indiacancer.org - Skin Cancer

	Skin Cancer

		What is the Skin?
		What is Cancer of the Skin?
		Who are the people at risk from Skin Cancer?
		How does Skin Cancer present?
		How is Skin Cancer detected?
		What are the premalignant lesions of the Skin?
		What are staging and grading?
		How are Skin Cancers treated?
		What are the side effects of treatment for Cancer of the Skin?
		What is the importance of follow up?

What is the Skin?

The skin or the integument, is the largest organ of the body. It serves a protective function against injuries, infection, heat and sunlight. It helps regulate body temperature, and produces Vitamin D using sunlight. It also acts as a reservoir of fat and body water. It comprises of two layers, the outer epidermis and the inner dermis.

The epidermis is made of the following layers:

The Skin with a hair folicle and a Sweat Gland

Flat cells; or squamous cells.

Round cells; or basal cells, which are beneath the squamous cells and which also contains melanocytes, which are cells producing the pigment melanin, the pigment which gives skin it's natural color. (A tan occurs when there is greater production of melanin in response to greater exposure to sunlight.)

The dermis contains various appendages, like:

Blood vessels.

Hair follicles.

Sweat glands, which produce sweat, which regulates skin temperature.

Sebum glands, which produce sebum, an oily substance required for lubricating the skin.

What is Cancer of the Skin?

	The cancer cells originate from the skin. Skin cancers may be of several types. The common skin cancers are:
		Squamous cell carcinoma
		Basal cell carcinoma
		Malignant melanoma (please browse through the section on malignant melanoma to know more about this cancer).
		Cutaneous T-cell lymphoma (please browse through the section on cutaneous T-cell lymphoma to know more about this cancer).

Who are the people at risk from Skin Cancer?

Fair skinned people who spend a lot of time in the sun are chief candidates for this type of cancer. That is why, this cancer is more common in western populations than in Indians, who are primarily a dark skinned race.

It is also common amongst albinos. Albinos are people lacking the genetic make up to form melanin. Hence albinos are extremely fair, and even their hair is usually a mousy brown or even blonde, inclusive of their eyebrows and eyelashes. These people, if exposed to extreme sunlight, are very prone to develop skin cancer.

How does Skin Cancer present?

	Skin cancer can present in several ways, the basic change being in the skin:
		A spot or lump on the skin.
		A sore or an ulcer which refuses to heal and bleeds readily on touch, but maybe absolutely painless.

How is Skin Cancer detected?

Once the doctor examines the sore or lump, he usually takes a biopsy, which involves the removal of a small piece of representative tissue for examination under the microscope. He also may take a sample of cells by inserting a needle (FNAC) into the neighboring lymph nodes, if they are enlarged. (Lymph nodes are small bean-shaped structures, which act as stations for drainage of lymph, a clear watery fluid, which courses through out the body in transparent, thin tubes called lymph channels or lymphatics,from various organs).

Basal cell cancers, also known as rodent ulcers, cause severe local damage and mutilation locally if left unchecked. They do not commonly spread to distant tissues. They show excellent response to therapy.

Squamous cell carcinomas also occur in the areas of highest exposure to the sun, such as the top of the nose, forehead, lower lips and hands (especially the back of the hands). Squamous cancers are more likely to spread to neighboring lymph nodes or distant tissues.

What are the premalignant lesions of the Skin?

	A premalignant or precancerous lesion is an abnormality in a tissue area which is just a step away form cancer. Not all premalignant lesions change to cancer, but most have greater potential for doing so than normal tissues. Some of the precancerous lesions are:
		Actinic or solar keratosis - these are common asymptotic lesions seen mostly on sun exposed areas of light skinned people. They are especially seen in those who 'burn' easily or tan poorly. Commonly seen on the back of the hands, the face, upper chest, upper back and lower lip.
		Chemical and other keratoses - skin lesions caused by exposure to arsenic, tar, polycyclic hydrocarbons, infrared radiation for a prolonged period at the work place (thermal keratosis) and scar keratosis, when a long standing scar develops a malignant potential.
		Large cell acanthoma - usually single, but maybe multiple as well, usually on sun exposed skin in fair people. Rare.
		Chondrodermatitis nodular helicis - usually seen in elderly people; they are tender, inflamed, scaly, reddish, slightly raised lesions.
		Cutaneous horn - a hard, raised nodule with a reddish base, usually seen in sun exposed areas in pale persons.
		Radiation dermatitis - skin damage due to exposure to X-rays or other sources of radiation, either occupational or accidental or due to treatment by radiotherapy. The skin is dry, scaly, reddish, thin and discolored.
		Bowen's disease - this is actually a cancer located totally within the top layer of the skin called the epidermis, and favors the sun exposed areas of the face, neck and extremities.
		Sebaceous naevi - they are present at birth or appear soon afterward, usually on the scalp.
		Porokeratosis - describes a wide variety of skin disorders.
		Fibroepithelioma of Pinkus - appear as flesh colored skin tags hanging from the back.
		Keratoacanthoma - a rapidly growing, red, raised lesion on the sun exposed areas of middle aged and elderly people.

What are staging and grading?

These are terms with which you must become familiar, if you are dealing with any form of cancer.

When we stage a cancer, we try to establish carefully, the degree of spread of the cancer and if indeed there is spread, to what extent and involving which organs.

The grading of a cancer is a microscopic issue, in which the pathologist lets you know how aggressive this particular type of cancer is; well differentiated means less aggressive, moderately differentiated intermediately aggressive, and poorly differentiated more aggressive.

Both grading and staging help your clinician to establish the prognosis or how serious your disease is, and what is going to be the likely outcome.

Staging may require additional imaging tests such as CT scan, MRI, sonography, bone scan, or chest x-ray.

How are Skin Cancers treated?

	A lot depends on the patient's constitution, the grade of his disease, and its staging. Patients are usually treated by a team of specialists, which utilizes a multipronged approach. This includes a surgical oncologist, a reconstructive or plastic surgeon and a radiotherapist. The plan of treatment is tailored to fit a patient's requirements. If necessary, chemotherapy may become an add-on. Treatment strategies The bastion of treatment for skin cancer is surgery. The various methods of removing the tumor include:
		Conventional surgery, when wide excision of the cancer is carried out, keeping a clear margin of healthy tissue around the tumor
		Electrodessication and curettage - an electric current first dehydrates the tumor and then the tumor is scraped or curetted out.
		Cryosurgery freezes the tumor and thus kills the cancer cells.
		Micrographic surgery is a special technique in which the doctor removes as little healthy tissue as possible, by subjecting every part of the tumor excised to microscopic scrutiny, in order to exactly determine the junction between normal and cancer cells.
		Laser surgery (Light Amplification by Stimulated Emission of Radiation) is a surgery in which a narrow beam of intense light is used to kill the cancerous cells.
	The alternative local therapy to surgery is radiation therapy. This involves the use of high energy, penetrative rays to destroy cancer cells. It affects cancer cells only in the zone treated. Radiation therapy is also employed for palliation i.e. control of symptoms alone in an advanced cancer. Radiation therapy can also be used in adjunct to surgery or chemotherapy, either before or after. Teletherapy or external radiation is given via a machine remote from the body while brachytherapy or internal radiation is given by implanting a radioactive source within the involved tissues. Patients may or may not require both modalities of radiation. Radiotherapy, after initial planning, usually takes just 5 to 10 minutes per day, 5 days a week for about 6 weeks. This time period is flexible depending upon the modality of radiation used. Besides local therapy, the best attempt to control cancer cells circulating in the body and lodged at places other than the skin is by using systemic therapy (therapy which affects the entire systems of the body) which is in the form of injections or oral drugs. This form of treatment is called chemotherapy. This form of treatment is given in a cyclical manner (each set of drugs is repeated usually after every 3-4 weeks). Chemotherapy can also be used in combination with surgery, radiotherapy or both, either before or after. Biological therapy employs Biological Response Modifiers (BRM's), which are substances that use the body's own immune system, either directly or indirectly, to fight cancer or to lessen the side effects of the anti cancer drugs. Some examples of BRM's are interferon-alfa and interleukin-2. Photodynamic therapy uses a special light combined with a special chemical to kill cancer cells.

What are the side effects of treatment for Cancer of the Skin?

	Unfortunately treatment for cancer does cause damage to the healthy tissues. Please ask the clinician about any possible side effects before any form of treatment commences. The effects of radiation depend upon the dose of radiation, the size of the area radiated, and the number and size of each fraction. The commonest side effect is extreme fatigue. Although bed rest is good, most radiotherapists advise the patient to be as mobile as possible. Another common problem is that of radiation dermatitis in which the skin covering the radiated area becomes red, dry, itchy, and may show signs of scaling off. This will slowly settle down after radiation ceases, but there may be a permanent 'bronzing' of the skin. It is important to note here that this skin problem is associated only with teletherapy or external radiation therapy. Radiation also may cause nausea and vomiting, diarrhea, urinary discomfort. There may also be a fall in the white blood cells, which are needed by humans to fight infection. Usually the radiotherapist can suggest the drugs and diet necessary to alleviate such problems. The various drugs in chemotherapy cause a varied spectrum of side effects. The severity and variability of these symptoms are very individualistic, changing from patient to patient. Some of the common side effects are:
		Skin rashes.
		Loss of hair.
		Diarrhea.
		Vomiting.
		Tingling and numbness in the fingers and toes.
		Hearing loss.
	Most are temporary and recede after therapy is over. Hair growth gradually starts after cessation of chemotherapy. The medical oncologist will usually be able to reduce the severity and spectrum of these side effects. The psychology of the patient is very important during therapy. Better psychologically prepared the patient is, better are his chances of having decreased side effects. The patient should drink large quantities of water while the therapy is in progress, and preferably avoid uncooked or raw food. Water should be filtered or boiled. Any relative or person who has any sort of infection such as common cold should be asked to desist from coming close to the patient. Biological therapy The side effects commonly encountered with this therapy are as follows:
		Low grade fever.
		Rashes and bruises.
		Nausea and vomiting (usually mild).
	All these problems disappear on cessation of therapy.

What is the importance of follow up?

The importance of follow-up cannot be overemphasized. It is a fatal fallacy to assume on the patient's part that once the primary or the first phase of treatment is over, then he is cured. It must be stressed here that cancer has a notorious proclivity of coming back again and again. The only way to fight this is to pick up any problem when it is still early, so that it can be nipped in the bud. And the only way to do this is to follow up when the doctor calls you for the next visit. Each such visit will include a detailed history, a physical examination (including an internal i.e. a rectal or vaginal examination), a chest x-ray, an ultrasonography or a CT scan, and various other blood studies as indicated.