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April 2010
Skin Cancers
Dr Sachin Varma
Cancers that form on the surface of the skin are called skin cancers. Skin cancer is the most common type of cancer seen today. It is estimated that over one million new cases occur annually across the globe!

There are six different types of skin, ranging from the extremely fair to the really dark complexion, based on the melanin content in our skin. Generally, Africans fall under the type 6 category, Caucasians fall under type 1 and 2 categories, and Indians, under the 3, 4 and 5 skin types. While people under the type 6 category are least prone to develop skin cancer, the ones falling under type 1 and 2 are most susceptible.

7 Causes of skin cancer
Genetic predisposition is by far the most important factor implicated in all cancers, especially for skin cancers. People who have parents or someone in the family with skin cancer have a higher risk of getting it.

Overexposure to UV (Ultra Violet) radiation, both UVA and UVB are implicated in causing skin cancers. Sun exposure between 10AM and 4PM is most intense and therefore most harmful. People living close to the sea or beach with high levels of UV rays should take more precautions to avoid these harmful rays. Also, environmental damage like the depletion of the ozone layer makes us prone to excessive ultraviolet rays, causing increase in the number of skin cancer patients.

Chronic non-healing wounds can result in skin cancers.

Large moles (nevi) larger than 20 mm (three quarters of an inch) in size are at higher risk for becoming cancerous.

Human Papilloma Virus (HPV) is also associated with development of skin cancers.

Occupational exposure to coal, tar, arsenic compounds, radium, and other chemicals, greatly increases your chances of getting skin cancer.

Regular smokers are more likely to get skin cancer than non-smokers.

Spot the Cancer
Our skin is made up of mainly two layers - the dermis, which is the inner layer and the outer layer called the epidermis. Based on the type of skin cell that develops cancer, the name is accorded to the cancer. Thus if the cancer develops from squamous cells it is called squamous cell carcinoma, that developing from the basal cell of the epidermis is basal cell carcinoma, that from melanocytes (pigment forming cells) is called melanoma etc. Though most skin cancers remain localised, these cancers, especially melanoma, can spread to other parts of body, if ignored.
4 Symptoms to Watch Out For

Skin cancer has very visible signs. Any indication of it should immediately be consulted with a dermatologist.
  • Increase in the size of an existent mole.
  • Sudden onset growth on the skin which is showing surface changes and bleeds spontaneously.
  • Unusual dark spots on skin. 4. Non-healing ulcers or growths that don’t resolve with medication. Dr. Sachin Varma is Consultant Dermatologist at Apollo Gleneagles Hospital, Kolkata

Basal Cell Carcinoma
usually looks like a raised, smooth, pearly bump on the sun-exposed skin of the head neck or shoulder. Crusting and bleeding in the centre of the tumour frequently develops. It is often mistaken for a sore that does not heal. This form of skin cancer is the least deadly and can be cured completely by surgery.

Squamous Cell Carcinoma (SCC) is the second most common skin cancer. It presents as red, scaly, thickened plaque (growth) on the skin, inside the mouth or on a chronic non-healing ulcer. Large chronic ulcerations, which suddenly undergo surface changes and bleed frequently, should be checked for skin cancer. When SCC is not treated, it can metastasize to other areas. Hence it is dangerous to ignore SCC. These are usually treated with wide surgical excision followed by skin grafting. Rarely, radiation would be required post surgery.

Melanomas are brown to black looking lesions. Signs that might indicate a malignant melanoma include change in size, shape, colour or elevation of a mole. Other signs are the appearance of a new mole during adulthood, which has started to pain, itch, ulcerate or bleed. The treatment from surgery to chemotherapy to radiotherapy is usually planned based on the stage of the cancer.

Treatment of skin cancers is usually the teamwork of a dermatologist, an oncologist and an oncosurgeon. After the cancer is established, it is graded, based on its area of involvement and spread, by a process called staging. Treatment is dependent on the type of cancer, location of the cancer, age of the patient, and more importantly, the staging of the cancer at the time of diagnosis.

Skin cancers usually are treated with surgery by local excision or by specialised surgical techniques. Cryosurgery and electrosurgery are also used in early low risk skin cancers. In the case of notorious skin cancers, especially melanomas and squamous cell carcinomas, additional lymph node excision radiotherapy or chemotherapy may be required.

If you are planning a trip to Australia this summer, ensure that you take adequate protection. Australia has the highest incidence of skin cancer in the world, with two in every three Australians at risk of developing skin cancer before the age of 70! The proximity to the equator gives Australia significant ultraviolet exposure, and their depleted ozone layer can’t keep the harmful UV rays out. Add to that, the susceptible Australian light skin.
Dr. Sachin Varma is Consultant Dermatologist at Apollo Gleneagles Hospital, Kolkata

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