The Functions and Structures of the Skin
A group of body tissues with special functions, the skin is actually the largest organ for the body. As a covering or barrier, the skin protects structures underneath from injury, blocks the entrance of bacteria, and prevents the loss of too much water and other fluids. The skin also regulates body temperature, helps rid the body of excess water and salts, and serves as a sense organ for touch, pressure, cold, heat, and pain. In performing its functions, the skin is helped by the hair, nerves, and glands within it. The skin has three main layers. The lower level is the subcutaneous fat. The middle level of connective tissue is the dermis. The thinnest, uppermost level is the epidermis.

What is Cancer
Cancer is really a number of diseases caused by the abnormal growth of cells. Normally the cells that make up the body divide and reproduce in an orderly manner, so that we can grow, replace worn out body tissue, and repair injuries. Sometimes, however, cells get out of control, divide more than they should, and form masses called tumors. Some tumors may interfere with body functions and need to be removed, but do not spread to other parts of the body. Generally, these are known as benign tumors. Malignant, or cancerous, tumors not only invade or destroy normal body tissue, but by a process known as metastasis, cells can break away from the original tumor and go to other parts of the body. There they may form additional malignant tumors. Although basal and squamous cell cancers do not normally spread to other parts of the body, they can do so, and are therefore considered malignant. Melanoma is much more likely to spread to other organs, particularly the lungs, liver, and bones.

Types Of Cancer
There are more than three types of skin cancer, but the three listed here account for the majority of malignant skin tumors. Other malignant skin conditions can be caused by cancers of the lymph system, of the glands within the skin, and by Kaposi's sarcoma, a connective tissue cancer that in this country sometimes develops in patients with AIDS.

Basal Cell Cancer
About 75% of all skin cancers are the basal type. They develop in the layer of cells that form the base of the epidermis, usually on the face and ears. Once thought of as a disease of middle or older age, basal skin cancer is being seen more and more among younger people. The rise among young people is believed to be primarily due to suntanning. Basal cell cancer is slow growing and does not usually spread to distant parts of the body. If left untreated, however, basal cell cancer can spread to nearby areas and invade the bone and other tissues beneath the skin. A person who develops basal cell cancer is at risk of having the cancer recur inn the same place or of developing a new basal cell cancer elsewhere. Within five years 35% of patients diagnosed with one basal cell cancer will develop a second basal cell carcinoma.

Squamous Cell Cancer
Accounting for about 20% of all skin cancers, squamous cell cancers also arise from the epidermis. They most commonly appear on sun-exposed areas of the body such as the face, ear, neck, lip, and hand. They can also develop within other skin lesions like scars or ulcers. Squamous cell cancers tend to be more aggressive than basal cell cancers and are more likely to invade structures beneath the skin. They are more likely to spread to distant parts of the body. Still, only 3% do so, although this figure rises to about 20% for squamous cell cancers that arise from burn or x-ray exposure.

Melanoma
Less common, but more dangerous than either basal cell or squamous cell cancers, melanoma begins in cells known as melanocytes. These cells produce the coloring of pigment known as as melanin. When exposed to sunlight, the melanin in normal melanocytes turns darker to produce a tan that can help protect the body from burning. Because malignant melanoma cells still produce the pigment, these tumors often include shades of brown and black. Among white men melanoma most often appears on the trunk; among white women, on the lower leg. The palms, skin under the nails, and the soles of the feet are the most common areas to develop among blacks, although the disease is rare among blacks. Melanoma is much more likely than the other forms of skin cancer metastasize or spread to other parts of the body. Melanoma that spreads to only nearby areas, usually the lymph nodes, can be cured in many cases. Although some cases of melanoma that have spread to distant parts of the body can be cured, most cannot. That is why melanoma accounts for only 5% of all the skin cancer cases, but 75% of the deaths.

Precancerous Skin Conditions
Solar Keratosis are flat, scaly reddish patches caused by over-exposure to the sun. They usually develop on the head, shoulder, and skin of middle-aged people. Solar keratosis are slow growing and most often cause no symptoms or signs other than visible patches on the skin. It is possible, but not common, for solar keratosis to turn into squamous cell cancer. Even though most Solar Keratosis do not become cancers, they are a warning that a persons skin has become damaged by the sun and that regular self-inspection of the skin and examinations by a doctor are needed. Some Solar Keratoses and other skin conditions that could become cancers may be removed, while others may be observed for changes that could indicate cancer.

Skin Cancer Risk Factors
The main cause of skin cancer is over-exposure to sunlight. Fair-skinned people, especially those with red or blonde hair, are most likely to get skin cancer. This is because their skin cells have less melanin, the pigment that helps prevent burning. The darker the skin, the more melanin present. Blacks, who have the greatest amount of melanin, are the least likely to develop skin cancer, and if it does occur, it is almost always in skin with less pigment. People who work outdoors, such as farmers and construction workers, those who go to the beach or boating often and play a lot of outdoor sports are at highest risk of developing skin cancer. The average age for the discovery of a first non-melanoma skin cancer is about 50. It rarely occurs in childhood, although skin cancer is becoming more common among younger people. Melanoma may develop anywhere from the mid-teens and onward, however, about 50% occur over age 50. Children or teenagers that suffer severe, blistering sunburns are more likely to later develop melanoma. Young people who work indoors all week and then try to "catch-up" on their tans by exposing themselves to hours of sunlight on the weekends are also at increased risk of developing melanoma. The sun’s ray are the strongest between 10 am and 3 p.m., and whenever possible, exposure to the sun should be avoided at these times. Those who are exposed to the sun should use a sun screen lotion with a sun protection factor (SPF) of 15 or more, wear enough clothing to cover the skin as much as possible, and wear a wide-brimmed hat. Sun screens should be used even when swimming, since the suds ray scan reach down three feet in to the water. Parents should remember to take these steps to protect their children from the sun.
Certain moles make it more likely that a person will develop melanoma. One type of mole, the dysplastic nevus , has varying shades of brown, black, and pink with a single mole, and irregular or uneven borders, with the coloring fading into the skin around the mole. Dysplastic nevi. can appear on areas that are often exposed to the sun, and areas that are usually not, such as the buttock, and scalp. They are often larger than other moles. Some people have many such moles but one is enough to increase the risk of melanoma. Dysplastic nevi are often common to members of the same family; 50% of those who have family members with the moles are likely to develop them themselves. Those who have one or more dysplastic nevi and two or more close relatives with malignant melanoma, have a 50% or greater risk of developing melanoma themselves. Although dysplastic nevi tend to run in families, the moles are not usually present at birth. Rather, they begin to appear in older children and teenagers. In families with a history of melanoma, skin examinations to look for dysplastic nevi should begin when children are age 8 to 10. If none are found then, the child should have another examination at age 12 to 14.
Another type of mole linked to melanoma is present at birth. This is the congenital melanocytic nevus, often called a birthmark. The risk of developing melanoma is one in a hundred for those without any kind of mole, 65 for those with congenital melanocytic nevi, and 6% to 10% for those with dysplastic nevi. The risk of developing melanoma, as well as basal and squamous cancers, is also increased for those with exoderma pigmentosa.

A rare, inherited condition that usually starts in childhood, it causes sore and discolored areas on the skin, and makes the body less able to repair damage to the cells. Risk factors include Ionizing radiation, the type given off by x-rays for their work, such as dentists and radiologists, and for those who have received x-ray treatments for acne and other conditions. Other less common risk factors include long term contact with coal tar, pitch, arsenic, and other industrial compounds. Strong government regulations have mostly eliminated the threat from such compounds, although arsenic may still be present in some well water.

Looking For Signs And Symptoms
of Skin Cancer
Any unusual sore, lump, blemish, or other skin change in the way an area of the skin looks or feel may be a sign of skin cancer or a warning that it is likely to occur. The skin might be crusty, scaly, oozing or bleeding. In later stages of the disease the skin may also feel itchy, tender and painful. Most skin problems do not turn out to be skin cancer, but only tests done by a doctor can determine for sure whether a growth on the skin is cancer or might lead to cancer. Only those who already know what their skin normally looks and feels like and are accustomed to its pattern of moles, blemishes, freckles, and other marks will be able to note any changes in the skin. The best way of become familiar with your normal skin is to examine it regularly, about every 6 to 8 weeks. The best time to do this is after a bath or shower, standing in front of a full-length mirror. A hand-held mirror can be held for those areas that are hard to see. The palms and soles, the spaces in between the fingers and toes, and the scalp should also be examined.
Basal cell cancers often first appear as small round or oval patches, shiny and firm, usually white or gray, but sometimes pink or red. Squamous cell cancers can differ more in the way they look, but are usually small, round, slightly raised, and red and crusty. Often, there is a sore in the center that does not heal. Although melanomas can appear on any area of the skin, they often occur where there is a mole. That is why it is important to become familiar with moles and note any changes. The ABCD rule can be used to help tell a normal mole or other marking from one that could be melanoma.
ABCD stands for:

1. Asymmetry- One half does not match the other.
2. Border Irregularity-The edges of the mole are ragged, notched, or blurred.
3. Color- The color is not the same over all of the mole, but may be differing shades of tan, brown, or black, sometimes with patches of red, white, or blue.
4. Diameter-The mole is wider than 6 millimeters (1/4") or is growing larger.

How the Diagnosis Is Made
The diagnosis of skin cancer begins with a complete medical history. The doctor or another health care worker will ask many questions. How old is the patient? What does the patient do for a living? Is the patient often, or has been in the past, outdoors and in the sun? Has the patient ever had sever, blistering sunburns? When did the patient first become worried about a mole or other marking an the skin? How has the condition changed since then? Is there any family history of dysplastic nevi and/or melanoma?
The doctor will then examine the suspected area, noting the size, shape, color, texture, and if there is any bleeding or scaling. The rest of the body will also be examined for markings and moles. Lymph nodes near suspected skin cancers will be felt to see if they are enlarged, which could be a sign that cancer has spread.
If the doctor thinks the patient may have skin cancer, a biopsy will be taken of any irregular areas. A small sample of tissue is removed from the area and examined under a microscope. Anesthesia is injected under the skin to numb the area before the sample is taken.
Most biopsies for suspected basal cell and squamous cell cancers can be done in the doctor’s office. If the sore or lump is very small, all of it will be removed at the time of biopsy. If it does prove to be a basal cell or squamous cell cancer, but the outer edges are free of cancer cells, no further treatment is needed. If the outer edges do contain cancer cells, additional treatment is planned.
Larger and deeper biopsy samples are often needed to diagnose melanoma and the patient may be referred to a dermatologist (skin specialist) or surgeon. Treatment will depend on the stage or extent of the disease.

Treatment
There are four main ways of treating skin cancer: excisional surgery (cutting the cancer out); clecttodissecation (destroying the cancer cells with heat); cryosurgery (freezing the cancer cells until they die); and radiation therapy.
The type of treatment chosen for basal cell or squamous cell cancer depends on how large the cancer is and it’s location. If the sample taken for biopsy shows that cancer cells are present on the outer edges of the sample, a surgeon or dermatologist will go back into the area to remove any remaining cancer including a safety margin of cancer-free cells. For squamous cell cancers, which are more likely to spread, surgery may be followed by radiation. Radiation may be used as the first treatment for hard-to-reach cancers, such as those around the eyes and nose, where scarring might be easily seen and harm the appearance. An alternative for those cases, especially among people younger than 60, is the use of microscopically controlled surgery. In this procedure, a thin slice of the cancer is removed and the bottom layer is examined for cancer cells. This process is repeated until a cancer-free layer is reached. Less normal tissue is removed in this procedure and the patient is spared the risk that radiation used for treating one skin cancer will someday cause another. Either microscopically controlled surgery or radiation may be used to treat basal and squamous cell cancers that have recurred.
Surgery is the only way melanoma can be cured. Melanomas are usually larger and deeper than other forms of skin cancer and a larger safety margin is also removed. If the disease has already spread to nearby lymph nodes, these too will be removed. If melanoma has spread to more distant parts of the body, lymph nodes, skin, and underlying tissue there may also be removed. Although this cannot usually cure the cancer, in some cases, it could help relieve pain and lead to longer survival.
Chemotherapy, treatment with anti-cancer drugs, has had only limited success in treating widespread melanoma. Because the standard methods of treating skin cancer have not been helpful for patients with later stage melanomas, these patients may be asked to consider experimental programs using new combinations of drugs and substances that can stimulate the body's immune system.

Follow-Up Care
Even when a skin cancer has been completely removed and is considered cured, follow-up examinations are needed to see if the cancer has returned, or recurred, which is most likely to occur in the first two years after treatment. In addition, a person who has had one skin cancer may still be at risk of developing another. Persons cured of skin cancer should continue to examine their skin every 6 to 8 weeks, have follow-up examinations as advised, and avoid overexposure to the sun.

Expected Survival Times
Patients who survive five or more years after being treated for cancer are considered cured. Nearly 99% of basal cell and squamous cell cancers that are detected early and treated promptly are cured. The overall 5-year survival rate is about 95%. For patients with melanoma, the overall 5-year survival rate is about 8 1 %. For early stage disease, the chances of cure are greater if the cancer has not invaded deep into the skin. For patients with early stage melanomas that are small, thin and limited to a single area, the survival rate is about 9 1 %. Once melanoma has spread to nearby areas, the survival rate falls to about 54%. If the cancer has spread to distant parts of the body, the survival rate is about 13%.

Hope For The Future
The real hope for the future lies in prevention and early detection of skin cancers. Most skin cancers can be prevented by avoiding overexposure to the sun. Any unusual mark on the skin , especially any that change in size, shape or color should be checked by a doctor.
Scientists are now looking at new ways of treating melanoma with substances that boost and reinforce the bodies own immune system. One of these substances, interleukin-2 has had some success against melanoma, but has harsh side effects and patients receiving it may feet very sick. Ongoing studies will determine whether this treatment, perhaps combined with chemotherapy and other agents that act on the immune system, will improve survival rates for patients with melanoma.

1. Do not "worship" sun. Try to avoid the sun when its rays are strongest-between
   10 a.m. and 3 p.m..
2. Those who cannot avoid being exposed to the sun should wear clothing to cover up as much of the skin as possible. A sun screen with a sun protection factor (SPF) of at least 15 should be applied to the exposed areas.
3. Do not use sun lamps or go to tanning salons or parlors.
4. Any usual blemish, mole, or other marking on the skin, especially one that changes in size or color, should be checked by a doctor.

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