What is non-melanoma skin cancer
Skin cancer is a disease caused by the abnormal and uncontrolled growth of the cells that make up the skin. They are arranged in layers, and according to which area is affected, the type of cancer is defined, which can be melanoma or non-melanoma (basal cell and squamous cell carcinomas). Among all types of malignant tumors registered in Brazil, non-melanoma skin cancer is the most frequent: it corresponds to about 30% of cases.
In the universe of neoplasms that affect the skin, it recorded the highest incidence in the country: for 2020, the INCA (Brazilian National Cancer Institute) estimated 176,930 new cases of non-melanoma skin cancer, compared to 185,380 total cases of skin cancer (about 95.5%). It is important to note, however, that skin cancer is known to be underreported, which means that the actual number of cases tend to be much higher.
Worldwide, non-melanoma skin cancer is the fifth most common cancer in men and women, with more than 1 million diagnoses per year.
It is more common after the age of 40 and rare in children and darker-skinned individuals – with the exception of those who already have other skin diseases. People with fair skin, sensitive to the action of sunlight or with previous skin diseases are the most affected.
Its most frequent cause is prolonged and repeated exposure to the sun’s ultraviolet rays, especially in childhood and adolescence. Sun damage is persistent and cumulative over a lifetime.
Types of non-melanoma skin cancer
There are two types of non-melanoma skin cancer:
- Basal Cell Carcinoma (BCC) – is the most prevalent among all types of skin cancer. It arises in the basal cells, which are in the deepest layer of the epidermis (the top layer of the skin). It is more common in regions that are often exposed to the sun without protection, such as the face, ears, neck, scalp, shoulders and back, and more rarely can develop in unexposed areas. Its most common type is nodular-ulcerative BCC – a red, shiny papule with a central crust that can bleed easily; and
- Squamous cell carcinoma (SCC) – is the second most prevalent among all types of cancer. It arises in the squamous cells, which make up most of the upper layers of the skin. It can manifest in all parts of the body, being more common in areas frequently exposed to the sun without protection, such as the face, ears, neck, scalp, shoulders and back. It is twice as common in men as in women. In addition to exposure to the sun’s ultraviolet rays, SCC can be associated with chronic wounds, skin scarring, use of immunosuppressive anti-rejection drugs for transplanted organs, and exposure to certain chemical agents or radiation. SCCs are usually reddish in color and present as thick, scaly sores or sores that do not heal and occasionally bleed, which may look like a wart.
Symptoms and signs of non-melanoma skin cancer
The main symptom of non-melanoma skin cancer is the appearance of spots or lesions on the skin with very striking characteristics, such as:
Skin patches that itch, burn, peel or bleed and
Wounds that do not heal within four weeks
When noticing these skin changes, it is important to check with a doctor. Your trusted doctor, your clinician, your gynecologist will be essential for this evaluation. A dermatologist should also be consulted for this assessment.
Diagnosis of non-melanoma skin cancer
The first step in diagnosing non-melanoma skin cancer is a clinical examination by a physician, preferably a dermatologist.
After detecting the possibility that a nodule, a spot or a wound could be a carcinoma, dermoscopy is performed, an exam exclusively performed by the dermatologist in which a device allows the visualization of some layers of the skin that are not seen with the naked eye. Usually, it needs to be complemented with histopathological inspection, which is the evaluation of the abnormality, partially or completely removed by biopsy. It is at this moment that the diagnosis is confirmed and the type of treatment is indicated.
In some cases, dermoscopy can spare patients from biopsy, an invasive procedure that leaves a surgical scar on the skin.
The most indicated standard treatment for non-melanoma skin cancer, whether basal cell or squamous cell, is surgery, which allows histopathological control of the lesion. The earlier the suspicion and diagnosis, the greater the chance of cure.
Micrographic surgery is a method that can be useful in some situations, as it allows greater control of the resected tumor margins, which allows a greater chance of cure. In some cases, radiotherapy may be associated with surgery.
Once non-melanoma skin cancer is diagnosed, the dermatologist may consider different treatment options, which will be discussed and designed according to the needs of each patient.
Photodynamic therapy (use of a photosensitive cream on the tumor, with subsequent application of a light source for the selective destruction of neoplastic cells) is an option for actinic keratosis (a precursor lesion of non-melanoma skin cancer), for the superficial basal cell carcinoma and for squamous cell carcinoma “in situ” (also called Bowen’s disease). Other options for these types of cancer are cryosurgery with liquid nitrogen, chemotherapy and topical immunotherapy.
Different methods have been shown to be effective, but the recommendation of an experienced dermatologist is necessary in order to avoid recurrence.
Since the greatest risk factor for the emergence of non-melanoma skin cancer is exposure to the sun’s ultraviolet rays, the best form of prevention is to avoid unprotected skin exposure from 10 am to 4 pm, when its incidence is most intense.
Even before and after these times, it is recommended to protect the skin with shade (natural or with an umbrella or tent), clothes, caps and hats, sunglasses with UV protection on the lenses. On the skin, a filter or sunscreen with an SPF of at least 30 should be applied. Lips require specific products for their protection as it is a more delicate area.