What is basal cell carcinoma?

Basal cell carcinoma is a light-coloured, white skin cancer that develops from the basal cell layer of the skin and the root sheaths of the hair follicles. Basal cell carcinoma is most common on the head and neck, but can also occur less frequently on the trunk, arms or legs. Basal cell carcinoma is the most common type of skin cancer, affecting more men than women on average.

While malignant melanoma also forms metastases in other organs, this is rarely the case with basal cell carcinoma. However, basal cell carcinoma can also grow into the surrounding tissue and attack bone or cartilage. The mortality rate of basal cell carcinoma is relatively low compared to that of black skin cancer.

How does basal cell carcinoma develop?

Basal cell carcinoma develops from a basal cell. These are cells in the top layer of the skin. UV radiation, for example, can cause changes in the basal cells and make them grow uncontrollably.

What are the risk factors for basal cell carcinoma?

Basal cell carcinoma is usually caused by years of intensive sun exposure, which is why people who are often exposed to UV radiation and who work outdoors a lot, for example, tend to develop basal cell carcinoma. Basal cell carcinoma is particularly common in areas that are exposed to a lot of sunlight, such as the nose, ears, lower lip, neck or hands.

In addition to UV radiation, basal cell carcinoma can also be due to a hereditary predisposition. People with a fair skin type are particularly affected by this. But it is also possible for a basal cell carcinoma to develop after the immune system has been suppressed with medication, for example after a transplant.

What are the symptoms of basal cell carcinoma?

Basal cell carcinoma can manifest itself as a skin-coloured to reddish nodular tumour. Typical symptoms are a bead-like border and the shimmering through of small blood vessels on the surface of the skin. If the basal cell carcinoma is already far advanced in its growth, ulcers can also develop, which become noticeable through wetness and/or minor bleeding.

How is basal cell carcinoma diagnosed?

If a basal cell carcinoma is suspected, the dermatologist will examine the corresponding skin area in detail under the so-called reflected-light microscope. With the help of oil and the polarising light of the reflected-light microscope, the skin can be examined more closely down to the deeper layers. This magnification usually enables the dermatologist to determine whether the skin change is benign or malignant.

The examination can also be carried out with a confocal laser microscope. In this case, the affected skin area is examined with the help of laser light in an appropriate wavelength. However, the patient only receives a confirmed diagnosis after the respective skin examination after the biopsy of the changed tissue. For this purpose, the tumour can either be removed completely and examined in the laboratory (excision biopsy) or a small tissue sample is taken and analysed (incision biopsy). If there is a suspicion that the basal cell carcinoma has already spread to deeper layers of the skin, for example to the bones, a computer tomography can also be carried out.

How is basal cell carcinoma treated?

The most important treatment methods for basal cell carcinoma are surgery, radiation therapy, local therapy or systemic therapy. Complete surgical removal of the basal cell carcinoma is the standard therapy. The tumour is cut out under local anaesthetic. If this is not completely successful the first time, an attempt is made to remove the remaining tumour tissue in a follow-up operation. This is to prevent the tumour from growing again in the same place.

If an operation is not possible because of the patient's general state of health or because of any other problems, alternative treatment methods can also be used, one of which is radiotherapy. Radiotherapy is also suitable, by the way, in the event that the tumour could not be completely removed during the first operation and a second surgical intervention is not an option for the patient.

In addition to radiotherapy, immunological treatment with imiquimod ointment is also possible. This type of treatment is mainly used for large, superficial basal cell carcinomas. The ointment with the active ingredient imiquimod activates the immune cells and also stimulates the production of messenger substances in the immune system. The application usually takes place several times a week for a total of six weeks and has an amazing success. More than 80 percent of patients do not develop basal cell carcinoma again after at least five years of treatment.

If the basal cell carcinoma is already far advanced, the so-called systemic therapy with hedgehog inhibitors is suitable. These are a series of antineoplastic drugs that inhibit cell growth and cell differentiation and are used specifically for tumour therapy.

What is the prognosis after basal cell carcinoma?

About one third of all patients develop basal cell carcinoma again even after it has been successfully treated. The risk of recurrence is significantly higher, especially with the non-surgical treatment methods, than with surgical removal. It is therefore recommended that patients attend the regular follow-up examinations by the dermatologist, but also check their skin independently for abnormalities. The period for follow-up examinations should be about every six months for patients who have had the tumour successfully and completely removed, while regular check-ups every three months are recommended for all others because of the higher risk of recurrence.

How can you prevent the reoccurrence of basal cell carcinoma?

Some patients may be advised to take a high intake of vitamin B3 (nicotinamide) to prevent basal cell carcinoma recurrence. Vitamin B3 counteracts UV cell damage and has an enhancing effect on the self-repair of DNA. Studies have shown that taking nicotinamide can reduce the risk of developing basal cell carcinoma by 20 percent. However, this effect only exists while taking the vitamin. If the vitamin is discontinued, the patient has a similar high risk of relapse. The same applies, by the way, if vitamin B3 is only prescribed in a low dose.