What is non-melanoma skin cancer
Skin cancer is a disease caused by the abnormal and uncontrolled growth of cells that make up the skin. They are arranged in layers, and depending on which layers are affected, the type of skin cancer is defined as either melanoma or non-melanoma (basal cell carcinoma and squamous cell carcinoma). Among all types of malignant tumors recorded in Brazil, non-melanoma skin cancer is the most frequent, accounting for about 30% of cases.
Skin Cancer: Incidence, Underreporting, and Risk Factors.
In the universe of neoplasms that affect the skin, it is the most incident in the country: for 2023-2025, the INCA (National Cancer Institute) estimated 483,000 new cases of non-melanoma skin cancer. It is important to note, however, that skin cancer is known to be underreported, which means that the actual numbers of cases are likely to be much higher.
In the world, non-melanoma skin cancer is the fifth most common in men and women, with over 1 million diagnoses per year. It is more common after the age of 40 and rare in children and individuals with dark skin – except for those already suffering from 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 ultraviolet rays from the sun, especially in childhood and adolescence. Solar damage is persistent and cumulative throughout life.
Subtypes 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 from basal cells, which are located in the deepest layer of the epidermis (the top layer of the skin). It is more common in areas frequently 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 the nodular-ulcerative BCC, a shiny, red papule with a central crust that can easily bleed; and
- Squamous cell carcinoma (SCC) – is the second most prevalent among all types of cancer. It arises from squamous cells, which make up the majority 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 ultraviolet rays from the sun, SCC can be associated with chronic wounds, scars on the skin, use of immunosuppressive drugs for organ transplant rejection, and exposure to certain chemicals or radiation.
SCCs (Squamous cell carcinomas) typically have a reddish color and present as thick, scaly sores or wounds that do not heal and occasionally bleed, resembling a wart.
Symptoms and signs of non-melanoma skin cancer
The main symptom of non-melanoma skin cancer is the appearance of marks or “lesions” on the skin with very distinctive characteristics:
- Spots on the skin that itch, burn, scale, or bleed; and
- Sores that do not heal within four weeks
When you notice these changes in your skin, it’s important to have a consultation with a doctor. Your trusted doctor, your clinician, your gynecologist will be essential for this evaluation. The dermatologist is an essential specialist at this time.
Diagnosis of non-melanoma skin cancer
The first step in diagnosing non-melanoma skin cancer is a clinical examination by a doctor, preferably a dermatologist.
If there is a possibility that a nodule, a spot, or a wound may be a carcinoma, dermatoscopy is performed. This examination is the exclusive competence of the dermatologist, in which a device allows the visualization of some layers of the skin not seen with the naked eye.
Usually, it needs to be complemented with histopathological examination, which is the evaluation of the abnormality, partially or totally removed by biopsy. This is where the diagnosis is confirmed and the best type of treatment is indicated.
In some cases, dermatoscopy can spare patients from biopsy, an invasive examination that leaves a surgical scar on the skin.
Treatment for non-melanoma skin cancer
- Surgery – 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 – This is a method that can be useful in some situations because it allows for greater control of the margins of the resected tumor, which increases the chance of cure. In some cases, radiation therapy can be associated with surgery. Once non-melanoma skin cancer is diagnosed, the dermatologist may consider different treatment options, which will be discussed and tailored to each patient.
- Photodynamic therapy – The use of a photosensitive cream on the tumor, followed by the 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), superficial basal cell carcinoma, and “in situ” squamous cell carcinoma (also known as Bowen’s disease).
Options for these types of cancer also include 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 to avoid recurrence.
Prevention of non-melanoma skin cancer
Since the greatest risk factor for non-melanoma skin cancer is exposure to ultraviolet rays from the sun, the best form of prevention is to avoid unprotected skin exposure from 10 a.m. to 4 p.m., when its intensity is highest.
Even before and after these hours, it is recommended to protect the skin with shade (natural or from umbrellas, parasols, and tents), clothing, hats, and sunglasses with UV protection lenses. On the skin, sunscreen with an SPF of at least 30 should be applied. Lips require specific products for protection since it is a more delicate area.
