Carol Ware Duff MSN, BA, RN
Skin cancer will affect one out of five Americans, making it the most common form of cancer. The American Academy of Dermatology (AAD) states there are greater than two million cases of nonmelanoma (basal cell and squamous cell) skin cancer diagnosed every year. Most skin cancers occur after the age of 50, but skin damage from the sun has long been taking place before the appearance of skin cancer. Australia has almost four times the rates of those skin cancer cases in the United States, Canada, and the United Kingdom which ranks that country as having the highest rates of skin cancer in the world.
Skin cancers are grouped into melanoma and nonmelanoma groups. This article will discuss nonmelanoma skin cancer as an earlier article (located on this site) discussed melanomas. Within the nonmelanoma group, basal cell carcinoma (BCC) represents the most common skin cancer while squamous cell carcinoma (SCC) ranks second. Skin cancer is simply an uncontrolled growth of abnormal skin cells.
Skin cancer is the most commonly diagnosed form of cancer. According to the British Association of Dermatologists, children from the ages of birth to 14 years and teenagers from 15 to 19 have the highest rates of skin cancers of any European country.
Basal Cell Carcinoma
The skin is basically made of two layers, the epidermis ( divided into several layers) which forms the outer protective layer and the dermis which is made of connective tissue which acts as a cushion for the body. In the dermis lie the sensory receptors, sweat glands, sebaceous glands, hair follicles, and the blood and lymphatic vessels.
Basal cell carcinomas originate in the epidermal layers of the skin and are caused by exposure to the sun and ultraviolet radiation. The areas of the skin which develop basal cell carcinoma are those areas that receive the most exposure to the sun such as the top of the head in a person who lacks hair and the face. This form of skin cancer was most common in people over the age of 40 but is now seen on the younger population. The risk for basal cell carcinoma increases in persons with light-colored skin, blue or green eyes, blond or red haired, and those who have had overexposure to x-rays or other forms of radiation.
Some features to look for when checking for skin cancer are: One half of the suspect skin area may be different than the other half, the borders or edges may be irregularly shaped, color (brown, black, tan, white, red, blue) can vary from one area of the skin to another, any skin growth that does not heal or bleeds, or can be larger than the diameter of a pencil eraser.
BCC can develop anywhere on the body, but mostly occur on the areas that are routinely exposed to the sun. Your healthcare provider will check your skin for any irregular or suspicious areas and will biopsy (there are many types) or take a small portion of the skin to check for cell changes that could represent cancer.
Treatment will vary according to the size, depth, and location of the cancer. Some procedures to remove this form of cancer will be; excision of the entire tumor and stitches to bring the skin edges back together, scraping and drying of the tissues by the use of electrical impulses (electrodessication), Mohs surgery where single layers of skin are removed and checked under a microscope until the skin sample is free of cancer cells, freezing of the cancer cells (cryosurgery), radiation if the cancer has spread to adjacent lymph nodes or to organs, or a skin cream containing imiquimod or 5-fluorouracil to apply anticancer agents directly to the area. Mohs surgery is mostly used for treatment of skin cancers of the face, nose, ears, and mouth.
Basal cell carcinoma does not often spread to other parts of the body but follow up skin examinations and self- checking of the skin (using a mirror for those hard to see places) will be continued. The Mohs surgical treatment has only a one percent rate of return of the cancer while the other forms of treatment offer a 10 percent rate.
Symptoms of this form of skin cancer are white or light pink areas, waxy appearance; colors can range from flesh-colored to brown. The skin may have a slightly raised area but can also be a flat which bleeds easily, oozing or crusting spots, a sore which will not heal, irregular blood vessels in or around the spot, or the appearance of a scar-like sore without a previous injury to the area. The sore may have a sunken area in the middle.
How to Avoid Sunlight Exposure
Try to avoid exposure to sunlight during the middle of the day, protect your skin with clothing in the form of hats and long sleeved shirts and long pants. Sun Protection factor compares the amount of time needed to produce sunburn on protected skin as opposed to unprotected skin. Wear a good quality sun screen which has a sun protection factor (SPF), which applies only to UVB wave length, rating of at least 15 which blocks both UVA and UVB light. Sunscreens with an SPF of 15 block 93 percent of UVB rays and those with an SPF of 30 block 97 percent of UVB rays. Apply sunscreen at least 30 minutes before going outdoors and reapply during sun exposure which can be in all seasons. No amount of UV radiation is safe.
Ultraviolet (UV) radiation from sunlight or artificial sources (tanning beds and sun lamps) is the main cause of all skin cancers. On the cellular level UV radiation destroys DNA and suppresses the immune system which then cannot prevent cancer from forming in the cells. UVA radiation from sun lamps and tanning beds is compounded and is 10 to 15 times stronger than being in the direct midday sun. UVA is described as aging rays and UVB as burning rays. UVB rays are blocked by glass while UVA rays are not.
What to Watch For on Your Skin
Look for an area on your skin which has changed in color, size, appearance, and texture. Also note if the sore itches, bleeds, is painful or red and swollen. Squamous cell cancer occurs when cells in the skin start to change. The changes may begin in normal skin or in skin that has been injured or inflamed. Most skin cancers occur on skin that is regularly exposed to sunlight or other ultraviolet radiation. Skin cancer is most often seen in people over age 50.
Squamous Cell Carcinoma
Squamous cell carcinoma (SCC) is the second most common cancer of the skin, but can also appear on the mouth, lips, esophagus, urinary bladder, prostate, lungs, vagina, or cervix of the uterus. This type of skin cancer represents a malignant tumor of the squamous (epithelium) layer of the skin. Ninety-five present can be cured if removed promptly, but new lesions can appear.
There are seven types of squamous cancers with differences in appearances and prognosis. SCC carries a greater risk of spreading to adjacent tissues. When SCC is on the lower lip, mucous membranes, forming from scars, and in immunocompromised people (HIV, AIDS, patients taking immunosuppressant drugs for medical reasons) it tends to metastasize or spread to surrounding tissues. One third of SCC when found in the mouth area (usually related to tobacco or alcohol use) has already spread before diagnosis. SCC, although it spreads slowly, will spread more quickly than basal cell carcinoma.
SCC Can Be Found in Other Areas of the Body
SCC as it relates to the skin is the focus of this article but there are other forms of SCC that afflict other portions of the human body. Human papilloma virus (HPV) is associated with squamous cell cancer of the lung, anogenital (anus and genital) region, fingers, and oropharynx (mouth and throat). Ninety percent of head and neck cancers are caused by SCC. Symptoms specifically for head and neck cancers can be hoarseness and/or a mouth ulcer that will not heal and any other problems in the area of the head and neck. Esophageal cancer may be either caused by ESCC (esophageal squamous cell carcinoma) or adenocarcinoma (EAC) with ESCC occurring closer to the mouth and EAC occurring closer to the stomach. Difficulty swallowing, solids more than liquids, and painful swallowing can be symptoms of these forms of cancer. SCC of the prostate is often aggressive. SCC of the vagina and cervix develop more slowly but can spread to the lungs and liver and is the most common type of vaginal cancer. Bladder cancer be of other types, but is often SCC.
Symptoms are highly variable depending on the involved organs. SCC of the skin begins as a small nodule (bump) and then enlarges with the center becoming necrotic (dead tissue) and sloughs off and then turns into an ulcer. These tumors grow rather slowly and are often evidence of sun damage to the skin such as in multiple actinic keratoses (solar keratoses).
A sore that does not heal or any change in an existing mole, wart, or skin lesion can signal that this is SCC. There may be an ulcer or reddish skin plaque that grows very slowly, may bleed occasionally (especially if located on the lip), may have an ulcerated center with raised, hard edges, may have a pearly quality with tiny blood vessels, may lie below the level of the surrounding skin and ulcerates and spreads to underlying tissues, is commonly present on sun-exposed areas (back of hands, lip (usually a small ulcer which will not heal and bleeds sporadically, ears (mostly the upper portion), and the scalp.
SCC in situ (has not spread) is the earliest form of squamous cell carcinoma. This form of SCC appears as a large reddish patch, often larger than one inch, which is also scaly and crusted. Actinic keratosis is a precancerous skin lesion and in rare cases may develop into squamous cell cancer.
Risks of developing squamous cell skin cancer are the same as basal cell carcinoma with long term daily exposure to the sun (working outside), and many sunburns early in life, and older age, exposure to a large number of x-rays and arsenic and chemical exposure .
According to the Skin Cancer Foundation, SCC makes up the majority of skin cancers which usually arise on areas of the skin where there has been a preexisting inflammation or burn injuries. Any disease, illness, or condition that weakens the body’s immune system can encourage the growth of skin cancers. The body has a natural ability to rid itself of some cancerous cells, but an immune system that is not functioning can allow for the growth of these cancers.
Treatment is the same for SCC as it is for basal cell carcinoma with the addition of the use of photodynamic therapy, a special type of light treatment which may be used to treat Bowen’s disease (BD), which can occur anywhere on the skin as well as in the areas of the body which is composed of mucosal membranes (such as the mouth). BD is an early stage of skin cancer and has historically been caused by exposure to arsenic. Today, it is caused by exposure to the harmful rays of the sun. Some squamous cell cancers can be more difficult to treat than others depending on; size and shape of the cancer, what the cancer cells reveal under the microscope, where the skin is located, and any other health problems.
Remember that a change of the color, appearance, size, or texture of the skin lesion can signal the signs of squamous cell carcinoma. You may also have inflammation, bleeding, and or pain in an existing skin sore.
Prevention of SCC is the same as BCC and the aim is to reduce sun exposure. Avoid areas where sunlight is reflected, as on the water, snow, sand, concrete, and white-painted areas. The sun is more intense at higher elevations. Also, stay away from tanning beds, sun lamps, and tanning salons.
Contact your healthcare provider to check suspicious growths which have a change in color, appearance, size and/ or texture. Additionally the development of pain, inflammation, itching, and/or bleeding should be brought to your healthcare provider’s attention.
- Cancer Council Australia, 2010. Accessed on May 26, 2011.
- Fryhofer, Sandra. Staying Sun Safe: Confessions of a Former Tanner Sandra A. Fryhofer, MD
- MedicineNet.com. 2011. Accessed on May 21, 2011.
- Pub Med Health, 2011. Accessed on May 21, 2011.
- Pub Med Health, 2011. Accessed on May 21, 2011.
- Skin Cancer Foundation, 2011. Accessed on May 21, 2011.