Cancer Guide

What is Skin Cancer?

At Ocean Radiation Oncology, we offer precise and convenient skin cancer radiation treatments. Our expertise in the use of electron radiation treatments ensures that we provide our skin cancer patients with state-of-the-art skin cancer radiation therapy care.


Skin cancers include squamous cell carcinomas, basal cell carcinomas, and melanomas. Radiation therapy can be a non-surgical alternative definitive treatment for certain skin cancers, often depending on body location and cancer type. Commonly, squamous cell carcinomas and basal cell carcinomas on cosmetically sensitive areas of the face (such as the eyelids, lips, nose) are well-suited for treatment with radiotherapy instead of surgery. For some skin cancers, radiation therapy may be an appropriate option after surgical removal of the cancer in order to decrease further the likelihood of cancer recurrence.

back to top


When you’re told that you have skin cancer, it’s natural to wonder what may have caused the disease. The main risk factor for skin cancer is exposure to sunlight (UV radiation), but there are also other risk factors. A risk factor is something that may increase the chance of getting a disease.

People with certain risk factors are more likely than others to develop skin cancer. Some risk factors vary for the different types of skin cancer.

Risks for Any Type of Skin Cancer

Studies have shown that the following are risk factors for the three most common types of skin cancer:

  • Sunlight: Sunlight is a source of UV radiation. It’s the most important risk factor for any type of skin cancer. The sun’s rays cause skin damage that can lead to cancer.
    • Severe, blistering sunburns: People who have had at least one severe, blistering sunburn are at increased risk of skin cancer. Although people who burn easily are more likely to have had sunburns as a child, sunburns during adulthood also increase the risk of skin cancer.
    • Lifetime sun exposure: The total amount of sun exposure over a lifetime is a risk factor for skin cancer.
    • Tanning: Although a tan slightly lowers the risk of sunburn, even people who tan well without sunburning have a higher risk of skin cancer because of more lifetime sun exposure.

Sunlight can be reflected by sand, water, snow, ice, and pavement. The sun’s rays can get through clouds, windshields, windows, and light clothing.

In the United States, skin cancer is more common where the sun is strong. For example, more people in Texas than in Minnesota get skin cancer. Also, the sun is stronger at higher elevations, such as in the mountains.

Doctors encourage people to limit their exposure to sunlight. See the Prevention section for ways to protect your skin from the sun.

  • Sunlamps and tanning booths: Artificial sources of UV radiation, such as sunlamps and tanning booths, can cause skin damage and skin cancer.  Health care providers strongly encourage people, especially young people, to avoid using sunlamps and tanning booths. The risk of skin cancer is greatly increased by using sunlamps and tanning booths before age 30.
  • Personal history: People who have had melanoma have an increased risk of developing other melanomas. Also, people who have had basal cell or squamous cell skin cancer have an increased risk of developing another skin cancer of any type.
  • Family history: Melanoma sometimes runs in families. Having two or more close relatives (mother, father, sister, brother, or child) who have had this disease is a risk factor for developing melanoma. Other types of skin cancer also sometimes run in families. Rarely, members of a family will have an inherited disorder, such as xeroderma pigmentosum or nevoid basal cell carcinoma syndrome, that makes the skin more sensitive to the sun and increases the risk of skin cancer.
  • Skin that burns easily: Having fair (pale) skin that burns in the sun easily, blue or gray eyes, red or blond hair, or many freckles increases the risk of skin cancer.
  • Certain medical conditions or medicines: Medical conditions or medicines (such as some antibiotics, hormones, or antidepressants) that make your skin more sensitive to the sun increase the risk of skin cancer. Also, medical conditions or medicines that suppress the immune system increase the risk of skin cancer.

Other Risk Factors for Melanoma

The following risk factors increase the risk of melanoma:

  • Dysplastic nevus: A dysplastic nevus is a type of mole that looks different from a common mole. A dysplastic nevus may be bigger than a common mole, and its color, surface, and border may be different. It’s usually wider than a pea and may be longer than a peanut. A dysplastic nevus can have a mixture of several colors, from pink to dark brown. Usually, it’s flat with a smooth, slightly scaly or pebbly surface, and it has an irregular edge that may fade into the surrounding skin.

    A dysplastic nevus is more likely than a common mole to turn into cancer. However, most do not change into melanoma. A doctor will remove a dysplastic nevus if it looks like it might have changed into melanoma.
  • More than 50 common moles: Usually, a common mole is smaller than a pea, has an even color (pink, tan, or brown), and is round or oval with a smooth surface. Having many common moles increases the risk of developing melanoma.

Other Risk Factors for Both Basal Cell and Squamous Cell Skin Cancers

The following risk factors increase the risk of basal cell and squamous cell skin cancers:

Other Risk Factors for Squamous Cell Cancer

The risk of squamous cell skin cancer is increased by the following:

  • Actinic keratosis: Actinic keratosis is a type of flat, scaly growth on the skin. It is most often found on areas exposed to the sun, especially the face and the backs of the hands. The growth may appear as a rough red or brown patch on the skin. It may also appear as cracking or peeling of the lower lip that does not heal. Without treatment, this scaly growth may turn into squamous cell skin cancer.
  • HPV (human papillomavirus): Certain types of HPV can infect the skin and may increase the risk of squamous cell skin cancer. These HPVs are different from the HPV types that cause cervical cancer and other cancers in the female and male genital areas.

back to top


Often the first sign of melanoma is a change in the shape, color, size, or feel of an existing mole. Melanoma may also appear as a new mole. Thinking of “ABCDE” can help you remember what to look for:

  • Asymmetry: The shape of one half does not match the other half.
  • Border that is irregular: The edges are often ragged, notched, or blurred in outline. The pigment may spread into the surrounding skin.
  • Color that is uneven: Shades of black, brown, and tan may be present. Areas of white, gray, red, pink, or blue may also be seen.
  • Diameter: There is a change in size, usually an increase. Melanomas can be tiny, but most are larger than the size of a pea (larger than 6 millimeters or about 1/4 inch).
  • Evolving: The mole has changed over the past few weeks or months.

Melanomas can vary greatly in how they look. Many show all of the ABCDE features. However, some may show changes or abnormal areas in only one or two of the ABCDE features.

In more advanced melanoma, the texture of the mole may change. The skin on the surface may break down and look scraped. It may become hard or lumpy. The surface may ooze or bleed. Sometimes the melanoma is itchy, tender, or painful.

back to top


If you have a change on your skin, your doctor must find out whether or not the problem is from cancer. You may need to see a dermatologist, a doctor who has special training in the diagnosis and treatment of skin problems.

Your doctor will check the skin all over your body to see if other unusual growths are present.

If your doctor suspects that a spot on the skin is cancer, you may need a biopsy. For a biopsy, your doctor may remove all or part of the skin that does not look normal. The sample goes to a lab. A pathologist checks the sample under a microscope. Sometimes it’s helpful for more than one pathologist to check the tissue for cancer cells.

You may have the biopsy in a doctor’s office or as an outpatient in a clinic or hospital. You’ll probably have local anesthesia.

There are four common types of skin biopsies:

  • Shave biopsy: The doctor uses a thin, sharp blade to shave off the abnormal growth.
  • Punch biopsy: The doctor uses a sharp, hollow tool to remove a circle of tissue from the abnormal area.
  • Incisional biopsy: The doctor uses a scalpel  to remove part of the growth.

Excisional biopsy: The doctor uses a scalpel to remove the entire growth and some tissue around it. This type of biopsy is most commonly used for growths that appear to be melanoma.

back to top


Treatment for skin cancer depends on the type and stage of the disease, the size and place of the tumor, and your general health and medical history. In most cases, the goal of treatment is to remove or destroy the cancer completely. Most skin cancers can be cured if found and treated early.

Sometimes all of the skin cancer is removed during the biopsy. In such cases, no more treatment is needed.

If you do need more treatment, your doctor can describe your treatment choices and what to expect. You and your doctor can work together to develop a treatment plan that meets your needs.

Surgery is the usual treatment for people with skin cancer. In some cases, the doctor may suggest chemotherapy, photodynamic therapy, or radiation therapy. People with melanoma may also have biological therapy.

You may have a team of specialists to help plan your treatment. Your doctor may refer you to a specialist, or you may ask for a referral. Specialists who treat skin cancer include dermatologists and surgeons. Some people may also need a reconstructive or plastic surgeon.

People with advanced skin cancer may be referred to a medical oncologist or radiation oncologist. Your health care team may also include an oncology nurse, a social worker, and a registered dietitian.

Because skin cancer treatment may damage healthy cells and tissues, unwanted side effects sometimes occur. Side effects depend mainly on the type and extent of the treatment. Side effects may not be the same for each person. Before treatment starts, your health care team will tell you about possible side effects and suggest ways to help you manage them.

Many skin cancers can be removed quickly and easily. But some people may need supportive care to control pain and other symptoms, to relieve the side effects of treatment, and to help them cope with the feelings that a diagnosis of cancer can bring.


In general, the surgeon will remove the cancerous growth and some normal tissue around it. This reduces the chance that cancer cells will be left in the area.

There are several methods of surgery for skin cancer. The method your doctor uses depends mainly on the type of skin cancer, the size of the cancer, and where it was found on your body.

Your doctor can further describe these methods of surgery:

  • Excisional skin surgery: This is a common treatment to remove any type of skin cancer. After numbing the area of skin, the surgeon removes the growth (tumor) with a scalpel. The surgeon also removes a border (a margin) of normal skin around the growth. The margin of skin is examined under a microscope to be certain that all the cancer cells have been removed. The thickness of the margin depends on the size of the tumor.
  • Mohs surgery (also called Mohs micrographic surgery): This method is often used for basal cell and squamous cell skin cancers. After numbing the area of skin, a specially trained surgeon shaves away thin layers of the tumor. Each layer is examined under a microscope. The surgeon continues to shave away tissue until no cancer cells can be seen under the microscope. In this way, the surgeon can remove all the cancer and only a small bit of healthy tissue. Some people will have radiation therapy after Mohs surgery to make sure all of the cancer cells are destroyed.
  • Electrodesiccation and curettage: This method is often used to remove a small basal cell or squamous cell skin cancer. After the doctor numbs the area to be treated, the cancer is removed with a sharp tool shaped like a spoon (called a curette). The doctor then uses a needle-shaped electrode to send an electric current into the treated area to control bleeding and kill any cancer cells that may be left. This method is usually fast and simple. It may be performed up to three times to remove all of the cancer.
  • Cryosurgery: This method is an option for an early-stage or a very thin basal cell or squamous cell skin cancer. Cryosurgery is often used for people who are not able to have other types of surgery. The doctor applies liquid nitrogen (which is extremely cold) directly to the skin growth to freeze and kill the cancer cells. This treatment may cause swelling. It also may damage nerves, which can cause a loss of feeling in the damaged area. The NCI fact sheet Cryosurgery in Cancer Treatment has more information.

For people with cancer that has spread to the lymph nodes, the surgeon may remove some or all of the nearby lymph nodes. Additional treatment may be needed after surgery. See the Staging section for information about finding cancer in lymph nodes.

If a large area of tissue is removed, the surgeon may do a skin graft. The doctor uses skin from another part of the body to replace the skin that was removed. After numbing the area, the surgeon removes a patch of healthy skin from another part of the body, such as the upper thigh. The patch is then used to cover the area where skin cancer was removed. If you have a skin graft, you may have to take special care of the area until it heals.

The time it takes to heal after surgery is different for each person. You may have pain for the first few days. Medicine can help control your pain. Before surgery, you should discuss the plan for pain relief with your doctor or nurse. After surgery, your doctor can adjust the plan if you need more pain relief.

Surgery nearly always leaves some type of scar. The size and color of the scar depend on the size of the cancer, the type of surgery, the color of your skin, and how your skin heals.

For any type of surgery, including skin grafts or reconstructive surgery, follow your doctor’s advice on bathing, shaving, exercise, or other activities.


Chemotherapy uses drugs to kill cancer cells. Drugs for skin cancer can be given in many ways.

Put directly on the skin

A cream or lotion form of chemotherapy may be used to treat very thin, early-stage basal cell or squamous cell skin cancer (Bowen disease). It may also be used if there are several small skin cancers. The doctor will show you how to apply the cream or lotion to the skin one or two times a day for several weeks.

The cream or lotion contains a drug that kills cancer cells only in the top layer of the skin:

  • Fluorouracil (another name is 5-FU): This drug is used to treat early-stage basal cell and squamous cell cancers.
  • Imiquimod: This drug is used to treat early-stage basal cell cancer.

These drugs may cause your skin to turn red or swell. Your skin also may itch, ooze, or develop a rash. Your skin may be sore or sensitive to the sun after treatment. These skin changes usually go away after treatment is over.

A cream or lotion form of chemotherapy usually does not leave a scar. If healthy skin becomes too red or raw when the skin cancer is treated, your doctor may stop treatment.

Swallowed or injected

People with melanoma may receive chemotherapy by mouth or through a vein (intravenous). You may receive one or more drugs. The drugs enter the bloodstream and travel throughout the body.

If you have melanoma on an arm or leg, you may receive drugs directly into the bloodstream of that limb. The flow of blood to and from the limb is stopped for a while. This allows a high dose of drugs in the area with the melanoma. Most of the chemotherapy remains in that limb.

You may receive chemotherapy in an outpatient part of the hospital, at the doctor’s office, or at home. Some people need to stay in the hospital during treatment.

The side effects depend mainly on which drugs are given and how much. Chemotherapy kills fast-growing cancer cells, but the drugs can also harm normal cells that divide rapidly:

  • Blood cells: When drugs lower the levels of healthy blood cells, you’re more likely to get infections, bruise or bleed easily, and feel very weak and tired. Your health care team will check for low levels of blood cells. If your levels are low, your health care team may stop the chemotherapy for a while or reduce the dose of the drug. There are also medicines that can help your body make new blood cells.
  • Cells in hair roots: Chemotherapy may cause hair loss. If you lose your hair, it will grow back after treatment, but the color and texture may be changed.
  • Cells that line the digestive tract: Chemotherapy can cause a poor appetite, nausea and vomiting, diarrhea, or mouth and lip sores. Your health care team can give you medicines and suggest other ways to help with these problems. They usually go away when treatment ends.

Photodynamic Therapy

Photodynamic therapy (PDT) uses a drug along with a special light source, such as a laser light, to kill cancer cells. PDT may be used to treat very thin, early-stage basal cell or squamous cell skin cancer (Bowen disease).

The drug is either rubbed into the skin or injected intravenously. The drug is absorbed by cancer cells. It stays in cancer cells longer than in normal cells. Several hours or days later, a special light is focused on the cancer. The drug becomes active and destroys the cancer cells.

The side effects of PDT are usually not serious. PDT may cause burning or stinging pain. It also may cause burns, swelling, or redness. It may scar healthy tissue near the growth. If you have PDT, you will need to avoid direct sunlight and bright indoor light for at least 6 weeks after treatment.

Biological Therapy

Some people with advanced melanoma receive a drug called biological therapy. Biological therapy for melanoma is treatment that may improve the body’s natural defense (immune system response) against cancer.

One drug for melanoma is interferon. It’s injected intravenously (usually at a hospital or clinic) or injected under the skin (at home or in a doctor’s office). Interferon can slow the growth of melanoma cells.

Another drug used for melanoma is interleukin-2. It’s given intravenously. It can help the body destroy cancer cells. Interleukin-2 is usually given at the hospital.

Other drugs may be given at the same time to prevent side effects. The side effects differ with the drug used, and from person to person. Biological therapies commonly cause a rash or swelling. You may feel very tired during treatment. These drugs may also cause a headache, muscle aches, a fever, or weakness.

Radiation Therapy

Radiation therapy uses high-energy rays to kill cancer cells. The radiation comes from a large machine outside the body. It affects cells only in the treated area. You will go to a hospital or clinic several times for this treatment.

Radiation therapy is not a common treatment for skin cancer. But it may be used for skin cancer in areas where surgery could be difficult or leave a bad scar. For example, you may have radiation therapy if you have a growth on your eyelid, ear, or nose. Radiation therapy may also be used after surgery for squamous cell carcinoma that can’t be completely removed or that has spread to the lymph nodes. And it may be used for melanoma that has spread to the lymph nodes, brain, bones, or other parts of the body.

Although radiation therapy is painless, it may cause other side effects. The side effects depend mainly on the dose of radiation and the part of your body that is treated. It’s common for the skin in the treated area to become red, dry, tender, and itchy. Your health care team can suggest ways to relieve the side effects of radiation therapy.

back to top

Cancer reference provided by the web site of the National Cancer Institute ( The NCI Web site is periodically revised, and content may be deleted or moved. We try to ensure that existing links will redirect to the new page(s).

Cancer Guide