What to know about melanoma

Melanoma is a type of skin cancer that occurs when pigment-producing cells called melanocytes mutate and begin to divide uncontrollably.

According to the American Cancer Society (ACS), although it is much less common than other types of skin cancer, it can be more dangerous as it is more likely to spread to other parts of the body.

Melanoma can develop anywhere on the body. In those with light skin, it is more likely to develop on:

• the chest and back, in males
• the legs, in females
• neck
• face

However, melanoma can also occur:

• in the eyes
• nose
• mouth
• throat
• genital or anal area

The ACS estimates that there will be about 100,640 new cases of melanoma in 2024. They also estimate that around 8,290 people will die due to melanoma in 2024.

Types

There are four main types of melanoma, which include:

• Superficial spreading melanoma: Superficial spreading melanoma is the most common type of melanoma. It begins by developing on the top layer of the skin. A person may notice a flat or slightly raised asymmetrical patch that has uneven borders. The patch can be shades of brown, black, tan, red, pink, blue, or white. It may also be the same color as the surrounding skin.
• Nodular melanoma: Nodular melanoma is the second most common type of melanoma, appearing on the trunk, head, or neck. It tends to grow quicker than other types, and it may appear as a reddish or blue-black color.
• Lentigo maligna melanoma: Lentigo maligna melanoma is less common and tends to develop in older adults, especially in parts of the body that have had excessive sun exposure over several years, such as the scalp, face, neck, ear, upper arms, and upper torso. A person may notice a flat or slightly raised blotchy patch that has uneven borders. It can be blue to black or varying shades of brown.
• Acral lentiginous melanoma: Acral lentiginous melanoma is the rarest kind of melanoma. It appears on the palms of the hands, soles of the feet, or under the nails. This tends to be the most common type of melanoma in those with dark skin tones.

In its early stages, melanoma can be challenging to detect. It is essential to check the skin for any signs of change.

Alterations in the appearance of the skin are vital indicators of melanoma. Doctors use them in the diagnostic process.

A person can look out for the following signs:

• any skin changes, such as a new spot or mole or a change in the color, shape, or size of an existing spot or mole
• a skin sore that fails to heal
• a spot or sore that becomes painful, itchy, or tender
• a spot or sore that starts to bleed
• a spot or lump that looks shiny, waxy, smooth, or pale
• a firm lump that bleeds or looks ulcerated or crusty
• a flat, inflamed spot that is rough, dry, or scaly

The ACS offers pictures of different skin cancers to help a person learn how to distinguish between normal and cancerous moles.

ABCDE examination

The ABCDE examination of moles is an important method for revealing potentially cancerous lesions. It describes five characteristics to check for in a mole that can help a person either confirm or rule out melanoma:

• Asymmetric: Non-cancerous moles tend to be round and symmetrical, whereas one side of a cancerous mole is likely to look different to the other side.
• Border: This is likely to be irregular rather than smooth and may appear ragged, notched, or blurred.
• Color: Melanomas tend to contain uneven shades and colors, including red, black, brown, and tan. They may even contain white or blue pigmentation.
• Diameter: Melanoma can cause a change in the size of a mole. For example, if a mole becomes larger than 6 millimeters, it might be cancerous.
• Evolving: A change in a mole’s appearance over weeks or months can be a sign of skin cancer.

The stage of cancer at diagnosis will indicate how far it has already spread and what kind of treatment will be suitable.

One method of assigning a stage to melanoma describes the cancer in five stages, from 0 to 4:

• Stage 0: The cancer is only present in the outermost layer of skin. Doctors refer to this stage as “melanoma in situ.”
• Stage 1: The cancer is up to 2 millimeters (mm) thick. It has not yet spread to lymph nodes or other sites, and it may or may not be ulcerated.
• Stage 2: The cancer is at least 1 mm thick but may be thicker than 4 mm. It may or may not be ulcerated, and it has not yet spread to lymph nodes or other sites.
• Stage 3: The cancer has spread to one or more lymph nodes or nearby lymphatic channels but not distant sites. The original cancer may no longer be visible. If it is visible, it can be any thickness and also ulcerated. It may also involve satellite tumors, which are tumors that develop near the primary tumor.
• Stage 4: The cancer has spread to distant lymph nodes or organs, such as the brain, lungs, or liver. The tumor may or may not be ulcerated.

The more advanced a cancer is, the harder it is to treat and the worse the outlook becomes.

Read more about late-stage melanoma.

Research into the exact causes of melanoma is ongoing. However, scientists do know that people with certain skin types are more prone to developing melanoma.

The following factors may also contribute to an increased risk of skin cancer:

The risk of melanoma is much higher for people with lighter skin color, red or blonde hair, blue or green eyes, or skin that burns easily.

Other risk factors include:

• a high density of freckles or a tendency to develop freckles following exposure to the sun
• a high number of moles
• 10 or more atypical moles
• the presence of actinic lentigines, also known as liver spots or age spots
• giant congenital melanocytic nevi, a type of brown birthmark
• high sun exposure, particularly if it produces a blistering sunburn, and if sun exposure is intermittent rather than regular
• older age
• a family or personal history of melanoma
• a previous organ transplant

Of these risk factors, only sun exposure and sunburn are avoidable. Avoiding overexposure to the sun and preventing sunburn can significantly lower the risk of skin cancer. Tanning beds are also a source of damaging ultraviolet (UV) rays.

A person can detect the early signs of melanoma themselves by regularly examining existing moles and other colored blemishes and freckles.

People should have their backs checked regularly, as it may be harder to see moles in this area. A partner, family member, friend, or doctor can help check the back and other areas that are hard to see without assistance.

Any changes in the skin’s appearance require further examination by a doctor.

Some apps claim to help a person identify and track changing moles. However, many are not reliable.

Learn more about apps for detecting skin cancer.

Clinical tests

Doctors and dermatologists may use microscopic or photographic tools to examine a lesion in more detail.

If they suspect skin cancer, they will have a dermatologist biopsy the lesion to determine whether or not it is cancerous.

A biopsy is a procedure wherein a medical professional takes a sample of a lesion and sends it for examination in the laboratory.

The treatment of skin cancer is similar to that of other cancers. However, unlike many cancers inside the body, it is easier to access the cancerous tissue and remove it completely. For this reason, surgery is the main treatment option for melanoma.

Surgery involves removing the lesion and some of the non-cancerous tissue around it. When the surgeon removes the lesion, they send it to pathology to determine the extent of the involvement of the cancer, and to make sure that they have removed all of it.

If melanoma covers a large area of skin, a skin graft may be necessary.

If there is a risk that the cancer has spread to the lymph nodes, a doctor may request a lymph node biopsy.

They may also recommend radiation therapy for treating melanoma.

Melanoma may metastasize, or spread, to other organs. If this happens, a doctor will request treatments depending on where the melanoma has spread, including:

• chemotherapy, in which a doctor uses medications that target the cancer cells
• immunotherapy, in which a doctor administers drugs that work with the immune system to help fight the cancer
• targeted therapy, which uses medications that identify and target particular genes or proteins specific to melanoma

Although there is no sure way to prevent melanoma, the most important way is to limit ultraviolet (UV) exposure. To do this, a person can:

• wear sun-protective clothing, such as:
  • wide-brimmed hats
  • sunglasses with UV protection
  • lightweight, long-sleeved shirts
• seek the shade
• avoid tanning beds

It is essential to apply sunscreen with an SPF of 30 or higher. The American Academy of Dermatology recommends the following:

• Apply sunscreen on all skin that is not covered by clothing, not forgetting the:
  • tops of the feet
  • ears
  • neck
  • top of the head
• Apply sunscreen 15 minutes before going outdoors.
• Reapply sunscreen every two hours, or after swimming or sweating.
• Apply a lip balm that contains an SPF of 30 or higher

Learn more about choosing the best sunscreen.

What about vitamin D?

The American Academy of Dermatology (AAD) does not currently recommend sun exposure (or tanning) for the purpose of obtaining vitamin D.

Instead, they suggest that healthy adults obtain vitamin D from a diet that includes foods naturally rich in vitamin D or foods and drinks fortified with vitamin D.

Can changing my diet help prevent melanoma?

According to 2023 research the effects of nutrients in reducing the risk of melanoma is not clear.

A 2021 article states that it is not currently possible to formulate recommendations for or against any specific diet or foods to help prevent melanoma.

Melanoma is an aggressive type of cancer that can be dangerous when it spreads. However, people who identify a lesion early can have a very good outlook.

The ACS have calculated the 5 year relative survival rates for melanoma. These compare the likelihood that a person with melanoma will survive for 5 years with that of a person without cancer.

The 5-year relative survival rate for melanoma is as follows:

Is melanoma curable?

The Skin Cancer Foundation states that melanoma is usually curable if it is found and treated early.

It is important to monitor any changing moles and seek medical attention for any that are changing, irregular, growing, or bleeding.

Melanoma is a type of skin cancer that develops when the pigment-producing cells mutate and divide uncontrollably.

Although less common than other types of skin cancer, it can be dangerous as it is likely to spread to other parts of the body.

A person should speak with a doctor if they notice any new moles or any changes to current moles.