|
Melanoma is a malignant tumour of
melanocytes.
Melanocytes predominantly occur in the
skin and is commonly referred to as
skin cancer, but can be found
elsewhere, especially the eye. The vast
majority of melanomas originate in the skin.
Melanoma Symptoms - Skin Cancer Symptoms
Diagnosis of skin
cancer (melanoma) requires expert knowledge, as
early skin cancer symptoms may look
identical to harmless moles or not have any color at
all. Beyond this expert knowledge a biopsy is
often required to assist in making the diagnosis of
skin cancer, confirming the diagnosis and in
defining the severity of the
melanoma. A popular method for remembering the signs and
symptoms of skin cancer is the mnemonic ABCD:
- Asymmetrical skin lesion
- Border of the lesion is irregular
- Color: melanomas are often black but can be multicolored; any change in color should prompt a
doctor's visit.
- Diameter: any mole that increases in diameter
or any large mole should be seen by a
dermatologist.
Sometimes the skin lesion may bleed, itch, or
ulcerate. A slow-healing lesion should be watched
closely, as that may be a sign of skin
cancer.
Cause of Melanoma - Skin Cancer
Epidemiologic studies suggest that
exposure to
ultraviolet radiation is one of the major
contributors to the development of skin
cancer. Other
candidates are mutations in or total loss of tumor
suppressor genes.
Important factors in determining risk include the
intensity and duration of solar exposure, the age at
which solar exposure occurs, and the degree of skin
pigmentation (see skin types).
Exposure during childhood is a more important
risk factor of skin cancer than exposure in adulthood. (This is
seen in migration studies in Australia where people
tend to retain the skin cancer risk profile of their country of
birth if they migrate to Australia as an adult).
Fair and red-headed people are at greater risk of
skin cancer.
Some other risk factors
of skin cancer include the "dysplastic
naevus syndrome", a previous history of melanoma
/ skin cancer,
and a history of melanoma / skin cancer in the immediate family.
Prognostic Factors of Skin Cancer
Features that affect prognosis are tumor
thickness in millimeters (Breslow's depth), depth
related to skin structures (Clark's levels), type of melanoma
/ skin cancer, presence of ulceration, presence of
satellite lesions, and presence of regional or
distant metastasis.
With regard to tumor thickness at the time of
diagnosis: thin melanomas
/ skin cancer (<0.75mm) have a good
prognosis, i.e. they can usually be cured by
surgical excision alone; tumors of more than 4 mm
thickness at the time of diagnosis are very often metastatic and can show very aggressive growth.
Skin Cancer Treatment
Melanoma (Skin
Cancer) treatment requires complete surgical
excision with adequate margins and assessment for
the presence of detectable metastatic disease along
with short and long term follow up is standard. A
"sentinel lymph node" biopsy is often included for
skin cancers of the limbs.
In metastatic melanoma
/ skin cancer chemotherapy (15-20%
respond to dacarbazine, also termed DTIC),
immunotherapy (with interleukin-2(IL-2) or
interferon) as well as local perfusion are used by
different centers. They can occasionally show
dramatic success, but the overall success in metastatic melanoma
(skin cancer) is quite limited. IL-2 (Proleukin®) is
the first new therapy approved for the treatment of
metastatic melanoma in 20 years. Studies have
demonstrated that IL-2 offers the possibility of a
complete and long-lasting remission in this disease.
Radiation therapy is often used after surgical
resection for patients with locally or regionally
advanced melanoma (skin cancer) or for patients with unresectable
distant metastases. In research setting other
therapies, such as gene therapy, may be tested.
|
