Skin cancer is the most common form of cancer in the United States. There are many types of skin cancers. They are classified as melanomas or non-melanomas. Melanomas begin in the melanocytes, the cells in skin that produce color. Melanoma can spread quickly to other parts of the body. It is the deadliest form of skin cancer. Non-melanomas originate in skin cells other than melanocytes. Non-melanomas are less aggressive and rarely spread.
Exposure to the ultraviolet (UV) rays in the sun and a history of childhood sunburns are the main causes of most skin cancers. In some cases, skin cancer may be prevented. Skin cancer that is detected and treated early is very curable. It is important to have regular skin and mole checks by a skin specialist. Untreated skin cancer can cause disfigurement, spread to other parts of the body, and cause death.
Your skin covers your body and protects it from the environment. Your skin is composed of three major layers, the epidermis, dermis, and subcutaneous tissue. The epidermis is the outermost layer of your skin. It protects your inner skin layers. The epidermis is made up of protein containing cells called keratinocytes, also referred to as squamous cells. The keratinocytes form at the bottom layer of the epidermis and move upward to the outer layer. They eventually wear off and are replaced by the next layer of cells. The epidermis also contains melanocytes. This type of cell contains color pigments called melanin. The lowest layer of the epidermis is composed of basal cells.
The dermis is your second layer of skin. It is made up of connective tissue and provides structure. It is composed of collagen and various elements that give your skin strength and elasticity. The dermis contains hair cells, sweat glands, and sebaceous glands that secrete oils to hydrate the skin.
Subcutaneous tissue composes your inner most layer of skin. Subcutaneous tissue contains fat cells. The fat cells insulate your body and make your skin appear plump and full. Below the subcutaneous tissue are fat tissues, your muscles, and bones.
Skin cancer results when cells in the skin grow abnormally and out of control, instead of dividing in an orderly manner. Melanoma is caused by changes in the melanocytes of the skin. Melanoma can also develop in the colored portion of the eye, the iris, or at the back of the eye, the retina. Melanomas are fast growing and aggressive cancers. They can quickly spread to vital organs in the body and are more likely to cause death than non-melanomas.
Basal cell carcinoma and squamous cell carcinoma are common non-melanomas that result from changes in the basal cells and squamous cells, respectively, in the epidermis layer of the skin. Non-melanomas are slower growing and tend to spread less aggressively than melanomas. However, if untreated, nonmelanoma skin cancers can grow quite large and cause disfigurement.
There are many different types of skin cancers, and they have several different appearances. Skin cancer can develop on normal skin, injured skin, or moles. Melanoma can develop on the skin, in a mole, or in the iris or retina of the eye. You should look for changes in the shape, texture, size, or color of a mole or new skin growth. Skin cancer may look like a sore that does not heal. Cancerous moles or skin areas may also develop pain, swelling, itching, and bleeding.
Nonmelanoma skin cancers tend to develop on places that have been exposed to the sun, such as the scalp, nose, ears, face, and the backs of the hands. Melanoma can develop anywhere on the skin, even in places that have not been exposed to the sun. However, the backs of men and the lower legs of women are the most frequent places that melanoma develops.
The ABCD method is useful when examining your skin for cancer related changes:
- A- Asymmetry: One half of the abnormal area does not match the other half.
- B- Border Irregularity: The growth or mole has uneven, notched, ragged, or irregular edges.
- C- Color: The abnormal area or mole contains different colors instead of one solid color. There may be different shades of tan, brown, black, red, blue, or white.
- D- Diameter: The mole or abnormal growth is larger than ¼ inch across. However, some melanomas may be smaller.
Actinic keratosis is a precancerous condition that can turn into melanoma. Actinic keratosis results from overexposure to the sun. They look like small rough dry patches on the skin. They may be pink-red or skin colored. They typically appear in areas that have been exposed to the sun. Actinic keratosis are slow growing. They may go away on their own and come back. Your doctor should remove actinic keratosis.
You should contact your doctor if you notice a change in the color, texture, or appearance of your skin or a mole and if you have a sore that does not heal. Your doctor will let you know how often you should have professional skin and mole examinations. Your eye doctor should check your irises and the retinas of your eye during your eye exams.
Your doctor can diagnose skin cancer by examining the growth and performing a biopsy of the suspected area. A biopsy is a simple procedure that takes tissue for examination. There are a few types of biopsy methods.
After numbing your skin, your doctor may perform a shave, punch, incisional, or excisional biopsy. A shave biopsy removes the top layers of the skin. A punch biopsy uses a round punch to cut through all of the layers of skin to remove a tissue plug. An incisional biopsy removes a part of the tumor, and an excisional biopsy removes the entire tumor. In some cases, the incisions will need to be stitched.
The tissue samples are sent to a laboratory for examination. Request to have your tissue sample examined by a dermapathologist. A dermapathologist is a pathologist with special training in skin cell disorders. The dermapathologist will determine if your tissue sample contains skin cancer and identify the type and extent of skin cancer.
Your doctor’s office will contact you with the results when they receive them. Skin cancer is classified based on how far it has spread. Stages are classified as 0-4, with 4 being a more serious cancer. There is more than one type of staging system, so make sure that you and your doctor are referring to the same one. Your doctor will order tests if metastasized (spreading) cancer is suspected.
The goal of treatment is to remove all of the cancer cells. Most skin cancers that are detected and treated early have very good cure rates. There are several types of removal methods. The treatment that you receive depends on the type, size, location, and stage of your cancer. Most treatments can take place in your doctor’s office and use a local anesthesia.
Electrodesiccation and curettage is a procedure that removes the surface layer of skin cancer and gently burns (“cauterizes”) its base to destroy any remaining cells. A simple excision is a method that cuts out the tumor and some healthy cells around it. The incision is stitched back together. Cryosurgery is a treatment method that uses liquid nitrogen to freeze and kill cancer cells.
A specialized technique, Mohs micrographically controlled surgery, is used to treat large skin cancers or skin cancers that have come back. For Mohs surgery, the doctor removes a layer of skin containing the cancerous cells and examines it under a microscope right away. The process is repeated until the skin samples are found to be free of cancer cells. The advantages of Mohs surgery are that only the minimum amount of tissue necessary is removed and the specimens are carefully examined. Mohs surgery is associated with high cure rates.
Skin grafting and reconstructive surgery may be necessary after the removal of large skin cancers. Scarring after skin cancer removal is common. Cosmetic surgery techniques can improve the appearance of scars. Some people choose to cover their scars with make-up.
If your cancer has spread, surgery, radiation, chemotherapy, and immunotherapy treatments may be necessary to treat the metastasized cancer or relieve symptoms. Skin cancer can return, even years later. Your doctor will let you know how often you should be rechecked. The five year survival rates are the best for small superficial cancers that were detected and treated early.
There are risk factors that you can and cannot control for skin cancer. You should try to reduce the risk factors that you can control. You should perform a full body skin and mole inspection monthly. It may be helpful to use a mirror or have someone else look at areas of your skin that are difficult for you to see. Promptly report any suspicious moles or areas of skin to your doctor.
The American Cancer Society recommends a yearly skin inspection by a qualified professional every year after the age of 40, and every three years for people ages 20-40. If you experience skin cancer your doctor may recommend more frequent skin inspections. You should make and attend all of your appointments.
You may be able to prevent skin cancer by limiting the amount of time that you are exposed to the sun. Anyone that is exposed to the sun should wear a sunblock that blocks both UV A and B sunrays. A sunscreen is a different product. Sunscreens allow you to spend a longer amount of time in the sun without burning than you could if you were not wearing sunscreen. Sunscreens may reduce your risk of getting skin cancer, but it is not a guarantee. If you are in the sun for a long time, even with sunscreen, you are at risk for developing skin cancer.
Most doctors recommend a sunblock that blocks both UV A and B rays and a sunscreen with a sun protection factor (SPF) of at least 15. A SPF of 15 provides protection from burning for 150 minutes. Sunscreen should be reapplied every 1 ½ hours or so depending on your activity level.
It is important to discard old sunblock and sunscreen. Their effectiveness is reduced over time. You should apply sunblock and sunscreen even in the winter. Remember to apply it to all of your skin that is exposed including your hands, ears, lips, lower legs, the backs of your knees, and the tops of your feet.
It is beneficial to avoid being in the sun between the hours of 10 AM and 4 PM, when the sun’s rays are the strongest. A good way to remember this is that if your shadow is shorter than you are tall, it is not a good time to be out in the sun. You can still be outside, but seek shade.
If you must spend time in the sun, it is smart to wear hats with a broad rim and tightly woven fabrics that are especially made to block the sun. Some clothing is rated for its SPF factor. Your doctor is happy to refer you to such clothing suppliers.
Wear sunglasses that block UVA and B sunrays. Wrap-around styled sunglasses protect your eyes and your eye area. Sun-related cancers can occur on the iris or inside of the eye. Wear sunglasses and make sure that your eye doctor checks for cancer at each of your eye exams.
You should avoid sun tanning outside and sun tanning lamps or booths. Artificial suntan lights give off harmful UV rays and can cause sunburns. An alternative is to use self-tanning products or spray on coloring cosmetics.
You should stop smoking and avoid cancer causing chemicals. If your job requires exposure to cancer causing agents, follow all of the safety instructions associated with the chemical’s use. Wear protective masks and gear as instructed.
Teach your children about protecting their skin in the sun. This is important because many skin cancers result from sunburns that occur before age 18. Make sure that your children learn to apply and reapply sunblock and sunscreen when they are playing outdoors.
Am I at Risk?
Risk factors may increase your likelihood of skin cancer, although some people that experience skin cancer may not have any risk factors. People with all of the risk factors may never develop skin cancer; however, the likelihood increases with the more risk factors you have. You should tell your doctor about your risk factors and discuss your concerns.
Risk factors for skin cancer:
- People with light colored skin (Caucasians), blue eyes, green eyes, gray eyes, blond hair, or red hair have an increased risk for developing skin cancer. However, people with darker complexions and dark hair may get skin cancer as well, but they have a lower risk.
- People that spend a lot of time in the sun, such as construction workers, farmers, fishermen, lifeguards, sunbathers, and outdoor sport enthusiasts have an increased risk for skin cancer.
- Receiving multiple severe sunburns in childhood or as a teenager is a big risk factor for developing skin cancer.
- People that have had skin cancer before are at risk for developing skin cancer again.
- Cigarette smoking can contribute to skin cancer. The tar in cigarettes is a known cancer causing agent.
- Exposure to cancer causing chemical agents, such as oils, tars, and arsenic (found in some herbicides) is associated with an increased risk for skin cancer.
- Chronically injured skin is a risk factor for skin cancer. Friction burns and injury can cause chronic skin injury.
- People with suppressed immune systems, such as organ transplant recipients or people that have AIDS, have an increased risk for skin cancer.
- Not wearing a sunblock for UVA and B rays while in the sun increases the risk of skin cancer.
- Your risk for skin cancer increases with age. Most cases develop in people that are middle aged or elderly, but it certainly can develop in younger people.
- People that sunburn easily are at a higher risk for developing skin cancer.
- People with multiple moles have a higher risk of developing skin cancer.
- People with dysplastic or atypical moles have an increased risk for developing melanoma.
- People with freckled skin have a higher risk of developing skin cancer.
- Artificial tanning lights used in tanning booths, beds, and lamps have harmful UV rays and increase the risk of skin cancer.
- Some people have a genetic predisposition to skin cancer. Skin cancer can run in families. If your close relatives have skin cancer, you have an increased risk for developing it.
- Overexposure to X-rays or other forms of radiation increases the risk of skin cancer.
- People with rare genetic disorders, such as nevoid carcinoma syndrome, basal cell nevus syndrome, xeroderma pigmentosum, or Bazex syndrome, have an increased risk for developing skin cancer.
- People with the human papilloma virus (HPV) carry an increased potential for developing squamous cell carcinoma.
- People that received X-ray treatment for acne in the 1950s have a higher risk of developing squamous cell carcinoma.
- Actinic keratosis is a skin condition that can develop into skin cancer. Actinic keratosis results from overexposure to the sun. It looks like rough dry patches on the skin. Your doctor should remove actinic keratosis.
- People treated with Psoralen and ultraviolet light for chronic psoriasis have an increased chance of developing squamous cell carcinoma and other types of skin cancer.
Melanoma is the most dangerous type of skin cancer. It can be very aggressive and grow quickly. Melanoma can metastasize to the blood vessels and lymphatic system. From there, it can easily spread throughout the body. Melanoma can spread to the bones and vital organs, such as the liver, lungs, and brain. Melanoma can be difficult to treat once it has spread, and it can cause death.
Untreated squamous cell carcinoma may grow quite large and result in disfigurement, such as the loss of an ear or nose. The cancer may turn into a large open sore that is vulnerable to infection. Squamous cell carcinoma can spread to other parts of the body, including fatty tissues, lymph nodes, and internal organs, and cause death. Squamous cell carcinomas located on the lip, ears, palm of the hand, or sole of the foot have the highest risk of spreading.
Untreated basal cell carcinoma can become large and disfiguring if they are at places of concern, such as the face, nose, and ears. Untreated basal cell carcinoma can spread, in rare instances, to the muscles, nerves, bones, and brain. In rare cases, it can result in death.
Skin cancers can come back, even many years later. People that have experienced skin cancer are at risk for developing additional skin cancers in the future. Because the potential consequences are so severe, you should be vigilant about checking your skin and attending all of your follow up appointments. It is important to do what you can to prevent future skin cancers.
Researchers have advanced the formulas in sunscreen and sunblock to offer better protection. Many cosmetics offer sun protection. New products are being developed since the damaging effects of UVA rays have been discovered fairly recently. Further, researchers are investigating alternatives to lotions, such as pills that offer protection from the sun.
Researchers have discovered a link between some types of HPV and squamous cell carcinoma. If you have HPV, you should ask your doctor about your risk and preventative screenings.
Researchers have a good understanding of how the sun’s UV rays damage certain genes and cause skin cancer. Scientists have found changes in genetic material that are both inherited and not inherited but caused by sunlight. It appears that some people can repair damage caused by the sun better than others can, and they are less likely to develop melanoma. Researchers hope to use this information to develop gene therapies to prevent and cure skin cancer.
Researchers hope to use gene therapy in several ways. Researchers anticipate replacing the damaged genes in cells with healthy genes. This has had limited success because usually there is more than one type of damaged gene in a melanoma cell.