parts of your body.
  • Stage I: The melanoma is less than 1 millimeter thick and is not found in the lymph nodes or other parts of the body.
  • Stage IA: The melanoma is less than 0.8 millimeter thick and does not have ulceration.
  • Stage IB: The cancer is less than 0.8 millimeter thick and has ulceration, or it's 0.8 to 1 millimeter thick and ulcerated or not. 
  • Stage II:  The melanoma is thicker but not in the lymph nodes or other parts of the body. 
  • Stage IIA: The melanoma is thicker than 1 millimeter but no thicker than 2 millimeters and is ulcerated. Or it’s thicker than 2 millimeters but no thicker than 4 millimeters and not ulcerated.
  • Stage IIB: The melanoma is thicker than 2 millimeters but no thicker than 4 millimeters and is ulcerated, or it's thicker than 4 millimeters and not ulcerated.
  • Stage IIC: The melanoma is thicker than 4 millimeters and ulcerated.
  • Stage III: Cancer may affect lymph nodes and/or nearby skin areas.
  • Stage IIIA: The melanoma is less than 0.8 millimeters thick and may or may not be ulcerated, or it's up to 2 millimeters thick and not ulcerated. Cancer affects as many as three lymph nodes.
  • Stage IIIB: One of the following:
    • There's no sign of a primary tumor, but cancer affects one lymph node or has spread to nearby skin areas.
    • The melanoma is less than 0.8 millimeter thick and may or may not be ulcerated, or it's up to 2 millimeters thick and not ulcerated. Cancer affects as many as three lymph nodes or affects nearby skin areas.
    • The melanoma is up to 2 millimeters thick and is ulcerated, or it's up to 4 millimeters thick and not ulcerated. Cancer affects as many as three lymph nodes, or it affects nearby skin areas.
  • Stage IIIC: One of the following:
    • There's no sign of a primary tumor. Cancer may affect up to four or more lymph nodes; matted (connected) nodes may be present; and cancer may have spread to nearby skin areas.
    • The melanoma is less than 0.8 millimeter thick and may or may not be ulcerated, or it's up to 4 millimeters thick and is not ulcerated. Cancer may affect up to four or more lymph nodes; matted nodes may be present; and cancer may have spread to nearby skin areas.
    • The melanoma is more than 2 millimeters thick but no more than 4 millimeters thick and is ulcerated, or it's thicker than 4 millimeters and not ulcerated. Up to one lymph node is affected, or cancer affects nearby skin areas.
    • The melanoma is thicker than 4 millimeters and ulcerated. Cancer affects up to one lymph node and nearby skin areas, or it affects as many as three nodes and no nearby skin areas.
  • Stage IIID: The melanoma is thicker than 4 millimeters and ulcerated. Cancer may affect as many as four or more lymph nodes; matted nodes may be present; and cancer may have spread to nearby skin areas.
  • Stage IV: The melanoma has spread to organs such as the lungs, liver or brain.

Genetic testing for melanoma

Should you get genetic testing for melanoma? In this video, Dr. Sancy Leachman, director of the melanoma research program at the OHSU Knight Cancer Institute, explains the "rule of three."

Learn more

War on melanoma

The War on Melanoma is an all-fronts effort to eliminate melanoma in Oregon. See resources:

More on melanoma

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By checking your own skin, you could save your own life. Learn what to look for and what to do if you find something. Start seeing melanoma.

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