Skin Cancer
medical conditions

Skin Cancer

Explore the available health information, treatment context, and integrative evidence for Skin Cancer.

Background
  • Skin cancer is the abnormal growth of skin cells. It most often develops on skin exposed to the sun, but can also occur on areas that are not ordinarily exposed to sunlight. Skin cancer is generally divided into two stages, local (where the cancer affects only the skin) and metastatic (where cancer has spread beyond the skin).
  • More than one million new cases of skin cancer will be diagnosed in the United States this year. One in five Americans will develop some form of skin cancer during their lifetime.
  • The skin consists of three layers including the epidermis, dermis, and the subcutaneous layer. The epidermis is the outermost layer and is very thin. It provides a protective layer of skin cells that sheds continually. Squamous cells lie just below the outer surface. Basal cells, which produce new skin cells, are at the bottom of the epidermis. The epidermis also contains cells called melanocytes, which produce melanin, the pigment that gives skin its normal color and causes moles. When exposed to the sun, these cells produce more melanin that helps protect the deeper layers of skin. The extra melanin is what produces the darker color of tanned skin.
  • There are three major types of skin cancer, including basal cell carcinoma, squamous cell carcinoma, and melanoma. Basal and squamous cell carcinomas are slow-growing and generally highly treatable. According to the Skin Cancer Foundation, if all forms of skin cancer are found early and treated appropriately, they are all nearly 100% curable. It is very important to limit or avoid exposure to ultraviolet (UV) radiation and pay close attention to suspicious changes in the skin.
  • Other less common types of skin cancer include Kaposi's sarcoma, Merkel cell carcinoma, and sebaceous gland carcinoma.
  • Basal cell carcinoma: Basal cell carcinoma (BCC) is the most common form of cancer, accounting for nearly 90% of all skin cancers. Basal cells are cells that line the deepest layer of the epidermis. An abnormal growth of cells in this deep layer is known as BCC. Although BCC can usually be diagnosed with a simple biopsy, has a low rate of metastasis, and is fairly easy to treat when detected early, 5-10% of BCCs can be logically aggressive and resistant to treatment. BCC may invade bone and cartilage, and if not treated appropriately and early, it may be very difficult to eliminate.
  • Squamous cell carcinoma: Squamous cell carcinoma (SCC) is the second most common form of skin cancer, with over 200,000 new cases per year estimated in the United States. Squamous cells are cells that compose most of the epidermis. An abnormal growth of squamous cells is known as a SCC. Most SCCs are not life-threatening when identified early and treated appropriately, but SCC may become more difficult to treat, can cause disfigurement, and a small percentage may spread (metastasize) to other organs resulting in death.
  • Melanoma: Although melanoma is not the most common of the skin cancers, it causes the most deaths. The American Cancer Society estimates that in 2007, there will be 59,940 new cases of melanoma in the United States. Melanoma is a malignant tumor that originates in melanocytes (produce melanin). The majority of melanomas are black or brown, although some melanomas occasionally stop producing pigment and may be skin tone, pink, red, or purple.
Risk Factors and Causes
  • Age: Older individuals have a higher risk of developing skin cancer, mainly because many skin cancers develop slowly. Damage by other risk factors that occurred during childhood or adolescence may not become apparent until middle age, but skin cancer can occur in all ages. Basal cell and squamous cell carcinomas are increasing rapidly among women younger than 40.
  • Environmental exposure: Exposure to harsh environmental chemicals, including arsenic, cosmetics, and some herbicides increases the risk of skin cancer.
  • Fair skin: The less pigment (melanin) the skin contains, the less protection from damaging UV radiation. People with blond or red hair, or light-colored eyes will freckle or sunburn more easily. These individuals are much more likely to develop skin cancer than a person with darker features.
  • Family history: Having a parent or a sibling who has developed skin cancer increases the risk of developing skin cancer. Some families are affected by a condition called familial atypical multiple mole melanoma (FAMMM) syndrome. The hallmarks of FAMMM include a history of melanoma in one or more close relatives and having more than 50 moles, some of which are atypical. Because people with this syndrome have an extremely high risk of developing melanoma, frequent screening for signs of skin cancer is crucial.
  • Fragile skin: If the skin is burned, injured, or weakened by treatments for other skin conditions, it is more susceptible to sun damage and skin cancer development.
  • Moles: Having lots of moles or abnormal moles (called dysplastic nevi) increases the risk of developing skin cancer. The abnormal moles are irregular and generally larger than normal moles, and are more likely than others to become cancerous.
  • Personal history: If an individual has developed skin cancer in the past, their risk for developing the disease again is increased. Even basal cell and squamous cell carcinomas that have been successfully removed can recur in the same spot, often within two to three years.
  • Precancerous skin lesions: Skin lesions known as actinic keratoses can increase the risk of developing skin cancer. These precancerous skin growths typically appear as rough, scaly patches that range in color from brown to dark pink. Actinic keratoses are most common on the face, lower arms and hands of fair-skinned people whose skin has been sun damaged.
  • Sun Exposure: Individuals who spend a considerable amount of time in the sun can develop skin cancer, especially if the skin isn't protected by sunscreen or clothing. Tanning is the skin's injury response to excessive UV radiation, and increases the risk of skin cancer.
  • Sunburn: Sunburn is the body's attempt to heal itself from the sun's damaging rays. Every time an individual gets sunburned, there is an increased risk of damaging skin cells and developing skin cancer. One or more severe, blistering sunburns can increase the risk of skin cancer as an adult.
  • Sunny or high-altitude climates: Individuals living in sunny, warm climates are exposed to more sunlight than those in colder climates. Higher elevations make UV rays stronger, and may also increase the risk of developing skin cancer.
  • Weak immune system: Individuals with weakened immunities are at a greater risk for developing skin cancer. This includes people living with HIV/AIDS, leukemia, and those taking immunosuppressant drugs after an organ transplant.
  • Damage in the epidermis to the normal DNA of skin cells may result in new cells growing out of control, and eventually forming an accumulation of cancer cells.
  • UV light: The ultraviolet (UV) radiation in sunlight and commercial tanning lamps and beds may cause DNA damage that can lead to skin cancer. UV light is divided into three wavelength bands, including ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC). Only UVA and UVB rays reach the earth. UVC radiation is completely absorbed by the atmospheric ozone. UVA and UVB rays play a role in the formation of skin cancer by causing changes in skin cell DNA, including the development of oncogenes, which are types of genes that can turn a normal cell into a malignant one. UVA penetrates the skin more deeply than UVB.
  • Tanning beds deliver high doses of UVA, which makes them especially dangerous. UVA puts an individual at greater risk of skin cancer than spending long hours in the sun because of the deep penetration of the rays.
  • Genetic predisposition: Although most cases of skin cancer are related to environmental factors, such as UV exposure, genetics may also play a role. Some people, especially those with fair skin that freckles easily, may be genetically predisposed to developing skin cancer. Therefore, having a family history of skin cancer may increase the risk of developing the disease.
  • Other factors: Exposure to toxic chemicals and radiation treatments may also cause skin cancer.
Signs and Symptoms
  • Skin cancer develops primarily on areas of sun-exposed skin, including the scalp, face, lips, ears, neck, chest, arms, hands, and on the legs in women. It also can form on areas not receiving as much light such as the palms, spaces between the toes, and the genital area.
  • A cancerous skin lesion can appear suddenly or develop slowly, it depends on the type of cancer.
  • Basal Cell Carcinoma: Basal cell carcinoma may appear as a flat, scaly red patch, a pearly or waxy bump on the face, ears, or neck (bumps may bleed or develop a crust), a patch with large blood vessels (may look like a birthmark), or a brown or black raised bump.
  • Squamous Cell Carcinoma: Squamous cell carcinoma may appear as a flat, scaly red patch (may look similar to a skin rash), a small, smooth, shiny, or waxy bump, a firm, red nodule on the face, lips, ears, neck, hands or arms, or a red or brown, scaly skin patch.
  • Malignant Melanoma: Although it can occur anywhere on the body, melanoma appears most often on the upper back or face in both men and women. Malignant melanoma may appear as a new mole, a mole that has gotten larger, a mole that changes color or shape, a mole that bleeds, a mole that itches or causes pain, or a mole with an uneven border or shape. Warning signs of melanoma include a large brownish spot with darker speckles located anywhere on the body, a simple mole located anywhere on the body that changes color, size, feel or that bleeds, or a small lesion with an irregular border and red, white, blue, or blue-black spots on the trunk or limbs. Other signs include shiny, firm, dome-shaped bumps located anywhere on the body and dark lesions on the palms, soles, fingertips and toes, or on mucous membranes lining the mouth, nose, vagina and anus.
  • Superficial spreading melanoma: This type of melanoma is the most common type, accounting for about 70% of all cases. Superficial spreading melanoma travels along the top layer of the skin for a fairly long time before penetrating more deeply. It is most common in younger people. The melanoma appears as a flat or slightly raised discolored patch that has irregular borders and is somewhat geometrical in form, with various colors (tan, brown, black, red, blue or white) in it. The melanoma can be found almost anywhere on the body, but is most likely to occur on the trunk in men, the legs in women, and the upper back in both. Other forms of melanoma include lentigo maligna, acral lentiginous melanoma, and nodular melanoma.
  • Kaposi's sarcoma: Kaposi's sarcoma is a rare form of skin cancer that develops in the skin's blood vessels and causes red or purple patches on the skin or mucous membranes. Like melanoma, it's a serious form of skin cancer. This form of skin cancer is mainly seen in people with weakened immune systems, such as people with AIDS or taking medications that suppress their immunity (immunosuppressive medications in transplant patients).
  • Merkel cell carcinoma: Merkel cell carcinoma is a rare cancer that appears as firm, shiny nodules occurring on or just beneath the skin and in hair follicles. The nodules may be red, pink, or blue and can vary in size from a quarter of an inch to more than two inches. Merkel cell carcinoma is usually found on sun-exposed areas of the head, neck, arms, and legs. Unlike basal and squamous cell carcinomas, merkel cell carcinoma grows rapidly and often spreads to other parts of the body.
  • Sebaceous gland carcinoma: Sebaceous gland carcinoma is an uncommon and aggressive form of skin cancer. This form of skin cancer originates in the oil producing glands in the skin. It usually appears as hard, painless nodules that can develop anywhere, but occurs most on the eyelids where they're frequently mistaken for benign conditions.
  • Precancerous skin lesions: Precancerous skin lesions, including actinic keratosis, can also develop into squamous cell skin cancer. Actinic keratoses appear as rough, scaly, brown or dark-pink patches. They're most commonly found on the face, ears, lower arms and hands of fair-skinned people whose skin has been damaged by the sun. Other precancerous skin lesions include actinic cheilitis (in the lips), arsenical keratosis (exposure to arsenic), Bowen's Disease (superficial SCC that hasn't spread), and leukoplakia (disease of the mucous membrane).
Diagnosis
  • Most doctors recommend a checkup for skin cancer when a new skin growth, a bothersome change in the skin, a change in the appearance or texture of a mole, or a sore that doesn't heal in two weeks appears.
  • Biopsy: If the doctor suspects skin cancer, a small sample of the skin (biopsy) will be removed and analyzed. A biopsy can usually be done in a doctor's office using local anesthetic.
  • Squamous cell carcinoma: A biopsy is often the only test needed to determine if the individual has squamous cell carcinoma. This cancer doesn't spread, and larger growths may require further testing.
  • Basal cell carcinoma: Nodular basal cell carcinoma is the most common type of skin cancer. This tumor usually resembles a smooth, round, waxy pimple, pale yellow or pearl gray, and may vary in size from a few millimeters to one centimeter. The skin covering the nodule is usually so thin that the slightest injury will cause it to bleed. These tumors are often depressed in the middle and display ulcerations. As the tumor grows, it destroys healthy structures in its path, including nerves, muscles, and blood vessels. Large tumors are easily diagnosed, but smaller ones are often difficult to tell from benign skin conditions, such as warts, seborrheic keratoses, moles, psoriasis, or fever sores. Other types of basal cell carcinomas include superficial, sclerosing, pigmented fibroepithelioma, basosquamous carcinoma, and basal cell nevus syndrome.
  • Melanoma: Moles, brown spots, and growths on the skin are usually harmless, but may increase the risk of developing melanoma, especially if there are more than 100 moles on the body. Diagnosis of melanoma will need to be made when moles appear to be asymmetric (if a line is drawn through the mole and the two halves don't match), have uneven borders, variety of colors (shades of brown, tan, or black), are large in size, or are changing. The type of melanoma will also be determined.
  • Once the type of melanoma has been established, the next step is to classify the disease as to its degree of severity. Melanoma, like other cancers, is classified in stages, and the stage will determine the treatment. Early melanomas (Stages I and II) are localized, and advanced melanomas (Stages III and IV) have spread to other parts of the body, or metastasized. There are also degrees within stages.
  • Breslow's thickness: The most important factor in staging a melanoma is the thickness of the tumor, known as Breslow's thickness, and the appearance of microscopic ulcerations (sores). Breslow's thickness measures in millimeters the distance between the upper layer of the epidermis and the deepest point of the tumor's penetration. The thinner the melanoma, the better the chance of a cure. Breslow's thickness diagnoses include: in situ melanoma confined to the epidermis, very thin tumors of less than 1.0 millimeter, thin tumors of 1.01=2.0 mm, intermediate tumors of 2.0-4.0 mm, and thick melanomas of 4.00 mm or more. The presence of microscopic ulcerations moves the tumor into a later stage.
  • Clark's level of invasion: Very thin tumors are classified according to Clark's level of invasion, which describes the number of layers of skin penetrated by the tumor. Clark's level I signifies the melanoma occupies only the epidermis. Clark's level II means that the melanoma penetrates to the layer immediately under the epidermis, the papillary dermis, Clark's level III means that the melanoma fills the papillary dermis and may touch the next layer known as reticular dermis, and Clark's level IV is when the melanoma penetrates into the reticular or deep dermis. Clark's level V melanoma invades the subcutaneous fat.
  • Stage I: This category is subdivided according to the thickness of the primary (original) tumor. In Stage 1a, the tumor is less than 1.0 mm in Breslow's thickness without ulceration and is in Clark's level II or III. In Stage Ib, the tumor is less than 1.0 mm in Breslow's thickness with ulceration and/or Clark's level III or IV, or it is 1.01 - 2.0 mm in thickness without ulceration.
  • Stage II: This category is also subdivided according to gradations in thickness and/or depth and the presence or absence of ulceration. In Stage IIa, the tumor is 1.01 - 2.0 mm in Breslow's thickness with ulceration, or is 2.01-4.0 mm in thickness without ulceration. In Stage IIb, the tumor is 2.01-4.0 mm in Breslow's thickness with ulceration, or is greater than 4.0 mm in thickness without ulceration. In Stage I?c, the tumor is greater than 4.0 mm in Breslow's thickness with ulceration.
  • Stage III: When a melanoma is in Stage III or greater, the tumor has either spread to the lymph nodes or to the skin between the primary tumor and the nearby lymph nodes. This can be determined by examining a biopsy of the node nearest the tumor, known as the sentinel node. Such a biopsy is now frequently done when a tumor is more than 1 mm in thickness, or when a thinner melanoma shows evidence of ulceration. In Stage III, the metastasis (spreading) is to the skin or underlying tissue (subcutaneous) for a distance of more than 2 centimeters (1 cm equals 0.4 inch) from the primary tumor, but not beyond the regional lymph nodes. These metastases are microscopic.
  • Stage IV: Stage IV melanoma has metastasized to lymph nodes far away from the primary tumor or to internal organs, most often the lung followed in descending order of frequency by the liver, brain, bone, and gastrointestinal tract.
Complications
  • Scarring: Some complications of skin cancer can be scars and disfigurement, but it is not usually life-threatening.
  • Metastasis: Once a melanoma is diagnosed past Stage III, metastasis may be found increasing the complications for the patient and treatment involved.
  • Recurrent skin cancer: Once there has been a diagnosis of skin cancer, a second tumor may be more likely.
Treatment
  • Treatment for skin cancer and the precancerous skin lesions known as actinic keratoses varies depending on the size, type, depth and location of the lesions. Often the abnormal cells are surgically removed or destroyed with topical medications. Most treatments require only a local anesthetic and can be done in an outpatient setting. Sometimes no treatment is necessary beyond an initial biopsy that removes the entire growth.
  • Freezing: Actinic keratoses and some small, early skin cancers may be destroyed by freezing them with liquid nitrogen (cryosurgery). The dead tissue sloughs off when it thaws. The treatment may leave a small, white scar.
  • Excisional surgery: Excisional surgery involves cutting out (excising) the cancerous tissue and a surrounding margin of healthy skin. A wide excision removing extra normal skin around the tumor may be recommended in some cases.
  • Laser therapy: A precise, intense beam of light vaporizes growths, generally with little damage to surrounding tissue, minimal bleeding, swelling, and scarring. This procedure may be used to treat superficial skin cancers or precancerous growths on the lips.
  • Mohs' surgery: This procedure is used for larger, recurring or difficult-to-treat skin cancers, which may include both basal and squamous cell carcinomas. The skin growth is removed layer by layer, with each examined under a microscope until no abnormal cells remain. This procedure allows cancerous cells to be removed without taking an excessive amount of surrounding healthy skin.
  • Curettage and electrodesiccation: This procedure involves the scraping away of cancer cell layers using a circular blade (curet), and the electric needle destroys any remaining cancer cells. This simple, quick procedure is common in treating small or thin basal cell cancers, and generally leaves a small, flat, white scar.
  • Radiation therapy: Radiation may be used to destroy basal and squamous cell carcinomas if surgery isn't an option.
  • Chemotherapy: Chemotherapy drugs are used to kill cancer cells. For cancers limited to the top layer of skin, creams or lotions containing anti-cancer agents may be applied directly to the skin. Topical drugs can cause severe inflammation and leave scars. Other types of chemotherapy can be used to treat skin cancers that have spread to other parts of the body.
  • Imiquimod (IMQ) and/or 5-fluorouracil (5FU) are two topical creams for skin cancers. IMQ works by stimulating the body's immune system to destroy cancerous cells (called topical immunotherapy). 5FU works as a topical chemotherapy, preventing rapidly dividing cells from growing. Both creams can cause redness and inflammation, and need to be used for many weeks to be effective. Occasionally, these creams may be used in addition to surgery for maximal success. Topical therapy allows for a low risk of scarring and may be applied at home.
  • Retinoids: Retinoids, such as tretinoin and isotretinoin, are drugs related to vitamin A and are sometimes used off-label to treat or prevent non-melanoma skin cancer. The retinoids may be taken by mouth or applied to the skin, and their use is being studied in clinical trials for treatment of squamous cell carcinoma. Many side effects exist with these medications, including flu-like symptoms and swelling in the feet and ankles (edema).
  • Photodynamic therapy: This treatment destroys skin cancer cells with a combination of laser light and drugs that makes cancer cells sensitive to light.
  • Biological therapy (also called immunotherapy): Interferon and interleukin-2 are currently under investigation to treat melanoma and non-melanoma skin cancers. These immunotherapy drugs stimulate the immune system to fight the cancer. Other medications applied to the skin, such as imiquimod (Aldara®), enhance the immune system's reaction to the presence of skin cancer.
  • Anti-inflammatory medications: The anti-inflammatory drug diclofenac as a topical cream is used off-label as a treatment in actinic keratinosis. Studies report uses for 60 to 90 days with positive results.
Prevention
  • Protection from the sun and ultraviolet (UV) rays: Avoid the sun between 10 a.m. and 4 p.m., because the sun's rays are strongest during this period. Try to schedule outdoor activities for other times of the day, even during the winter months or when the sky is cloudy. Sunburns and suntans cause skin damage that can increase the risk of developing skin cancer. Sun exposure accumulated over time may also lead to skin cancer. Five or more sunburns double the risk of developing skin cancer in a lifetime.
  • Sunscreen may not filter out all harmful UV radiation, especially the radiation that can lead to melanoma, but they play a major role in an overall sun-protection program. A broad-spectrum sunscreen with a sun protection factor (SPF) of at least 15 is recommended when going outside year-round. For the most protection, apply sunscreen 20 to 30 minutes before sun exposure and reapply it every two hours throughout the day, as well as after swimming or exercising.
  • In July 2006, the U.S. Food and Drug Administration (FDA) approved a new over-the-counter sunscreen marketed as Anthelios SX®. The new sunscreen offers better protection from UVA rays than traditional broad-spectrum sunscreens, according to the manufacturer. This may help reduce the risk of various types of skin cancer, including melanoma, basal, and squamous cell carcinomas.
  • It's recommended to wear dark, tightly woven clothing that covers the arms and legs, sunglasses (with UVA and UVB protection), and a broad-brimmed hat, which provides more protection than a baseball cap or visor.
  • Avoid tanning beds and tan-accelerating agents: Tanning beds emit UVA rays that penetrate deeper into the skin and can cause precancerous skin lesions.
  • Sun-sensitizing medications: Some common prescription and over-the-counter drugs, including some antibiotics, some cholesterol, high blood pressure and diabetes medications, birth control pills, nonsteroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen, and the acne and the chemotherapy agent isotretinoin can make the skin more sensitive to sunlight. Also, some herbal supplements may increase sun sensitivity, such as St. John's wort, commonly used for mild depression. A pharmacist can help determine medications that may cause sun sensitivity.
  • Regular check-ups: Examining the skin often for new skin growths or changes in existing moles, freckles, bumps and birthmarks is very important in preventing all forms of skin cancer. Healthcare professionals recommend a complete skin exam every year if an individual is older than 40, or more often if they are at high risk of developing skin cancer.
References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

  • American Academy of Dermatology. . Accessed April 28, 2009.
  • American Academy of Family Physicians. . Accessed April 28, 2009.
  • American Cancer Society. . Accessed April 28, 2009.
  • Fecher LA, Cummings SD, Keefe MJ, et al. Toward a molecular classification of melanoma. J Clin Oncol. 2007 Apr 20;25(12):1606-20. View Abstract
  • Gimotty PA, Elder DE, Fraker DL, et al. Identification of high-risk patients among those diagnosed with thin cutaneous melanomas. J Clin Oncol. 2007 Mar 20;25(9):1129-34. View Abstract
  • Markovic SN, Erickson LA, Rao RD, et al. Malignant melanoma in the 21st century, part 2: staging, prognosis, and treatment. Mayo Clin Proc. 2007 Apr;82(4):490-513. View Abstract
  • National Cancer Institute (NCI). . Accessed April 28, 2009.
  • Natural Standard: The Authority on Integrative Medicine. . Copyright © 2009. Accessed April 28, 2009.
  • Satzger I, Schenck F, Thol F, et al. Therapeutic use of erythropoietin in dermatooncology. J Dtsch Dermatol Ges. 2007 Apr;5(4):280-5. View Abstract
  • Scope A, Benvenuto-Andrade C, Agero AL, et al. Correlation of dermoscopic structures of melanocytic lesions to reflectance confocal microscopy. Arch Dermatol. 2007 Feb;143(2):176-85. View Abstract
  • Skin Cancer Foundation. . Accessed April 28, 2009.