Skin Cancer – Squamous cell carcinoma

November 12, 2012

Skin Cancer - Squamous cell carcinoma

The first form of skin cancer is called actinic (or solar) keratosis and shows as rough, red bumps on the back of hands, scalp, face and ears. They tend to be visible on skin which is blotchy and been damaged by the sun. These bumps can be painful and sore to the touch which is disproportionate to the way they look. The speed of the keratosis penetrating further into the skin and becoming fully-developed is likely to be in the scale of ten to twenty per cent over a period of ten years, but it could be less than this period of time. Should the appearance change, e.g. thicker and more painful this could be an indication the actinic keratosis has changed into an invasive squamous cell carcinoma.

Squamous cells are thin and flat and have the appearance of fish scales when viewed by microscope and the name originates from the interpretation of the Latin word squama “the scale of a fish or serpent” as this is how the cells look. Squamous cell carcinomas are located in the tissue which forms the surface of the skin, lining of the hollow organs of the body and the passages of the respiratory and digestive tracts, and because of this squamous cell carcinomas can start in any of these tissues. This type of carcinoma of the skin appears approximately 25% more often than basal cell carcinoma. Fair skinned and sun exposure play a part in suffering this type of cancer than a basal cell carcinoma. The style of hair and clothes worn can also affect things. Men are more inclined than woman to be affected by this cancer, and woman who have hair covering their ears are less likely to have squamous cell carcinomas in this area than men.

There is a fast developing squamous cell carcinoma which develops a mound with a crater in the center and this is known a keratoacanthoma. Although many do not regard this as a true form of cancer (they see it as a condition that takes care of itself) for the most part pathologists believe it is a type of squamous cell cancer and it is therefore taken care of appropriately.

Further types of squamous cell carcinoma that have not yet penetrated further into the skin are actinic cheilitis which affects the lower part of the lip with scales and redness. It also makes the edge of the lip and the skin around it indistinct. Squamous cell carcinoma in situ, also known as Bowen’s disease shows as scaly areas on the trunk and extremities which have experienced exposure to the sun. Bowenoid papulosis are warts on the genital areas and when looked at under a microscope appear like Bowen’s disease but they do not behave like cancers, they act like warts.

Exposing the skin to the sun is the main cause of creating squamous cell carcinomas. Growths can arise from precancerous spots, which are called actinic or solar keratoses. The damage from the sun on areas such as forehead, cheeks and back of hands can cause these lesions. It can take years of sun damage to raise the risk of skin cancer and it is not uncommon for people who stopped exposing their skin to the sun and causing damage to go on to develop precancerous or cancerous spots many years after they stopped the sun exposure.

Less common causes which may lead to squamous cell carcinoma are contact with arsenic, hydrocarbons, heat and x-rays. Certain forms of the human papillomavirus (HPV) which is the cause of genital warts may cause squamous cell carcinoma in the anogenital area to develop. Medication or infection which may suppress the immune system may also allow such growths to develop.

Squamous cell carcinomas can spread (metastasize) to other areas of the body unlike basal cell carcinomas. Tumors normally start as firm, skin-colored or red nodules. The lower lip is an area which is susceptible to metastic spread and it is very important to receive the correct diagnosis. Squamous cell cancers which first appear within solar keratoses or sun damaged skin do not metastasize as frequently as those which form in traumatic or radiation scars.

Doctors will carry out a biopsy to ensure a correct diagnosis, as they do with basal cell carcinoma. A local anesthetic by injection is given and a sample is taken by removing a small piece of skin which is looked at under the microscope to detect if there are any cancer cells. The technique is known as a punch biopsy as a circular punch blade is used.

The treatments used for squamous cell carcinoma are not dissimilar to those for basal cell carcinoma. One of the preferred techniques used by dermatologists is curettage and desiccation and involves digging out the carcinoma by a curette which is like a spoon. Desiccation consists of applying an electric current to control bleeding and kill any lingering cancer cells and the skin heals with no need for stitches. Curettage and desiccation is an appropriate treatment for small cancers in the trunk and extremities. The tumor can be removed by cutting it out and then the skin being stitched which is known as a surgical excision.

Radiation therapy is often carried out by doctors on skin cancers which appear in parts of the body which would involve complicated surgery. Approximately, twenty five to thirty treatments would be required to achieve a decent cosmetic outcome. Decent results can be achieved by cyrosurgery which is carried out by trained doctors. This involves freezing cell carcinomas by applying liquid nitrogen to the growth which freezes it and kills off the cells which are abnormal.

Another form of treatment is known as Mohs micrographic surgery, named after its pioneer, Dr. Frederic Mohs. A better term for this technique is microscopically controlled excision. The procedure involves a surgeon carefully removing a small piece of the tumor which is examined under the microscope when the surgery is taking place. Cutting the tumor and then examining it allows the basal cell carcinoma to be measured correctly therefore the surgeon knows exactly the size of the lesion. The removal of normal healthy tissue is reduced by this technique and the success rate is high, over 98%.The preferred surgery on large basal cell carcinomas, those reappearing after they had been treated, lesions on body parts where experience has shown they can occur again e.g. scalp, forehead, ears, corners of the nose, is Mohs micrographic surgery. In some cases, a plastic or reconstructive surgeon works alongside the surgeon performing the Mohs technique to realize the best appearance possible.

Medical therapy applying creams which attack the cancerous cells, e.g. 5-Fluorouracil–5-FU, Efudex, Fluoroplex or cream which stimulates the immune system (Aldara) have a role to play in fighting some types of skin cancer. Apply these creams a number of times over a period of several weeks. These creams do generate irritation and inflammation of the skin. By using the creams surgery is avoided and the treatment is carried out at home and a better cosmetic result may be achieved. The disadvantages associated with using the cream are suffering severe discomfort and also a lower cure rate, meaning that this medical treatment is not suitable for some skin cancers on the face.

Because there is always a chance of metastasis, early and correct diagnosis of squamous cell carcinomas is necessary in order to treat correctly.

Attend checkups on a regular basis and reduce the amount of time the skin is exposed to the sun as this is crucial in preventing cell carcinomas. These preventative methods apply to basal cell carcinomas and squamous cell carcinomas.

When the radiation in the sun is at its highest do not expose the skin. Wear a hat with a wide rim and also protective clothing. Water resistant or waterproof sunscreen with UVA protection and SPF 30 or higher should be used. If you notice any change on your skin, contact the doctor immediately for an examination.

Do not use tanning beds prior to a vacation to a sunny destination, some people try to achieve an artificial tan or base coat in order to stop sun damage. The level of protection by those who are able to get a tan is to SPF6 level. The preferred level is SPF30. People who freckle receive no protection from trying to tan; it only causes increase of sun damaged skin.

Apply generous amounts of sunscreen and reapply frequently every two to three hours. Always reapply after activities which encourage perspiration and swimming as sunscreen can be less effective. This includes sunscreen which is deemed waterproof.

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