Fact sheet: Preventing and detecting skin cancer

For many people, summer, holiday and sunshine go hand in hand. Others worry that sunbathing might lead to skin cancer – especially malignant (cancerous) melanoma, so-called “black skin cancer”.

Most people never get melanoma – the average risk is not high. Individual risk can be different, however. Researchers have identified several factors that may help when assessing your own risk. The most widely known factor is ultraviolet radiation (UV radiation): The risk of getting skin cancer is higher if you have been exposed to intense sun radiation without protection for longer periods of your life. Besides UV light, other factors play a role in the development of skin cancer as well. In this fact sheet, we will describe these factors and explain options for preventing and detecting skin cancer.  

What is the structure of the skin and where does skin cancer develop?

The skin protects the body from environmental factors such as dampness and cold, but also from germs and harmful substances. It consists of three layers:

• Epidermis: the outermost layer of the skin made up of different cell sublayers
• Dermis: the middle layer of the skin, which contains sweat, scent and sebaceous glands, nerve fibers, blood and lymph vessels as well as hair roots
• Subcutaneous layer (hypodermis): lower layer of the skin, which consists mainly of fat and connective tissue

The corneal layer of the epidermis is the visible part of our skin. You can read more about how the skin works here. Skin cancer most commonly develops in the epidermis, below the corneal layer.


What is skin cancer and what types are there?

Skin cancer develops when the division of skin cells gets out of control. This can lead to a malignant tumor – cancer. The affected areas can be flaky or dark in color, and sometimes distinctly raised, too. Skin cancer can develop from pigmented nevi or papules – but most moles or spots will remain harmless. Pigmented nevi are also commonly called moles, birthmarks or lentigines.

There are different types of skin cancer. Here are the most important ones:

• Basal cell carcinoma: Basal cell carcinoma is the most common malignant skin tumor, but it is only very rarely life-threatening. About 1 person out of 1,000 people who have this skin cancer die from it (0.1%). But this cancer can destroy tissue, and can occur on the face, for example. So an operation might leave behind a big scar. The most common places for basal cell carcinoma are the face, the nape of the neck or other areas of the head.
• Squamous cell carcinoma: Squamous cell carcinoma is less common than basal cell carcinoma, but more frequently has severe consequences: about 43 out of 1,000 people who have got this disease die from it (4.3%). Squamous cell carcinoma almost always occurs on parts of the body that are exposed to the sun – especially on the face, the ears or the back of the hand.
• Malignant melanoma (black skin cancer): This is the most dangerous type of skin cancer. 150 out of 1,000 men (15%) and 100 out of 1,000 women (10%) who have this disease die from it within 5 years. Malignant melanomas can develop anywhere, even in areas that hardly get any sun.
  
  

There are a number of other different rare types of skin cancer, which we will not include here.

What causes skin cancer and what increases the risks?

Several factors favor skin cancer, yet the sun is the most important risk factor. Sunlight contains UV radiation, which can damage the skin and cause cancer. Artificial UV light used in solariums is also suspected to cause skin cancer. Another main factor besides UV rays that will influence the likelihood of someone getting skin cancer is genetic disposition.

Your risk of developing a skin tumor at some point in your life is mainly influenced by the following factors:

• Skin type: People with fair skin have a higher risk than people with dark skin.
• Sun exposure: Being in the sun without protection is the most important cause of skin cancer. If you want to get an idea of how you deal with sun exposure, you should think about your habits during work, in your free time and on vacation. In particular, shifts between periods of intense sun radiation on vacation or at the weekends and periods of little sun the rest of the time can favor skin cancer.
• Sunburn: A lot of sunburn or severe sunburn – especially as a child – increases the risk of getting skin cancer.
• Pigmented nevi: People with a lot of moles/lentigines or with unusual or big ones get skin cancer more often.
• Family risk: There is an increased risk if you or a family member has already had skin cancer.
• Age: The risk of skin cancer grows as you get older.

Also, people with a weakened immune system are more frequently affected by skin cancer. Some chemicals and certain drugs can also favor the development of skin cancer. UV exposure at work is also often easily underestimated. A lot of other causes are being discussed, but there is often no scientific proof of a connection actually existing. You can find more detailed explanations of the risk factors in our article on skin cancer.

Some of these risk factors simply have to be accepted, but others can be influenced. Looking at the individual risk factors might help you decide whether to pay particular attention to preventing skin cancer.

What can I do to prevent skin cancer?

The most important thing you can do to prevent skin tumors is to protect yourself from too much UV radiation. Sun radiation is particularly high in summer between 10 am and 4 pm. So in order to minimize UV radiation to the skin it makes sense not to go outside without protection at noontime for too long. This is especially important when travelling to countries further south.

Shade can offer effective protection from UV light. It reduces UV radiation by 50 to 95%. Wearing a hat and clothes also reduces UV radiation on the skin.

Sunscreen is an important aid to prevent (painful) sunburn. It is not clear however whether sunscreen also prevents skin cancer. All indications are that people develop squamous cell carcinoma less frequently when they put on sunscreen. But generally there are no conclusive scientific trials to reliable assess whether sunscreen protects from skin cancer. It might be misleading, for example, to rely on sunscreen alone for prevention because sometimes people who have put on sunscreen stay in the sun for longer. This means, however, that they are also exposed to UV radiation for a longer time.

To prevent sunburn it is important to use sunscreen with a high enough sun protection factor (SPF), and that suits the respective skin type. To find out more about choosing the right sun protection factor click here. Some sunscreens need to be put on some time before sunbathing, while other – especially mineral – sunscreens take immediate effect. It is important to put on enough sunscreen, and to put it on again regularly. Adults are recommended to apply about one teaspoon of sunscreen on their face, and 6 on their entire body.

If you do not use solariums you eliminate one potential risk factor for skin cancer. In Germany, children and teenagers under the age of 18 years are legally prohibited from using solariums.

Smoking increases the risk of cancer in general, and people who smoke probably are also more likely to develop skin cancer. If you would like to quit smoking you can find more information here.

Many different dietary supplements and types of food are promised to protect you from getting skin cancer. Yet there is no reliable proof that a certain diet can prevent skin cancer.

How can skin cancer be detected?

A doctor can examine your skin and look for irregularities. A skin specialist as well as your family doctor can do this examination if they have the appropriate qualification. When doing this examination the doctor checks all of your skin and visible mucous membranes for any suspicious spots.

Anyone can also check his or her own body for irregularities. Particularly for people who have already had skin cancer once before, it may be a good idea for them to also check their body themselves. Most people who develop a malignant melanoma again discover the tumor either on their own or with the help of their partner or a relative.   

It is often not so easy to see differences between normal pigmented nevi, reddened skin and skin bumps and a malignant disease. Most skin abnormalities are harmless. It is important to check your entire body meticulously, also the places between your toes, the soles of your feet and your ears. It helps to have good light and to ask someone you know well to assist you with hard-to-get-to parts of your body.

It might also help to pay attention to skin spots that are changing in size or shape, getting discolored, or that are unusual or ugly. Black melanomas come in a great variety of shapes. The following ABCDE signs can help to detect melanoma:

Asymmetry:	The pigmented nevus has an asymmetrical (uneven) shape, meaning that it is not round or oval.
Border:	The edge of the pigmented nevus has an irregular border, meaning it is frayed, not clear, or jagged.
Color:	The color of the pigmented nevus has changed; it may also contain different or unusual colors like white, blue or red.
Diameter:	The pigmented nevus is getting larger, in particular more than 6 mm (0.25 inches, the diameter of a pencil); yet melanomas that do not grow out of a lentigo are usually smaller.
Evolving:	The pigmented nevus evolves and changes; it may for example bleed, be wet, itch, form a scab or crust, or change its size, shape, color or its surface consistency, or it may be raised.

If you have a lot of pigmented nevi and do not really know how to keep good track of all of them, it may help to keep watch for an “ugly duckling”. An ugly duckling is a spot that is conspicuous because it looks different from the others. By doing this you can more readily detect a suspicious part of your skin.

You can read more about what the different types of skin cancer look like and how you can detect them here.

What can screenings do?

As of 2008, anyone with statutory health insurance over the age of 35 can have a free skin cancer screening in Germany. Some statutory insurers also cover the costs for younger people as well. Someone with statutory health insurance is eligible for screening every two years. The screening is done by skin specialists or family doctors with the appropriate qualification. When doing the examination the doctor will also ask about risk factors and check the entire body for unusual skin spots. If your family doctor finds unusual spots he will refer you to a specialist for skin diseases to confirm or rule out the suspected diagnosis.

If the skin specialist suspects cancer, he or she will remove some tissue in a minor operation, and this tissue will then be checked for tumor cells. If the skin changes are small, the suspicious spots can also be removed completely.

Research has shown this type of screening program can help to detect skin cancer at an early stage. It is not yet clear, however, whether a screening program also leads to fewer people dying of skin cancer. It also remains an unanswered question whether screening can improve the course of the disease or reduce negative consequences like scars or skin defects. The success of skin cancer screening in Germany is to be assessed a few years after its introduction.

Author: German Institute for Quality and Efficiency in Health Care (IQWiG)

Next planned update: July, 2014. You can find out more about how our health information is updated here.

© IQWiG (Institute for Quality and Efficiency in Health Care)