What Are the Five Stages of Melanoma?

Untreated melanoma can be life-threatening.

Melanoma is a serious type of skin cancer that develops when melanocytes (the cells that give the skin its pigmentation, or color) grow out of control. Untreated melanoma can spread (metastasize) to internal organs and can be life-threatening. It is less common than other types of skin cancers, such as basal or squamous cell skin cancers, but can be more deadly.

Symptoms and signs of melanoma include changes in skin lesions or moles or the development of new moles that can be remembered by the ABCDEs:

• Asymmetry: irregularly shaped, each half looks different
• Border: jagged, uneven, irregular edges
• Color: mole is several different colors
• Diameter: size greater than ¼ inch (about the side of an eraser on the end of a pencil)
• Evolution: changes in size, shape, or color

Other signs and symptoms of melanoma skin lesions include the following:

• Bleeding
• Swelling
• Redness
• Crusting
• Itching
• Burning

When melanoma spreads (metastasizes) symptoms and signs may include

• feeling unwell (malaise),
• headaches and seizures (symptoms of spread to the brain),
• shortness of breath (symptoms of spread to the lungs), and
• bone pain and fractures (symptoms of spread to the bones).

In some cases, melanoma is caused by acquired genetic mutations, that is, changes to the genes that happen during a person's lifetime, rather than genetic mutations a person is born with.

Exposure to ultraviolet (UV) rays from the sun and artificial sources such as tanning beds is a major cause of melanoma. The UV rays damage the skin cells and cause mutations, which lead to cancer.

Less commonly, people inherit a genetic mutation, that is, the gene is passed on in families, that causes them to develop melanoma.

Here are risk factors for developing melanoma:

• Ultraviolet (UV) exposure from the sun or tanning beds
• Having certain types of moles
• Having fair skin that freckles or burns easily, light hair, and blue or green eyes
• Family history of melanoma
• Personal history of melanoma or other skin cancers such as basal or squamous cell skin cancers
• Having a compromised immune system, such as people who have HIV/AIDS, are organ transplant recipients, or are receiving certain medical treatments such as chemotherapy
• Older age
• Being male
• Xeroderma pigmentosum (a rare, genetic condition)

A doctor will examine the skin all over the body. If your doctor suspects melanoma, he or she will perform a biopsy. In a biopsy, your doctor will remove a sample of skin from the abnormal lesion. In some cases, your doctor will remove the entire abnormal area and examine it under a microscope to diagnose melanoma.

Treatment for melanoma usually depends on the stage of the cancer and includes

• surgery to remove the cancer,
• chemotherapy,
• radiation therapy,
• immunotherapy, and
• targeted therapy.

The staging system most often used for melanoma is the American Joint Committee on Cancer (AJCC) TNM system, which is based on three factors:

• T: The extent of the primary tumor (T)
• N: Has the cancer spread to nearby lymph nodes (N)
• M: Has the cancer spread (metastasized -- M) to different sites

• Stage 0: The cancer is confined to the outermost skin layer (Tis). It has not spread to nearby lymph nodes (N0) or to distant parts of the body (M0).
• Stage I: The tumor is no more than 2 mm thick and might or might not be ulcerated (T1 or T2a). The cancer has not spread to nearby lymph nodes (N0) or to distant parts of the body (M0). This stage is also known as melanoma in situ.
• Stage II: The tumor is more than 1 mm thick (T2b or T3) and may be thicker than 4 mm (T4). It might or might not be ulcerated. The cancer has not spread to nearby lymph nodes (N0) or to distant parts of the body (M0).
• Stage IIIA: The tumor is no more than 2 mm thick and might or might not be ulcerated (T1 or T2a). The cancer has spread to one to three nearby lymph nodes, but it is so small it is only seen under the microscope (N1a or N2a). It has not spread to distant parts of the body (M0).
• Stage IIIB: There is no sign of the primary tumor (T0) AND:
  • The cancer has spread to only one nearby lymph node (N1b) OR
  • It has spread to very small areas of nearby skin (satellite tumors) or to skin lymphatic channels around the tumor (without reaching the nearby lymph nodes) (N1c).
  • It has not spread to distant parts of the body (M0).
    • OR
  • The tumor is no more than 4 mm thick and might or might not be ulcerated (T1, T2, or T3a) AND:
  • The cancer has spread to only one nearby lymph node (N1a or N1b) OR
  • It has spread to very small areas of nearby skin (satellite tumors) or to skin lymphatic channels around the tumor (without reaching the nearby lymph nodes) (N1c) OR
  • It has spread to two or three nearby lymph nodes (N2a or N2b).
  • It has not spread to distant parts of the body (M0).
• Stage IIIC: There is no sign of the primary tumor (T0) AND:
  • The cancer has spread to two or more nearby lymph nodes, at least one of which could be seen or felt (N2b or N3b) OR
  • It has spread to very small areas of nearby skin (satellite tumors) or to skin lymphatic channels around the tumor, and it has reached the nearby lymph nodes (N2c or N3c) OR
  • It has spread to nearby lymph nodes that are clumped together (N3b or N3c)
  • It has not spread to distant parts of the body (M0).
    • OR
  • The tumor is no more than 4 mm thick, and might or might not be ulcerated (T1, T2, or T3a) AND:
  • The cancer has spread to very small areas of nearby skin (satellite tumors) or to skin lymphatic channels around the tumor, and it has reached nearby lymph nodes (N2c or N3c) OR
  • The cancer has spread to 4 or more nearby lymph nodes (N3a or N3b), or it has spread to nearby lymph nodes that are clumped together (N3b or N3c)
    • OR
  • It has not spread to distant parts of the body (M0).
  • The tumor is more than 2 mm but no more than 4 mm thick and is ulcerated (T3b) OR it is thicker than 4 mm but is not ulcerated (T4a).
  • The cancer has spread to one or more nearby lymph nodes AND/OR it has spread to very small areas of nearby skin (satellite tumors) or to skin lymphatic channels around the tumor (N1 or higher).
  • It has not spread to distant parts of the body.
    • OR
  • The tumor is thicker than 4 mm and is ulcerated (T4b) AND:
  • The cancer has spread to one to three nearby lymph nodes, which are not clumped together (N1a/b or N2a/b) OR
  • It has spread to very small areas of nearby skin (satellite tumors) or to skin lymphatic channels around the tumor, and it might (N2c) or might not (N1c) have reached 1 nearby lymph node)
  • It has not spread to distant parts of the body (M0).
• Stage IIID: The tumor is thicker than 4 mm and is ulcerated (T4b) AND:
  • The cancer has spread to 4 or more nearby lymph nodes (N3a or N3b) OR
  • It has spread to nearby lymph nodes that are clumped together (N3b)
  • It has spread to very small areas of nearby skin (satellite tumors) or to skin lymphatic channels around the tumor, AND it has spread to at least two nearby lymph nodes, or to lymph nodes that are clumped together (N3c) OR
  • It has not spread to distant parts of the body (M0).
• Stage IV: The tumor can be any thickness and might or might not be ulcerated (any T).
  • The cancer might or might not have spread to nearby lymph nodes (any N).
  • It has spread to distant lymph nodes or to organs such as the lungs, liver or brain (M0).

Life expectancy for melanoma depends on the stage of the cancer and whether it has metastasized. Life expectancy is often expressed in 5-year survival rates, that is, how many people are alive 5 years after diagnosis.

If melanoma is localized, which means it has not spread beyond the initial tumor, the 5-year survival rate is 99%, meaning 99% of people will be alive 5 years following diagnosis.

Melanoma that is regional, meaning it has spread to nearby structures and lymph nodes, has a 65% 5-year survival rate.

Melanoma that is distant, meaning it has spread to distant parts of the body, such as the lungs, liver, or skin on other parts of the body, has a 25% 5-year survival rate.

Melanoma can be prevented by protecting your skin from the sun's ultraviolet (UV) rays.

• Wear sunscreen at least SPF 50, and reapply every 2 hours or after sweating or swimming.
• Avoid the midday sun (from 10 a.m. to 4 p.m.).
• Wear sun-protective clothing such as a wide-brimmed hat, long-sleeved shirt, and long pants.
• Do not use tanning beds.
• If you are in a high-risk group for developing melanoma, get your skin checked by a dermatologist regularly.