Stage 3 melanoma is a skin cancer that has spread to the lymph nodes and areas of skin near the primary tumor. Depending on the tumor’s thickness, doctors may treat stage 3 melanoma with surgery and other treatments.

Doctors classify melanoma according to stages that relate to whether the tumor has spread.

After staging the cancer, they can recommend a suitable treatment plan.

This article discusses stage 3 melanoma. It looks at its symptoms, causes, treatment options, and more.

A doctor is examining a person's back.Share on Pinterest
LordHenriVoton/Getty Images

Melanoma is a type of skin cancer that occurs when the cells that give the skin its color (melanocytes) grow out of control.

The American Cancer Society (ACS) states that the staging system that doctors use to classify melanoma derives from three key pieces of information:

  • the extent of the primary tumor
  • the spread to nearby lymph nodes
  • the spread to distant sites

Stages 3A to 3D involve the tumor being between 2 millimeters (mm) and 4 mm thick. Stage 3 means the cancer has spread to at least one lymph node and small areas of nearby skin. However, in stage 3 melanoma, the cancer has not spread to distant parts of the body.

In comparison, stages 0–2 mean that the tumor may be more than 4 mm thick but has not spread to lymph nodes or other parts of the body. In stage 4 melanoma, the tumor may be any thickness, may be ulcerated, and has spread to distant lymph nodes or organs such as the lungs, liver, or brain.

New spots or moles on the skin or ones that change size, color, or shape are important warning signs of melanoma. The ABCDE approach is a visual guide to melanoma signs:

  • A is for asymmetry: A mole or spot may not be symmetrical.
  • B is for border: Spots or moles on the skin may have an irregular edge that can look ragged or blurred.
  • C is for color: The mole may have color variations, including shades of pink, brown, black, or blue.
  • D is for diameter: A spot may be larger than 6 mm in diameter, but melanomas can sometimes be smaller than this.
  • E is for elevated surface or evolving: The spot or mole is elevated and changes its size, color, or shape.

Not all melanomas fit these characteristics. Other signs include:

  • sore skin that doesn’t heal
  • changes in skin sensation such as itching or tenderness
  • changes to the surface of a mole, such as scaling or oozing

Additionally, melanoma can start in places other than the skin, such as under nails, inside the mouth, or in the eye’s iris.

Furthermore, a person with stage 3 melanoma may have additional signs and symptoms if the cancer has spread to other body parts. It is important to inform a doctor about every symptom a person may be experiencing.

Scientists don’t know exactly why some moles turn into melanoma. However, researchers have found that gene changes inside mole cells may cause melanomas to develop.

A person may acquire gene changes during their lifetime or inherit them. Acquired gene changes may be due to the effects of ultraviolet (UV) rays that damage cells.

If a doctor suspects melanoma, they may refer a person to a dermatologist for further investigation. A dermatologist is a doctor who specializes in skin conditions. They may use a technique known as dermoscopy to look at spots and take an image of the affected area.

Various tests can help with diagnosing and staging melanoma. A skin biopsy involves removing a sample of the affected area for analysis under a microscope.

A doctor may also order imaging tests to see whether or how far the cancer has spread. These include:

  • ultrasound
  • MRI scan
  • CT scan
  • chest X-ray
  • positron emission tomography (PET) scan

A person’s doctor will be able to advise on the tests they order and what they involve.

There are two main types of surgical treatments that doctors may recommend for stage 3 melanoma: Wide excision of the primary tumor and lymph node dissection.

Wide excision of the primary tumor

Wide excision of the primary tumor is a fairly minor operation that may be suitable for most thin melanomas.

Doctors inject a local anesthetic into the area to numb it before cutting out the tumor site along with a small margin of skin around the edges.

Medical professionals view the sample under a microscope to ensure that there are no cancer cells left at the edge of the area.

Lymph node dissection

Lymph node dissection involves removing all of the lymph nodes near the primary tumor.

The ACS notes that it is unclear if lymph node dissection can cure cancer that has spread to these areas, but some doctors believe that it may prolong a person’s life and ease the pain of cancer growing in the lymph nodes.

Complete lymph node dissection may cause long-term side effects, including lymphedema, in which fluid builds up, causing swelling and an increased risk of infection.

A person’s doctor can advise on ways to reduce the risks of long-term side effects and how to manage any that develop.

Other treatments

Other treatments that doctors may recommend for stage 3 melanoma include:

Here are some frequently asked questions about stage 3 melanoma.

Is stage 3 melanoma curable?

The ACS notes that wide excision of the primary tumor will cure most thin melanomas. However, it also states that current treatments may not cure some people with stage 3 melanoma.

It is best for a person to speak with their doctor about their treatment options and outlook.

What is the survival rate of stage 3 melanoma?

According to the ACS, survival rates derive from the Surveillance, Epidemiology, and End Results (SEER) database, which groups cancer by factors other than stages. The five-year relative survival rate for regional melanoma that has spread to lymph nodes is 71%.

A relative survival rate helps give an idea of how long a person with a particular condition will live after receiving a diagnosis compared with those without the condition. For example, if the 5-year relative survival rate is 70%, it means that a person with the condition is 70% as likely to live for 5 years as someone without the condition.

It is important to remember that these figures are estimates. A person can consult a healthcare professional about how their condition is going to affect them.

Is stage 3 melanoma considered advanced?

Stage 3 melanoma is an advanced type of melanoma. It is more advanced than stages 0–2 but less advanced than stage 4 melanoma.

Stage 3 melanoma is a cancer that starts in the cells that produce skin color. It spreads to nearby areas of the skin and lymph nodes, but at this stage, it is not present in other organs. Symptoms can include an irregular, new, or growing mole or spot.

Skin biopsies and imaging tests can help doctors to diagnose and stage cancer. Doctors can treat stage 3 melanoma with surgery and other therapies such as radiation therapy and chemotherapy.

It is best to contact a doctor for advice as soon as a person has concerns about melanoma.