Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/cancer/public_html/connection.php on line 2

This Website is for Pateints only. We do not deal with Medical Institutions or Pharmaceutical Companies


Skin Cancer - Basal and Squamous Cell

Click here to go to the treatment:

What are basal and squamous cell skin cancers?

To understand basal and squamous cell skin cancers, it helps to know about the normal structure and function of the skin.

Normal skin : The skin is the largest organ in your body. It does many different things:

Covers the internal organs and helps protect them from injury

Serves as a barrier to germs such as bacteria

Prevents the loss of too much water and other fluids

Helps control body temperature

Protects the rest of the body from ultraviolet (UV) rays

Helps the body make vitamin D


The skin has 3 layers: the epidermis, the dermis, and the subcutis.

Epidermis : The top layer of skin is the epidermis. The epidermis is thin, averaging only 0.2 millimeters thick (about 1/100 of an inch). It protects the deeper layers of skin and the organs of the body from the environment.

Keratinocytes are the main cell type of the epidermis. These cells make an important protein called keratin that helps the skin protect the rest of the body.

The outermost part of the epidermis is called the stratum corneum. It is composed of dead keratinocytes that are continually shed as new ones form. The cells in this layer are called squamous cells because of their flat shape.

Living squamous cells are found just below the stratum corneum. These cells have moved here from the lowest part of the epidermis, the basal layer. The cells of the basal layer, called basal cells, continually divide to form new keratinocytes. These replace the older keratinocytes that wear off the skin's surface.

Cells called melanocytes are also found in the epidermis. These skin cells make a brown pigment called melanin. Melanin gives the skin its tan or brown color. It protects the deeper layers of the skin from some of the harmful effects of the sun. When skin is exposed to the sun, melanocytes make more of the pigment, causing the skin to tan or darken.

The epidermis is separated from the deeper layers of skin by the basement membrane. This is an important structure because when a skin cancer becomes more advanced, it generally grows through this barrier and into the deeper layers.

Dermis : The middle layer of the skin is called the dermis. The dermis is much thicker than the epidermis. It contains hair follicles, sweat glands, blood vessels, and nerves that are held in place by a protein called collagen. Collagen, made by cells called fibroblasts, gives the skin its elasticity and strength.

Subcutis : The deepest layer of the skin is called the subcutis. The subcutis and the lowest part of the dermis form a network of collagen and fat cells. The subcutis helps the body conserve heat and has a shock-absorbing effect that helps protect the body's organs from injury.

Types of skin cancer 

Melanomas :  Cancers that develop from melanocytes, the pigment-making cells of the skin, are called melanomas. Melanocytes can also form benign growths called moles. Melanoma and moles are discussed in our document, Melanoma Skin Cancer.

Skin cancers that are not melanoma are sometimes grouped together as non-melanoma skin cancers because they tend to act very differently from melanomas.

Keratinocyte cancers : These are by far the most common skin cancers. They are called keratinocyte carcinomas or keratinocyte cancersbecause when seen under a microscope, their cells share some features of keratinocytes, the most common cell type of normal skin. Most keratinocyte cancers are basal cell carcinomas or squamous cell carcinomas.

Basal cell carcinoma : This is not only the most common type of skin cancer, but the most common type of cancer in humans. About 8 out of 10 skin cancers are basal cell carcinomas (also called basal cell cancers). They usually develop on sun-exposed areas, especially the head and neck. Basal cell carcinoma was once found almost entirely in middle-aged or older people. Now it is also being seen in younger people, probably because they are spending more time out in the sun.

When seen under a microscope, basal cell carcinomas share features with the cells in the lowest layer of the epidermis, called the basal cell layer. These cancers tend to grow slowly. It is very rare for a basal cell cancer to spread to nearby lymph nodes or to distant parts of the body. But if a basal cell cancer is left untreated, it can grow into nearby areas and invade the bone or other tissues beneath the skin.

After treatment, basal cell carcinoma can recur (come back) in the same place on the skin. People who have had basal cell cancers are also more likely to get new ones elsewhere on the skin. As many as half of the people who are diagnosed with one basal cell cancer will develop a new skin cancer within 5 years.

Squamous cell carcinoma : About 2 out of 10 skin cancers are squamous cell carcinomas (also called squamous cell cancers). The cells in these cancers share features with the squamous cells seen in the outer layers of the skin.

These cancers commonly appear on sun-exposed areas of the body such as the face, ears, neck, lips, and backs of the hands. They can also develop in scars or chronic skin sores elsewhere. They sometimes start in actinic keratoses (described below). Less often, they form in the skin of the genital area.

Squamous cell carcinomas tend to grow and spread more than basal cell cancers. They are more likely to invade fatty tissues just beneath the skin, and are more likely to spread to lymph nodes and/or distant parts of the body, although this is still uncommon.

Keratoacanthomas are dome-shaped tumors that are found on sun-exposed skin. They may start out growing quickly, but their growth usually slows down. Many keratoacanthomas shrink or even go away on their own over time without any treatment. But some continue to grow, and a few may even spread to other parts of the body. Their growth is often hard to predict, and many skin cancer experts consider them a type of squamous cell skin cancer and treat them as such.

Less common types of skin cancer : Along with melanoma and keratinocyte cancers, there are some other much less common types of skin cancer. These cancers are also non-melanoma skin cancers, but they are quite different from keratinocyte cancers and are treated differently. They include:

Merkel cell carcinoma

Kaposi sarcoma

Cutaneous (skin) lymphoma

Skin adnexal tumors

Various types of sarcomas

Together, these types account for less than 1% of non-melanoma skin cancers.

Merkel cell carcinoma : This uncommon type of skin cancer develops from neuroendocrine cells (hormone-making cells that resemble nerve cells in some ways) in the skin. They are most often found on the head, neck, and arms but can start anywhere.

These cancers are thought to be caused in part by sun exposure and in part by Merkel cell polyomavirus (MCV). About 8 out of 10 Merkel cell carcinomas are thought to be related to MCV infection. MCV is a common virus. Many people are infected with MCV, but it usually causes no symptoms. In a small portion of people with this infection, changes in the virus' DNA can lead to this form of cancer.

Unlike basal cell and squamous cell carcinomas, Merkel cell carcinomas often spread to nearby lymph nodes and internal organs. They also tend to come back after treatment. Treatment of Merkel cell carcinoma is described in the section, “Treating Merkel cell carcinoma.”

Kaposi sarcoma :  This cancer usually starts within the dermis but can also form in internal organs. It is related to infection with Kaposi sarcoma herpesvirus (KSHV), also known as human herpesvirus 8 (HHV8). Before the mid-1980s, this cancer was rare and found mostly in elderly people of Mediterranean descent. Kaposi sarcoma has become more common because it is more likely to develop in people with human immunodeficiency virus (HIV) infection and the acquired immunodeficiency syndrome (AIDS). It is discussed in our document, Kaposi Sarcoma.

Skin lymphomas :  Lymphomas are cancers that start in lymphocytes, a type of immune system cell found throughout the body, including in the skin.

Most lymphomas start in lymph nodes (bean-sized collections of immune system cells) or internal organs, but some types of lymphoma begin mostly or entirely in the skin. Primary cutaneous lymphoma is the medical term for lymphomas that start in the skin. The most common type of primary cutaneous lymphoma is cutaneous T-cell lymphoma (most of these are called mycosis fungoides). Cutaneous lymphomas are discussed in our document,Lymphoma of the Skin.

Adnexal tumors : These tumors start in the hair follicles or glands (such as sweat glands) of the skin. Benign (non-cancerous) adnexal tumors are common, but malignant (cancerous) ones, such as sebaceous adenocarcinoma and sweat gland adenocarcinoma, are rare.

Sarcomas :  Sarcomas are cancers that develop from connective tissue cells, usually in tissues deep beneath the skin. Much less often they may start in the skin’s dermis and subcutis. Several types of sarcoma can start in the skin, includingdermatofibrosarcoma protuberans (DFSP) and angiosarcoma (a blood vessel cancer). Sarcomas are discussed in our document, Sarcoma – Adult Soft Tissue Cancer.

Pre-cancerous and pre-invasive skin conditions :  These conditions may develop into skin cancer or may be very early stages in the development of skin cancer.

Actinic keratosis (solar keratosis) :  Actinic keratosis, also known as solar keratosis, is a pre-cancerous skin condition caused by too much exposure to the sun. Actinic keratoses are usually small (less than 1/4 inch across), rough or scaly spots that may be pink-red or flesh-colored. Usually they develop on the face, ears, backs of the hands, and arms of middle-aged or older people with fair skin, although they can arise on other sun-exposed areas. People with one actinic keratosis usually develop many more.

Actinic keratoses tend to grow slowly. They usually do not cause any symptoms. They often go away on their own, but they may come back. In some cases actinic keratoses may turn into squamous cell cancers.

Even though most actinic keratoses do not become cancers, they are a warning that your skin has suffered sun damage. Some actinic keratoses and other skin conditions that could become cancers may have to be removed. Your doctor should regularly check any that are not removed for changes that could indicate cancer.

Squamous cell carcinoma in situ (Bowen disease) :  Squamous cell carcinoma in situ, also called Bowen disease, is the earliest form of squamous cell skin cancer. “In situ” means that the cells of these cancers are still only in the epidermis and have not invaded the dermis.

Bowen disease appears as reddish patches. Compared with actinic keratoses, Bowen disease patches tend to be larger (sometimes over 1/2 inch across), redder, scalier, and sometimes crusted.

Like invasive squamous cell skin cancers, the major risk factor is too much sun exposure. Bowen disease can also occur in the skin of the anal and genital areas. This is often related to sexually transmitted infection with human papilloma viruses (HPVs), the viruses that can also cause genital warts.

Benign skin tumors : Most tumors of the skin are not cancerous and rarely if ever turn into cancers. There are many kinds of benign skin tumors, including:

Most types of moles (see our document, Melanoma Skin Cancer for information on moles)

Seborrheic keratoses: tan, brown, or black raised spots with a waxy texture or rough surface

Hemangiomas: benign blood vessel growths often called strawberry spots or port wine stains

Lipomas: soft tumors made up of fat cells

Warts: rough-surfaced growths caused by a virus

What are the risk factors for basal and squamous cell skin cancers?

A risk factor is anything that affects your chance of getting a disease such as cancer. Different cancers have different risk factors. Some risk factors, like smoking and excess sun exposure, can be changed. Others, like a person’s age or family history, can’t be changed.

But risk factors don’t tell us everything. Having a risk factor, or even several risk factors, does not mean that you will get the disease. And some people who get the disease may have few or no known risk factors. Even if a person with basal or squamous cell skin cancer has a risk factor, it is often very hard to know how much that risk factor may have contributed to the cancer.

The following are known risk factors for basal cell and squamous cell carcinomas. (These factors don't necessarily apply to other forms of non-melanoma skin cancer, such as Kaposi sarcoma and cutaneous lymphoma.)

Ultraviolet (UV) light exposure :  Ultraviolet (UV) radiation is thought to be the major risk factor for most skin cancers. Sunlight is the main source of UV rays, which can damage the DNA in your skin cells. Tanning beds are another source of UV rays. People who get a lot of exposure to light from these sources are at greater risk for skin cancer.

Ultraviolet radiation is divided into 3 wavelength ranges:

UVA rays age cells and can damage cells’ DNA. They are mainly linked to long-term skin damage such as wrinkles, but are also thought to play a role in some skin cancers.

UVB rays can directly damage DNA, and are the main cause of sunburns. They are also thought to cause most skin cancers.

UVC rays don’t get through our atmosphere and therefore are not present in sunlight. They do not normally cause skin cancer.

While UVA and UVB rays make up only a very small portion of the sun’s rays, they are the main cause of the damaging effects of the sun on the skin. UV rays damage the DNA of skin cells. Skin cancers begin when this damage affects the DNA of genes that control skin cell growth. Both UVA and UVB rays damage skin and cause skin cancer. UVB rays are a more potent cause of at least some skin cancers, but based on what is known today, there are no safe UV rays.

The amount of UV exposure a person gets depends on the strength of the rays, the length of time the skin is exposed, and whether the skin is protected with clothing or sunscreen.

People who live in areas with year-round, bright sunlight have a higher risk. For example, the risk of skin cancer is twice as high in Arizona compared to Minnesota. The highest rate of skin cancer in the world is in Australia. Spending a lot of time outdoors for work or recreation without protective clothing and sunscreen increases your risk.

Many studies also point to exposure at a young age (for example, frequent sunburns during childhood) as an added risk factor.

Having light-colored skin :  The risk of skin cancer is much higher for whites than for African Americans or Hispanics. This is due to the protective effect of the skin pigment melanin in people with darker skin. Whites with fair (light-colored) skin that freckles or burns easily are at especially high risk. This is one of the reasons for the high skin cancer rate in Australia, where much of the population descends from fair-skinned immigrants from the British Isles.

Albinism is a congenital (present at birth) lack of protective skin pigment. People with this condition may have pink-white skin and white hair. They have a high risk of getting skin cancer unless they are careful to protect their skin.

Older age :  The risk of basal and squamous cell skin cancers rises as people get older. This is probably because of the buildup of sun exposure over time. These cancers are now being seen in younger people as well, probably because they are spending more time in the sun with their skin exposed.

Male gender : Men are about twice as likely as women to have basal cell cancers and about 3 times as likely to have squamous cell cancers of the skin. This is thought to be due mainly to higher levels of sun exposure.

Exposure to certain chemicals : Exposure to large amounts of arsenic increases the risk of developing non-melanoma skin cancer. Arsenic is a heavy metal found naturally in well water in some areas. It is also used in making some pesticides.

Workers exposed to industrial tar, coal, paraffin, and certain types of oil may also have an increased risk for non-melanoma skin cancer.

Radiation exposure : People who have had radiation treatment have a higher risk of developing skin cancer in the area that received the treatment. This is particularly a concern in children who have had radiation treatment for cancer.

Previous skin cancer : Anyone who has had a basal or squamous cell cancer has a much higher chance of developing another one.

Long-term or severe skin inflammation or injury : Scars from severe burns, areas of skin over severe bone infections, and skin damaged by some severe inflammatory skin diseases are more likely to develop skin cancers, although this risk is generally small.

Psoriasis treatment : Psoralens and ultraviolet light treatments (PUVA) given to some patients with psoriasis (a long-lasting inflammatory skin disease) can increase the risk of developing squamous cell skin cancer and probably other skin cancers also.

Xeroderma pigmentosum (XP)  : This very rare inherited condition reduces the skin's ability to repair damage to DNA caused by sun exposure. People with this disorder often develop many skin cancers starting in childhood.

Basal cell nevus syndrome (Gorlin syndrome) :  In this rare congenital (present at birth) condition, people develop many basal cell cancers over their lifetime. People with this syndrome may also have abnormalities of the jaw and other bones, eyes, and nervous tissue.

Most of the time this condition is inherited from a parent. In families with this syndrome, those affected often start to develop basal cell cancers as children or teens.

Reduced immunity : The immune system helps the body fight cancers of the skin and other organs. People with weakened immune systems (from certain diseases or medical treatments) are more likely to develop non-melanoma skin cancer, including squamous cell cancer and less common types such as Kaposi sarcoma and Merkel cell carcinoma.

For example, people who get organ transplants are usually given medicines that weaken their immune system to prevent their body from rejecting the new organ. This increases their risk of developing skin cancer. The rate of skin cancer in people who have had transplants can be as high as 70% within 20 years after the transplant. Skin cancers in people with weakened immune systems tend to grow faster and are more likely to be fatal.

Treatment with large doses of corticosteroid drugs can also depress the immune system. This may also increase a person's risk of skin cancer.

Human papilloma virus (HPV) infection : Human papilloma viruses (HPVs) are a group of more than 100 viruses that can cause papillomas, or warts. The warts that people commonly get on their hands and feet are not related to any form of cancer. But some of the HPV types, especially those that people get in their genital and anal area, seem to be related to skin cancers in these areas.

Smoking : People who smoke are more likely to develop squamous cell skin cancer, especially on the lips. Smoking is not a known risk factor for basal cell cancer.

Do we know what causes basal and squamous cell skin cancers?

Most basal cell and squamous cell skin cancers are caused by skin exposure to ultraviolet (UV) rays from sunlight, as well as from man-made sources such as tanning beds.

Repeated and unprotected sun exposure over many years increases a person’s risk of skin cancer. Most skin cancers are probably caused by exposures that happened many years earlier. The pattern of exposure may also be important. For example, frequent sunburns in childhood may increase the risk for basal cell cancer many years or even decades later.

DNA is the chemical in each of our cells that makes up our genes – the instructions for how our cells function. We usually look like our parents because they are the source of our DNA. But DNA affects more than just how we look.

Some genes contain instructions for controlling when our cells grow, divide into new cells, and die. Genes that help cells grow and divide are called oncogenes. Genes that keep cell growth in check by slowing down cell division or causing cells to die at the right time are called tumor suppressor genes. Cancers can be caused by DNA changes that turn on oncogenes or turn off tumor suppressor genes. Changes in several different genes are usually needed for a cell to become cancerous.

UV radiation can damage DNA. Sometimes this damage affects certain genes that control how and when cells grow and divide. Usually the cells can repair the damage, but in some cases this results in abnormal DNA, which may be the first step on the path to cancer.

Researchers don’t yet know all of the DNA changes that result in skin cancer, but they have found that many skin cancers have changes in tumor suppressor genes.

The gene most often found to be altered in squamous cell cancers is called TP53. This tumor suppressor gene normally causes cells with damaged DNA to die. When TP53 is altered, these abnormal cells may live longer and perhaps go on to become cancerous.

A gene often mutated in basal cell cancers is the “patched” (PTCH) gene, which is part of the hedgehog signaling pathway. This pathway is vital in the development of the embryo and fetus and is important in some adult cells. PTCHis a tumor suppressor gene that normally helps keep cell growth in check, so changes in this gene can allow cells to grow out of control. People who have basal cell nevus syndrome, which is often inherited from a parent and results in many basal cell cancers, have an altered PTCH gene in all the cells of their body.

These are not the only gene changes that play a role in the development of skin cancer. There are likely to be many others as well.

People with xeroderma pigmentosum (XP) have a high risk for skin cancer. XP is a rare, inherited condition resulting from a defect in an enzyme that repairs damage to DNA. Because people with XP are less able to repair DNA damage caused by sunlight, they develop huge numbers of cancers on sun-exposed areas of their skin.

The link between squamous cell skin cancer and infection with some types of the human papilloma virus (HPV) also involves DNA and genes. These viruses have genes that affect the growth-regulating proteins of infected skin cells. This can cause skin cells to grow too much and to not die when they're supposed to.

Scientists are studying other links between DNA changes and skin cancer. In the future, better understanding of how damaged DNA leads to skin cancer might be used to design treatments to overcome or repair that damage.

Can basal and squamous cell skin cancers be prevented?

Not all basal and squamous cell skin cancers can be prevented, but there are things you can do that might reduce your risk of getting skin cancer.

Limiting ultraviolet (UV) exposure

The most important way to lower your risk of basal and squamous cell skin cancers is to limit your exposure to UV radiation. Practice sun safety when you are outdoors. Simply staying in the shade is one of the best ways to limit your UV exposure. If you are going to be in the sun, “Slip! Slop! Slap!… and Wrap” is a catch phrase that can help you remember some of the key steps you can take to protect yourself from UV rays:

Slip on a shirt.

Slop on sunscreen.

Slap on a hat.

Wrap on sunglasses to protect the eyes and sensitive skin around them.

Seek shade :  An obvious but very important way to limit your exposure to UV light is to avoid being outdoors in direct sunlight too long. This is particularly important in the middle of the day between the hours of 10 am and 4 pm, when UV light is strongest. If you are unsure about the sun's intensity, use the shadow test: if your shadow is shorter than you are, the sun's rays are the strongest, and it is important to protect yourself.

When you are outdoors, protect your skin. Keep in mind that sunlight (and UV rays) can come through light clouds, can reflect off water, sand, concrete, and snow, and can reach below the water’s surface.

The UV Index: The amount of UV light reaching the ground depends on a number of factors, including the time of day, time of year, elevation, and cloud cover. To help people better understand the intensity of UV light in their area on a given day, the National Weather Service and the US Environmental Protection Agency have developed the UV Index. It gives people an idea of how strong the UV light is in their area, on a scale from 1 to 11+. A higher number means a higher chance of sunburn, skin damage, and ultimately skin cancers of all kinds. Your local UV Index should be available daily in your local newspaper, on TV weather reports,  and on many smartphone apps.

Protect your skin with clothing :  Clothes provide different levels of UV protection, depending on many factors. Long-sleeved shirts, long pants, or long skirts protect the most. Dark colors generally protect more than light colors. A tightly woven fabric protects better than loosely woven clothing. Dry fabric is generally more protective than wet fabric.

Be aware that covering up doesn't block out all UV rays. If you can see light through a fabric, UV rays can get through, too.

Some companies in the United States now make clothing that is lightweight, comfortable, and protects against UV exposure even when wet. These sun-protective clothes may have a label listing the ultraviolet protection factor (UPF) value – the level of protection the garment provides from the sun’s UV rays (on a scale from 15 to 50+). The higher the UPF, the higher the protection from UV rays.

Newer products, which are used in the washing machine like laundry detergents, can increase the UPF value of clothes you already own. They add a layer of UV protection to your clothes without changing the color or texture. This can be useful, but it’s not exactly clear how much it adds to protecting you from UV rays, so it is still important to follow the other steps listed here.

Wear a hat :  A hat with at least a 2- to 3-inch brim all around is ideal because it protects areas often exposed to intense sun, such as the ears, eyes, forehead, nose, and scalp. A dark, non-reflective underside to the brim can also help lower the amount of UV rays reaching the face from reflective surfaces such as water. A shade cap (which looks like a baseball cap with about 7 inches of fabric draping down the sides and back) also is good, and will provide more protection for the neck. These are often sold in sports and outdoor supply stores.

A baseball cap can protect the front and top of the head but not the neck or the ears, where skin cancers commonly develop. Straw hats are not as protective as ones made of tightly woven fabric.

Use sunscreen : Use sunscreens and lip balms on areas of skin exposed to the sun, especially when the sunlight is strong (for example, between the hours of 10 am and 4 pm). Sunscreens with broad spectrum protection (against UVA and UVB rays) and with sun protection factor (SPF) values of 30 or higher are recommended. Use sunscreen even on hazy days or days with light or broken cloud cover because UV rays still come through.

Always follow directions when applying sunscreen. Ideally, a 1-ounce application (a palmful of sunscreen) is recommended to cover the arms, legs, neck, and face of the average adult. Protection is greatest when sunscreen is used thickly on all sun-exposed skin. To ensure continued protection, sunscreens should be reapplied. It is often recommended to do so every 2 hours. Many sunscreens wash off when you sweat or swim and then wipe off with a towel, so they must be reapplied for maximum effectiveness. And don't forget your lips; lip balm with sunscreen is also available.

Some people use sunscreen because they want to stay out in the sun for long periods of time without getting sunburned. Sunscreen should not be used to spend more time in the sun than you otherwise would, as you will still end up with damage to your skin.

Remember that sunscreens are a filter. The sunscreen’s SPF number is a measure of how long it would take you to get sunburned, compared to how long it would have taken if you were not using it. For example, if you would normally burn after only 5 minutes in the sun, using a product with an SPF of 30 would mean you would still get burned in 150 minutes. And that’s assuming that you applied it as directed, which unfortunately many people do not.

Sunscreen can reduce your chance of actinic keratoses and squamous cell cancer. But there is no guarantee, and if you stay in the sun a long time, you are at risk of developing skin cancer even if you have applied sunscreen.

Wear sunglasses :  Wrap-around sunglasses with at least 99% UV absorption provide the best protection for the eyes and the skin area around the eyes. Look for sunglasses labeled as blocking UVA and UVB light. Labels that say “UV absorption up to 400 nm” or “Meets ANSI UV Requirements” mean the glasses block at least 99% of UV rays. If there is no label, don't assume the sunglasses provide any protection.

Avoid tanning beds and sunlamps : Many people believe the UV rays of tanning beds are harmless. This is not true. Tanning lamps give out UVA and usually UVB rays as well, both of which can cause long-term skin damage and can contribute to skin cancer. Most skin doctors and health organizations recommend not using tanning beds and sun lamps.

If you want a tan, one option is using a sunless tanning lotion, which can provide the look without the danger. These lotions contain a substance called dihydroxyacetone (DHA). DHA interacts with proteins on the surface of the skin to give it a darker color. You do not have to go out in the sun for these to work. The color tends to wear off after a few days. These products can give skin a darker color (although in some people it may have a slight orange tinge), but if you use one you still need to use sunscreen and wear protective clothing when going outside. These tans do not protect against UV rays.

Some tanning salons offer DHA as a spray-on tan. A concern here is that DHA is approved for external use only and should not be inhaled or sprayed in or on the mouth, eyes, or nose. People who choose to get a DHA spray tan should make sure to protect these areas.

Protect children from the sun : Children need special attention, since they tend to spend more time outdoors and can burn more easily. Parents and other caregivers should protect children from excess sun exposure by using the steps above. Older children need to be cautioned about sun exposure as they become more independent. It is important, particularly in parts of the world where it is sunnier, to cover your children as fully as is reasonable. You should develop the habit of using sunscreen on exposed skin for yourself and your children whenever you go outdoors and may be exposed to large amounts of sunlight.

Babies younger than 6 months should be kept out of direct sunlight and protected from the sun with hats and protective clothing. Sunscreen may be used on small areas of exposed skin only if adequate clothing and shade are not available.

A word about sun exposure and vitamin D : Doctors are learning that vitamin D has many health benefits. It may even help to lower the risk for some cancers. Vitamin D is made naturally by your skin when you are in the sun. How much vitamin D you make depends on many things, including how old you are, how dark your skin is, and how strong the sunlight is where you live.

At this time, doctors aren't sure what the optimal level of vitamin D is. A lot of research is being done in this area. Whenever possible, it is better to get vitamin D from your diet or vitamin supplements rather than from sun exposure, because dietary sources and vitamin supplements do not increase risk for skin cancer, and are typically more reliable ways to get the amount you need.

For more information on how to protect yourself and your family from UV exposure, 

Avoiding harmful chemicals :  Exposure to certain chemicals, such as arsenic, can increase a person's risk of skin cancer. People can be exposed to arsenic from well water in some areas, pesticides and herbicides, some medicines (such as arsenic trioxide) and herbal remedies (in some imported traditional herbal remedies), and in certain occupations (such as mining and smelting).

Checking your skin regularly :  Checking your skin regularly may help you spot any new growths or abnormal areas and show them to your doctor before they even have a chance to turn into skin cancer. For more information, see the section, “Can basal and squamous cell skin cancers be found early?”

Can basal and squamous cell skin cancers be found early?

Basal cell and squamous cell skin cancers can be found early. As part of a routine cancer-related checkup, your health care professional should check your skin carefully.

You can also play an important role in finding skin cancer early. It’s important to check all over your skin, preferably once a month. Self-exams are best done in a well-lit room in front of a full-length mirror. Use a hand-held mirror for areas that are hard to see. Learn the patterns of moles, blemishes, freckles, and other marks on your skin so that you’ll notice any changes.

All areas should be examined, including your palms and soles, scalp, ears, nails, and your back. (For a more thorough description of a skin self-exam, see our document, Skin Cancer: Prevention and Early Detection .Friends and family members can also help you with these exams, especially for those hard-to-see areas, such as your scalp and back. Be sure to show your doctor any areas that concern you and ask your doctor to look at areas that may be hard for you to see.

Spots on the skin that are new or changing in size, shape, or color should be seen by a doctor promptly. Any unusual sore, lump, blemish, marking, or change in the way an area of the skin looks or feels may be a sign of skin cancer or a warning that it might occur. The skin might become scaly or crusty or begin oozing or bleeding. It may feel itchy, tender, or painful. Redness and swelling may develop.

Basal cell and squamous cell skin cancers can look like a variety of marks on the skin. The key warning signs are a new growth, a spot or bump that's getting larger over time, or a sore that doesn't heal within a couple of months. 

How are basal and squamous cell skin cancers diagnosed?

Most skin cancers are brought to a doctor’s attention because of signs or symptoms a person is having. If you have an abnormal area of skin that may be skin cancer, your doctor will use certain medical exams and tests to find out if it is cancer or some other skin condition. If there is a chance the skin cancer may have spread to other areas of the body, other tests may be done as well.

Signs and symptoms of basal and squamous cell skin cancers

Skin cancers rarely cause bothersome symptoms until they become quite large. Then they may bleed or even hurt. But typically they can be seen or felt long before they reach this point.

Basal cell carcinomas usually develop on areas exposed to the sun, especially the head and neck, but they can occur anywhere on the body. They often appear as flat, firm, pale areas or small, raised, pink or red, translucent, shiny, pearly areas that may bleed after a minor injury. They may have one or more abnormal blood vessels, a lower area in their center, and blue, brown, or black areas. Large basal cell carcinomas may have oozing or crusted areas.

Squamous cell carcinomas may appear as growing lumps, often with a rough, scaly, or crusted surface. They may also look like flat reddish patches in the skin that grow slowly. They tend to occur on sun-exposed areas of the body such as the face, ear, neck, lip, and back of the hands. Less often, they form in the skin of the genital area. They can also develop in scars or skin sores elsewhere.

Both of these types of skin cancer may develop as a flat area showing only slight changes from normal skin.

Other types of non-melanoma skin cancers are much less common, and may look different.

Kaposi sarcoma generally starts as small bruise-like areas that develop into brownish or purplish tumors under the skin.

Mycosis fungoides (a type of skin lymphoma) usually begins as a rash, often on the buttocks, hips, or lower abdomen. It can look like skin allergies, eczemas, and other types of skin irritations.

Adnexal tumors appear as bumps within the skin.

Skin sarcomas appear as large lumps under the skin surface.

Merkel cell tumors are usually firm, pink, red, or purple nodules or ulcers (sores) found on the face or, less often, the arms or legs.

If your doctor suspects you might have skin cancer, he or she will use one or more of the following tests or exams.

Medical history and physical exam

Usually the doctor's first step is to take your medical history. The doctor will ask when the mark on the skin first appeared, if it has changed in size or appearance, and if it has caused any symptoms (pain, itching, bleeding, etc.). You may also be asked about past exposures to causes of skin cancer (including sunburns and tanning practices) and if you or anyone in your family has had skin cancer.

During the physical exam, the doctor will note the size, shape, color, and texture of the area(s) in question, and whether there is bleeding or scaling. The rest of your body may be checked for spots and moles that could be related to skin cancer.

The doctor may also check nearby lymph nodes, which are bean-sized collections of immune system cells that can be felt under the skin in certain areas. Some skin cancers may spread to lymph nodes. When this happens, the lymph nodes may become larger and firmer than usual.

If you are being seen by your primary doctor and skin cancer is suspected, you may be referred to a dermatologist (a doctor who specializes in skin diseases), who will look at the area more closely.

Along with a standard physical exam, some dermatologists use a technique called dermatoscopy (also known asdermoscopy, epiluminescence microscopy [ELM] or surface microscopy) to see spots on the skin more clearly. The doctor uses a dermatoscope, which is a special magnifying lens and light source held near the skin. Sometimes a thin layer of oil is used with this instrument. The doctor may take a digital photo of the spot.

When used by an experienced dermatologist, this test can improve the accuracy of finding skin cancers early. It can also often help reassure you if a spot on the skin is probably benign (non-cancerous) without the need for a biopsy.

Skin biopsy :  If the doctor thinks that a suspicious area might be skin cancer, he or she will take a sample of skin from the area and have it looked at under a microscope. This procedure is called a skin biopsy. If the biopsy removes the entire tumor, it is often enough to cure basal and squamous cell skin cancers without further treatment.

There are different ways to do a skin biopsy. The doctor will choose one based on the suspected type of skin cancer, where it is on your body, the size of the affected area, and other factors. Any biopsy is likely to leave at least a small scar. Different methods may result in different scars, so ask your doctor about possible scarring before the biopsy is done. No matter which type of biopsy is done, it should remove as much of the suspected area as possible so that an accurate diagnosis can be made.

Skin biopsies are done using a local anesthetic (numbing medicine), which is injected into the area with a very small needle. You will probably feel a small prick and a little stinging as the medicine is injected, but you should not feel any pain during the biopsy.

Shave biopsy :  For a shave biopsy, the doctor first numbs the area with a local anesthetic. The doctor then shaves off the top layers of the skin with a small surgical blade. Usually the epidermis and the outer part of the dermis are removed, although deeper layers can be taken as well if needed. Bleeding from the biopsy site is then stopped by applying an ointment or a small electrical current to cauterize the wound.

Punch biopsy : A punch biopsy removes a deeper sample of skin. The doctor uses a tool that looks like a tiny round cookie cutter. Once the skin is numbed with a local anesthetic, the doctor rotates the punch biopsy tool on the surface of the skin until it cuts through all the layers of the skin, including the dermis, epidermis, and the upper parts of the subcutis. The edges of the biopsy site are then stitched together.

Incisional and excisional biopsies :  To examine a tumor that may have grown into deeper layers of the skin, the doctor may use an incisional or excisional biopsy. An incisional biopsy removes only a portion of the tumor. An excisional biopsy removes the entire tumor. After numbing the area with a local anesthetic, a surgical knife is used to cut through the full thickness of skin. A wedge or sliver of skin is removed for examination, and the edges of the wound are stitched together.

Examining the biopsy samples : All skin biopsy samples are sent to a lab, where they are looked at under a microscope by a pathologist (a doctor trained in looking at tissue samples to diagnose disease). Often, the samples are sent to a dermatopathologist, a doctor who has special training in making a diagnosis from skin samples.

Lymph node biopsy :  Rarely, when basal or squamous cell skin cancer spreads, it usually goes first to nearby lymph nodes, which are small, bean-shaped collections of immune cells. If your doctor feels lymph nodes near the tumor that are too large and/or too firm, a lymph node biopsy may be done to determine whether cancer has spread to them.

Fine needle aspiration biopsy : A fine needle aspiration (FNA) biopsy uses a syringe with a thin, hollow needle to remove very small tissue fragments. The needle is smaller than the needle used for a blood test. A local anesthetic is sometimes used to numb the area first. This test rarely causes much discomfort and does not leave a scar.

An FNA biopsy is not used to diagnose a suspicious skin tumor, but it may be used to biopsy large lymph nodes near a skin cancer to find out if the cancer has spread to them. FNA biopsies are not as invasive as some other types of biopsies, but they may not always provide enough of a sample to find cancer cells.

Surgical (excisional) lymph node biopsy :  If an FNA does not find cancer in a lymph node but the doctor still suspects the cancer has spread there, the lymph node may be removed by surgery and examined. This can often be done in a doctor's office or outpatient surgical center using local anesthesia and will leave a small scar.

How are basal and squamous cell skin cancers staged?

The stage of a cancer is a description of how widespread it is. For skin cancers this includes its size and location, whether it has grown into nearby tissues or bones, whether it has spread to the lymph nodes or any other organs, and certain other factors.

Because basal cell skin cancer is almost always cured before it spreads to other organs, it is seldom staged unless the cancer is very large. Squamous cell cancers have a greater (although still quite small) risk of spreading, so staging may sometimes be done, particularly in people who have a high risk of spread. This includes people with suppressed immune systems, such as those who have had organ transplants and people infected with HIV, the virus that causes AIDS.

The tests and exams described in the section called “How are basal and squamous cell skin cancers diagnosed?” are the main ones used to help determine the stage of the cancer. In rare cases, imaging tests such as x-rays, CT scans, or MRI scans may be used as well.

Physical exams and other tests may be used to assign T, N, and M categories and a grouped stage. The TNM system for staging contains 3 key pieces of information:

T stands for tumor (its size, location, and how far it has spread within the skin and to nearby tissues).

N stands for spread to nearby lymph nodes (small bean-shaped collections of immune system cells, to which cancers often spread first).

M is for metastasis (spread to distant organs).

T categories

The possible values for T are:

TX: The main (primary) tumor cannot be assessed.

T0: No evidence of primary tumor.

Tis: Carcinoma in situ (tumor is still confined to the epidermis, the outermost skin layer).

T1: The tumor is 2 centimeters (cm) across (about 4/5 inch) or smaller and has no or only 1 high-risk feature (see below).

T2: Tumor is larger than 2 cm across, or is any size with 2 or more high-risk features.

T3: Tumor has grown into facial bones, such as the jaw bones or bones around the eye.

T4: Tumor has grown into other bones in the body or into the base of the skull.

High-risk features: These features are used to distinguish between some T1 and T2 tumors.

Tumor is thicker than 2 millimeters (mm).

Tumor has invaded down into the lower dermis or subcutis (Clark level IV or V).

Tumor has grown into tiny nerves in the skin (perineural invasion).

Tumor started on an ear or on non-hair-bearing lip.

Tumor cells look very abnormal (poorly differentiated or undifferentiated) when seen under a microscope.

N categories

The possible values for N are:

NX: Nearby lymph nodes cannot be assessed.

N0: No spread to nearby lymph nodes.

N1: Spread to 1 nearby lymph node which is on the same side of the body as the main tumor and is 3 centimeters (cm) or less across.

N2a: Spread to 1 nearby lymph node which is on the same side of the body as the main tumor and is larger than 3 cm but not larger than 6 cm across.

N2b: Spread to more than 1 nearby lymph node on the same side of the body as the main tumor, none of which are larger than 6 cm across.

N2c: Spread to nearby lymph node(s) on the other side of the body from the main tumor, none of which are larger than 6 cm across.

N3: Spread to any nearby lymph node that is larger than 6 cm across.

M categories

The M values are:

M0: No spread to distant organs.

M1: Spread to distant organs.

Stage grouping

To assign a stage, information about the tumor and whether it has spread to lymph nodes and other organs in the body is combined in a process called stage grouping. The stages are described using the number 0 and Roman numerals from I to IV. In general, patients with lower stage cancers tend to have a better prognosis for a cure or long-term survival.


Stage 0


Tis, N0, M0

Stage I

T1, N0, M0

Stage II

T2, N0, M0

Stage III

T3, N0, M0

T1 to T3, N1, M0

Stage IV

T1 to T3, N2, M0

Any T, N3, M0

T4, any N, M0

Any T, any N, M1

Click here to go to the treatment:


Recent News and Articles Obesity primes the colon for cancer, study finds Common Respiratory Diseases Tied to Lung Cancer Risk