How a Mole Develops into Stage 4 Melanoma

Health Writer
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What is melanoma?

Melanoma gets its name because it develops in the pigment-producing cells of the skin, which are called melanocytes. It is the deadliest form of skin cancer and is often caused by UV rays, either from the sun or from tanning beds, according to the Skin Cancer Foundation. Only four percent of skin cancers are melanoma, but it accounts for three-quarters of all skin cancer-related deaths.


Types of melanoma

The four main types of melanoma are:

  • Superficial spreading melanoma, which grows in the top layer of the skin before spreading

  • Lentigo maligna, which remains close to the skin surface before spreading; it results from chronic exposure to the sun

  • Acral lentiginous melanoma, which appears as discoloration under the nails, on the soles of the feet or palms of the hand

  • Nodular melanoma, which is an aggressive form of melanoma and rapidly spreads to other parts of the body


Is melanoma curable?

If melanoma is detected and treated in the early stages, it is almost always cured., However, if it’s not diagnosed and treated until advanced stages, it is difficult to treat and often results in death, according to the Skin Cancer Foundation. Approximately 10,000 people die from melanoma each year. Early detection and treatment is extremely important.


What makes melanoma deadly?

When not treated, melanoma spreads, or metastasizes, to other parts of the body. It usually first travels to the lymph nodes nearest to the original cancer site and from there it spreads to internal organs, most often to the liver, lungs, bones and brain, according to the Melanoma Research Foundation.


Melanoma symptoms

The first sign of melanoma is often a change in the color, shape, texture or size of an existing mole. However, some melanomas appear as a new skin lesion. According to the National Cancer Institute, melanoma lesions often have

  • Asymmetry: the shape of one half does not match the other half
  • Borders that are irregular, ragged, notched, or blurred
  • Color that is uneven
  • Diameter larger than ¼ inch
  • Evolving, with changes in size, shape, color or texture over the past few weeks or months


The ugly duckling concept in melanoma

The ugly duckling concept states that moles on an individual tend to resemble one another, according to the Skin Cancer Foundation. When a mole looks different from the others near it, it is suspicious and should be examined for skin cancer. This knowledge can help individuals and doctors when monitoring moles and skin lesions over time.


The stages of melanoma

Melanoma is classified into stages of advancement:

  • Stage 0 – Cancer cells are in the outer layer of skin but have not spread to surrounding tissue.

  • Stages 1 and 2 – Tumors are two to four millimeters thick, and may or may not have breaks in the skin (ulceration).

  • Stage 3 – Tumors may be any thickness, with or without ulceration, and have spread to nearby lymph nodes.

  • Stage 4 – Cancer has spread (metastasized) beyond the original site of the tumor and nearby lymph nodes to other parts of the body.


Melanoma prognosis

The five-year survival rate for stage 4 melanoma is 15 to 20 percent, meaning that this amount of people with stage 4 will live for five years, according to the American Cancer Society. The 10-year survival rate is 10 to 15 percent. Research continues in the quest to improve life expectancy for people with advanced melanoma.


Can treatment be successful at stage 4?

Yes, stage 4 skin cancer can be treated successfully if it’s caught in time and aggressively treated. Your type of treatment will depend on where the cancer has spread, your overall health, and how advanced the cancer is. Treatments for stage 4 melanoma include immunotherapy, targeted therapies, chemotherapy, and surgery.


Melanoma prevention

Using sun protection outdoors and avoiding tanning beds is important to prevent skin cancer. Monthly self-skin checks can help you identify any changes to existing moles or spot any new skin lesions so you can have these checked by a dermatologist. In addition, you should talk to your doctor or dermatologist to determine your risk factors and decide how often you should have a whole-body skin check completed by a dermatologist.