Obviously, the topmost layers of the skin are the first to be affected; the three major types of skin cancer, basal cell carcinoma (rodent ulcer), squamous cell carcinoma and melanoma, all develop in the upper layer of the skin known as the epidermis. Basal cell carcinoma, the most frequent of the three, causes local erosions of tissue if neglected, while squamous cell carcinoma may spread if untreated. Fortunately, both these types can be successfully treated in nearly all cases. Squamous cell carcinoma sometimes occurs on the vulva in women after menopause and may be more difficult to deal with.
Melanoma, the least common of the three, occurs more frequently in sunny countries. Although a certain amount of sun on the skin is beneficial because it forms vitamin D, too much is dangerous. The danger has increased now that high levels of ultraviolet A radiation are reaching the earth's surface from the sun due to depletion of the ozone layer by flurocarbon chemicals from widespread use of spray cans. Melanomas are the most serious of the three skin cancers, once it starts to grow, it can spread rapidly. If detected and treated early enough, melanomas may be cured in about 75 per cent of cases.
The lighter your skin and eye colour, the more easily you will sunburn and the more likely you are to develop skin cancer. This likelihood increases with exposure to sunlight over both short periods - sunbathing on the beach to a point of, say, blistering - and long periods - pursuing an occupation, such as farming, in which many activities take place outdoors. Even moderate sunbathing after summer increases the odds that you will get skin cancer. The damage to the cells accumulates over time, so that people in their middle or later years are more likely to develop the disease.
The simplest way to avoid skin cancer is to reduce the exposure of you skin to the sun's cancer causing rays. Protect you skin by limiting your time in the sun and wear full clothing, those parts of the skin that are still exposed apply a good quality sunscreen to. The chemical composition of sunscreens block most of the sun's harmful rays.
Basal and squamous cell cancers have similar symptoms, while melanomas have their own special set of warning signs. What all skin cancers have in common, however, is change. That is what you should be on the lookout for. Basal and squamous cell cancers may start out small, rough patches of skin that are redder or paler that the surrounding skin. They can also start as tiny lumps or as small sores that bleed easily and seem to heal very slowly or not at all. If left untreated these tiny spots will soon grow and spread to surrounding tissue. Melanoma usually indicates its presence by altering the colour or appearance of a mole. Since melanoma involves cells that produce brown or black pigments, you should be aware of changes in dark spots or patches or moles and be on the lookout for new moles, moles that bleed, or any dark spot, new or old that changes colour, shape or size. Melanomas can be cured if treated in its early stage; those that go untreated may spread to other parts of the body, where they may attack vital organs.
Since skin cancer grows on the surface of the body, the first step in diagnosing them involves visual examination by a dermatologist. An experienced dermatologist can often determine whether a growth on the skin is or is not cancerous just by looking at it. If he suspects skin cancer he will remove a small sample and send it to a laboratory for examination under a microscope. There a pathologist will determine if the cells are skin cancer forming cells. If the samples reveal skin cancer, the dermatologist will remove the growth in one of a number of ways. Certain pre-cancerous skin problems may be treated by the application of a skin lotion containing anticancer drugs. In the case of basal or squamous cell cancer at an early stage, doctors remove the growth either surgically with a knife or by freezing it with liquid nitrogen. Melanomas, which are potentially more dangerous, are nearly always removed surgically together with surrounding tissue. Remember if the melanoma spreads to other parts of the body, other kinds of treatment such as chemotherapy - may be required. Radiotherapy, unfortunately, does not seem to be effective in treating melanoma. The key to treat this type of skin cancer is early detection.