About Skin Cancer
About Skin Cancer/Melanoma
Melanoma develops when normal pigment-producing skin cells called melanocytes become abnormal, grow uncontrollably, and invade surrounding tissues. Usually only one melanoma develops at a time. Although melanomas can begin in an existing mole or other skin growth, most start in unmarked skin. Melanoma is not as common as other types of skin cancer, but it is the most serious and only affects the skin but can spread to other organs and bones. As with other cancers, treatment for melanoma works best when the cancer is found early.
Causes melanoma
One of the most common causes of melanoma is too much sun exposure which causes normal skin cells to become abnormal. These abnormal cells quickly grow out of control and attack the tissues around them.
Melanoma tends to run in families. Other risk factors include abnormal, or atypical, moles. Atypical moles may fade into the skin and have a flat part that is level with the skin. They may be smooth or slightly scaly, or they may look rough and "pebbly." Having many atypical moles increases the risk of melanoma.
Causes of skin cancer
- Sun exposure is the main cause of malignant melanoma and non-melanoma skin cancers.
- Other factors that influence the risk of skin cancer are:
- People with light eyes or hair, who sunburn easily or do not tan, have an increased risk of skin cancer.
- People with a lot of moles, unusually shaped or large moles, or a lot of freckles have a higher risk of melanoma.
- A history of sunburn doubles the risk of melanoma and also increases the risk of non-melanoma skin cancer.
- Use of sunbeds, especially by young people, increases the risk of skin cancer. In England, more than one quarter of a million children aged 11-17 are risking their health by seeking a tan from sunbeds. In Liverpool and Sunderland 50 per cent of 15-17 year-old girls aim to tan on sunbeds and more than two in five use them at least once a week.
- People with a previous non-melanoma skin cancer have a much higher risk of developing a second one.
- People with a close relative diagnosed with skin cancer have a higher risk of developing it themselves.
Melanoma is classified as primary or metastatic.
Primary melanoma
Primary melanoma usually follows a predictable pattern of growth through the skin layers. Early detection and surgery to remove the melanoma cure most cases of primary melanoma. If not treated, most melanomas spread to other parts of the body over time. Melanomas rarely go away without treatment. Prognosis, with primary melanoma depends on:
- How deeply the melanoma penetrates the skin (melanoma thickness).
- Whether an open sore is present over the primary tumour (ulceration).
Metastatic melanoma
Metastatic melanoma can spread through the lymph system to nearby skin, lymph nodes, or through the bloodstream to other organs such as the brain or the liver. Metastatic melanoma usually cannot be cured.
The estimated 5-year survival rate for melanoma is:
- 98% if cancer is found early and treated before it has spread.
- 62% if the cancer has spread to close-by tissue.
- 15% if the cancer has spread farther away, such as to the liver, brain, or bones