Aideen M. Tarpey, BSc (Hons), RN, CertHealthEd.
Nurse Adviser, NHS Direct, Winchester, HampshireMalignant melanoma is a tumour of the melanocytes (Gawkrodger, 1999). There are two main groups of skin cancer: malignant melanoma and non-melanoma skin cancer (basal and squamous cell carcinoma). Malignant melanoma is the rarest but also the most serious type. It affects the pigment-producing cells (melanocytes) and can appear as a new mole or changes to an existing mole.
Malignant melanoma is a tumour of the melanocytes (Gawkrodger, 1999). There are two main groups of skin cancer: malignant melanoma and non-melanoma skin cancer (basal and squamous cell carcinoma). Malignant melanoma is the rarest but also the most serious type. It affects the pigment-producing cells (melanocytes) and can appear as a new mole or changes to an existing mole.
The incidence of melanoma is approximately 1:10 000 in the UK and is rising (Livingstone, 1998).
Malignant melanoma can develop anywhere on the body (BMA, 2000) but most common sites for melanoma are the legs (for women, who are 1.5 times more likely to develop melanoma than men) and the back (for men) (Mackie, 1998), which suggests the nature of how people expose themselves to sunlight during sunbathing. It is very rare in children, with an incidence of less than 0.3%.
Exposure to sunlight is associated with melanoma and intermittent intense exposure is the most harmful. Children who have been sunburned (that is, with blistering/peeling) are five times more likely to develop symptoms in adulthood (Wessex Cancer Trust, 2000). Melanoma is also linked with prolonged use of sunbeds to maintain a year-round tan (CancerBACUP, 2001).
Melanoma can arise from previously clear skin or from a pre-existing mole (Figure 1). It occasionally presents in the eye, the mouth, under the nails or on the soles of the feet, which may lead to late diagnosis and increased risk of mortality. A change in the size or shape of a mole may be the first warning signs of a malignant melanoma. The majority grow outwardly at first (Figure 2), which is how they are first noticed.
If diagnosis is made at an early stage, a complete cure is possible. However, if the tumour has increased in depth, as shown in Figure 3, it is classed as invasive and acts like any other neoplasm, invading other parts of the patient's body by distribution of cells via the blood and lymphatic circulations.
As well as a new mole appearing or an existing one changing, melanomas can develop in unusual sites such as the lining of the mouth and soles of the feet. These can go undetected for a long time and are potentially the ones that can prove fatal. Other symptoms include changes in colour, shape or size with inflammation, itchiness and bleeding at later stages. No pain will be present unless the patient is at a very advanced stage of disease.
An unchecked melanoma can spread to other parts of the body and is potentially fatal therefore early detection, diagnosis and treatment is essential. Lymphatic spread is common with tumours arising in the breasts, brain, eyes and liver.
The only method of diagnosis is by excision biopsy. If metastatic disease is suspected, scanning is required.
Wide local excision is indicated for malignant melanoma. However, excision depth and breadth will be dependent on the spread and amount of invasion of the melanoma. Grafting may be necessary to close the wound if the melanoma is deep and invasive.
With metastatic disease, lymph glands may need to be excised along with any other tissues affected. Some cases may not be suitable for surgery as the tumours are in surgically inaccessible areas. Palliative care may be indicated if metastases are widespread (for example, in the brain or liver) and the patient's symptoms can be treated symptomatically.
There is no evidence to suggest chemotherapy is of benefit in advanced stages of disease.
Help and advice is also available from:
- CancerLink, 89 Albert Embankment, London SE1 7UQ. Tel: 0808-808 0000.
- Cancer Care Society, 21 Zetland Road, Redland, Bristol BS6 7AH. Tel: 0117-942 7419.
- Macmillan Cancer Relief, 89 Albert Embankment, London SE1 74Q. Macmillan Information Line: 0845-601 6161.
- Marie Curie Cancer Care, 89 Albert Embankment, London SE1 7IP. Tel: 020-7599 7729.
- MARCS Line Resource Centre, (Melanoma and Related Cancers of the Skin), Dermatology Treatment Centre, Level 3, Salisbury District Hospital, Salisbury, Wiltshire SP2 8BJ. Tel: 01722-415071.
- Tak Tent Cancer Support - Scotland, Flat 5, 30 Shelley Court, Gartnavel Complex, Glasgow G12 0YN. Tel: 0141-211 0122.
- Tenovus Cancer Information Centre, 43 The Parade, Cardiff CF24 3AB. Tel: 0808-808 1010.
- Ulster Cancer Foundation, 40-42 Eglantine Avenue, Belfast BT9 6DX. Tel: 0800-783 3339.
WHO IS AT RISK OF MALIGNANT MELANOMA?
Mainly adults with:
- A lot of moles
- Unusual, large and irregular shaped moles
- A tendency to burn easily
- A lot of freckles
- A family history of skin cancer
- A past history of 'cured' malignant melanoma
Malignant melanoma is generally accepted to be a disease triggered by exposure to the sun. Unlike other skin cancers that are triggered by prolonged exposure, such as basal and squamous cell carcinoma, malignant melanoma develops in people who normally do not expose themselves to strong sunlight.
THE NURSE'S ROLE
Advice to patients should include the following:
- Avoid sunburn
- Keep babies and small children out of the sun
- Use high-factor skin protection (minimum SPF 15)
- Limit exposure, sit in the shade
- Do not sunbathe when the sun is at its strongest between 11am and 3pm
- Do not spend a long time in the sun even if a high-protection sun lotion is used
- Wear a hat and keep your body covered where possible
- Do not assume you are safer in the water. Though you may be cooler, the sun's rays will still burn you
- If snorkelling, wear a T-shirt and remember to put waterproof sun protection on the backs of your legs and around your ankles
- Do enjoy the summertime but be careful, especially in the UK. It may be overcast but the sun's rays are still reaching you
- If you must have a tan, experiment with fake-tan lotions. New products are arriving on the market which give an effect that looks like the real thing and do not have the unpleasant smells associated with lotions available in the past.
The Australian Cancer Network runs the successful Slip, Slap, Slop campaign to promote sun-protection advice:
- SLIP on a shirt
- SLAP on a hat
- SLOP on the suntan cream
British Medical Association. (2000)Complete Health Guide. London: Dorling Kindersley.
CancerBACUP. (2001)Understanding Malignant Melanoma. London: CancerBACUP.
Gawkrodger, D.J. (1999)Dermatology (2nd edn). London: Churchill Livingstone.
Livingstone, R. (1998)Funny Moles and Malignant Melanoma (information leaflet). Stamford, Lincs: The Little Surgery.
Mackie, R.M. (1998)Clinical Dermatology (4th edn). Oxford: Oxford University Press.
Wessex Cancer Trust. (2000)Skin Cancer (information leaflet 26). Southampton: Wessex Cancer Trust.