Skin cancer is skin growth with varying degrees of malignancy. Skin cancer generally develops in the outermost layer of skin (epidermis). Although it can be disfiguring, skin cancers are treatable and rarely cause deaths. 

The three most common skin cancers are basal cell carcinoma (BBC), squamous cell carcinoma (SCC), and melanoma, each named after the type of skin cell from which it arises.

Basal cell carcinoma (BBC) is characterized by pearly translucency and a fleshy color of the skin growth with tiny blood vessels on the surface and sometime ulceration of the tumour.  Basal cell carcinomas are present on sun-exposed areas of the skin, especially the face. They rarely metastasize and rarely cause death. . Age, exposure to sun, exposure to ultraviolet radiation, therapeutic radiation are the major risk factors in this kind of skin cancer.

Squamous cell carcinoma (SCC) commonly presents as a red, crusted, or scaly patch on the skin. It is usually a very rapidly growing tumour. The BCC and the SCCs often carry a UV-signature mutation indicating that these cancers are caused by UV-B radiation via the direct DNA damage. Squamous cell carcinoma is the second most common skin cancer. It is dangerous, but not nearly as dangerous as a melanoma.

Malignant melanoma is a skin cancer that begins in the melanocytes – the cells that produce the skin colouring or pigment known as melanin. Melanin helps protect the deeper layers of the skin from the harmful effects of the sun.

Although melanoma accounts for only a small percentage of skin cancer, it is far more dangerous than other skin cancers and causes most skin cancer deaths. It appears as an asymmetrical patch often more than 6 mm diameter with an irregular border and profound colour variation. Of the three types of skin cancers, melanomas occur most rarely. However, they frequently metastasize and could potentially cause death once they spread.

Risk Factors for Skin Cancer

It is well established that ultraviolet (UV) radiation from sun exposure is the primary cause of skin cancer. Other risk factors include:

• Aging
• Light skin colour
• Chronic non-healing wounds
• Presence of multiple moles on the body surface
• Environmental carcinogens
• Genetic syndromes

Incidence of Skin Cancer

In India, skin cancers constitute a small proportion of patients with cancer. Australia and New Zealand exhibit one of the highest rates of skin cancer incidence in the world, almost four times the rates registered in the United States, the UK and Canada. Fortunately, the ozone layer over India is in place, though there is a trend towards depletion, say meteorologists.

*Image courtesy: © Thinkstock photos/ Getty Images
*Inputs:Dr. Uma Singh, Medical Director of Ozone Ayurvedics