Skin cancer is the most common type of cancer. The main types of skin cancer are squamous cell carcinoma, basal cell carcinoma, and melanoma. Melanoma is much less common than the other types but much more likely to invade nearby tissue and spread to other parts of the body.
What Is Skin Cancer is the most common type of cancer. The main types of skin cancer are squamous cell carcinoma, basal cell carcinoma, and melanoma. Melanoma is much less common than the other types but much more likely to invade nearby tissue and spread to other parts of the body. Most deaths from skin cancer are caused by melanoma. Explore the links on this page to learn more about skin cancer prevention, screening, treatment, statistics, research, clinical trials, and more.
Skin cancer develops primarily on areas of sun-exposed skin, including the scalp, face, lips, ears, neck, chest, arms and hands, and on the legs in women. But it can also form on areas that rarely see the light of day — your palms, beneath your fingernails or toenails, and your genital area.
Skin cancer affects people of all skin tones, including those with darker complexions. When melanoma occurs in people with dark skin tones, it’s more likely to occur in areas not normally exposed to the sun, such as the palms of the hands and soles of the feet.
Basal cell carcinoma signs and symptoms
Basal cell carcinoma usually occurs in sun-exposed areas of your body, such as your neck or face.
Basal cell carcinoma may appear as:
- A pearly or waxy bump
- A flat, flesh-coloured or brown scar-like lesion
- A bleeding or scabbing sore that heals and returns
Squamous cell carcinoma signs and symptoms
Most often, squamous cell carcinoma occurs on sun-exposed areas of your body, such as your face, ears and hands. People with darker skin are more likely to develop squamous cell carcinoma in areas that aren’t often exposed to the sun.
Squamous cell carcinoma may appear as:
- A firm, red nodule
- A flat lesion with a scaly, crusted surface
Melanoma signs and symptoms
Melanoma can develop anywhere on your body, in otherwise normal skin or in an existing mole that becomes cancerous. Melanoma most often appears on the face or the trunk of affected men. In women, this type of cancer most often develops on the lower legs. In both men and women, melanoma can occur on skin that hasn’t been exposed to the sun.
Melanoma can affect people of any skin tone. In people with darker skin tones, melanoma tends to occur on the palms or soles, or under the fingernails or toenails.
Melanoma signs include:
- A large brownish spot with darker speckles
- A mole that changes in colour, size or feels or that bleeds
- A small lesion with an irregular border and portions that appear red, pink, white, blue or blue-black
- A painful lesion that itches or burns
- Dark lesions on your palms, soles, fingertips or toes, or mucous membranes lining your mouth, nose, vagina or anus
Signs and symptoms of less common skin cancers
Other, less common types of skin cancer include:
- Kaposi sarcoma. This rare form of skin cancer develops in the skin’s blood vessels and causes red or purple patches on the skin or mucous membranes. Kaposi sarcoma mainly occurs in people with weakened immune systems, such as people with AIDS, and in people taking medications that suppress their natural immunity, such as people who’ve undergone organ transplants.Other people with an increased risk of Kaposi sarcoma include young men living in Africa or older men of Italian or Eastern European Jewish heritage.
- Merkel cell carcinoma. Merkel cell carcinoma causes firm, shiny nodules on or beneath the skin and in hair follicles. Merkel cell carcinoma is most often found on the head, neck and trunk.
- Sebaceous gland carcinoma. This uncommon and aggressive cancer originates in the oil glands in the skin. Sebaceous gland carcinomas — which usually appear as hard, painless nodules — can develop anywhere, but most occur on the eyelid, where they’re frequently mistaken for other eyelid problems.
Cells involved in skin cancer
Skin cancer begins in your skin’s top layer — the epidermis. The epidermis is a thin layer that provides a protective cover of skin cells that your body continually sheds. The epidermis contains three main types of cells:
- Squamous cells lie just below the outer surface and function as the skin’s inner lining.
- Basal cells, which produce new skin cells, sit beneath the squamous cells.
- Melanocytes — which produce melanin, the pigment that gives skin its normal colour — are located in the lower part of your epidermis. Melanocytes produce more melanin when you’re in the sun to help protect the deeper layers of your skin.
Most skin cancers are preventable. To protect yourself, follow these skin cancer prevention tips:
- Avoid the sun during the middle of the day. For many people in North America, the sun’s rays are strongest between about 10 a.m. and 4 p.m. Schedule outdoor activities for other times of the day, even in winter or when the sky is cloudy. You absorb UV radiation year-round, and clouds offer little protection from damaging rays. Avoiding the sun at its strongest helps you avoid the sunburns and suntans that cause skin damage and increase your risk of developing skin cancer. Sun exposure accumulated over time also may cause skin cancer.
- Wear sunscreen year-round. Sunscreens don’t 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. Use a broad-spectrum sunscreen with an SPF of at least 30, even on cloudy days. Apply sunscreen generously, and reapply every two hours — or more often if you’re swimming or perspiring. Use a generous amount of sunscreen on all exposed skin, including your lips, the tips of your ears, and the backs of your hands and neck.
- Wear protective clothing. Sunscreens don’t provide complete protection from UV rays. So cover your skin with dark, tightly woven clothing covering your arms and legs, and a broad-brimmed hat, which provides more protection than a baseball cap or visor.Some companies also sell photo-protective clothing. A dermatologist can recommend an appropriate brand.Don’t forget sunglasses. Look for those blocking both types of UV radiation — UVA and UVB.
- Avoid tanning beds. Lights used in tanning beds emit UV rays and can increase your risk of skin cancer.
- Be aware of sun-sensitising medications. Some common prescription and over-the-counter drugs, including antibiotics, can make your skin more sensitive to sunlight. Ask your doctor or pharmacist about the side effects of any medications you take. If they increase your sensitivity to sunlight, take extra precautions to stay out of the sun to protect your skin.
- Check your skin regularly and report changes to your doctor. Examine your skin often for new skin growths or changes in existing moles, freckles, bumps and birthmarks.