What is skin cancer?
The skin is the largest organ of the body. It provides protection, helps regulate body temperature, and plays a role in sensation. It is also the most common site of cancer. Each year, about 2 million people in the United States are diagnosed with skin cancer.
The most common skin cancers are basal cell carcinoma, squamous cell carcinoma, and melanoma. Each originates from a different type of skin cell. Basal cell carcinomas are often smooth and shiny, may be skin-toned or slightly darker, and may be raised with a central dimple. Squamous cell carcinomas may also be shiny, but they tend to be scalier and may have flat, reddish patches.
The appearance of melanomas is often described as ABCDE, where A stands for asymmetrical; B stands for borders, which are often irregular; C stands for color, which may be black, brown, tan, or even blue, red, or white; D stands for diameter, which is often larger than 6 mm (.24 inches); and E is for evolving, meaning the appearance of the mole has changed in recent weeks or months.
The risk factors for developing any of these three types of skin cancers are similar, and include fair skin and excessive sun exposure. The use of tanning beds also contributes to the development of these cancers.
Both basal and squamous cell cancers are usually easily treatable with simple removal and typically do not spread to distant sites (metastasize). Melanoma is a more aggressive and dangerous type of skin cancer. If it is not detected and treated early, melanoma has a higher risk of spreading and can possibly be fatal.
Skin cancers can be serious. Seek prompt medical care if you notice any suspicious changes in your skin, including sores that don’t heal, have a shiny, raised appearance or a scaly appearance, or bleed easily. Prompt medical care should be sought for any skin changes that are asymmetrical, have irregular borders, are changing in appearance or color, or are greater than 6 mm in diameter.
What are the different types of skin cancer?
There are three main types of skin cancer: basal cell carcinoma, squamous cell carcinoma, and malignant melanoma:
Basal cell carcinoma is the most common type of skin cancer, accounting for approximately 80% of all skin cancers. This highly treatable cancer starts in the epidermis (the top layer of skin) and grows very slowly. Basal cell carcinoma usually appears as a small, shiny bump or nodule on the skin. It mainly affects those areas exposed to the sun, such as the head, neck, hands and face. It commonly occurs among people with light-colored eyes, hair, and complexion.
Squamous cell carcinoma is less common and more aggressive than basal cell carcinoma, but still highly treatable. Squamous cells are the most superficial cells within the epidermis and they express keratin, the scaly protein that protects the skin surface. It accounts for nearly 20% of all cases of skin cancer. Squamous cell carcinoma may appear as nodules or red, scaly patches of skin. It may be found on the face, ears, lips and mouth. But it can spread to other parts of the body. This type of skin cancer is usually found in fair-skinned people.
- Melanoma accounts for only 1% of all skin cancer cases, but it causes most skin cancer deaths. Malignant melanoma starts in the melanocytes, which are cells that produce pigment in the skin. Malignant melanomas usually begin as a mole that then turns cancerous. This cancer may spread quickly. It affects people with all skin types but most often appears on fair-skinned men and women.
What are the symptoms of skin cancer?
It is important to routinely self-check your own skin and be aware of the moles and spots present, so you can monitor any changes in appearance or any new areas that appear.
Talk to your doctor or dermatologist if you notice any areas of concern on your skin, but pay special attention to these signs and symptoms of skin cancer.
ABCDE symptoms of melanoma
Dermatologists encourage people to check for potentially cancerous spots and moles by looking for the “ABCDE’s” of melanoma:
Asymmetrical: The spot or mole has an irregular shape or two halves that look very different.
Border: The border of the spot or mole is jagged or irregular.
Color: The spot or mole is uneven in color, or has unusual coloring, such as black, blue, red or white.
Diameter: The spot or mole is larger than the size of a pea.
- Evolving: The appearance of the spot or mole has changed in recent weeks or months.
Talk to your dermatologist right away if you notice any of these warning signs. Melanoma can grow quickly, but when caught early it can be successfully treated and has a 5-year relative survival rate of 99%. The later the stage at the time of diagnosis, the worse the prognosis.
Other symptoms of skin cancer
Other common symptoms of skin cancer include:
Area with a shiny, pearly or waxy appearance
Non-healing scab or ulcer
Noticeable blood vessels in or near an area of skin change
Raised area with rounded edges, possibly with a central dimple
Scaly area of skin
Scar-like appearance in an area that has not been injured
Skin sore that may bleed and crust over but does not go away
Shift in appearance of a mole or other skin lesion
- Spread of a skin abnormality to a larger area
Symptoms that might indicate a serious condition
Skin cancer, especially melanoma, can be a serious condition that should be evaluated without delay. Seek prompt medical care for any of these serious symptoms:
Area of skin change that is larger than 6 mm (0.24 inches) in diameter
Area of skin that turns red, black, brown, tan, blue or white
Bump or discoloration of the skin that has irregular borders
Bump or discoloration of the skin that is asymmetrical
Skin change that seems to be spreading
Skin sore that bleeds easily
Skin sore that does not heal
- Swollen regional lymph nodes
What are the stages of skin cancer?
Like many other cancers, skin cancer is staged at diagnosis, meaning the doctor identifies whether the cancer has spread, and if so, how far.
Staging for skin cancer varies based on the type of skin cancer diagnosed, using what’s known as the TNM system:
T (tumor): the tumor’s location, size and depth of growth into the skin
N (node): whether the cancer has spread to nearby lymph nodes or tissue
- M (metastasis): whether the cancer has spread to other organs in the body
Basal cell cancer and squamous cell cancer stages
For basal cell and squamous cell cancers, certain factors at diagnosis indicate the tumor is at high risk for spreading or recurring after treatment. This elevated risk is associated with cancers that:
Are more than 2 mm thicker
Have spread into the lower layers of the skin
Have affected the nerves in the skin
- Are located on the ear or on a hair-bearing lip
Because most basal cell skin cancers are treated effectively before they spread, doctors typically do not need to stage them. When basal cell or squamous cell cancers are staged, doctors follow these guidelines:
Stage 0: Cancer is only in the upper layer of the skin (epidermis) and has not spread deeper. This stage is also called carcinoma in situ.
Stage I: Cancer is less than 2 cm (0.8 inches) across, has not spread, and has one or zero high-risk factors.
Stage II: Cancer is more than 2 cm (0.8 inches) across and has not spread, or there is a tumor of any size with two or more high-risk factors.
Stage III: Cancer has spread into one nearby lymph node or into facial bones, but not to other organs in the body.
- Stage IV: Cancer has spread to one or more lymph nodes and may have spread to other organs or bones in the body.
Like basal cell cancer and squamous cell cancer, melanoma follows the TNM system to determine staging. Within the tumor analysis, doctors also evaluate ulceration, when the skin above the melanoma has broken down. Cases with ulceration tend to have a worse prognosis.
Stages for melanoma are outlined as:
Stage 0: Cancer is only in the upper layer of the skin (epidermis) and has not spread deeper. This stage is also called melanoma in situ.
Stage I: Cancer is no more than 2 mm (0.08 inches) across and has not spread. The tumor may or may not be ulcerated.
Stage II: Cancer is more than 1 mm (0.04 inches) and up to 4 mm (0.16 inches) thick. It has not spread, and it may or may not be ulcerated.
Stage III: This includes a range of sub-stages (A to D) in which the primary tumor can range from undetectable to more than 4 mm (0.16) inches, may or may not be ulcerated, has affected local lymph nodes, or has spread to small areas of nearby skin (satellite tumors). In any level of stage III, the cancer has not spread to distant parts of the body.
- Stage IV: Cancer has spread to other areas of the body, including distant lymph nodes and organs, such as the brain, liver or lungs. The primary tumor can be any thickness, may or may not be ulcerated, and may or may not have spread to nearby lymph nodes.
Your doctor will discuss your specific diagnosis with you, including staging, in the context of your medical history and individual risk factors. From there, you can discuss treatment options and next steps in your cancer care.
What causes skin cancer?
While the specific cause is not known, excessive lifelong exposure to ultraviolet (UV) rays is a primary factor in the development of skin cancer. UV rays damage the DNA in skin cells, which can result in mutations that increase the risk of forming cancer cells.
People with skin cancer risk factors should limit time in the sun, or take precautions, such as sunscreen, umbrellas, or long sleeves and pants when spending extended time outdoors. (UV rays can travel through clouds too.)
Tanning beds are an intense source of UV rays at close range, making them a leading risk factor for skin cancer. Research shows that in people under 35, the risk of developing skin cancer goes up by 75% after just one indoor tanning session. There are no safe tanning beds.
Dermatologists advise people of all skin tones to avoid tanning of any kind, whether outdoors or in a tanning bed. There is no such thing as a “healthy” tan. Skin damage can start with your first tan, and the risk of skin cancer increases after just one intense sunburn.
What are the risk factors for skin cancer?
A number of factors increase the risk of developing skin cancer. Not all people with risk factors will get skin cancer. Risk factors for skin cancer include:
Certain genetic conditions
Compromised immune system due to such conditions as HIV/AIDS or taking corticosteroids or medications for organ transplant
Exposure to certain chemicals or radiation
Exposure to excessive UV radiation (sunny climates, high altitudes)
Family or personal history of skin cancer
Multiple moles on the body or abnormal moles (dysplastic nevi). Moles that are present at birth and atypical moles have a greater chance of becoming malignant.
Personal history of a blistering sunburn as a child
Personal history of a bad burn
Precancerous lesions such as actinic keratosis
- Tanning bed use
Reducing your risk of skin cancer
You may be able to lower your risk of skin cancer by:
Using a broad-spectrum sunscreen with a minimum 15 SPF year-round, even on cloudy days
Avoiding tanning beds and excessive sun exposure. Particularly avoid the midday sun from 10 a.m. to 4 p.m.
Being aware of medications that cause sensitivity to the sun
Prompt diagnosis and treatment of precancerous skin lesions
Protecting your skin with a hat, long sleeves, and pants
- Routine full-body skin checks by you and your doctor
What are the diet and nutrition tips for skin cancer?
Diet alone cannot prevent or cure skin cancer. However, certain foods have been shown to help repair sun damage and potentially reduce your risk of developing cancer.
When your skin is exposed to the sun, ultraviolet (UV) rays create free radicals, a type of oxygen molecule that triggers inflammation and can damage the DNA in your skin cells. This damage could increase your risk of mutations that develop into cancerous cells.
Research shows benefits from eating foods high in antioxidants, which act as a natural defense against free radicals. Aside from the potential cancer-fighting effects, eating a nutritious diet rich in antioxidants also promotes overall good health and can prevent other chronic conditions.
Doctors also note that it is best to consume antioxidants through food, rather than through available supplements. Your body is better able to process the antioxidants and nutrients in food, maximizing their potential benefits.
Antioxidants to include in your diet to maintain skin health and reduce your risk of skin cancer include:
Beta carotene, found in leafy green, orange and yellow fruits and vegetables, including apricots, broccoli, cantaloupe, carrots, spinach, squash, and sweet potatoes
Lycopene, the red pigment that gives tomatoes and other fruits their bright color (and protects them from sun damage). Foods high in lycopene include apricots, blood oranges, guava, mangoes, papaya, pink grapefruit, red bell peppers, red cabbage, tomatoes, and watermelon.
Omega-3 fatty acids, found in cold-water fatty fish like albacore tuna, herring, mackerel, salmon, sardines; nuts and seeds, including chia seeds, flax seeds, and walnuts; and plant oils, such as canola oil, flaxseed oil, and soybean oil.
Polyphenols, found in fresh-brewed black or green tea
- Selenium, found in Brazil nuts; fish such as halibut, tuna and sardines; meats including ham, beef, and organ meats; and shrimp
Ask your healthcare provider for guidance before making significant changes to your diet.
How do doctors diagnose skin cancer?
Your doctor will perform a visual exam of your skin to look for irregular or abnormal areas, then will likely order tests to confirm a diagnosis of skin cancer.
Tests for skin cancer
Procedures to diagnose and evaluate skin cancer include:
Biopsy, in which an entire mole or small sample of tissue is removed and analyzed in a lab to determine if cells are cancerous. A biopsy is the only way to confirm a skin cancer diagnosis. For some skin cancers, the removal of the entire growth for testing also constitutes effective treatment.
- Sentinel lymph node biopsy, which removes a lymph node near the original site to test for cancer cells
What are the treatments for skin cancer?
The goal of skin cancer treatment is to permanently cure the cancer or bring about a complete remission of the disease. Remission means that there is no longer any sign of the disease in the body, although it may recur or relapse later.
Common treatments for skin cancer
Common treatments for skin cancer include:
Chemotherapy to attack cancer cells
Cryotherapy to freeze off cancers
Curettage and electrocautery to scrape and burn off cancers
Immunotherapy to enhance the immune system’s ability to fight cancer
Laser therapy to remove lesions
Mohs surgery, a targeted form of skin cancer surgery designed to remove as little healthy tissue as possible
Participation in a clinical trial testing promising new treatments for skin cancer
Photodynamic therapy, in which light is used to activate chemicals that attack cancer cells
Surgery to remove cancer
- Topical cream to treat superficial cancers
Alternative treatments for skin cancer
Some complementary treatments may help some people to better deal with skin cancer and its treatments. These treatments, sometimes referred to as alternative therapies, are used in conjunction with traditional medical treatments. Complementary treatments are not meant to substitute for traditional medical care.
Be sure to notify your doctor if you are consuming nutritional supplements or homeopathic (nonprescription) remedies as they may interact with the prescribed medical therapy.
Complementary treatments may include:
Herbal remedies, tea beverages, and similar products
In cases in which skin cancer has progressed to an advanced stage and has become unresponsive to treatment, the goal of treatment may shift away from curing the disease and focus on measures to keep a person comfortable and maximize the quality of life. Hospice care involves medically controlling pain and other symptoms while providing psychological and spiritual guidance, as well as services to support the patient’s family.
How does skin cancer affect quality of life?
As with any cancer, a diagnosis of skin cancer can cause emotional and mental distress. Even with a positive prognosis, patients may worry about the effects of treatments, such as chemotherapy or surgery. Some may have cosmetic concerns about possible scarring after surgical removal of tumors. For those with a later-stage diagnosis of melanoma, questions about survival and mortality may preoccupy their mind.
Even after successful treatment for skin cancer, patients may feel lingering concerns about recurrence and have anxiety about spending time in the sun. Immediate family members may also find a case of skin cancer troubling, as it indicates an elevated risk of developing skin cancer themselves.
If you are finding it difficult to cope with your diagnosis or with the effects of skin cancer treatment, talk with your doctor or care team. They can offer guidance and refer you to resources that provide support for people living with or recovering from skin cancer.
What are the potential complications of skin cancer?
Basal cell carcinoma rarely spreads to other areas of the body, but it can continue to spread along the skin to involve larger and larger areas resulting in functional damage or disfigurement. Left untreated, squamous cell cancer is somewhat more likely to spread to other areas of the body and can spread locally to involve larger and larger areas of the skin. Melanoma is the most dangerous of the skin cancers, since this cancer may spread to lymph nodes and internal organs.
Complications of skin cancer include:
Adverse effects of treatment
Local or distant (metastatic) spread of the disease
Recurring cancer after treatment
- Secondary cancer (metastatic cancer), such as brain or lung cancer
What is the survival rate and prognosis for skin cancer?
Survival rates for most cancers are meant to provide an estimate for how long people live after receiving their diagnosis. However, it is important to remember that each case—and person—is different, and survival rates are not a prediction of your individual outcome. New cancer treatments are consistently in development, and online statistics may be based on older data. Talk with your doctor about your specific prognosis.
Generally, cancers are measured with a 5-year relative survival rate, which compares how likely it is for someone with a specific cancer to live for five years after their diagnosis compared to someone without that cancer. So for example, if someone has a cancer with a 5-year relative survival rate of 95%, that person is 95% as likely to be alive in five years as someone who does not have that cancer.
Basal cell skin cancer and squamous cell cancer survival rates
Because most nonmelanoma cancers are caught early and treated effectively, it is very rare for someone to die of basal cell or squamous cell cancer. There is no specific data about survival rates for these cancers because they are not reported to or tracked by cancer registries.
Melanoma survival rates
Data for melanoma does not evaluate cancers by stage, but by a simpler breakdown of localized (cancer has not spread beyond the original site, regional (cancer has spread only to nearby tissue or lymph nodes), and distant (cancer has spread to other organs in the body).
By those measures, the 5-year relative survival rates for melanoma from 2010 to 2016 were:
- Overall: 93%
Again, these numbers do not necessarily reflect your individual outcome. Talk to your doctor if you have questions about your prognosis and treatment plan.
Skin cancer awareness
Awareness campaigns around skin cancer focus on prevention, reminding people to perform self-checks of their skin and avoid risk factors like sun exposure and tanning beds. Because skin cancers—including melanoma—are highly treatable when caught in the first stages, doctors and activist groups promote routine screenings and early detection. They aim to educate people to be aware of their own skin and act quickly when they notice changes or areas of concern.
May is Skin Cancer Awareness Month, marked by a black ribbon.