What Is Melanoma? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Melanoma is the most dangerous form of skin cancer. It is the fifth most common cancer overall, behind breast, lung, prostate, and colorectal. (1)

Melanoma is most often caused by exposure to ultraviolet (UV) rays. Overexposure to UV rays — whether from the sun, sun lamps, or tanning beds — damages the DNA of genes that control skin-cell growth. These damaged genes (mutations) instruct cells to multiply rapidly and form malignant tumors.

A melanoma often looks like a mole. It is usually black or brown, but it can also be skin-colored, purple, blue, red, pink, or white.

There are visible distinctions between benign and cancerous spots or growths. Knowing those differences and getting to a doctor as soon as you’ve detected something suspicious is vital.

When melanoma is caught early, as four out of five cases are, it is almost always curable. The five-year survival rate for melanoma that has not metastasized is over 98 percent. (1)

But when melanoma goes undiagnosed it can spread to other parts of the body, becoming more difficult to treat, with a higher risk of becoming deadly. (2)

There are three main categories of cells in the top layer of the skin, known as the epidermis:

• Squamous cells are flat cells in the surface of the skin. When they wear out, the body sheds and replaces them.
• Basal cells are located just beneath the squamous cells. They continually divide, creating new squamous cells to replace the old ones sloughed off.
• Melanocytes, at the bottom of the epidermis, produce a pigment called melanin that protects the deepest layers of the skin from the sun. These cells create moles, which are usually harmless, but may occasionally become cancerous.

Squamous-cell cancer and basal-cell cancer are much more common than melanoma. In fact, they are more common than any other type of cancer anywhere in the body.

But melanoma is more dangerous than other types of skin cancer because it is more likely to spread. Melanoma metastasis can be fatal. (3)

How Common Is Melanoma?

More than 1.2 million Americans are living with melanoma, with just about 100,000 new cases diagnosed each year.

Melanoma is more common in people with fair complexions. For white Americans, the lifetime risk is 2.6 percent, versus 0.1 percent (1 in 1,000) for Black Americans and 0.58 percent (1 in 172) for Hispanic Americans.

Rates of melanoma have been rising for the past 30 years. Even in the past decade the number of new cases has been going up. Rates are now increasing by about 1.5 percent annually. (1)

While young people can and do get melanoma — it is one of the most common cancers in young adults, especially women — the average age of diagnosis is 63.

More than 7,000 Americans die of melanoma annually. (4)

Melanomas That Aren’t on the Skin

Melanomas can develop in any part of the body with melanocytes.

Melanoma can also develop in the eye. Around 2,000 new cases of ocular melanoma are diagnosed in the United States each year.

Mucosal melanoma, which is also rare, can occur in any mucous membrane, including nasal passages, the throat, vagina, anus, or mouth. (5)

Keeping skin healthy requires taking some common-sense measures every day to avoid overexposure to UV radiation.

Finding shade, especially during the peak UV hours of 10 a.m. to 4 p.m., is critical.

Other ways to minimize UV exposure include covering up with clothing and a hat, using sunscreen (and reapplying it every two hours, or right away after swimming or heavy sweating), and avoiding tanning beds.

If you don’t succeed in preventing melanoma, you’ll want to catch the cancer early. An annual skin examination by a dermatologist as well as monthly self-exams — which require scrutinizing your skin from scalp to sole, using a hand mirror and a full-length mirror when necessary — can be a lifesaver.

Regular self-exams will help familiarize you with all the moles, spots, and other growths on your body. Having this baseline knowledge will make it easier to detect any changes in color, size, shape, or other traits that may indicate cancer. (6)

Treating — and Surviving — Melanoma

Melanoma caught early can generally be treated with surgery. With the patient under local anesthesia, the doctor cuts the tumor out, along with an area of healthy tissue surrounding it (this is called the margin).

If melanoma cells have spread to the lymph nodes or to distant parts of the body, surgery alone is not enough. In addition to removing the tumor and lymph nodes, the medical team will deploy an arsenal of treatments, often in combination.

Immunotherapy, which stimulates the body’s own immune system to destroy cancer cells, has emerged in recent years as a powerful, front-line treatment for metastatic melanoma.

In 2015, President Jimmy Carter credited a combination of surgery, radiation, and the immunotherapy drug pembrolizumab (Keytruda) with sending his cancer into full remission after melanoma had metastasized from his liver to his brain. (7)

And in 2016, a study of pembrolizumab offered some of the most impressive results ever with advanced melanoma patients. The researchers found that more than 40 percent of the patients were alive three years after starting treatment, with a significant number becoming and remaining cancer-free.

There have also been impressive advances in the field of targeted therapy. This treatment identifies mutations (genetic defects) in certain melanomas that enable scientists to create drugs that can attack specific points of vulnerability.

About half of all melanomas, for instance, have mutations in the BRAF gene. A medication called a BRAF inhibitor can prevent those cancer cells from growing, helping patients live longer. (8)

To prevent melanoma, avoiding overexposure to UV rays is the smartest thing you can do.

If you’re outside, shun the sun by wearing a broad-brimmed hat, UV-protective glasses, and garments that cover as much skin as possible. Tightly woven, loose-fitting, and dark or brightly colored clothes are the best UV shields.

A broad-spectrum sunscreen with an SPF of 15, 30, or higher is a no-brainer, offering good (though imperfect) protection.

An adult should apply about one ounce of sunscreen (about a shot glass full) at least a half-hour before UV exposure. Repeat at least every two hours or immediately after swimming or heavy sweating.

Studies show that most people use only a quarter as much as they should, getting a lot less protection than they may think. 

Learn More About Preventing Melanoma

Catching melanoma early, before it has time to spread, is the best way to come away from the experience with just a few stitches.

What’s key is knowing how to distinguish a harmless spot or growth from a potentially harmful one.

Simply put, a malignant spot or growth may just look different than the other ones near it. In a term that bridges storybook and medical lingo, public-health experts call it “an ugly duckling.”

More precisely, a mole may be malignant if it has any of the characteristics in this ABCDE guide:

A) It is asymmetrical.

B) It has an irregular border.

C) It contains more than one color or is an unusual color.

D) Its diameter is unusually big.

E) It evolves, changing size, color, shape, or another trait.

Learn More About the Signs and Symptoms of Melanoma

There are several types of skin melanoma that differ in key ways — including how common they are, where on the body they tend to develop, and how aggressive they can be.

The most prevalent, accounting for around 70 percent of cases, is superficial spreading melanoma. It typically grows slowly across the top layer of skin before penetrating.

The most aggressive is nodular melanoma, which occurs in about 10 to 15 percent of cases. This fast-growing cancer is usually invasive when it presents or is diagnosed.

Acral lentiginous, while rare, is the most common melanoma for Black Americans and other people of color. It generally appears as a dark mark underneath toenails or fingernails, on the sole of the foot, or on the palm of the hand. (2)

Learn More About the Types of Melanoma

Staging melanoma is a complex, vitally important process that both indicates how severe the cancer is and what kinds of treatment could help most.

Doctors define severity along a continuum that begins with stage 0 (zero) and goes up to stage 4. The later the stage, the more advanced the cancer.

While myriad considerations go into staging melanoma, there are three fundamentals:

1. The first focuses on the tumor itself. Doctors measure its thickness and determine whether the skin above it has ulcerated, meaning it has broken down microscopically (a danger sign).
2. The second involves examining the lymph nodes nearest the tumor to find out whether cancer cells have spread there.
3. The third requires searching for cancer cells that have metastasized to more distant sites in the body, such as the lung. These generally have the lowest survival rate.

Learn More About Melanoma Stages

Melanoma caught early, before it has time to spread, is typically fairly easy to treat: A doctor might simply excise it — cut it out — as an office or outpatient procedure.

Newer surgical methods do a much better job at sparing healthy tissue around the tumor, resulting in fewer stitches and a smaller scar.

Metastatic melanoma has traditionally been very difficult to treat. But advances in the fields of immunotherapy and targeted therapy have completely changed the game.

Immunotherapy involves triggering the body’s own immune system to fight disease. Medication is already adding months and years to many people’s lives, and even appears to be sending some patients into long-term remission.

Researchers are exploring how novel combinations of existing treatments might increase survival, with fewer side effects. 

Learn More About Melanoma Treatment

The majority of melanomas are caught at an early stage, when the cancer is still localized. When the cancer has spread beyond the site of its origin, it has metastasized. Metastatic melanoma is more difficult to treat than localized melanoma. Treatment options for metastatic melanoma include immunotherapy and targeted therapies.Learn More About Metastatic Melanoma

Favorite Orgs for Melanoma

Melanoma Research Foundation

MRF is the largest independent organization devoted to melanoma. Check out their unique peer-to-peer support plan designed to connect melanoma patients or caregivers with survivors or family members who have “been there.” Volunteers listen, share experiences, and provide emotional support and advice.

The American Melanoma Foundation

The mission of AMF is to raise public awareness about melanoma, while providing education, support, and advocacy opportunities. Their Memorials page allows you to post a heartfelt biography of a loved one who has passed away from melanoma.

Melanoma Research Alliance

The mission of the Melanoma Research Alliance is to end suffering and death due to melanoma by helping to accelerate research, advance cures, and prevent future cases. You can search for the latest melanoma clinical trials via their website.

American Cancer Society

The American Cancer Society is a go-to source for people dealing with cancer. They offer the latest in cancer news, information, and resources. We like their short and simple guide that explains the basics of melanoma.

Favorite Online Support Networks

AIM at Melanoma Foundation

Want to bond with others or talk to an expert? AIM at Melanoma Foundation makes it easy to stay connected by joining an in-person or online support group. You can also speak with a melanoma expert who can answer your top questions.

Daily Strength

Daily Strength’s skin cancer support group page allows patients and loved ones to discuss their experiences, connect with others, and find support online.

Favorite Online Store for Melanoma Products

IMPACT Melanoma

IMPACT Melanoma provides education, prevention, and support for people battling melanoma. Check out their shop, which includes a variety of sunscreen dispensers and other skin protection products.

Favorite App

SkinVision

This innovative app lets you perform high-tech skin checks on your mobile device. Simply snap a picture of your skin spot, and SkinVision will give you a low-, medium-, or high-risk score within 30 seconds. So far, the app has identified more than 27,000 skin cancers.

Favorite Blog

Melanoma Research Alliance

We love that the Melanoma Research Alliance features real-life stories of melanoma survivors on their blog page. The blog also covers information on clinical trials and new treatments.

Favorite Annual Meetings

International Congress of the Society for Melanoma Research

Want to hear about the latest breakthroughs in melanoma treatment? This is the leading conference for cutting-edge data on melanoma, with over 1,000 healthcare professionals in attendance, including researchers, oncologists, dermatologists, and surgical oncologists.