Diagnosing melanoma

Tests for melanoma

The first step in diagnosing a melanoma is a close examination of the spot. If the spot looks suspicious, the doctor will remove it so it can be checked in a laboratory. In some cases, further tests will be arranged.

Staging

The pathology report and any other test results will show whether you have melanoma and whether it has spread to other parts of the body. Called staging, it helps your team recommend the most appropriate treatment for you. The melanoma will be given an overall stage of 0–4 (usually written in Roman numerals as 0, I, II, III or IV).

Stage 0 (in situ)

• it is confined to the top, outer layer of the skin (epidermis)
• very early or localised melanoma

Stage 1

• it has not moved beyond the primary site and is less than 1 mm thick with or without ulceration, or 1-2 mm thick without ulceration
• early or localised melanoma

Stage 2

• it has not moved beyond the primary site and is 1.1-2 mm Breslow thickness with ulceration, or more than 2 mm thick with or without ulceration
• early or localised melanoma

Stage 3

• it has spread from the primary site to nearby lymph nodes or surrounding tissue (in-transit disease)
• locoregional melanoma

Stage 4

• it has spread to distant skin or tissues and/or other parts of the body, such as lungs, brain, bone, or distant lymph nodes
• advanced or metastatic melanoma

Genomic testing

If the melanoma has spread (stage 3 or 4), you may have genomic tests for a particular gene change (mutation). These gene mutations are due to changes in cancer cells – they occur during a person’s lifetime and are not the same thing as genes passed through families.

About 50% of people with melanoma have a mutation in the BRAF gene, which makes the cancer cells grow and divide faster. About 15% have a mutation in the NRAS gene, which controls how cells divide. C-KIT is a rare mutation affecting less than 4% of people with melanoma.

Genomic tests can be done on the tumour tissue sample removed during surgery. The test results will help doctors work out whether particular drug therapies may be useful.

Prognosis

Prognosis means the expected outcome of a disease. You may wish to discuss your prognosis and treatment options with your doctor, but it is not possible for anyone to predict the exact course of the disease. Instead, your doctor can discuss any concerns you may have.

Melanoma can be treated most effectively in its early stages when it is still confined to the top layer of the skin (epidermis). The deeper a melanoma grows into the lower layer of the skin (dermis), the greater the risk that it could spread to nearby lymph nodes or other organs.

In recent years, newer drug treatments such as immunotherapy and targeted therapy have improved the prognosis for people with melanoma that has spread from the primary site (advanced or metastatic melanoma) or is at very high risk of spreading.