Skin Cancer Facts
What skin cancer looks like
The skin is the largest organ in the body. Skin cancer is the most common of all human cancers. Some form of skin cancer is diagnosed in more than 3 million people in the United States each year.
Cancer occurs when normal cells undergo a transformation during which they grow abnormally and multiply without normal controls.
- As the cells multiply, they form a mass called a tumor. Tumors of the skin are often referred to as skin lesions.
- Tumors are said to be cancerous only if they are composed of malignant cells. This means that they encroach on and invade neighboring tissues because of their uncontrolled growth.
- Tumors may also travel to remote organs via the bloodstream or lymphatic system.
- This process of invading and spreading to other organs is called metastasis.
- Tumors overwhelm surrounding tissues by invading their space and taking the oxygen and nutrients the normal cells need to survive and function.
Skin cancers are of three major types: basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma.
- The vast majority of skin cancers are BCCs or SCCs. While malignant, these are unlikely to spread to other parts of the body. They may be locally disfiguring if not treated early.
- A small but significant number of skin cancers are malignant melanomas. Malignant melanoma is a highly aggressive cancer that tends to metastasize relatively early and aggressively, thereby spreading to other parts of the body. These cancers may be fatal if not found and treated early.
Like many cancers, skin cancers start as precancerous lesions. These precancerous lesions are changes in skin that are not cancer but could become cancer over time. Medical professionals often refer to these changes as dysplasia. Some specific dysplastic changes that occur in skin are as follows:
Moles (nevi) are simply growths on the skin. They are very common. Very few moles become cancer.
- Most people have 10-40 moles on their body.
- Moles can be flat or raised; some begin as flat and become raised over time.
- The surface is usually smooth.
- Moles are round or oval and no larger than ¼-inch across.
- Moles are usually pink, tan, brown, or the same color as the skin. Other colors are sometimes noted.
- An individual's moles usually look pretty much alike. A mole that looks different from the others should be examined by your healthcare professional.
Dysplastic nevi are not cancer, but they can become cancer.
- People with dysplastic nevi often have a lot of them, perhaps as many as 100 or more.
- People with many dysplastic nevi are more likely to develop melanoma, either within an existing nevus or on an area of normal-appearing skin.
- Dysplastic nevi are usually irregular in shape, with notched or fading borders.
- Dysplastic nevi may be flat or raised, and the surface may be smooth or rough ("pebbly").
- Dysplastic nevi are often large, at least ¼-inch across or even larger.
- Dysplastic nevi are typically of mixed color, including pink, red, tan, and brown.
Recent studies demonstrate that the number of skin cancer cases in the United States is growing at an alarming rate. Fortunately, increased awareness on the part of Americans and their healthcare professional has resulted in earlier diagnosis and improved outcomes.
What Causes Skin Cancer?
Ultraviolet (UV) light exposure, most commonly from sunlight, is overwhelmingly the most frequent cause of skin cancer.
Other important causes of skin cancer include the following:
- Use of tanning booths
- Immunosuppression - This means impairment of the immune system. The immune system protects the body from foreign entities, such as germs or substances that cause an allergic reaction. This suppression may occur as a consequence of some diseases or can be due to medications prescribed to combat conditions such as autoimmune diseases or prevent organ transplant rejection.
- Exposure to unusually high levels of X-rays
- Contact with certain chemicals-arsenic (miners, sheep shearers, and farmers), hydrocarbons in tar, oils, and soot (may cause squamous cell carcinoma)
The following people are at the greatest risk:
- People with fair skin, especially types that freckle, sunburn easily, or become painful in the sun
- People with light (blond or red) hair and blue or green eyes
- Those with certain genetic disorders that deplete skin pigment such as albinism, xeroderma pigmentosum
- People who have already been treated for skin cancer
- People with numerous moles, unusual moles, or large moles that were present at birth
- People with close family members who have developed skin cancer
- People who had at least one severe sunburn early in life
Basal cell carcinomas and squamous cell carcinomas are more common in older people. Melanomas can occur at any age. It is most commonly diagnosed at between 55 and 75 years of age, but about 1/3 occur before the age of 50. For example, melanoma is the most common cancer in people younger than 30.
Self-examination is important in the detection of skin cancer.
What Are the Symptoms of Skin Cancer?
A basal cell carcinoma (BCC) usually looks like a raised, smooth, pearly bump on the sun-exposed skin of the head, neck, or shoulders.
- Small blood vessels may be visible within the tumor.
- A central depression with crusting and bleeding (ulceration) frequently develops.
- A BCC is often mistaken for a sore that does not heal.
A squamous cell carcinoma (SCC) is commonly a well-defined, red, scaling, thickened patch on sun-exposed skin.
- Like BCCs, SCCs may ulcerate and bleed.
- Left untreated, SCC may develop into a large mass.
The majority of malignant melanomas are brown to black pigmented lesions.
- Warning signs include change in size, shape, color, or elevation of a mole.
- The appearance of a new mole during adulthood, or new pain, itching, ulceration, or bleeding of an existing mole should all be checked by a healthcare professional.
The following easy-to-remember guideline, "ABCD," is useful for identifying malignant melanoma:
- Asymmetry-One side of the lesion does not look like the other.
- Border irregularity-Margins may be notched or irregular.
- Color-Melanomas are often a mixture of black, tan, brown, blue, red, or white.
- Diameter-Cancerous lesions are usually larger than 6 mm across (about the size of a pencil eraser), but any change in size may be significant.
When to See a Doctor about Skin Cancer
Many people, especially those who have fair coloring or have had extensive sun exposure, should periodically check their entire body for suggestive moles and lesions.
Have your primary healthcare professional or a skin specialist (dermatologist) check any moles or spots that concern you.
See your healthcare professional to check your skin if you notice any changes in the size, shape, color, or texture of pigmented areas (such as darker areas of skin or moles).
If you have skin cancer, your skin specialist (dermatologist) or cancer specialist (oncologist) will talk to you about symptoms of metastatic disease that might require care in a hospital.
What Exams and Tests Diagnose Skin Cancer?
If you have a worrisome mole or other lesion, your primary-care provider will probably refer you to a dermatologist. The dermatologist will examine any moles in question and, in many cases, the entire skin surface.
- Any lesions that are difficult to identify, or are thought to be skin cancer, may then be checked.
- A sample of skin (biopsy) will be taken so that the suspicious area of skin can be examined under a microscope.
- A biopsy can almost always be done in the dermatologist's office.
If a biopsy shows that you have malignant melanoma, you will probably undergo further testing to determine the extent of spread of the disease, if any. This may involve blood tests, a chest X-ray, and other tests as needed.
What Is the Treatment for Skin Cancer?
Treatment for basal cell carcinoma and squamous cell carcinoma is straightforward. Usually, surgical removal of the lesion is adequate. Malignant melanoma, however, may require several treatment methods, including surgery, radiation therapy, and chemotherapy or immunotherapy or both. Because of the complexity of treatment decisions, people with malignant melanoma may benefit from the combined expertise of the dermatologist, a cancer surgeon, and a medical oncologist.
Self-Care at Home for Skin Cancer
Home treatment is not appropriate for skin cancer. These conditions require the care of a dermatologist or specialist in skin cancers.
Be active in preventing and detecting skin cancer on yourself and others. Perform regular self-examinations of your skin and note any changes. Avoid unnecessary exposure to direct sunlight. Wear sunscreen daily.
Medical Treatment for Skin Cancer
Surgical removal is the mainstay of therapy for both basal cell and squamous cell carcinomas. For more information, see Surgery.
People who cannot undergo surgery may be treated by external radiation therapy. Radiation therapy is the use of a small beam of radiation targeted at the skin lesion. The radiation kills the abnormal cells and destroys the lesion. Radiation therapy can cause irritation or burning of the surrounding normal skin. It can also cause fatigue. These side effects are temporary. In addition, a topical cream has recently been approved for the treatment of certain low-risk nonmelanoma skin cancers.
In advanced cases, immune therapies, vaccines, or chemotherapy may be used. These treatments are typically offered as clinical trials. Clinical trials are studies of new therapies to see if they can be tolerated and work better than existing therapies.
Skin Cancer Surgery
Small lesions may be removed through a variety of techniques, including simple excision (cutting it away), electrodesiccation and curettage (burning the tissue with an electric needle), and cryosurgery (freezing the area with liquid nitrogen).
Larger tumors, lesions in high-risk locations, recurrent tumors, and lesions in cosmetically sensitive areas are removed by Mohs micrographic surgery. The surgeon carefully removes tissue, layer by layer, until the cancer-free tissue is reached.
Malignant melanoma is treated more aggressively than just surgical removal. To ensure the complete removal of this dangerous malignancy, 1-2 cm of normal-appearing skin surrounding the tumor is also removed by wide excision with or without skin grafting to cover the defect left by the procedure. Another technique called Moh's micrographic surgery can be used in melanoma, but some controversy exists about this. Moh's technique is more commonly used for non-melanoma skin cancers. Depending on the thickness of the melanoma, neighboring lymph nodes may also be removed and tested for cancer. The sentinel node method uses a small amount of radioactive substance injected into the region of the tumor to identify which lymph nodes the cancer is most likely to have first spread to if it has spread at all. The sentinel node is then removed. Only if it is positive melanoma are other lymph nodes are considered for removal in that region. Extensive lymph node removal can result in some chronic problems if performed, thus, the sentinel node technique may reduce both the extent and problems with a more extensive lymph node removal procedure.
What Is the Follow-up for Skin Cancer?
Most skin cancer is cured surgically in the dermatologist's office. Of skin cancers that do recur, most do so within three years. Therefore, follow up with your dermatologist (skin specialist) as recommended. Make an appointment immediately if you suspect a problem.
If you have a more deeply invasive or advanced malignant melanoma, your oncologist may want to see you every few months. These visits may include total body skin examinations, regional lymph node checks, and periodic chest X-rays. Over time, the intervals between follow-up appointments will increase. Eventually these checks may be done only once a year.
Sun-Damaged Skin: Pictures of Sun Spots, Wrinkles, Sunburns
Skin Cancer Prevention
You can reduce your risk of getting skin cancer.
- Limit sun exposure. Attempt to avoid the sun's intense rays between 10 a.m. and 2 p.m.
- Apply sunscreen frequently. Use a sunscreen with sun protection factor (SPF) of at least 15 both before and during sun exposure. Select products that block both UVA and UVB light. The label will tell you.
- If you are likely to sunburn, wear long sleeves and a wide-brimmed hat.
- Avoid artificial tanning booths.
- Conduct periodic skin self-examinations.
Monthly self-examination improves your chances of finding a skin cancer early, when it has done a minimum of damage to your skin and can be treated easily. Regular self-exam helps you recognize any new or changing features.
- The best time to do a self-exam is right after a shower or bath.
- Do the self-exam in a well-lighted room; use a full-length mirror and a handheld mirror.
- Learn where your moles, birthmarks, and blemishes are, and what they look like.
- Each time you do a self-exam, check these areas for changes in size, texture, and color, and for ulceration. If you notice any changes, call your primary-care provider or dermatologist.
Check all areas of your body, including "hard-to-reach" areas. Ask a loved one to help you if there are areas you can't see.
- Look in the full-length mirror at your front and your back (use the handheld mirror to do this). Raise your arms and look at your left and right sides.
- Bend your elbows and look carefully at your palms, your forearms (front and back), and upper arms.
- Examine the backs and fronts of your legs. Look at your buttocks (including the area between the buttocks) and your genitals (use the handheld mirror to make sure you see all skin areas).
- Sit down and examine your feet carefully, including the soles and between the toes.
- Look at your scalp, face, and neck. You may use a comb or blow dryer to move your hair while examining your scalp.
What Is the Prognosis for Skin Cancer?
Although the number of skin cancers in the United States continues to rise, more and more skin cancers are being caught earlier, when they are easier to treat. Thus, illness and death rates have decreased.
When treated properly, the cure rate for both basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) approaches 95%. The remaining cancers recur at some point after treatment.
- Recurrences of these cancers are almost always local (not spread elsewhere in the body), but they often cause significant tissue destruction.
- Less than 1% of squamous cell carcinomas will eventually spread elsewhere in the body and turn into dangerous cancer.
In most cases, the outcome of malignant melanoma depends on the thickness of the tumor at the time of treatment.
- Thin lesions are almost always cured by simple surgery alone.
- Thicker tumors, which usually have been present for some time but have gone undetected, may spread to other organs. Surgery removes the tumor and any local spread, but it cannot remove distant metastasis. Other therapies, new targeted agents or older approaches such as radiation therapy or chemotherapy, are used to treat the metastatic tumors.
- Malignant melanoma causes more than 75% of deaths from skin cancer.
- Of the approximately 70,000 malignant melanomas diagnosed in the United States in 2007, the vast majority were cured. Still, thousands of people die of melanoma each year.
Skin Cancer Support Groups and Counseling
Living with cancer presents many new challenges for you and for your family and friends.
- You will probably have many worries about how the cancer will affect you and your ability to "live a normal life," that is, to care for your family and home, to hold your job, and to continue the friendships and activities you enjoy.
- Many people feel anxious and depressed. Some people feel angry and resentful; others feel helpless and defeated.
For most people with cancer, talking about their feelings and concerns helps.
- Your friends and family members can be very supportive. They may be hesitant to offer support until they see how you are coping. Don't wait for them to bring it up. If you want to talk about your concerns, let them know.
- Some people don't want to "burden" their loved ones or prefer talking about their concerns with a more neutral professional. A social worker, counselor, or member of the clergy can be helpful if you want to discuss your feelings and concerns about having cancer. Your dermatologist or oncologist should be able to recommend someone.
- Many people with cancer are profoundly helped by talking to other people who have cancer. Sharing your concerns with others who have been through the same thing can be remarkably reassuring. Support groups of people with cancer may be available through the medical center where you are receiving your treatment. The American Cancer Society also has information about support groups all over the United States.
Pictures of Skin Cancer: What Does Skin Cancer Look Like?
Skin cancer. Malignant melanoma. Click to view larger image. Skin cancer. Basal cell carcinoma. Click to view larger image. Skin cancer. Superficial spreading melanoma, left breast. Photo courtesy of Susan M. Swetter, MD, Director of Pigmented Lesion and Cutaneous Melanoma Clinic, Assistant Professor, Department of Dermatology, Stanford University Medical Center, Veterans Affairs Palo Alto Health Care System. Click to view larger image. Skin cancer. Melanoma on the sole of the foot. Diagnostic punch biopsy site located at the top. Photo courtesy of Susan M. Swetter, MD, Director of Pigmented Lesion and Cutaneous Melanoma Clinic, Assistant Professor, Department of Dermatology, Stanford University Medical Center, Veterans Affairs Palo Alto Health Care System. Click to view larger image. Skin cancer. Melanoma, right lower cheek. Photo courtesy of Susan M. Swetter, MD, Director of Pigmented Lesion and Cutaneous Melanoma Clinic, Assistant Professor, Department of Dermatology, Stanford University Medical Center, Veterans Affairs Palo Alto Health Care System. Click to view larger image.
Reviewed on 8/30/2021
Medically reviewed by John A. Daller, MD; American Board of Surgery with subspecialty certification in surgical critical care
"Screening and early detection of melanoma"