...cancer.melanoma...

Melanoma

Melanoma is the fourth most common cancer, usually appearing as a pigmented skin lesion. Australia has the world’s highest incidence rate for melanoma.

Incidence and mortality

Melanoma represents 10% of all cancers, with more than 10,000 cases diagnosed annually. Around 1250 people die from melanoma each year.

Screening

Self-examination of the skin surface for skin lesions that are irregular and changing. Skin doctors annually screen individuals with dysplastic naevi.

Symptoms and diagnosis

Usually asymptomatic but can be associated with ABCDE - Asymmetry, irregular Border, uneven Colour, Diameter (usually over 6 mm), Evolving (that is changing and growing). Can also cause dark areas under nails or on membranes lining the mouth, vagina or anus. Diagnosis is by biopsy to remove the whole lesion.

Staging

After removing the lesion if it is thick, a biopsy of the first draining lymph node (sentinel node) is performed. The most important feature of a melanoma in predicting its outcome is its thickness (stage 0 is less than 0.1mm, stage I less than 2mm, stage II greater than 2mm, stage III spread to lymph nodes and stage IV distant spread). The presence of ulceration also predicts a poor outcome. If distant spread is suspected, CT scans of the chest abdomen and pelvis are performed. The blood test LDH can sometimes be useful to assess metastatic disease

Causes

Melanoma risk increases with exposure to UV radiation, particularly with episodes of sunburn, Also at risk are people who have: increased numbers of unusual moles (dysplastic naevi); depressed immune systems; a family history (in 10%, some having mutations in genes CDKN2A and CDK4); fair skin and; had a previous melanoma.

Prevention

Avoiding sunburn by minimising sun exposure when the SunSmart UV Alert exceeds 3 and especially between the hours of 10am and 3pm when UV levels reach their peak, ie. seek shade, wear a hat that covers the head, neck and ears, wear sun protective clothing and close-fitting sunglasses, and wear an SPF30+ sunscreen. Avoid using tanning salons.

Treatment

Surgery can be curative for thin melanomas and requires that the melanoma be removed with at least 1-2cm of normal skin around it. If the draining lymph nodes are involved they are removed.
For thick melanomas some centres offer high dose interferon after surgery, however many offer clinical trials of vaccines because there is no routine therapy mandated. Surgery should be the mainstay of treating relapsed melanoma if it is possible to remove all of the disease.
For widespread disease, chemotherapy is borderline effective and drugs such as dacarbazine can palliate symptoms, as can biologicals like interferon or interleukin 2. Radiotherapy may palliate local symptoms.

Prognosis

After diagnosis of melanoma 92% of people will be alive in five years which rises to 99% if the melanoma is detected before it has spread. If spread is within the region of the primary melanoma the five-year survival is 65%, dropping to 15% if the disease is widespread.

http://www.cancer.org.au/aboutcancer/cancertypes/melanoma.htm .visit this website for more imformation.