Metastatic Melanoma: Symptoms, Stages, Treatment

Metastatic melanoma is an advanced form of melanoma. This subtype is one of the most dangerous types of skin cancer.

Melanoma begins in skin cells called melanocytes. Melanocytes produce melanin, the pigment that gives skin much of its color and provides some natural protection against ultraviolet radiation. These skin cells also produce moles, which are usually harmless but occasionally can become cancerous.

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

What Is Metastatic Melanoma, and How Does It Differ From Melanoma?

Melanoma is any cancer that originates in the melanocytes, while metastatic melanoma is melanoma that spreads from the skin to other parts of the body, such as the lymph nodes, liver, lungs, bones, and brain.

Causes and Risk Factors for Metastatic Melanoma

Everyone — of every age, sex, race, and ethnicity — faces some level of melanoma risk, including the metastatic kind, but certain factors raise the odds. These include:

Family History of Melanoma: Around 10 percent of people with melanoma have a first-degree family member with the disease, such as a parent, sibling, or child.

Personal History of Melanoma or Other Skin Cancers: Having had melanoma raises the risk of getting it again. Having another type of skin cancer, such as basal or squamous cell skin cancer, is also a risk factor.

Having a Weakened Immune System: People with conditions that weaken the immune system, such as HIV, are at higher risk of developing melanoma. People taking medication to suppress the immune system after an organ transplant are also at higher risk.

Advanced Age: Older people are more likely to develop melanoma than younger people. But younger people aren’t free of risk. In fact, melanoma is one of the most common cancers in people younger than 30.

Gender: Among people in the United States older than 50 years old, men are at a higher risk of developing melanoma than women. Before age 50, women are at greater risk.

What Are the Symptoms of Metastatic Melanoma?

Many people find out they have melanoma when symptoms prompt them to visit the doctor.

They may be concerned about a mole that is painful, itchy, or bleeding; that oozes or becomes scaly or lumpy; or that shows other signs of abnormality.

Doctors look for evidence of cancer in moles using what’s called the ABCDE method:

• 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, typically larger than 6 millimeters (mm), or ¼ inch.
• E: It evolves, changing size, color, shape, or another characteristic.

It’s possible that by the time a physician diagnoses melanoma on the skin, cancer cells have already spread to other parts of the body. Melanoma can also spread to a different part of the body after initial diagnosis and treatment.

Lymph Nodes

Symptoms of melanoma that has spread to the lymph nodes may include:

• Hard lumps under the skin
• Difficulty swallowing (because of swollen lymph nodes in the neck)
• Swelling in the neck or face (because of fluid buildup, a condition called lymphedema)

Lungs

Melanoma that has spread to the lungs can cause the following symptoms:

• A persistent cough
• Breathlessness
• Ongoing chest infections
• Coughing up blood
• Fluid buildup between the chest wall and the lung

Liver

Metastatic melanoma in the liver can cause:

• Discomfort or pain on the right side of the abdomen
• Poor appetite and weight loss
• Abdominal swelling
• Yellowing of the skin and eyes (jaundice)
• Itchy skin

Bone

The following symptoms may indicate metastatic melanoma:

• Gnawing pain (caused by the breakdown of bone)
• Worsening backache
• Weaker bones that break more easily
• Raised blood calcium, which can cause dehydration, confusion, abdominal pain, and constipation
• Low levels of blood cells (which are produced in healthy bone but crowded out by cancer cells), which can cause bruising, bleeding, and an increased risk of infection

Brain

Melanoma that has spread to the brain can cause:

• Headaches
• Muscle weakness
• Seizures
• Personality or mood changes
• Eyesight changes
• Confusion

Diagnosis of Metastatic Melanoma

During a physical exam, a doctor will examine any suspicious moles or areas of the skin for signs of melanoma. They will also ask about possible risk factors.

The physician may also feel the lymph nodes under the skin in the neck, underarm, groin, or behind the knees near the abnormal area to check for any unusual enlargement.

Next, the doctor will likely collect a skin sample from the area in question to study under a microscope for cancer cells. If the lab results confirm melanoma, physicians may take samples of other tissues, too, to check for metastases. In this case, the doctor may start with the lymph nodes nearest the primary skin lesion.

Imaging tests, such as X-rays or computerized tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET) scans, can also look for enlarged lymph nodes or cancerous spots on the lungs, liver, and other body parts.

In rare cases, melanoma metastasizes quickly, before the original tumor on the skin is large enough to be detected. In these cases, physicians may first biopsy tissue from an area of metastasis to figure out what type of cancer the patient has.

For instance, a biopsy may determine that cancerous spots on the liver are not liver cancer (cancer that originates in liver cells) but skin melanoma that has metastasized.

Stages of Metastatic Melanoma

Assigning a stage to a melanoma aims to describe how advanced the cancer is.

For patients with metastatic disease, determining the stage is crucial for identifying those who may be eligible for experimental treatments.

Stage 0

The melanoma is confined to the outermost layer of the skin; it has not spread.

Stage 1

The melanoma is no more than 2 mm thick and has not spread to lymph nodes or distant sites. Stage 1 is further divided according to tumor thickness and ulceration.

Stage 2

The melanoma has not spread to lymph nodes or distant sites but has features associated with higher risk, based primarily on its thickness and whether it is ulcerated, which is a sign of danger characterized by a breakdown of the skin over the tumor.

Stage 3

Stage 4

Metastatic Melanoma Treatment Options

Immunotherapy

Immunotherapy uses the body’s own powerful immune system to treat metastatic melanoma.

Another viable approach for using immunotherapy to treat metastatic melanoma is to combine checkpoint blockade therapies. Doing so may increase the chance of serious side effects, yet researchers are finding that this strategy can improve survival rates to such an extent that it’s a valuable option for some patients, despite the risks involved.

Targeted Therapies

A new generation of melanoma therapies works by targeting mutations (DNA defects) in melanoma cells, shrinking tumors or slowing their growth.

About one-half of all melanomas have mutations (DNA defects) in the BRAF gene that are responsible for out-of-control cellular growth.

These three combination therapies are now approved:

• dabrafenib (Tafinlar) and trametinib (Mekinist)
• vemurafenib (Zelboraf) and cobimetinib (Cotellic)
• encorafenib (Braftovi) and binimetinib (Mektovi)

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Prognosis for Metastatic Melanoma

Until recent years, a metastatic melanoma prognosis gave patients very little reason to hope.

But since 2011, physicians have had access to remarkable new drugs that are helping many patients live significantly longer.

Many patients with metastatic melanoma are responding to the new treatments, extending their lives by months and years. Some are even going into long-term remission.