What is Melanoma?
Melanoma is the most lethal form of skin cancer. The incidence of melanoma in Australia and New Zealand is 12 times the global average rate. Over 13200 cases were diagnosed in 2016, which is about a 50% increase since 2000. 1,770 of these were advanced cases.
Melanoma is the third most common form of cancer for both men and women. It is the most common cause of cancer for Australians aged 15 to 44 years.
Melanoma typically develops in the skin as a growth of abnormal melanocyte cells.
Normal melanocyte cells exist in the epidermis (the outer layer of the skin). They produce melanin, which is the pigment that is responsible for colouring the skin, eyes and hair. Melanoma is usually caused by melanocytes being over exposed to UV rays, particularly with sunburn and especially during childhood. The effect is cumulative. The more exposure over time, the higher the risk of melanoma.
Melanoma sometimes occurs in other parts of the body that are not typically sun-exposed including under finger or toenails (subungual melanoma).
Melanocytes also exist in the eye, the heart, bowel, inner ear, bones and membranes of the central nervous system.
The risk of melanoma is highest for those people who have:
- fair skin, freckles, red hair, light coloured eyes and a tendency to burn rather than tan
- a family history of melanoma
- an increased number of unusual moles (dysplastic naevi)
- depressed immune system (including transplant patients on immune-suppression treatments)
- previous melanoma or non-melanoma skin cancers.
Early detection is crucial, and effective.
Melanoma is easily treated when diagnosed in its early stage. However, because of its aggressive nature, it can quickly become life-threatening.
Know your skin and check it regularly. We also recommend that you get your partner (or doctor) to regularly check you all over.
Watch out for new spots or spots that change. Early melanomas are often flat changing lesions. DO NOT wait until they become raised, sore or bleed. A changing mole is a suspicious mole. Get it checked NOW.
If you have any concerns about your skin, or notice any changes, consult your GP or dermatologist immediately.
How to check your skin
There are 5 stages of melanoma (0-IV) and these are based on its thickness and whether or not it has spread to other parts of the body.
Early stages of melanoma are confined to the epidermis (in-situ, stage 0) or less than 2mm thick (stage 1) and have not spread. Stage III and IV are more advanced stages of melanoma where it has become metastatic and spread to either the lymph nodes or other parts of the body (lungs, liver, brain or bones.). Advanced stage melanoma spreads through the body via the lymphatic system, or travels through the blood system. When this happens, small cells of the original melanoma circulate throughout the body and attach themselves to other parts of the body. Then they start to multiply. The cancer is then said to be metastatic.
Patients diagnosed with melanoma will need to have the melanoma surgically removed with a safety margin. Some stage I and II patients might also need a lymph node biopsy to determine whether there has been spread of the disease to a nearby lymph node.
Patient experiences are very different. Those with early stage melanoma will need to have their melanoma surgically excised with a margin. Repeat excisions may be required to achieve an adequate safety margin. In some cases a special form of surgery called Mohs surgery may be used to make sure the melanoma has been fully removed.
Patients will then need regular check-ups as the risk of a second melanoma is increased. Regular check-ups will enable early detection of any new lesions, as well as early detection of disease recurrence around the scar, in the skin or in lymph nodes should this happen.
Those with advanced melanoma have very different experiences. Treatment is multifaceted and some elements can have side-effects. There are several therapies for the treatment of advanced melanoma including surgery, radiation therapy, immunotherapies and chemotherapy. New drugs are now emerging which are showing very promising results.
Much will depend on the patient’s stage of melanoma, their age and general health. If diagnosed early, the five-year survival rate is 91% rising to nearly 100% if the melanoma has not spread.
The prognosis for advanced-stage melanoma (stages III and IV) is poorer. The five-year survival rate is 65% for stage III disease but falls to 5% if the cancer is widespread.