What Is the Most Common Cancer?

Skin cancer is the most common type of cancer diagnosed in the United States. In fact, more people are diagnosed with skin cancer each year in the United States than all other cancers combined.

Skin cancer can affect anyone, regardless of skin color. Thankfully, the most common forms of skin cancer—basal cell carcinoma, squamous cell carcinoma, and melanoma—are highly treatable with early detection and treatment.

Here you can find out all about the different types of skin cancers, including risk factors, prevention, and prognosis.

Statistics About Skin Cancer

By current estimates, one in five Americans will develop skin cancer in their lifetime, and approximately 9,500 people in the United States are diagnosed with skin cancer every day.

That number has been growing for several years, likely due to early detection, increased sun exposure, and longer life spans. The diagnosis and treatment of non-melanoma skin cancers—such as squamous cell carcinoma and basal cell carcinoma—increased by 77% between 1994 and 2014 in the United States.

Although the number of people diagnosed with skin cancer is increasing, advances in treatment have accelerated a decline in the mortality rate of skin cancers in the past five years; from 2013 to 2017, the death rate for melanoma declined by 7% per year in adults younger than 50 years of age and by 5.7% per year in older adults.

The great news is that 99% of all skin cancer cases are curable if diagnosed and treated early enough.

Types of Skin Cancer

There are three main types of skin cancer: squamous cell carcinoma, basal cell carcinoma, and melanomas, as well as some less common cancers.

Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common form of skin cancer, accounting for up to 80% of cases. The lifetime risk of developing basal cell carcinoma is around 30%.

BCC usually begins on areas exposed to the sun, such as the face, neck, and hands. It is a slow-growing cancer that rarely spreads to other parts of the body, but people with a history of BCC are at higher risk for getting a second case.

Treatments are very effective when BCC is found and treated promptly.

Squamous Cell Carcinoma

Squamous cell carcinoma (SCC) accounts for 16 to 20% of skin cancers and occurs twice as often in men as in women. These are the most common type of skin cancers found in people with darker skin tones.

Unlike basal cell carcinomas, these cancers may spread (metastasize) if they become large. It usually occurs on the face, ear, neck, lips, and backs of the hands. SCC can also begin within scars or skin ulcers on other places on the body.

As with basal cell carcinoma, the available treatments are very effective if the tumor is detected while it is small and thin.

Melanoma

Melanoma is less common than basal cell and squamous cell cancer, but it is responsible for the majority of deaths from the disease as a whole.

Melanoma may arise in normal skin but often begins in an existing mole. It is found most frequently on the back in men, on the legs in women, and on the palms of the hands, soles of the feet, and under the fingernails or toenails of people of both sexes with darker skin colors.

That said, these cancers may occur anywhere, including areas of the skin that have never been exposed to the sun.

The prognosis of melanoma is good when found early, but drops sharply when it spreads to distant lymph nodes or organs, such as the bones, the lungs, the liver, and the brain.

Rare Skin Cancers

The other types of cancer that can arise in the skin or skin-related structures are far less common. A few of these include:

• Merkel cell carcinoma: Merkel cell carcinomas are rare skin cancers most often found around the eye in middle-aged people. For unknown reasons, these cancers are increasing. They tend to be aggressive and spread rapidly to other parts of the body.
• Kaposi's sarcoma: This cancer is caused by the Kaposi sarcoma herpesvirus, and is usually found in people with HIV/AIDS or who are immunosuppressed for other reasons, such as an organ transplant. It presents as large red, blue, or brown splotches around the body along with swelling that can be severe. Fortunately, it often responds well to HIV medications.
• Sebaceous gland carcinoma: These cancers originate in sebaceous glands and occur most often in older women, around the eye.

Risks for Skin Cancer

The following factors increase your skin cancer risk:

Skin Tone

Skin tone can be a significant risk factor for the development of skin cancer. People who have fair skin have the highest risk because the pigment melanin (responsible for skin color) offers some protection from ultraviolet (UV) radiation and they simply have less of it than those with darker skin.

Moles

Most adults have between 10 and 40 moles. Although common moles are not cancerous, people who have more than 50 common moles have an increased chance of developing melanoma.

Genetics

The influence that genetics plays in the development of skin cancer can vary depending on the particular type. It can be difficult to separate out risks related to genetics and hereditary characteristics, such as skin tones.

Identical twin studies suggest that almost half of a person's risk for basal cell and squamous cell carcinomas is caused by genetic factors. While known inherited gene mutations account for only about 1% of melanomas, a 2016 study suggested that up to 58% of melanoma risk is related to inherited factors.

UV Exposure

About 90% of non-melanoma skin cancers are associated with exposure to ultraviolet (UV) radiation from the sun. Squamous cell carcinoma, however, is the type most closely tied to sun exposure. The amount of UV light exposure depends on the strength of the light—which can vary with the angle of the sun—the length of exposure, and whether the skin was covered with clothing or sunscreen.

Preventing Skin Cancer

Most skin cancer cases and deaths are caused by exposure to UV radiation, and thus potentially preventable. The sun can do damage to your skin in as little as 15 minutes, so it’s essential to do everything you can to protect your skin while you’re spending time outdoors.

The Skin Cancer Foundation recommends that you:

• Seek the shade: This is especially important between 10 a.m. and 4 p.m.
• Don’t get sunburned: A history of three or more blistering sunburns before age 20 greatly increases your risk of melanoma.
• Cover up: Wear clothing, a broad-brimmed hat, and UV-blocking sunglasses.
• Wear sunscreen: Use sunscreen with an SPF of 15 or higher every day. For extended outdoor activity, use a water-resistant, broad-spectrum sunscreen with an SPF of 30 or higher. Apply 1 ounce (2 tablespoons) of sunscreen to your entire body 30 minutes before going outside. Reapply every two hours or after swimming or excessive sweating.
• Examine your skin: Look over your skin head-to-toe every month.
• Get regular skin checks: See a dermatologist at least once a year for a professional skin exam.

A Word From Verywell

Many of the millions of skin cancer cases diagnosed every year could be prevented by protecting skin from excessive sun exposure and not using indoor tanning devices.

If caught early, skin cancer is highly treatable. Even melanoma, the deadliest skin cancer, has an average five-year survival rate of 92%.

The best way to detect skin cancer early is to be aware of new or changing skin spots or growths, particularly those that look unusual. Any new lesions, or a progressive change in a lesion’s appearance (size, shape, or color), should be evaluated promptly by a clinician.