What is melanoma?
Melanoma, which means "black tumor," is the most dangerous type of skin cancer. It grows quickly and has the ability to spread to any organ. Early detection is important because treatment success is directly related to the size and depth of the cancerous growth.
Melanoma comes from skin cells called melanocytes. These cells produce melanin, the dark pigment that gives skin its color. Most melanomas are black or brown in color, but some are pink, red, purple, or skin-colored.
Any area of the body can be affected by melanoma. Men are more prone to develop melanoma on the trunk. Women are more likely to have melanoma on the arms and legs. About 30% of melanomas begin in existing moles, but the rest arise in normal skin.
How common is melanoma?
Melanoma accounts for only about 1% of all skin cancers, but causes the great majority of skin cancer-related deaths. It is one of the most common cancers in young people under 30, especially in young women.
The incidence of melanoma has been dramatically increasing over the past 30 years.
What are the signs of melanoma?
Knowing how to spot a melanoma is important because early melanomas are highly treatable. Melanoma can appear as moles, scaly patches, open sores, or raised bumps.
Use the American Academy of Dermatology's "ABCDE" memory device to learn the warning signs that a spot on your skin may be melanoma:
- Asymmetry: One half does not match the other half.
- Border: The edges are not smooth.
- Color: The color is mottled and uneven, with shades of brown, black, gray, red, or white.
- Diameter: The spot is greater than the tip of a pencil eraser (6.0 mm).
- Evolving: The spot is new or changing in size, shape, or color.
Some melanomas do not fit the ABCDE rule, so tell your doctor about any sores that won't go away, unusual bumps or rashes, or changes in your skin or in any existing moles.
Another tool that can be used to recognize melanoma is the “ugly duckling” sign. If a mole looks different from the others, it is the ‘ugly duckling’ and should be seen by a dermatologist.
Symptoms and Causes
What causes melanoma?
Most experts agree that a major risk factor for melanoma is overexposure to sunlight, especially sunburns in youth. Ultraviolet (UV) radiation from tanning beds also increases the risk of melanoma and has been designated a carcinogen (cancer-causing) by the World Health Organization.
Although anyone can develop melanoma, an increased risk for developing the disease is seen in people with:
- A personal history of melanoma.
- A family history of melanoma.
- Fair skin, freckles, blond or red hair, and blue eyes.
- A history of prolonged or excessive sun exposure, including blistering sunburns.
- A history of tanning bed use.
- Many moles, especially “atypical” moles.
- A weakened immune system.
Melanoma is more common in Caucasians but can occur in people of all skin types. Nonwhite individuals most often get melanoma on the palms, soles and nails.
Diagnosis and Tests
How is melanoma diagnosed?
If you have a mole or other spot that looks suspicious, your doctor may remove it and look at it under the microscope to see if it contains cancer cells. This is called a biopsy.
Once diagnosed, melanoma will be categorized based on several factors, such as how deeply it has spread and the appearance under the microscope. Tumor thickness is the most important characteristic in predicting outcomes.
Melanomas are grouped into the following stages:
- Stage 0 (Melanoma in situ): The melanoma is only in the top layer of skin (the epidermis).
- Stage I: Low-risk primary melanoma with no evidence of spread. This stage is generally curable with surgery.
- Stage II: There are features indicating higher risk of recurrence but there is no evidence of spread.
- Stage III: The melanoma has spread to nearby lymph nodes or nearby skin.
- Stage IV: The melanoma has spread to more distant lymph nodes or skin or has spread to internal organs.
Some patients may need a biopsy of nearby lymph nodes to determine if the melanoma has spread. This is called sentinel lymph node biopsy. Other necessary tests may include a chest X-ray, a computed tomography (CT) scan, a magnetic resonance imaging (MRI) scan, a positron emission tomography (PET) scan, and blood work.
Management and Treatment
How is melanoma treated?
Treatment depends on the stage of the melanoma and health of the patient.
Surgery is generally the main treatment for melanoma. The procedure involves cutting out the cancer and some of the normal skin surrounding it. The amount of healthy skin removed will depend on the size and location of the skin cancer. Typically, surgical excision of melanoma can be performed under local anesthesia in the dermatologist's office.
In the early stages of melanoma, surgery has a high probability of being curative. More advanced cases may require other types of treatment in addition to or instead of surgery. Other treatment options may include lymphadenectomy (removal of surrounding lymph nodes), radiation therapy, immunotherapy (using the patient's immune system to attack the cancer cells), and chemotherapy .
Some patients with skin cancer may participate in a clinical trial. A clinical trial is a research program conducted with patients to evaluate a medical treatment, drug or device.
Can melanoma be prevented?
You may reduce your risk of melanoma by protecting yourself from excess sun and sunburns.
- Avoid sun and seek shade, especially between 10 a.m. and 4 p.m.
- Do not use tanning beds.
- Whenever possible, wear hats with brims, sunglasses, long-sleeved shirts, and pants.
- Use a broad-spectrum sunscreen with a skin protection factor (SPF) of 30 or higher and reapply often.
- Use a lip balm with sunscreen.
- Don't forget to apply sunscreen to young children and to infants older than 6 months.
Early detection is important to minimize the risks associated with melanoma. Be sure to tell your doctor about any new or changing moles, sores, or discolorations. In addition, have your doctor routinely perform a total skin examination to look for signs of skin cancer.
Outlook / Prognosis
What is the outlook for people with melanoma?
Most skin cancers can be cured if they are treated before they have a chance to spread. However, more advanced cases of melanoma can be fatal. The earlier skin cancer is found and removed, the better your chances for a full recovery.
When should I call my doctor?
You should have a skin examination by a doctor if you have any of the following:
- A personal history of skin cancer or atypical nevi (moles).
- A family history of skin cancer.
- A history of intense sun exposure as a young person and painful or blistering sunburns.
- New, numerous, or large moles.
- A mole that is changing in size, color, or shape.
- Any mole that itches, bleeds or is tender.