Skin Cancer
Definition of Skin Cancer
Skin cancer is a disease in which malignant cancer cells are found in the outer layers of the skin. Skin cancer is the most common type of cancer in the U.S., affecting more than 1 million people each year.
Description of Skin Cancer
The skin has two main layers - the outer layer called the epidermis and the inner layer called the dermis. The outer layer contains three kinds of cells - squamous cells which are flat, scaly cells in the surface, basal cells which are round cells located under the squamous cells and melanocytes which are cells (called melanin) that give the skin its color and are located throughout the basal layer.
Causes and Risk Factors of Skin Cancer
The main cause of skin cancer is exposure to ultraviolet (UV) radiation from the sun. UV radiation is invisible rays that are part of the energy that comes from the sun. There are two types of rays - UVA and UVB. UVA rays are responsible for the tans, sunburns and production of vitamin D. UVB is the harmful ray that causes skin cancer. Artificial sources of sunlight such as tanning booths and sunlamps can also cause skin cancer.
A number of things can put a person at risk for skin cancer. The risk factors are:
- Fair skin and red or blond hair
- Light-colored eyes
- Sunburning easily when exposed to the sun
- Having many moles, freckles or birthmarks
- Working or playing outside
- Being in the sun a lot as a child
- Having had a serious sunburn
- A family history of skin cancer
- Trying to get a tan in the sun or with a sunlamp
- Where a person lives - people who live in areas that get high levels of UV radiation are more likely to get skin cancer
- Lifetime exposure to UV radiation - most skin cancers appear after the age of 50, but the sun's damaging effects began at an early age
Symptoms of Skin Cancer
The warning signs of basal and squamous cell carcinoma are: - A skin growth increases in size and appears pearly, translucent, tan, brown, black or multicolored.
- A mole, birthmark, beauty mark or any brown spot that:
- changes color
- increases in size or thickness
- changes in texture
- is irregular in outline
- is bigger than 6mm (size of a pencil eraser)
- appears after age 21
- is a spot or sore which continues to itch, hurt, crust, scab, erode or bleed
- is an open sore that does not heal within three weeks
The signs of melanoma can be detected using the "ABCDE rule" devised by the American Academy of Dermatology.
Asymmetry. Most moles are symmetrical. If you drew a line through the middle, the two halves would mirror each other. Melanomas are asymmetric: their two halves are not mirror images.
Border. Most moles have a distinct border. The border of a melanoma is likely to be notched, scalloped, or indistinct.
Color. Moles may be either dark or light, but they tend to be all the same color. Early melanomas are more likely to be uneven in color or a mixture of several different hues.
Diameter. Once a melanoma has acquired its A, B, and C characteristics, it is also likely to be more than 6 millimeters wide (about the size of a pencil eraser).
Elevation. A mole that is raised above the skin and has an uneven surface.
Changes in the skin are not sure signs of cancer; however, it is important to see a doctor if any signs last longer than four (4) weeks.
Diagnosis of Skin Cancer
Suspicious lumps, moles, or changes in the skin that persist for four to six weeks merit a visit to a physician for evaluation. At the office a biopsy (the surgical removal of tissue to determine the exact diagnosis) of the suspected growth may be done. The tissue is then examined under a microscope, and a diagnosis is made.
Treatment of Skin Cancer
If the tissue is cancerous the doctor considers a number of factors to determine the best treatment for skin cancer, such as the location of the cancer, its size, and whether or not the cancer has spread beyond the skin. There are three basic surgical techniques available to remove the cancerous growth - curettage and electrodesiccation, conventional surgery and Mohs' surgery. Curettage and electrodesiccation scrapes the cancerous skin with a curette, an instrument with a sharp, spoon-shaped end. The area then is generally treated by electrodesiccation. Electrodesiccation is an electric current from a special machine that is used to control bleeding and kill any cancer cells remaining around the edge of the wound.
Conventional surgery cuts the cancer from the skin along with some of the healthy tissue around it.
Mohs' technique shaves off one thin layer of skin at a time until the entire tumor is removed.
Doctors may opt for other non-surgical techniques such as cryosurgery (freezing the tumor), laser therapy (uses a narrow beam of light to remove or destroy cancer cells), radiation therapy (uses high-energy rays to damage cancer cells and stop them from growing), or topical chemotherapy (anticancer drugs in cream or lotion form that are applied to the skin).
For treatment of actinic keratosis, the doctor has many options available. Topical chemotherapy, cryosurgery, curettage and electrodesiccation, laser therapy, dermabrasion (removing the top layer of skin with a special machine) or shave excision (shaving the very top layer of skin) have all been successful in the treatment of this condition.
Prevention of Skin Cancer
Here are some preventive tips for reducing the risk of developing skin cancer: - Avoid the sun during peak intensity (10:00 a.m. to 3:00 p.m.)
- Wear sunglasses, a hat and tightly woven clothes when in the sun
- Don't use sun lamps or tanning booths
- Use sunscreen with a sun-protection factor (SPF) of 15 to 30
- Check skin every month to every three (3) months for signs of skin cancer
Note: in conjunction with the self examination the individual should "body map" as well. Body mapping is drawing an outline of the body and marking/measuring all the moles on the map while doing the self examination. This initial body map can then be used each time a self-exam is done. If new moles appear or existing moles have changed the individual will be aware of the difference and can alert the doctor.
The Skin Cancer Foundation recommends the following steps:
Step 1. Examine the face, especially the nose, lips, mouth and ears
Step 2. Examine the scalp. Use a hair dryer and a mirror to expose each section
Step 3. Check the hands and continue up the wrists and forearms
Step 4. Examine the elbows and underarms
Step 5. Examine the neck, chest and torso. For women, lift the breasts to check underneath
Step 6. With the back to the mirror, use a hand mirror to inspect the back of the neck, shoulders, upper back
Step 7. Using the hand mirror scan the lower back, buttocks and backs of legs
Step 8. Examine legs, feet and genital areas
Questions To Ask Your Doctor About Skin Cancer
Is it skin cancer?
What type is it?
What are the probable causes?
Can it be removed?
What method will be used?
Will it be completely cured?
What can be done to prevent a recurrence?
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