Melanoma is a type of skin cancer that originates in the cells that produce melanin, which gives skin its color. It is one of the most common cancers. If it’s caught early, it can usually be treated easily and cured. However, melanoma can spread and become fatal if left untreated.
Key Facts | Causes | Symptoms | Diagnosis | Treatment | Outlook | Next Steps
- When normal cells divide, they copy their genetic material (or DNA), which make up genes. Melanoma occurs when a melanocyte skin cell makes a mistake in copying one or more genes that control cell growth, leading to abnormal or uncontrolled growth. This is most often caused by damage from ultraviolet (UV) radiation, which can come from too much exposure to the sun.
- Common signs of melanoma are irregular moles, lesions, or other marks or sores on the surface of the skin.
- Depending on the melanoma’s severity, there are a variety of treatments. These include non-surgical options such as radiation therapy and medical therapy, as well as surgical options.
Melanoma forms when the DNA in melanocytes, skin cells that produce melanin which gives skin its pigment, becomes damaged. This can often lead to mutations that make the skin cells multiply out of control, eventually forming cancerous growths.
DNA damage in melanocytes is most often caused by ultraviolet (UV) radiation, such as from the sun or tanning beds. Excessive UV exposure, especially when it results in sunburns, can increase the risk of melanoma years later.
Other factors that can increase the risk of developing melanoma include the following:
- Age: Melanoma is more common among older people, although it can occur at any age. In fact, it is one of the most common cancers for people under 30.
- Fair Skin: Having a fair complexion means there is less melanin (pigment) in the skin to protect against harmful UV radiation. However, melanoma can still develop in those with darker complexions.
- Family History: Those who have had a close relative (such as a parent, sibling, or child) develop melanoma are at a greater risk of developing melanoma themselves.
- Presence of Many Moles: A large number of moles, especially if they are big or have an irregular shape, can indicate an increased risk of developing melanoma.
The first sign or symptom of melanoma is typically an unusual mole, blemish, sore, or some other type of mark on the skin. In most cases, it will develop in places that regularly receive exposure to the sun, such as the face, neck, arms, or legs. But melanoma can also appear in areas that do not get much UV exposure, such as the soles of the feet or underneath a nail.
Identifying Unusual Moles
Unusual moles, lesions, or other marks that may be a sign of melanoma usually have certain characteristics. To help identify them, physicians use the ABCDE rule:
- A is for Asymmetry: One half of a mole or birthmark does not match the other half.
- B is for Border: The edges are irregular, ragged, notched, or blurred.
- C is for Color: The color is not the same all over and may include shades of brown or black, or sometimes patches of pink, red, white, or blue.
- D is for Diameter: The spot is larger than 6 millimeters across (about ¼ inch – the size of a pencil eraser), although melanomas can sometimes be smaller than this.
- E is for Evolving: The mole changes size, shape, or color over time.
Some moles or marks may have all of these characteristics, while others may have only one or two of them — or none at all. Because cancerous (malignant) moles can look very different, it is important to always have them checked by a physician.
Identifying Other Types of Melanoma
Melanoma doesn’t always present itself as an unusual mole or mark on the skin. Sometimes, it can appear in less obvious places and be mistaken for something else. These are described as hidden melanomas. They include the following:
- Acral-Lentiginous Melanoma: This is a rare type of melanoma that occurs beneath toenails and fingernails, or sometimes on the palms of hands or soles of feet. It can look like a dark streak, bruise, or spot.
- Mucosal Melanoma: This type of melanoma develops in the mucous membranes within the body. This means it may occur in the digestive tract, urinary tract, mouth, or vagina. Symptoms may include itching, bleeding, discoloration, or pain.
- Ocular Melanoma: This type of melanoma develops in the eye. The most common sign is a sudden change in vision.
Diagnosing melanoma will begin with a thorough review of the patient’s medical history, followed by a physical exam. During this exam, the doctor may closely inspect the patient’s entire body for any signs of melanoma (see above). The doctor may also check for enlarged lymph nodes, which are a sign that cancer may have spread.
If the doctor suspects melanoma, a biopsy may be done. This involves removing a sample of tissue so that it can be examined for cancerous cells under the microscope. There are several different types of biopsies:
- Shave Biopsy: The top layer of skin is removed with a small surgical blade. This type of biopsy is usually done when the risk of melanoma is low.
- Punch Biopsy: Using a small circular blade, a portion of each layer of skin is removed. The edges are then stitched back together.
- Incisional Biopsy: A sliver or wedge of the lesion is removed for further examination.
- Excisional Biopsy: The entire lesion is removed.
If melanoma is diagnosed, then the next step is to determine how far the cancer has spread (its stage). Depending on the suspected severity, there are several different ways to do this:
- Sentinel Lymph Node Biopsy: A radiolabeled protein and a blue dye are injected into the skin immediately surrounding the melanoma, often at the time of melanoma resection. The protein and dye get taken up by the lymph nodes that drain that area of skin. These lymph nodes are removed and examined under the microscope to determine if melanoma cells are present. A positive or negative sentinel lymph node biopsy is one of the strongest predictors of whether the melanoma has spread to other parts of the body.
- Imaging Tests: In advanced cases, imaging tests may be used to examine other organs for cancer. These test often include a CT scan of the chest, abdomen, and pelvis, brain MRI, and PET/CT scan.
Depending on its severity, there are several different types of treatments available for melanoma.
If the melanoma is detected early and has not spread, then the best treatment is often surgical removal. For small lesions, this can be done during the biopsy. In other cases, a surgeon can remove the melanoma tumor. In many cases, no other treatment will be needed.
If the cancer has spread, the following are some other treatment options:
- Lymph node dissection: The surgical removal of any affected lymph nodes. This is often paired with additional treatment, such as radiation therapy, to ensure the cancer is removed.
- Radiation Therapy: High doses of radiation, such as x-rays, are directed at the cancer. This treatment may be used to remove cancer from lymph nodes or from areas where a tumor cannot be surgically removed.
- Targeted Therapy: Drugs that target specific growth pathways in melanoma can be administered. Examples of these drugs include dabrafenib (a BRAF inhibitor) and trametinib (a MEK inhibitor). The combination of dabrafenib and and trametinib can be used for melanomas that have a BRAF V600 mutation.
- Immunotherapy: Drugs are given that help the body’s own immune system to target and attack cancer cells. This treatment is often used after surgery. Examples of these drugs include PD-1 antibodies such as pembrolizumab and nivolumab and CTLA-4 antibodies such as ipilimumab. These drugs essential take the brakes off the immune system, allowing the immune system to fight the melanoma.
- Chemotherapy: Drugs are administered throughout the body to kill cancerous cells. This type of treatment is usually only used when the melanoma has spread to other parts of the body and other treatments have not worked.
See Melanoma Treatments for more detailed information.
When melanoma is diagnosed early and treated before it has spread, it can usually be removed or destroyed completely. Even when it has spread to lymph nodes or other organs, there are still plenty of viable treatment options. However, as with any cancer, there is always the risk that it will come back. This is why it’s important to take preventative measures, get regular follow-up care, and sometimes get additional treatments.
The American Cancer Society divides the five-year survival rate for melanoma skin cancer into localized cases (no sign the cancer has spread), regional cases (it has spread to nearby lymph nodes), and distant cases (it has spread throughout the body):
- Localized: 99 percent
- Regional: 65 percent
- Distant: 25 percent
Anyone who has had melanoma, even if it was diagnosed and treated early, is at a higher risk of developing it again. This makes it important to continually check for unusual moles or any other marks, as well as schedule regular appointments with a dermatologist or oncologist. Depending on the severity of the melanoma, these appointments may need to take place as infrequently as once a year or as often as every six months.
Taking steps to lower the risk of melanoma is important for those who have had it. The best way to do this is to limit exposure to UV radiation. Avoid tanning beds and take necessary precautions when out in the sun, such as applying sunscreen, wearing a hat or other protective clothing, and using sunglasses.
Whether you need diagnosis, treatment, or preventative care, the Melanoma Center offers each patient access to a comprehensive list of services. These include a variety of both surgical and non-surgical treatments, as well as additional programs like clinical trials and support groups.
Call us at (212) 305-0273 to schedule an appointment.