ABCDE rule for self-examination of moles
PDF | 3.33 MB
Skin cancer is a malignant tumour of the skin. Dermatologists differentiate between different forms of skin cancer: most cases are non-melanoma skin cancer, which includes both squamous cell carcinoma and basal cell carcinoma. Melanoma skin cancer (malignant melanoma) is less common, but often all the more malignant. As a general rule, with early detection by a doctor and appropriate treatment, the chances of recovery are good in both melanoma and non-melanoma skin cancer.
Overview of skin cancer
If skin cancer develops, that means that cells in the skin begin to grow uncontrollably. The type of cells that are growing in this way determines which form of skin cancer is present.
In Switzerland, almost a quarter of all patients are under the age of 50 when malignant skin cancer is discovered. The average age of people at the point of diagnosis with basal cell carcinoma is 60. However, it is important to note that more and more younger people now suffer from it and require treatment. Women are affected roughly as often as men. A different picture emerges with squamous cell carcinoma. This occurs more often in men than in women. Patients’ age at diagnosis is 70 years old on average.
Melanoma skin cancer (malignant melanoma)
Melanoma arises from pigment-forming skin cells, known as melanocytes, in the basal cell layer, i.e. the lowest layer of the epidermis. Melanocytes are responsible for the tanning of the skin and for the reaction that protects it against sunlight.
One in ten people affected by skin cancer has melanoma. This is the most malignant type of skin cancer and the fifth most common type of cancer overall. In Switzerland, melanoma accounts for 7 % of all cancers. It can form secondary tumours (metastases) in other organs early on and thus become life-threatening. In rare cases, melanoma can also occur in the eye or in the mucous membranes (anus, genital area, sinuses).
Would you like to learn more about melanoma skin cancer? Click here to read our article on melanoma skin cancer.
Non-melanoma skin cancer
Non-melanoma skin cancer is the most common type of cancer in humans. Types of non-melanoma skin cancer include basal cell carcinoma (basal cell epithelioma, basalioma) and squamous cell carcinoma (squamous cell epithelioma, spinalioma). In contrast to malignant melanoma, non-melanoma types of skin cancer generally only grow locally and do not spread (metastasise).
Basal cell carcinoma (basal cell cancer, basalioma)
Basal cell carcinoma develops from stem cells between the basal cell layer and the upper dermis, along the hair follicles.
Squamous cell carcinoma (squamous cell cancer, spinalioma)
Squamous cell carcinoma develops from horny cells (keratinocytes) in the squamous cell layer. Actinic keratosis and Bowen’s disease are possible precursors of this form of skin cancer.
Do you need more information about non-melanoma skin cancer? Click here to read our article on non-melanoma skin cancer.
An overview of the different types of skin cancer
Melanoma
Spinalioma
Actinic keratosis
Basalioma
Causes and risk factors
UV radiation (from sunbeds or sunlight) is the main cause of all three forms of skin cancer. Exposure to strong UV radiation, with lots of episodes of sunburn, promotes melanoma. However, it can also occur in places that do not normally come into contact with sunlight, such as in the mouth. Frequent sunbathing over many years and/or regular episodes of sunburn, on the other hand, can lead to non-melanoma skin cancer (squamous cell carcinoma, basal cell carcinoma). Here, the main risk comes not so much from individual incidents of sunburn, but mainly in the total radiation dose to which the body is exposed over the course of a person’s life.
There are many other risk factors that can play a key role in one or more forms of skin cancer, including:
- A pale skin type
- Many moles
- Previous history of skin cancer
- Cases of skin cancer in the family
- Rare hereditary diseases such as xeroderma pigmentosum
- Chronic skin inflammation, such as a leg ulcer (ulcus cruris)
- Frequent use of sunbeds
- A weakened immune system, for example due to HIV or certain medications
- Contact with carcinogenic substances such as arsenic or tar (in cigarette smoke)
Symptoms
As skin cancer can look different in different people, any new moles or marks on the skin, or those that have changed colour, are fast-growing or bleeding, as well as any existing moles, should be examined. What a malignant tumour looks like and where it usually develops depends on the form of the cancer. If any changes occur, it is best to have them examined by a specialist.
Symptoms of melanoma skin cancer
Melanoma is treacherous because it can occur anywhere on the body, even in places that rarely or never get sunlight. It can develop as skin cancer on the scalp, on the mucous membranes in the genital area or under the fingernails and toenails, among other places. It appears as a dark or black patch, which may be raised, lumpy or flat.
Melanoma can either arise from existing pigmented marks (dark birthmarks or moles) or develop as new lesions on the skin. The ABCDE rule can help to distinguish between melanoma skin cancer and a healthy mole/mark:
- Asymmetry: Melanoma often has an irregular, asymmetrical shape.
- Border: A melanoma does not have clearly defined borders, so it has a blurred, ‘scalloped’ or jagged edge.
- Colour: If a healthy mole/mark develops into a melanoma, a change in colour often occurs. Uneven, patchy, dark colouring is typical. Certain melanomas also have an unusual colouration, such as bluish or white.
- Diameter: Is the diameter of the mole greater than 5 millimetres?
- Evolving: Healthy moles and marks remain more or less unchanged. Melanomas, on the other hand, often change their colour, size, shape or thickness. Changes are usually slow, as melanoma skin cancer usually develops over several months or years. That’s why it’s important to keep an eye on suspicious moles and marks, check them regularly using the ABCDE rule, and, if in doubt, consult a dermatologist at an early stage and have the necessary examinations carried out.
Important: It should be noted that melanoma skin cancer does not always show all of these characteristics. Itchy moles or bleeding pigmented marks can also be a sign of cancer.
Symptoms of basal cell carcinoma (non-melanoma skin cancer)
Basal cell cancer develops in particular on sun-exposed parts of the body, such as on the lip, forehead, nose, ear, bald scalp and back of the hand. Patients’ torso, arms and legs are affected less frequently.
Hardening of the skin is often the first sign of basal cell carcinoma. This can form a glassy-white to reddish nodule in which very fine blood vessels can be identified. If the cancer progresses, moist ulcers or crusts develop in these areas.
Symptoms of squamous cell carcinoma (non-melanoma skin cancer)
Squamous cell carcinoma also occurs primarily in areas that are often exposed to sunlight. It appears as a skin nodule (or papule). This slow-growing cancerous growth hardens and forms a crust that can break open and eventually become moist or bleed.
Medical history
In the event of a suspicious change to your skin, the initial consultation will involve gathering information on your medical history. As part of this, we find out when you first noticed the skin change and whether it has changed in size, colour or shape since then. In addition, you will need information on whether there have already been skin cancer cases in your family. This can be followed by different types of examinations, depending on the assessment.
Skin examination
The skin all over the body is checked. Particular attention is paid to pigmented marks/moles, abnormalities of all kinds and suspicious changes in the skin. A special microscope, known as a dermatoscope or incident light microscope, is used for the examination.
Tissue sample
Depending on the case, it may be necessary to take a tissue sample (skin biopsy under local anaesthesia) for a diagnosis. Finally, the skin sample is examined in the laboratory. This makes it possible to determine whether it is really skin cancer or a precursor to cancer. If the areas of altered skin are small, they can be completely cut out and sent to the laboratory for analysis. In the case of melanoma, additional tests may be necessary, depending on the tumour thickness. These include ultrasound examinations, PET/CT and sentinel lymph node biopsy.
Imaging techniques
If the laboratory confirms the suspicion of skin cancer, further tests are carried out. These include imaging techniques such as ultrasound, X-rays, computed tomography and magnetic resonance imaging. These methods help to determine the exact location and extent of the cancer, as well as to determine its severity.
Treatment
Different therapies are available to treat skin cancer, including cold therapy, surgery, chemotherapy and radiotherapy. The different forms of therapy can also be combined with each other and adapted to the patient’s particular cancer. Decisive factors in the choice of treatment include the location of the cancer, its form and extent, and factors such as the patient’s age and general state of health.
Skin cancer removal is usually carried out on an outpatient basis. In the case of basal cell and squamous cell carcinomas, this is usually enough to eliminate the cancer. Treatment success depends on the stage and extent of the illness. For melanomas below 1 mm, the probability of treatment success is between 94 and 98 %. Regardless of whether the skin cancer being treated is melanoma or non-melanoma, check-ups are necessary for all patients.
Prevention
Skin tumours can best be prevented by protecting the skin from too much UV radiation. People with a large number of moles should have them checked regularly, ideally annually, by a dermatologist. The most important recommendations for preventing skin cancer are:
- Avoid sunburn
- Stay in the shade if possible between 11 am and 3 pm
- Wear a hat, sunglasses and clothing to protect yourself in strong sunlight
- Apply sunscreen with a sufficiently high sun protection factor
- Do not use sunbeds
These recommendations should be followed by people of all ages, especially if there is an increased risk of skin cancer, such as if they have fair skin or have already had cases of skin cancer in the family. Very many (more than 100) pigmented marks/moles on the body, previous skin cancer or immunodeficiency can also lead to an increased risk of skin cancer. In all these cases it is a good idea to have regular examinations with a dermatologist, so that it is detected early if it does occur.
FAQ
What are the most common types of skin cancer?
Non-melanoma skin cancer, which includes basal cell carcinoma and squamous cell carcinoma, is the most common type of skin cancer. Melanoma skin cancer, also known simply as melanoma, is less common but more malignant.
What symptoms could indicate skin cancer?
Typical symptoms are skin changes. These include, for example, noticeable moles that are new or changing, changes in the colour or shape of moles, and areas that are not healing or bleeding. In malignant melanoma, these symptoms can appear early. It is therefore extremely important to have them examined by a dermatologist to prevent skin cancer from developing.
How can skin cancer be detected in its early stages?
Skin cancer can be detected at an early stage if you check your skin yourself regularly and are then examined by a doctor. Noticeable changes should always be investigated by a dermatologist at an early stage in order to increase the chances of successful treatment.
Is an increased risk of skin cancer hereditary?
Yes, a higher risk of developing skin cancer can run in families. Predisposition plays a role in melanoma in particular. However, most cases are caused mainly by UV radiation, sunlight and frequent sunburn.
Is skin cancer curable?
Skin cancer is often curable if discovered early. The treatment options range from various therapies to surgery, depending on the tumour. Patients who are diagnosed early usually have a very good chance of recovery.
Centres 2
-
Tumor centre Bern
Monbijoustrasse 10
3011 Bern
