Skin Cancer Overview

Microscopic image of skin cancer.
What skin cancer looks like under the microscope. See more pictures of skin problems.
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Warnings about skin cancer seem to come from all sides -- from scientific researchers and family doctors, from parents to children, even from adult children to elderly parents. You may think you already know something about the disease and that you don't spend much time in the sun anyway. But as skin cancer rates continue to rise, greater awareness can help reduce its occurrence and save lives.

Whether a person seeks out the sun or hides in the shade, skin cancer is a real possibility for virtually anyone. It is the most common type of cancer in the United States, affecting more than 1 million people each year [source: American Academy of Dermatology]. Almost half of Americans who live to age 65 will have some form of skin cancer at some point in their lives [souce: National Cancer Institute].


It's important to understand exactly what skin cancer is before discussing the details of the disease. If a person is diagnosed with skin cancer, it means that malignant (life-threatening) cancer cells have been found in the skin's outer layers.

Learning about skin cancer also requires a little knowledge about the structure of the epidermis, the skin's outer layer. The epidermis is made up of three different kinds of cells -- squamous cells, basal cells and melanocytes.

Squamous cells are scaly, flat cells that make up most of the cells in the outer layer. Basal cells are round cells that can be found beneath the squamous cells. Deeper within the epidermis are the melanocytes, which give skin its color [source:] Some types of skin cancers are named for the cells where the cancer is found, such as squamous cell carcinoma.

People who are most at risk of developing skin cancer are those who sunburn easily and are fair-skinned [source: American Academy of Dermatology]. These and other factors relating to skin cancer will be discussed in this article as well as symptoms, preventive measures and treatments. Read on to first learn about the various types of skin cancer.


Types of Skin Cancer

Skin cancers are not all the same. Some types are more common than others, and some are more treatable than others. They also differ according to their growth, appearance and where they occur. Most importantly, the various forms of skin cancer differ by symptoms, rate of occurrence, and treatments and preventions. Therefore, it's a good idea to gain a solid understanding of each.

There are three main types of skin cancer. These three -- basal cell carcinoma, squamous cell carcinoma and melanoma -- are the most commonly occurring types of the disease, with melanoma being the most deadly.


Basal cell carcinoma and squamous cell carcinoma are sometimes grouped together and referred to as the non-melanoma skin cancers. These two skin cancers act very differently from melanoma [source: American Cancer Society]. They're also the most common of skin cancers.

By far, the most commonly occurring type of skin cancer is basal cell carcinoma. It accounts for more than 90 percent of skin cancers in the United States, affecting 800,000 Americans each year [source: College of American Pathologists]. Although that's a frightening fact, this type of skin cancer is easier to detect and more treatable than other skin cancers [source: University of Maryland Medicine]. Compared to melanoma, basal cell carcinoma is slow-growing. It appears as small fleshy bumps and is a problem for people of all ages, especially those with fair skin and those who spend a lot of time outdoors [source: College of American Pathologists].

The second most common type of skin cancer is squamous cell carcinoma, affecting about 200,000 Americans a year. This type is more dangerous than basal cell carcinoma, but it has a 95 percent cure rate. Squamous cell carcinoma appears as patches of skin that are red and scaly [source: University of Maryland Medicine].

The most serious kind of skin cancer is melanoma. It strikes more than 50,000 Americans each year. Melanoma has more than doubled in its rate of occurrence in the past 30 years [source: National Cancer Institute]. This cancer is found in the melanocytes, the cells that give skin its color. A malignant melanoma usually appears black or brown in color as atypical looking moles. Anyone can get melanoma, but as with the other two types of skin cancer, fair-skinned people are most at risk for it [source: The Skin Cancer Foundation].

Read on to learn about the symptoms of skin cancer.


Skin Cancer Symptoms

It's important to catch skin cancer early. This can be difficult because it doesn't cause pain in its early stages, but there are signs to be on the lookout for.

Basal cell carcinoma usually appears on the areas of the body that are exposed to the sun, such as the face, head, neck, arms and hands. This cancer appears as a shiny bump or nodule on the skin [source: University of Maryland Medicine]. It can also appear as a red patch, a scarred area or a pink colored growth. Watch out for an area of skin that is itchy, painful or inflamed and changes in color or texture [source: College of American Pathologists].


Squamous cell carcinoma is important to look out for because, unlike basal cell carcinoma, it can spread beyond the skin to organs. In its early form, it appears as rough or firm red bumps. Look for them on the face, lips, ears, scalp and backs of the hand [source: Rockoff]. They can also look scaly and flat and even crusty [source: Mayo Clinic].

The most important warning signs of basal and squamous cell cancers are a growth or spot that wasn't there before or one that is getting larger in a matter of months. A sore that won't heal within a few months is also a red flag [source: American Cancer Society].

Melanomas are distinctly different from the other two types of skin cancer. They appear as new moles or old moles that have changed shape and color. They are black or bluish black. In spotting melanomas it helps to remember ABCD:

  • The A stands for asymmetry. If the shape of one half of a mole doesn't match the other half, it could be melanoma.
  • The B is for border -- as in, the growth has irregular edges.
  • Color -- C -- is the next thing to look for. Most often, melanomas are dark, but occasionally they can be white, gray, pink, or red.
  • And finally, D stands for diameter. If there is a change in size, it may be melanoma. Melanoma growths are usually larger than the end of a pencil.

[source: National Cancer Institute]

Now that you know the symptoms of skin cancer, it is also important to learn about how to avoid them completely. Read on to learn about how to prevent skin cancer.


Preventing Skin Cancer

Even in its most serious form, namely melanoma, most types of skin cancers can be treated successfully if they're caught early. But there are also things one can do to minimize the risks of getting skin cancer.

Certain factors increase the risk of skin cancer. Fair skin puts you at greater risk. So does getting older. Exposure to chemicals such as arsenic, a metal found in well water but also used in pesticides, can increase risk too. Men are two to three times more likely than women to get skin cancer [source: American Cancer Society].


Despite the risks, there are things that can be done to reduce the likelihood of getting the disease. First and foremost, limiting exposure to strong ultraviolet rays is necessary. Keep your skin covered with clothing or sunblock when you're out in the sun. Use sunscreen with a sun protection factor (SPF) of 15 or higher, and reapply every few hours. It should protect against both UVA and UVB rays [source: University of Maryland Medicine]. It's easy to forget about sun protection, especially in the fall or winter months. But time in the sun -- at any time of year -- should be limited during the hours of 10 a.m. to 4 p.m.

Another method of prevention is being knowledgeable and proactive. Skin self-exams should be done monthly. Having one done by a dermatologist is equally important, at least once a year [source: National Cancer Institute]. Learning what to look out for, combined with routine exams, can go a long way in helping to avoid the disease.

While all the risk factors and preventive measures also apply to melanoma, there is another thing to consider in this particular type of skin cancer. Melanoma is more likely to occur in someone if a family member has had melanoma [source: American Academy of Dermatology].

It's important to remember that anyone can get skin cancer, even if you have darker skin or don't get sunburns [source: American Academy of Dermatology].

Although recognizing and preventing skin cancer is the goal, it's also necessary to get proper tests done if you suspect you may have it. Read on to learn about skin cancer screening.


Skin Cancer Screening

Practicing good prevention and awareness is the key to keeping skin cancer away. Proper screening for skin cancer is important for everyone, but especially those with skin cancer risk factors.

Screening involves having a doctor examine your skin for possible skin cancer growths. During a regular office visit, the doctor does a head-to-toe check of the patient's skin. If you're older than 40, the American Cancer Society advises that, at minimum, you should have one once a year [source: Mayo Clinic]. Patients with risk factors may be advised to get screenings more often. Also, patients who find an unusual marking or growth that suddenly appears on the skin are advised to come in for a screening.


A routine screening can help prevent a skin cancer growth from reaching an advanced stage.

Screenings can be especially helpful in detecting melanoma in its early stages, because melanoma growths are visible to the naked eye. A doctor can immediately spot the characteristic signs of melanoma [source: National Cancer Institute].

For people who have been diagnosed with melanoma, doctors recommend regular screenings that vary according to what stage the melanoma has reached. At stage I, doctors recommend a yearly exam. For those at stage II, a screening is done every six months for the first two years and then once a year after that. For stage III patients, it's necessary to have a screening done every three months for the first year, every four months for the second year, and every six months to a year after that [source: New York Times Health].

Combined with at-home self-exams, screenings can be a good way to help prevent the advancement of skin cancer. However, when a malignant growth has been found, good treatment is the next step. Read on to learn about the various treatments available.


Skin Cancer Treatments

As mentioned, skin cancer -- even melanoma -- can be treated successfully if it's caught early enough. The treatments vary according to the type of cancer and how advanced it is. There are also factors about the individual patient to be considered in choosing a treatment. A patient's age, overall health and tolerance for certain medications and procedures must be considered. And the patient makes the final decision -- a person may have a preference for or against a particular treatment [source: University of Maryland Medicine].

Treatments can be surprisingly simple when a skin cancer isn't too deep. If a basal skin cancer is superficial, for example, a topical medication can be used to treat it [source: College of American Pathologists].


Surgery is obviously a less simple treatment. There are several surgeries that can be done to remove skin cancer. Cryosurgery is the freezing of the cancer using liquid nitrogen in order to kill its cells. A lesion can also be removed by burning it, after which the doctor then removes it with a sharp instrument. This is known as electrodessication and curettage [source: University of Maryland Medicine]. A technique known as Mohs surgery is used when it is important to remove as little skin as possible, such as when the cancer is near a patient's eye. The surgeon removes and examines a thin layer of skin. The doctor will only remove more skin if cancer is found under that layer [source: American Cancer Society]. There is also laser therapy, which involves killing and removing cancer cells using a thin beam of light [source: University of Maryland Medicine].

Some common nonsurgical treatments include radiation therapy and chemotherapy. Radiation therapy uses x-rays to kill cancer cells, while chemotherapy attacks the cells with drugs uses drugs to kill the cancer.

With greater awareness, methods of prevention and treatments, it's possible to be protected from skin cancer.

To find out more information about common skin problems and diseases, follow the links on the next page.


Lots More Information

Related HowStuffWorks Articles

  • American Academy of Dermatology. "Skin Cancer." (Accessed 8/7/09)
  • American Cancer Society. "Detailed Guide: Skin Cancer -- Basal and Squamous Cell." (Accessed 8/8/09)
  • Associated Press. "Study: Tanning Beds Can Be As Deadly As Arsenic." MSNBC health. July 29, 2009. (Acccessed 8/8/09)
  • College of American Pathologists. "Skin Cancer: Basal Cell Carcinoma." (Accessed 8/8/09)
  • Mayo Clinic. "Skin Cancer." (Accessed 8/8/09)
  • Mayo Clinic. "Melanoma" (Accessed 8/8/09).
  • "Definition of Epidermis." (Accessed 8/7/09)
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  • National Cancer Institute. "NCI Health Information Tip Sheet for Writers: Artificial Tanning Booths and Cancer." (Accessed 8/7/09)
  • National Cancer Institute. "What You Need to Know About Melanoma." (Accessed 8/8/09)
  • National Skin Cancer Institute. "Skin Cancer Screening." (Accessed 8/8/09)
  • New York Times Health. "Melanoma." (Accessed 8/8/09)
  • Rockoff, Alan. "Skin Cancer (Nonmelanoma Skin Cancer)." (Accessed 8/8/09)
  • SkinCancerNet. "Four Types of Melanoma." (Accessed 8/8/09)
  • The Skin Cancer Foundation. "Understanding Melanoma." (Accessed 8/8/09)
  • University of Maryland Medicine. "Skin Cancer." (Accessed 8/8/09)