Like all cancers, melanoma develops when DNA damage in a cell triggers genetic mutation that cause the cell to multiply rapidly and to form new, abnormal cells.

In melanoma, the damage occurs in a type of skin cell called a melanocyte. Melanocytes make a brown pigment called melanin that protects the deeper layers of the skin from some of the harmful effects of the sun.

Melanomas can form anywhere on the skin, and they can also form in the eyes, mouth, and genital and anal areas.

Nearly 74,000 Americans were expected to be diagnosed with melanoma in 2015, and nearly 10,000 were expected to die from it, according to the National Cancer Institute. Close to one million people were living with melanoma in 2012, the last year for which statistics are available.

The rate of new cases of melanoma has been on the rise for the past 40 years, even among children. Here’s what you need to know about this deadly form of cancer.

What Are the Risk Factors?

A major risk factor for melanoma is exposure to ultraviolet (UV) rays. People who regularly expose themselves to direct sunlight, tanning beds, or sun lamps are at a higher risk for melanoma. Some of the other risk factors for melanoma include:

  • A family history of melanoma or of dysplastic nevus syndrome (also called familial atypical multiple mole melanoma syndrome)
  • A personal history of melanoma
  • Fair skin that burns and freckles easily
  • A personal history of blistering sunburns
  • A weakened immune system, either from a disease or medical treatment
  • Being a man over 45
  • Increased age (although melanoma is one of the most common cancers among people under 30)

Anyone with an increased risk of melanoma should have their skin checked regularly by a dermatologist and should additionally keep an eye on their own skin for signs of cancer.

What are the Signs of Melanoma?

The first sign of melanoma is often a new mole or changes in an existing mole.

The American Cancer Society recommends using the ABCDE rule for monitoring your skin and checking your moles. Those letters stand for:

A: asymmetrical shape

B: irregular borders

C: different colors within one mole

D: a diameter bigger than a pencil eraser

E: evolving shape, color, or size of a mole

A mole that itches, oozes, bleeds, or is ulcerated is also suspect and should be examined by a dermatologist.

Not all melanomas have a mole-like appearance, however. A type of melanoma called acral lentiginous melanoma usually appears as a black or brown discoloration under the nails or on the soles of the feet or palms of the hands. This type of melanoma is the most common among African-Americans and Asians, and the least common among Caucasians, according to the Skin Cancer Foundation.

What Are the Treatment Options?

Depending on how early the melanoma is caught, treatment can range from minimal surgery to remove the cancerous tissue to more extensive surgery, chemotherapy, radiation, immunotherapy, and targeted therapy.

The stage at which the melanoma is diagnosed largely determines the choice of treatment:

Stage 0: The cancer is in the outer layer of the skin and can usually be treated with surgery to remove it, as well as a small amount of normal tissue.

Stage I and Stage II: The cancerous area is surgically removed, and a biopsy of the nearby lymph nodes may be recommended, since melanoma frequently spreads from the skin to the lymph nodes.

Stage III: In this stage, the cancer has spread to the lymph nodes. The cancerous skin is removed, as are the affected lymph nodes. Treatment for Stage III melanoma may also include radiation, chemotherapy and other targeted therapy options.

Stage IV: Cancer diagnosed at this stage is very hard to cure, as the disease has spread from the skin and lymph nodes to other parts of the body. Surgery, radiation, chemotherapy and targeted therapy may all be part of the treatment plan.

What’s the Survival Rate?

Survival rates are a standard way of estimating a person’s prognosis. The 5-year and 10-year survival rates indicate the percentage of people who have lived at least that long following a diagnosis with melanoma.

Stages 0 or I: If melanoma is found early, in stages 0 or I, the 5-year survival rate is as high as 97 percent, and the 10-year survival rate is as high as 95 percent, according to the American Cancer Society. That’s because cancers that only affect the skin are much less dangerous.

Stage II: The 5-year survival rate for stage II melanomas ranges from 53 to 81 percent, and the 10-year survival rate ranges from 40 to 67 percent.

Stage III: As the initial diagnosis stage becomes more severe, the survival rate declines. For Stage III cancers, the 5-year survival rate ranges from 40 to 78 percent, and the 10-year survival rate ranges from 24 to 68 percent.

Stage IV: When the cancer is found in Stage IV, the 5-year survival rate drops to 15 to 20 percent, and the 10-year rate to 10 to 15 percent.

This highlights the importance of both protecting your skin to avoid melanoma, and regularly checking skin for irregularities.

How Can I Prevent Melanoma?

Avoiding UV radiation is one of the best and easiest ways you can reduce your risk of melanoma. You can reduce your exposure by doing the following:

  • Limiting your exposure to the sun by:
    • Staying in the shade, especially at midday
    • Wearing clothing and hats that cover most of your skin and head
    • Wearing sunglasses to protect your eyes and the skin around them
    • Wearing sunscreen on skin that isn’t covered by clothing
  • Avoiding tanning beds and booths
  • Avoiding black-light lamps
  • Wearing protective clothing and UV shields if your job involves arc welding or using xenon or xenon-mercury arc lamps or plasma torches

Protect children from excessive sun exposure by having them wear clothes, hats, and sunscreen when spending time outdoors.

You should start by scheduling your annual physical today. People with a family history of melanoma should ask their doctor about getting regular skin exams and learning to do self-exams.