Melanoma is a form of skin cancer that starts in the pigment-producing skin cells called melanocytes. These cells become abnormal, grow uncontrollably, and aggressively invade surrounding tissues. Although melanoma is less common than other types of skin cancer, it is the most serious.
Fortunately, melanoma may be cured if caught and treated in its early stages when it affects only the skin. In more advanced stages, it may spread, or metastasize, through the blood or lymph system to other organs and bones, making a cure less likely.
You can also review the tabs at top of this page for information on melanoma risks and prevention, diagnosis, and treatment.
Unfortunately, everyone has some risk of melanoma, which is why the American Cancer Society recommends a monthly self-exam. Several factors can increase this risk, including sun exposure, skin type, genetics, and the number and type of moles you have.
Although people with light complexions tend to have a much higher risk, it’s a myth that those with darker skin are immune to melanoma. African-Americans and Hispanics, for example, tend to develop lesions on the palms and soles of the feet, where they may not be as easily detected as moles on the arms or face.
Knowing your risk factors can help you make informed decisions about prevention and screening options.
Detecting melanoma early is crucial for the successful treatment of melanoma. In fact, the five-year survival rate for melanoma that has been diagnosed at its earliest stage is approximately 99 percent. Melanoma diagnosed in later stages has a much higher mortality rate, and requires more complicated treatment as well.
Early detection techniques include:
- Self-examination: Since each of us is at risk for melanoma, the American Cancer Society recommends doing a thorough self-exam every month.
The warning signs of melanoma are often referred to as ABCDE, as in:
- Asymmetry: Two halves of a lesion that are not the same
- Border: Borders of a lesion are irregular, scalloped or vague
- Color: Color varies from one area to another, including shades of tan or brown as well as black, blue, red and white
- Diameter: A lesion that is greater than 6 millimeters in diameter, about the size of a pencil eraser
- Evolution: Lesions that change or evolve
Review all of these criteria each time you do your self-exam.
You’ve probably heard that the most effective means of preventing melanoma is to avoid the sun. Indeed, overexposure to the sun not only causes skin damage, it can contribute to the development of melanoma. Sunburns, in particular, have been conclusively linked to this type of cancer.
However, sunlight in moderation is beneficial since the skin synthesizes vitamin D through exposure. In addition to promoting bone and joint health, vitamin D has also been linked to prevention of certain types of cancer and autoimmune diseases. Dietary supplements can be helpful but are not sufficient.
According to Dr. Gregory Daniels of Moores Cancer Center, people need a minimum of 15 minutes of sun exposure each day, on hands, arms, and face, to produce enough vitamin D.
That said, it’s important to control your exposure. The following guidelines can help you to actively prevent melanoma:
- Limit your exposure to the sun, especially from 10 a.m. to 4 p.m. (hours of peak ultraviolet exposure).
- When outside for extended periods of time, wear protective clothing, including a wide-brimmed hat, a long-sleeved shirt, and pants.
- Wear sunglasses that block UV rays.
- Use a broad spectrum UVA/UVB sunscreen and apply it liberally and often. Look for the words “broad spectrum” on the product label. The “sun protective factor” or SPF number can be misleading. Some sunscreens with a high SPF prevent the skin from turning red, but allow potentially damaging UV rays to pass through.
- Apply sunscreen half an hour before exposure, and re-apply every two to three hours after swimming or perspiring.
- Use a lip balm or cream with broad spectrum sunscreen to protect your lips from getting sunburned or developing cold sores.
- Avoid tanning booths and sunlamps, which emit UV radiation and can cause skin damage.
- Don’t smoke.
- If you’re concerned about a mole or other spot on your skin, tell your doctor.
The first step in diagnosing melanoma is a thorough evaluation with your physician. In addition to an examination, you’ll be asked to answer questions about your past sun exposure, history of moles and other skin growths, and any family history of melanoma or other cancer.
While melanoma can sometimes be recognized solely by appearance, it’s typically diagnosed with a biopsy. To perform a biopsy, your physician will remove part or all of the mole or suspicious growth. This sample will be evaluated by a pathologist to see whether it contains cancerous cells.
If the sample reveals the presence of melanoma, your doctor will next determine the stage, or extent, of the cancer. By analyzing the thickness, depth of penetration and spread of the melanoma, your physician can define it by stage and decide on the appropriate treatment plan.
Other diagnostic tools for melanoma include:
A computed tomography (CT) scan uses x-rays to take detailed pictures of structures within the body. Unlike a conventional x-ray, a CT scan can show the details in soft tissues and internal organs. This diagnostic test can help to show if lymph nodes or organs are enlarged, which could be attributed to the spread of melanoma.
Also called surface microscopy or dermatoscopy, this non-invasive procedure involves the use of a dermatoscope, a special magnifying lens and light source, to microscopically examine lesions or other spots on the skin. A digital or photographic image of the spot may also be taken. Using dermascopy can dramatically increase the accuracy of a melanoma diagnosis and can also reveal that a suspicious lesion is benign (non-cancerous).
The melanoma unit offers a weekly high risk pigmented lesion clinic using dermascopy, conducted by Dr. Anna Di Nardo.
Lymph node testing
One of the keys to accurate diagnosis and treatment of melanoma is knowing whether it has spread. Lymph nodes, which filter the lymphatic system throughout the body, can show the presence or absence of cancer. Your physician may biopsy or remove lymph nodes around the site to check them.
In a test known as sentinel lymph node testing, dye is injected into the site of the lesion, where it then spreads to the closest (“sentinel”) lymph nodes. These dyed nodes can then be removed and tested for cancer without having to remove other unaffected nodes.
Genetic testing can provide information about your risk of melanoma by looking for specific gene mutations. If testing proves that you have an increased risk of cancer, you can help to reduce those risks through prevention and early detection practices.
Consider genetic testing if you have:
- A personal history of melanoma and at least one close family member with melanoma
- Two or more close family members with melanoma
- A personal history that includes three or more melanomas, even if you don’t have a family history of the disease
The primary curative treatment for melanoma is surgical removal of the cancerous tissue. Depending on the how deeply the cancer penetrates, some unaffected surrounding tissue or surrounding lymph nodes may be removed as well.
Surgery is most effective and yields the best prognosis if the lesion is very thin -- less than 1 mm -- and has not spread to the lymph nodes. You should discuss lymph node evaluation with your surgical and medical oncologists.
If the melanoma is deep (over 4 mm) or if cancer has spread to the lymph nodes, the odds shift, and there is a good chance the disease will return. In this case, adjuvant treatment – any therapy given in addition to the primary treatment – may be used after the surgery to increase the chance of a cure.
Standard adjuvant treatment may include immune stimulation, radiation therapy, participation in a clinical trial, or observation. Specific treatments include:
This form of immune stimulation (also known as biologic therapy or immunotherapy) is given intravenously five days per week for four weeks. Patients are treated in the outpatient infusion room by nurses familiar with the management of treatment-related symptoms. After this period, patients are able to give themselves a lower dose of the injection at home three times a week for 11 months.
Interferon is FDA approved for the treatment of patients at significant risk for disease recurrence (over 4mm or ulcerated primary lesion or lymph node positive). The success of this treatment depends on proper patient education and the experience of the medical center, both hallmarks of Moores Cancer Center.
Interleukin 2, also known as IL 2
This is a vaccine-like drug given by injection at the lesion site that stimulates the body’s own immune system to fight recurrence of melanoma. The use of IL 2 also requires a highly trained staff and special protocols to deliver it safely and effectively.
Interferon and interleukin 2 are not appropriate for all patients. UCSD has an active clinical trials program looking at novel therapies for the prevention of melanoma recurrence. Current and past clinical trials have included biologic and chemotherapy combinations, vaccines and immune stimulants.
In some patients, close observation is a more appropriate adjuvant treatment than interferon or a clinical study. Aggressive use of imaging (PET, CT and MRI) coupled with a coordinated program of medical oncology, surgical oncology and dermatology are utilized in following patients.
Other treatment options
Thousands of patients have been enrolled in clinical studies in an effort to identify more effective therapies. For example, patients have been treated with combination chemotherapy (multiple chemotherapies given together), biochemotherapy (interferon and/or interleukin 2 with chemotherapy), or vaccines.Unfortunately, to date these agents have failed to show a delay in disease recurrence or an increase in survival. In some cases, therapies that appeared to “make sense” (for example, a vaccine against your own tumor) appear to have actually increased death from melanoma compared to observation.
Until clear evidence of benefit exists for these unproven therapies, caution should be used and their use should be limited to well-designed clinical studies.