Skin carcinomas represent the most commonly diagnosed malignancy, surpassing lung, breast, colorectal and prostate cancer. Tumors develop primarily on areas of sun-exposed skin, including the scalp, face, lips, ears, neck, chest, arms and hands, and on the legs in women. Contrary to popular conception, skin cancers affect people of all skin tones, including those with darker complexions. Most skin cancers appear after age 50, but the sun’s damaging effects begin at an early age, therefore protection should start in childhood in order to prevent skin cancer later in life.
Types of Skin Cancer
The main types of skin tumours are:
1. Melanomas are skin cancers that form in melanocytes (skin cells that make pigment). Even though it is rare, malignant melanoma is responsible for 75 % of all skin cancer related death cases.
2. Basal Cell carcinomas are skin cancers that form in basal cells (small, round cells in the base of the outer layer of skin).
3. Squamous Cell carcinomas are skin cancers that form in squamous cells (flat cells that form the surface of the skin).
Rarer types of skin tumors are:
1. Neuroendocrine carcinomas which form in neuroendocrine cells (cells that release hormones in response to signals from the nervous system.) carcinoma of the skin.
2. Dermatofibrosarcoma protuberans.
3. Merkel cell carcinoma.
4. Kaposi’s sarcoma.
Risk factors for non melanoma and melanoma skin cancers include: unprotected and or excessive exposure to ultraviolet (UV) radiation, fair complexion, occupational exposures to; coal tar, pitch, creosote, arsenic compounds, radium, family history, multiple or atypical moles, and severe sunburns as a child. Anyone with a family history of skin tumour also has an increased risk of developing cancers.
Signs of Skin Melanomas
Signs of melanoma may include: A large brownish spot with darker speckles located anywhere on your body, a simple mole located anywhere on your body that changes in color, size or feel or that bleeds, a small lesion with an irregular border and red, white, blue or blue-black spots on your trunk or limbs, shiny, firm, dome-shaped bumps located anywhere on your body, dark lesions on your palms, soles, fingertips and toes, or on mucous membranes lining your mouth, nose, vagina and anus.
Signs of basal cell carcinoma can vary depending on the type and may include skin changes such as a: Firm, pearly bump with tiny blood vessels in a spider like appearance (telangiectasias). Signs of squamous cell carcinoma include any: persistent, firm, red bump on sun-exposed skin.
Depending on the type of skin cancer, dermatologic surgical treatments include: surgical excision; electrodessication and curettage which involves alternately scraping or burning the tumor in combination with low levels of electricity, cryosurgery and laser surgery. Other dermatologic treatments include radiation therapy and photodynamic therapy (a chemical is applied to the skin prior to exposure to a light source). Mohs micrographic surgery is preferred for large basal cell carcinomas, those that recur after previous treatment, or lesions affecting parts of the body where experience shows that recurrence is common after treatment by other methods.
Skin cancer can be deadly, but nearly all types can be treated if detected and diagnosed early, however skin cancers can recur, so it is important that you examine your skin regularly for any changes and see your doctor for a check-up every six to 12 months.