Skin cancer - the abnormal growth of skin cells - most often develops on skin exposed to the sun. But this common form of cancer can also occur on areas of the skin not ordinarily exposed to sunlight. Skin cancer is a disease in which cancer (malignant) cells are found in the outer layers of your skin. Your skin protects your body against heat, light, infection, and injury. It also stores water, fat, and vitamin D.

Melanoma is a form of skin cancer that occurs in the melanocytes, which are cells in the outer layer of the skin (the epidermis). Melanoma is the most serious form of skin cancer. Melanoma may be cured if caught and treated early, but if left untreated the majority of melanomas eventually spread to other parts of the body. Early detection and surgery to remove the melanoma are successful in curing most cases of melanoma; however it is rarely curable in its later stages.

Facts

There are three types of skin cancer: the two most common are Basal Cell and Squamous Cell Carcinomas. They are easily treated and rarely fatal. The third and most dangerous is the malignant melanoma.

Skin cancer is the second most common cancer in the United Kingdom, with about 40,500 new cases each year, of which 6,000 are malignant melanomas. About 1,500 people die from melanomas in Britain every year.

Melanomas can spread two ways: horizontally, which gives rise to the superficial spreading melanoma, or they can grow downwards and the cells will invade the lymph glands, which is much more dangerous.

Over the past 60 years, damage to the planet's ozone layer has increased the amount of harmful radiation that reaches your skin.

Causes

Skin cancer begins in your skin's top layer - the epidermis. The epidermis is as thin as a pencil line, and it provides a protective layer of skin cells that your body continually sheds. The epidermis contains three types of cells:

Sunburn and Ultra Violet light exposure causes maximum damage resulting in DNA damage to the skin. The body can usually repair this damage before gene mutations occur. But when a person's body cannot repair the damaged DNA, then it results in skin cancer.

Squamous cells lie just below the outer surface.

Basal cells, which produce new skin cells, sit beneath the squamous cells.

Melanocytes, which produce melanin - the pigment that gives skin its normal color, are located in the lower part of your epidermis. Melanocytes produce more melanin when you're in the sun to help protect the deeper layers of your skin. Extra melanin produces the darker color of tanned skin.

Treatment

Freezing. Your doctor may destroy actinic keratoses and some small, early skin cancers by freezing them with liquid nitrogen (cryosurgery). The dead tissue sloughs off when it thaws. The treatment may leave a small, white scar. You may need a repeat treatment to remove the growth completely.

Excision: Small cancers can be removed by excising them out. It will be done under local anaesthetic.

Laser therapy. A precise, intense beam of light vaporizes growths, generally with little damage to surrounding tissue and with minimal bleeding, swelling and scarring. A doctor may use this therapy to treat superficial skin cancers or precancerous growths on lips.

Radiation therapy. Radiation may destroy basal and squamous cell carcinomas if surgery isn't an option.

Mohs surgery. This procedure is for larger, recurring or difficult-to-treat skin cancers, which may include both basal and squamous cell carcinomas. Your doctor removes the skin growth layer by layer, examining each layer under the microscope, until no abnormal cells remain.