The skin is made up of the dermis and the epidermis that covers it. The latter is made up of two cell types: melanocytes and keratinocytes.
Keratinocytes are present in the body in superimposed layers, forming a barrier against external aggression. In particular, these cells ensure the renewal of the epidermis.
Melanocytes, located at the base of the epidermis, are responsible for melanin production.
Types of carcinoma
Skin cancers come in a variety of forms, which doctors distinguish between non-melanoma and melanoma skin cancers. Non-melanoma cancers - or white cancers - are common and generally less aggressive. They develop from keratinocyte cells and mainly include :
Basal cell carcinoma (BCC)
Basal cell carcinoma is the most common skin cancer. It forms in the basal layer - the deepest layer - of the epidermis. It develops slowly and is rarely fatal, but can cause significant damage by spreading to neighbouring tissues. Lesions, plaques, excrescences... basal cell carcinoma can take many forms.
Squamous cell carcinoma
The second most common form of skin cancer, squamous cell carcinoma results from rapid, abnormal proliferation of the squamous cells that make up the majority of the epidermis. It is more prone to spread and can be more aggressive than basal cell carcinoma, but usually remains localized if treated promptly. It usually appears as red patches or lesions.
Other rare types
Other less common forms of skin cancer include Merkel's carcinoma, Kaposi's sarcoma and cutaneous lymphoma. These types are rarer, but require a specialized approach to diagnosis and treatment.
Symptoms of carcinoma
Symptoms vary depending on the type of skin cancer but may include changes in the appearance of the skin, such as:
- A growth
- A change in an existing mole or the appearance of a new lesion
- An area of skin that itches, bleeds, scabs or has a sore that won't heal
It's important to monitor any changes in the skin.
Causes of carcinoma skin cancer
Exposure to ultraviolet (UV) rays - from the sun and artificial devices such as solariums - is the main cause of skin cancer. Prolonged exposure to solar radiation or sunburn can cause damage to the DNA of skin cells, leading to mutations and the development of cancer.
Risk factors for carcinoma skin cancer
Several factors can increase the risk of developing skin cancer, including:
- Age
- Excessive unprotected sun exposure
- Family or personal history of skin cancer
- The presence of numerous moles or atypical moles
- Phototype 1 (very pale skin, red hair)
Treating carcinoma ski cancer
Surgery is generally the most effective treatment, but varies according to the type, size and location of the tumour, and the patient's general condition. The most common treatments include:
- Curettage: superficial scraping of the tumour
- Surgery: removal of the cancer with a margin of healthy tissue to ensure complete elimination. Laser treatment is possible, but controversial: while it can destroy cancer, little is known about its impact on cells.
- Photodynamic therapy: Combination of a photosensitizing drug and intense red light for targeted destruction of cancer cells.
- Cryotherapy: Exposure of the tumor to intense freezing conditions, applying liquid nitrogen to kill cancer cells.
The risk of metastasis is very rare for carcinoma (one case in 10,000), and in this exceptional case chemotherapy or immunotherapy is possible.
Evolutions and possible complications
Most non-melanoma cancers progress slowly and are rarely fatal if treated early. However, they can spread locally, causing damage to surrounding tissues.
Preventing carcinoma
To reduce the risks, we recommend protecting the skin as much as possible from UV rays:
- Wear covering clothing/hats
- Avoid the sun during the hottest hours, or opt for shaded areas.
- Apply sunscreen with a minimum protection factor of 30. Note that sunscreen does not totally prevent the onset of carcinoma, and is no substitute for physical UV protection.
Regular self-examinations are also recommended to detect any changes. People with numerous moles can consult a dermatologist annually for a screening examination.
When should you contact the Doctor?
Unusual skin changes or beauty gains, wounds that don't heal, bleeding or itching justify medical consultation.
Care at Hôpital de La Tour
As a preventive measure, photo mapping can be carried out to monitor the evolution of moles. If carcinoma is suspected, the dermatologist performs a meticulous clinical examination of the suspected area. If necessary, a biopsy is performed to take a tissue sample for laboratory analysis. Further treatment will depend on the initial results, and may involve additional imaging tests (ultrasound, CT scan, MRI) to clarify the depth of the tumor. Hôpital de La Tour offers a multidisciplinary team specializing in the treatment of skin cancers.
FAQ on carcinoma
What are the main risk factors for skin cancer?
The main risk factors are excessive exposure to UV rays (natural or artificial), sunburn, fair skin, advanced age, family history and the presence of atypical moles.
What is the most common type of skin cancer?
Basal cell carcinoma is the most common type of skin cancer, accounting for 90% of all skin cancers. Because they develop slowly, they can be effectively treated.
How can I recognize the signs of skin cancer?
Signs to look out for include the appearance of a new spot or growth, a change in the appearance of an existing mole (size, shape, color, irregular edges, etc.), sores that won't heal, lesions that bleed or are painful, or a painful or itchy area. Any noticeable change in the appearance of the skin requires serious consideration.
Are sunburns dangerous?
Yes, repeated sunburn considerably increases the risk of developing skin cancer. It's best to avoid direct exposure to the sun during the hottest part of the day, or to wear protective clothing. In the event of direct exposure, use SPF 30 protection.
How can I check my skin?
It's advisable to carry out regular skin self-examinations, and to consult a dermatologist if any abnormalities are detected. To do this, methodically examine all areas of the body, paying particular attention to sun-exposed areas and moles. For the latter, use the ABCDE method developed by dermatologists:
A: Asymmetry. B: Edges (irregular). C: Color (inhomogeneous). D: Diameter (>6mm). E: Evolution
In the event of abnormality, it is important to consult a specialist for a thorough examination.