Dr. Charles Zugerman is a physician at the Department of Dermatology at Northwestern Memorial Hospital in Chicago, USA. In addition, he teaches as a professor of clinical dermatology at the Medical Faculty of Northwestern University in Chicago. In addition to numerous scientific publications, he has also led many further education events in front of a specialist audience. He is a specialist in allergic contact dermatitis, occupational skin diseases and cosmetic dermatology. Among other things, he is a member of the American Academy of Dermatology and the dermatological and medical society in Chicago.
: How common is skin cancer?
Prof. Zugerman: The frequency data on individual types of skin cancer essentially depend on the maturity of the reporting systems for the respective diseases in individual countries. There are usually approximately three times as many skin cancer cases worldwide as in the United States. The rate of skin cancer varies from place to place, depending on how many fair-skinned people live there, how intense the sun is shining, and what outdoor recreational activities exist and are perceived. Skin cancer is the most common cancer in the United States; The world's highest skin cancer rates are found in South Africa and Australia.
There are many different types of skin cancer. The three main ones are basal cell carcinoma, squamous cell carcinoma and melanoma. What about the basalioma?
As for basalioma, the most common type of skin cancer, there are approximately 900, 000 cases per year in the United States. It occurs in approximately 146 cases per 100, 000 inhabitants, the numbers are even higher, for example, Florida, California, Australia or South Africa, so considered places with high solar radiation. In contrast, the frequency is lower in countries with lower solar radiation, such as Austria, Scandinavia or the UK, where fair-skinned people live. A basalioma usually has a pink to red color and can last for years. My patient with the longest history in this regard was someone who had a spot on his face for 20 years, which eventually turned out to be a basalioma. This cancer is growing and developing very slowly. An alarm signal is when a skin spot is enlarged or has a pinkish color. I have already seen 13-year-old with basalioma. I would like to reiterate that people rarely die of basal cell carcinoma although it is very common. If predominantly dark-skinned people lived in these countries, the incidence of skin cancer would be even lower. In the United States, very few of the 900, 000 suffer from basal cell death. From my own experience so far I can not remember a single case in which someone had died of a basalioma. The most fatal cases are those in which there are large, aggressive tumors that expand locally, for example in the brain, bones or vessels, without necessarily metastasizing. However, this is very rare.
The other common skin cancer is squamous cell carcinoma. What can you tell us about it?
Squamous epithelial cells are thin, long cells that resemble fish scales and are found in tissue on the surface of the skin. Squamous cell carcinoma most commonly occurs in people over 50 years old. This skin cancer usually has a hard, touch-sensitive surface and can increase in size relatively quickly within a few months. However, squamous cell carcinomas are less common than basal cell carcinomas, but usually more aggressive, depending on their etiology. There are approximately 200, 000 cases per year in the US. More people die of squamous cell carcinoma than of basalioma.
And the third common type of skin cancer, melanoma?
Melanomas develop from melanocytes, which are located in the lowest layers of the skin. In the US, the diagnosis is likely to be about 34, 000 cases per year, compared to about 90, 000 cases worldwide. And in the United States, approximately 7, 200 people die from melanoma each year.
What is the cause of these common forms of skin cancer?
The ultraviolet or UV radiation of the sun is the major cause of skin cancer. In addition, artificial UV sources such as sunbeds can cause skin cancer. As I mentioned before, the highest skin cancer rates are in South Africa and Australia, because in these countries UV radiation is very high.
And what is the cause of melanoma?
Melanomas arise in three ways. Some melanomas occur as a result of sun exposure and then find themselves in the same body sites as basal cell carcinomas or squamous cell carcinomas. Melanoma is more common in people who work outdoors. For example, someone who works for a telephone company and installs telephone poles, or someone who plays golf outdoors every weekend, is more likely to develop melanoma than someone who never goes outside.
What can be done to prevent skin cancer?
Which would help against most basaliomas and squamous cell carcinomas and some melanomas: reduce sun exposure. It is important to understand that skin cancer is much more prevalent in people who have been exposed to intense sunlight for the first 18 years of life. So first of all it is necessary to protect children and in the second place adults from the sun. People who get sunburned and then browned are very hurtful. Any kind of sunburn is harmful. I always tell my patients to avoid the midday sun. People with fair complexions, blue eyes and red hair, who are easily freckled, are more likely to have problems than dark-skinned Asians, black people or residents of the Mediterranean. Life in the tropics is also a risk factor. High-risk, light-skinned people living in the tropics should avoid the sun between 10 in the morning and 2 in the afternoon.
What do you think about sun creams?
The use of sun creams is a precaution. You should use a sunscreen and be careful to apply it 30 to 45 minutes before sun exposure. The cream should protect against both UVA and UVB rays. A sunburn is mainly caused by UVB radiation, which could also be called sunburn radiation. But there are also synergistic effects with the tanning, long-wave UVA radiation. The sunscreen should therefore shield against as much radiation as possible, both in the long-wave and short-wave range. For fair-skinned people, a sunscreen with a minimum SPF of 30 is recommended; for dark-skinned people the SPF may also be lower.
Are there any other precautions?
Another way to protect yourself from too much light is to use either an umbrella or dark, opaque clothing or a wide brimmed hat. Another important aspect of prevention is to notice unnatural changes and to make people aware of what to look for in the three different skin cancers. People at high risk should seek the help of a dermatologist at regular intervals, depending on their individual risk. Someone who has ever had skin cancer, is easily sunburned or has a positive family history of skin cancer should be seen by a dermatologist at least twice a year. In addition, high-risk patients should also regularly examine their own skin before a full-length mirror and additionally with a hand mirror for the back.
At what age and how often should the skin be examined?
Anyone who wishes to have an exam for whatever reason, for example because he is worried about having a mole, should undergo this examination. I know a number of people who control 7- or 8-year-old children, with only very rarely finding skin cancer in children under the age of 16. If someone has ever had skin cancer, he should be examined at least four times a year. Patients with basaliomas are usually examined twice a year. Patients with skin cancer in the family history should be examined once or twice a year.
There is so much skin cancer from sun exposure and yet here in the summer we see thousands of people sitting in the sun for hours without any worries.
They sit in the sun for the same reasons why other people continue to smoke. Smoking is dangerous, but people still smoke. Obesity is dangerous, but people are still overweight. Eating high cholesterol foods is dangerous, yet people continue to do it. Why? Because it is pleasant and comfortable. Why do people sit in the sun? Because they feel good about it. They love to tan, they like their appearance afterwards and they like the feeling of sun on their skin. People are influenced by magazines or friends and they want to be tanned; consequently, they have a higher risk of developing skin cancer. Basically, there's nothing to stop people from going to the sun as long as they're reasonably intelligent.