Skin cancer is the most common cancer in the United States. When it’s detected and treated early, the cure rate is high.
What is skin cancer?
Skin cancers begin in cells that make up your skin. Different types start in different kinds of cells within the skin, such as basal cells, squamous cells or melanocytes.
Types of skin cancer
The most common types of skin cancer in the United States are basal cell carcinoma, squamous cell carcinoma and melanoma.
- When detected and treated early, nonmelanoma skin cancers have a cure rate of more than 95 percent. But having one of these cancers increases your risk for developing other skin cancers.
- Melanoma skin cancer is much less common but much more serious than basal or squamous cell carcinoma. It causes the vast majority of skin cancer deaths in the U.S.
Basal cell carcinoma
Basal cell carcinoma, or basal cell skin cancer, accounts for about 80 percent of skin cancers.
- This disease is caused by sun exposure and is usually found on sun-exposed areas of the skin, like the scalp, forehead, face, nose, neck and back. Read more about skin cancer risk factors.
- It is most common in older men who worked outdoors for many years, but the number of women diagnosed has been rising and the average age at diagnosis has been dropping.
- Basal cell carcinoma is slow growing and rarely spreads. If untreated, however, it may eventually spread to other tissues.
Squamous cell carcinoma
Squamous cell carcinoma, also called squamous cell skin cancer, accounts for about 20 percent of skin cancers.
- It affects the middle layer of the skin and may occur on any part of the body, including the mucous membranes.
- Sun exposure is the most common cause. This cancer appears most often in areas exposed to the sun, including the face, neck, scalp, lower lip and rim of the ear. Read more about risk factors.
- It often starts as a precancerous condition called actinic keratosis (learn more on our skin cancer signs and symptoms page).
- It is relatively slow growing but more aggressive than basal cell carcinoma.
- It has a high cure rate, about 95 percent, if detected early and treated. If not treated, it may spread to other parts of the body.
Melanoma can spread quickly to other organs. Though it’s uncommon compared to basal and squamous cell skin cancers, it causes 75 percent of the country’s skin cancer deaths.
- It usually develops in or around an existing mole, usually on the skin of the trunk or extremities. But it can occur in other places, such as the eye or the lining of nose, mouth or gut.
- As for basal and squamous cell carcinoma, sun exposure is an important risk factor for melanoma.
- In its earliest stage, melanoma doesn’t grow much beyond the outermost layer of the skin. If it is not removed when it is thin, it can penetrate deeper and spread throughout the body.
- Because of differences between melanoma and nonmelanoma skin cancers, we have a dedicated melanoma section where you can learn more about this type.
Other skin cancer types
- Merkel cell carcinoma — A rare disease in which cancerous cells are found on or just beneath the skin.
- Kaposi’s sarcoma — Generally starts as a small bruise-like area, and then develops into a tumor. Often occurs in people with acquired immunodeficiency syndrome (AIDS).
- Mycosis fungoides — A type of lymphoma that starts on the skin. Usually begins as a rash on the buttocks, hips or lower abdomen. It can be missed because it looks similar to skin allergies and other types of irritation.
- Adnexal tumors — Appear as bumps within the skin.
- Skin sarcomas — Appear as large masses under the skin’s surface.
Symptoms of skin cancer
The best way to detect skin cancer before it spreads and becomes difficult to cure is to carefully and regularly examine your own skin and to have routine exams by your health care provider.
Looking for signs of skin cancer can be a challenge because most of us have some brownish spots on our skin — birthmarks, moles, freckles — which are usually normal. But some may be skin cancers.
Other possible signs of skin cancer — such as a small sore that bleeds, scabs and heals or a reddish patch that crusts over and itches — can be a benign (noncancerous) condition or something more serious.
- Become familiar with specific signs and symptoms of different types of skin cancer as well as actinic keratosis (pre-cancer). We’ve included photos to help you know what to look for.
- Learn more about how to check yourself for early warning signs of skin cancer, including the “ABCDE” guide to make early detection easier.
Diagnosing skin cancer
Examine your skin regularly to watch for changes and for new suspicious growths.
Call your doctor if:
- You notice a change in the color, size, texture or appearance of a mole or skin lesion.
- You have bleeding, itching, inflammation or pain in a lesion.
- You have another sign or symptom that could result from skin cancer.
If you have an abnormal-looking growth on your skin that might be cancer, your doctor will:
- Review and ask about your medical history and family history.
- Ask about your sun exposure, lifestyle, medications and other risk factors.
- Ask about your symptoms, when the skin lesion first appeared and if the lesion has changed in size or appearance.
- Perform a thorough physical exam and check the skin lesion, any other suspicious moles or marks and your lymph nodes.
Next you may have a skin biopsy, which involves taking a sample of suspicious tissue so a pathologist can examine the cells under a microscope to look for cancer.
Common types of skin biopsies include:
- Shave biopsy — A sterile razor blade is used to shave off the lesion.
- Punch biopsy — An instrument called a punch is used to remove a circle of tissue from the lesion.
- Excisional biopsy — A scalpel is used to remove the entire growth.
Sentinel lymph node mapping and biopsy
This is a procedure in which a radiolabeled substance and a blue dye are injected near your tumor. The substance flows through lymph ducts to the first lymph node or nodes where cancer cells are likely to spread (sentinel nodes). Your surgeon removes only the nodes where the substance appears. A pathologist checks the sentinel nodes for cancer.
Imaging studies and lab tests
Your doctor might recommend other tests or scans to learn more about your condition, especially if your tumor is deep or your lymph nodes are involved. These may include a computed tomography (CT) scan, chest X-ray, positron emission tomography (PET) scan, magnetic resonance imaging (MRI) scan or bone scan and tissue, blood or urine tests.
Stages of skin cancer
The stage of your cancer helps your doctors determine the best treatment options for you. The process of staging tells us whether or not your cancer has spread and, if it has, how far. When skin cancer is diagnosed at an early stage, it is more likely to be cured.
Skin cancers are assigned a stage from 0 to IV, with 0 being the least advanced (in situ, found only in the outermost layer of skin) and IV being the most advanced.