Everything about Skin Cancer

Skin cancer is the uncontrolled growth of cancer cells in the skin. Left untreated, with certain types of skin cancer, these cells can spread to other organs and tissues, such as lymph nodes and bone. Skin cancer is the most common cancer in the United States, affecting 1 in 5 Americans during their lifetimes, according to the Skin Cancer Foundation.

How your skin works

Your skin works as a barrier to protect your body against things like water loss, bacteria, and other harmful contaminants. The skin has two basic layers: a deeper, thicker layer (the dermis) and an outer layer (the epidermis). The epidermis contains three main types of cells. The outermost layer is composed of squamous cells, which are constantly shedding and turning over. The deeper layer is called the basal layer and is made of basal cells. Lastly, melanocytes are cells that make melanin, or the pigment that determines your skin color. These cells produce more melanin when you have more sun exposure, causing a tan. This is a protective mechanism by your body, and it’s actually a signal that you are getting sun damage.

The epidermis is in constant contact with the environment. While it sheds skin cells regularly, it can still sustain damage from the sun, infection, or cuts and scrapes. The skin cells that remain are constantly multiplying to replace the sloughed skin, and they can sometimes begin to replicate or multiply excessively, creating a skin tumor that may either be benign or skin cancer.

Here are some common types of skin masses:

Actinic keratosis

Actinic keratosis, also known as solar keratosis, appears as a red or pink rough patch of skin on sun-exposed areas of the body. They are caused by exposure to UV light in sunlight. This is the most common form of precancer and can develop into squamous cell carcinoma if left untreated.

Basal cell carcinoma

Basal cell carcinoma is the most common form of skin cancer, comprising about 90 percent of all cases of skin cancer. Most common in the head and neck, basal cell carcinoma is a slow-growing cancer that rarely spreads to other parts of the body. It usually shows on skin as a raised, pearly or waxy pink bump, often having a dimple in the middle. It can also appear translucent with blood vessels near the skin’s surface.

Squamous cell carcinoma

Squamous cell carcinoma affects cells in the outer layer of the epidermis. It is typically more aggressive than basal cell carcinoma and can spread to other body parts if left untreated. It appears as red, scaly, and rough skin lesions, typically on sun-exposed areas such as the hands, head, neck, lips, and ears. Similar red patches may be squamous cell carcinoma in situ (Bowen’s disease), the earliest form of squamous cell cancer.

Melanoma

While overall less common than basal and squamous cell carcinoma, melanoma is by far the most dangerous, causing about 73 percent of all skin cancer-related deaths. It occurs in the melanocytes, or skin cells that create pigment. While a mole is a benign collection of melanocytes that most people have, a melanoma can be suspected if a mole has:

• Asymmetrical shape
• Border irregularities
• Color that isn’t consistent
• Diameter larger than 6 millimeters
• Evolving size or shape

The four major types of melanoma

• superficial spreading melanoma: the most common type of melanoma; lesions are usually flat, irregular in shape, and contain varying shades of black and brown; it can occur at any age
• lentigo maligna melanoma: usually affects the elderly; involves large, flat, brownish lesions
• nodular melanoma: can be dark blue, black, or reddish-blue, but may have no color at all; it usually starts as a raised patch
• acral lentiginous melanoma: the least common type; typically affects the palms, soles of the feet, or under finger and toenails

Kaposi sarcoma

While not typically considered a skin cancer, Kaposi sarcoma is another type of cancer that involves skin lesions that are brownish-red to blue in color and usually found on the legs and feet. It affects the cells that line blood vessels close to the skin. This cancer is caused by a type of herpes virus, typically in patients with weakened immune systems such as those with AIDS.

Who is at risk?

While there are several different types of skin cancers, most share the same risk factors, including:

• prolonged exposure to UV rays found in sunlight
• being over the age of 40
• having a family history of skin cancers
• having a fair complexion
• having received an organ transplant

However, young people or those with a dark complexion can still develop skin cancer.

Types of skin cancer

The four most common types of skin cancer include:

Melanoma

Melanoma is skin cancer that forms in melanocytes. These are the skin cells that produce melanin, a pigment responsible for skin color.

Melanoma is the most dangerous type of skin cancer, but it’s also a less common type.

Melanoma skin cancer usually presents as a brown or black spot that’s larger than a mole.

The spot or bump can have an irregular border and shades of different colors. The bump might be reddish in color with black, blue, or purple spots mixed in.

Melanoma can develop anywhere on the body, such as the:

• chest
• back
• legs
• soles of the feet
• underneath the nails

Basal cell carcinoma

Basal cell carcinoma is the most common type of skin cancer. It accounts for more than 80 percent of skin cancer diagnoses.

It forms in the basal cells and is found on parts of the body heavily exposed to the sun. Although basal cell carcinoma grows slowly and doesn’t usually spread to surrounding areas, it can be life-threatening if left untreated.

Symptoms of basal cell carcinoma include:

• flat white or yellowish area
• raised red patches
• pink or red shiny bumps
• pink growths with raised edges
• open sore that doesn’t heal

Squamous cell carcinoma

Squamous cell carcinoma also has a low death rate. It’s slow-growing and can develop on the:

• face
• neck
• back
• chest
• ears
• back of the hands

Symptoms include:

• rough, scaly red patches
• raised bumps or lumps with a slight indentation in the center
• open sores that don’t heal
• wartlike growths

Merkel cell carcinoma

Merkel cell carcinoma starts in the Merkel cells. These are located below the top layer of skin near the nerve endings.

It’s an aggressive type of skin cancer that’s difficult to treat, but it’s rare. It’s more likely to occur in people older than 50 and those with a weaker immune system.

Merkel cell carcinoma is fatal if it spreads to the brain, lungs, liver, or bones.

An early sign of Merkel cell carcinoma is a fast-growing flesh-colored bump or nodule that may bleed. Nodules can also be red, blue, or purple.

Stages of skin cancer

If you receive a skin cancer diagnosis, the next step is to identify its stage.

Staging is how doctors determine whether the cancer has spread to other parts of your body. Staging is common with melanoma and Merkel cell carcinoma, because these cancers are more likely to spread.

Typically, basal cell and squamous cell carcinomas don’t involve staging. These skin cancers are easily treated and don’t usually spread. However, your doctor may recommend staging for larger lesions.

Staging is based on the size of the growth and whether it has high-risk features. High-risk features include:

• larger than 2 millimeters thick
• spreads into the lower levels of the skin
• spreads into the space around a nerve
• appears on the lips or ears
• appears abnormal under a microscope

Here’s a general breakdown of skin cancer stages:

• Stage 0. The cancer hasn’t spread to surrounding areas of the skin.
• Stage 1. The cancer is 2 centimeters (cm) across or less, with no high-risk features.
• Stage 2. The cancer is more than 2 cm across and has a least two high-risk features.
• Stage 3. The cancer has spread to the bones in the face or nearby lymph nodes.
• Stage 4. The cancer has spread to the lymph nodes or internal organs.

Skin cancer survival rates

The outlook, or survival rate, for skin cancer depends on the type of skin cancer and stage of cancer at diagnosis.

Typically, the earlier you receive a diagnosis with skin cancer, the better your outcome. Cancer is harder to treat once it spreads to other parts of the body.

Melanoma survival rate

Melanoma is a deadly cancer when it spreads, but it’s curable in its early stages.

The five-year survival rate for melanoma stages 0, 1, and 2 is 98.4 percent, according to the Melanoma Research Alliance.

The five-year survival rate of stage 3 melanoma is 63.6 percent. It’s 22.5 percent for stage 4 melanoma.

Merkel cell survival rate

According to the American Cancer Society, the five-year survival rate for Merkel cell stages 0, 1, and 2 is 78 percent. It’s 51 percent for stage 3 and 17 percent for stage 4.

Basal cell and squamous cell survival rates

Because basal cell and squamous cell carcinomas are lower-risk skin cancers, there’s little information on survival rates based on stage.

Both types of cancer have a very high cure rate. According to the Canadian Cancer Society, the five-year survival rate for basal cell carcinoma is 100 percent. The five-year survival rate for squamous cell carcinoma is 95 percent.

Skin cancer prevention

Skin cancer is a very preventable cancer. Here’s how to protect yourself when outdoors:

• Use sunscreen with an SPF of at least 30 or higher. Follow product instructions and reapply as needed.
• Wear sunglasses.
• Wear a wide-brimmed hat to protect your face, head, ears, and neck.
• Wear pants and long sleeves to protect your arms and legs.
• Stay in the shade when possible.
• Avoid indoor tanning.
• Avoid the sun during the middle of the day when it’s at its strongest.
• Tell your doctor of any new skin growths or changes to moles, bumps, or birthmarks.

What to do if you receive a skin cancer diagnosis

Once a skin biopsy confirms skin cancer, your doctor will recommend a treatment based on the stage of the cancer.

To improve your outlook, it’s important that you complete your treatment and schedule follow-up appointments as needed. Your doctor may want to see you every few months to make sure the cancer hasn’t returned.

Also schedule annual skin exams with a dermatologist. Get into the habit of checking your own skin for abnormal growths, too. This includes your back, scalp, soles of feet, and ears.

Excision surgery for skin cancer

How it works

Your doctor will use a scalpel to remove the tumor as well as the area of tissue that surrounds it. The site will then be closed with stitches. The tissue sample will be sent to a lab for analysis. Learn more about surgical excision here.

What type of skin cancer is it used for?

• basal cell carcinoma
• squamous cell carcinoma
• melanoma

Side effects

A second procedure may be necessary if cancer cells are still present following sample analysis. If a very large area of skin is removed, a graft or reconstructive surgery may be necessary.

Mohs micrographic surgery for skin cancer

How it works

Your doctor will use a scalpel or other surgical tool to remove the tumor in thin layers. This tissue layer is then thoroughly evaluated under a microscope.

If tumor cells are still present, the process is repeated. Your doctor will continue to remove small layers of tissue until the last layer removed is cancer-free when viewed under a microscope.

What type of skin cancer is it used for?

• basal cell carcinoma
• squamous cell carcinoma
• melanoma

Side effects

Mohs micrographic surgery is advantageous over regular excision surgery because it can save a greater amount of normal tissue. Depending on the location of the tumor, some reconstructive surgery may still be required.

Curettage and electrodessication for skin cancer

How it works

For this treatment, a sharp-tipped instrument called a curette is used in combination with an electric current. The curette is used to scrape off the tumor or growth. An electric current is then applied to the site, generating heat to destroy remaining tumor cells and limit any bleeding.

What type of skin cancer is it used for?

• basal cell carcinoma
• squamous cell carcinoma

Side effects

This procedure is typically repeated several times to be sure that any remaining cancer cells have been destroyed. Due to the nature of a treatment, it can often leave a scar.

Freezing treatment for skin cancer

How it works

Your doctor will destroy your tumor using liquid nitrogen. The tumor will become crusty and scabby after treatment and will eventually fall off. Sometimes the freezing procedure is repeated several times at the same appointment in order to make sure all cancer cells are destroyed. This procedure is also called cryosurgery.

What type of skin cancer is it used for?

• basal cell carcinoma
• squamous cell carcinoma

Side effects

The procedure itself involves no bleeding or cutting, but the site of the treatment may blister or swell afterwards. In some cases, you may have a scar. Freezing is generally less effective than other surgical treatments and is often used for precancerous growths.

Photodynamic therapy for skin cancer

How it works

During photodynamic therapy (PDT), your doctor will apply a light-reactive chemical to cancerous lesions. Cancer cells and precancerous cells will take up the chemical. You’ll then be exposed to a strong light. The cancer cells and precancerous cells that have taken up the chemical will be killed while healthy cells will survive.

What type of skin cancer is it used for?

• basal cell carcinoma
• squamous cell carcinoma

Side effects

Following treatment, you may experience redness and swelling at the site. Additionally, you should try to avoid indoor and outdoor light after treatment since the area will still be sensitive.

Systemic chemotherapy for skin cancer

How it works

In chemotherapy, anticancer drugs are injected intravenously (IV). They then travel through your bloodstream to attack cancer cells. Because of this, chemotherapy can be effective at treating cancer that has spread to other parts of your body.

What type of skin cancer is it used for?

• basal cell carcinoma (rarely)
• squamous cell carcinoma
• melanoma

Side effects

Chemotherapy can have side effects, such as:

• nausea
• vomiting
• tiredness or fatigue
• hair loss
• an increased risk of infection

Typically, these side effects will go away when your chemotherapy treatments have finished.

Topical medications for skin cancer

How it works

Topical skin cancer medications block the ability of cancer cells to grow and divide. In this treatment, you rub a cream or gel medication onto your tumor several times per week for a specified amount of time. Examples of topical medications are imiquimod and 5-fluorouracil. These are considered noninvasive treatments for skin cancer.

What type of skin cancer is it used for?

• basal cell carcinoma
• squamous cell carcinoma

Side effects

Side effects from topical medications for skin cancer can include redness and swelling. Additionally, since none of the tumor tissue is removed for biopsy, there is no sure way to tell how much of the cancer has been destroyed.

Radiation for skin cancer

How it works

During radiation therapy, your doctor will aim high-energy beams or particles at your tumor in order to destroy the cancer cells. The process is quite similar to getting an X-ray, but the radiation used is stronger.

What type of skin cancer is it used for?

• basal cell carcinoma
• squamous cell carcinoma
• melanoma

Side effects

Radiation therapy can be used when surgery isn’t an option. It can lead to side effects such as:

• nausea
• fatigue or tiredness
• skin problems
• hair loss

Immunotherapy for skin cancer

How it works

Immunotherapy utilizes biological materials to encourage your body’s immune system to fight your cancer.

For example, the drug nivolumab (Opdivo) targets a protein called PD-1 that is located on a specific type of immune cell. PD-1 normally prevents these cells from attacking cancer cells in your body. However, when nivolumab binds to and blocks PD-1, these cells are no longer inhibited and are free to attack cancer cells. Learn more about immunotherapy for skin cancer.

What type of skin cancer is it used for?

• melanoma

Side effects

Many immunotherapy drugs can have significant negative side effects. Your doctor will have to decide if the benefit of immunotherapy treatment outweighs these negative side effects.

Targeted therapy for skin cancer

How it works

This treatment targets specific genes or proteins of cancerous cells. Because of this, targeted therapy can work to destroy cancer cells while avoiding damaging healthy cells.

An example of targeted therapy is BRAF inhibitors. BRAF is a gene that is mutated in melanoma cells. Cells with this mutation produce a slightly different BRAF protein than normal cells. This slightly altered protein is what the BRAF inhibitor targets.

What type of skin cancer is it used for?

• basal cell carcinoma
• squamous cell carcinoma
• melanoma

Side effects

Targeted therapy can have some side effects such as:

• skin rash
• nausea
• development of less-aggressive skin cancers, such as squamous cell carcinoma

Prevention tips

Be sure to follow the guidelines below to reduce your risk of developing skin cancer:

• Try to stay in the shade during the hottest hours of the day. The sun is typically the strongest between 10:00 a.m. and 4:00 p.m.
• Use sunscreen that has an SPF of 15 or higher as well as UVA and UVB protection. Be sure to reapply every two hours.
• Avoid using indoor tanning beds. Consider using a self-tanning product instead.
• Wear clothing that protects your skin. This includes clothing that covers most of your arms and legs, hats with a wide brim, and sunglasses that wrap around.
• Be aware of your surroundings. Snow, water, and sand can all reflect light from the sun. This can increase your chance of getting a sunburn.
• Check your skin regularly. If you see a suspicious-looking mole or mark, make an appointment with your dermatologist. Also, make a yearly appointment with your dermatologist for a skin exam.

What’s the outlook?

The prognosis for skin cancer can vary depending on the type of the skin cancer, the stage of the skin cancer, and your overall health. Your doctor will work with you to generate a treatment plan that is appropriate for the type and severity of your skin cancer.

When identified and treated early, the prognosis for many skin cancers is very good.

Because of this, it’s very important make a yearly appointment with your dermatologist for a skin exam. Additionally, if you find a suspicious spot or mole on your body, you should make an appointment with your dermatologist to have them look at it.