Stages of melanoma

The risk profile and extent of melanoma spread is described as staging. Each stage is based on characteristics such as tumour thickness, ulceration and the involvement of lymph nodes or organs. Once diagnosed, the stage of melanoma then guides the treatment approach.

There are three ways to stage the extent of a melanoma:

  • Microstaging - A histopathologist looks closely at tissue under a microscope using special dyes and techniques to look for specific features that will help inform how far the disease has spread.
  • Clinical staging - The lymph node groups that relate to the location of the melanoma are carefully examined to for any evidence of spread, usually seen by enlarged lymph nodes.
  • Staging after investigation - Imaging scans that allow doctors to see inside the body. They include CT, MRI, and PET scans.

All patients will undergo at least two of these these three methods of staging.

Once the staging has been determined it is described with a number (I-IV) and often with a substage (a-d). The following table outlines the different stages of melanoma:

Stage 0 The melanoma is confined to the cells in the top layer of the skin (epidermis) and has not invaded the deeper layers (dermis). It is also known as in situ melanoma. Surgical removal.
Stage I Stage I melanoma can be defined in two ways: 2mm without ulceration, metastases or lymph node involvement; or up to 1mm with ulceration, but without metastases or lymph node involvement. Surgical removal. The removal of nearby lymph nodes may also be considered if the melanoma is between 1-4mm thick and/or shows signs of rapid growth.
Stage II Stage II melanoma is defined by thickness and ulceration. There is no lymph node involvement or spread to organs. Surgical removal is the main treatment, however the removal of nearby lymph nodes is also a treatment option to prevent further spread. Drug treatment or radiation may also be required to lower the risk of the cancer returning.
Stage III Stage III melanoma can be any thickness and lymph nodes have become involved. Surgical removal of the lymph nodes is usually required. Drug treatment and radiation may also be considered.
Stage IV Stage IV melanoma can be any thickness and has spread to distant lymph nodes and organs e.g. lungs, liver, brain or bone. Systematic drug therapies including immunotherapy and targeted therapy. Surgery and radiation may also be used to relieve symptoms.

To learn more about how melanoma is staged download a detailed information brochure (PDF).