Definition

Basal cell carcinoma is a type of skin cancer originating from basal cells, which are located in the lower part of the epidermis and are responsible for producing new skin cells to replace those that die. It is the most common form of skin cancer, with the incidence of this cancer type increasing each year.

Causes

Basal cell carcinoma occurs when mutations or structural changes in the genetic material of basal cells happen. These cells are situated in the basal layer of the epidermis and are responsible for cellular regeneration. Normally, as new cells form, they push older cells to the surface, where the latter die and shed off. Genetic mutations can disrupt this process, causing basal cells to proliferate uncontrollably and form malignant tumors visible on the skin.

The mutations leading to basal cell carcinoma are often attributed to ultraviolet (UV) radiation, particularly UVB rays from the sun or tanning lamps. However, not all individuals with basal cell carcinoma have a history of excessive sun exposure, making the precise cause of the disease uncertain.

Risk factor

Factors increasing the risk of basal cell carcinoma include:

• Prolonged Sun Exposure: Extended exposure to sunlight or tanning lamps elevates the risk, particularly in sunny or high-altitude areas where UV exposure is greater. Sunburn also raises the risk.
• Radiation Therapy: Previous radiation treatment for acne or other skin conditions can heighten the risk of basal cell carcinoma in the irradiated areas.
• Fair Skin: Individuals with freckles, light skin, red or blonde hair, or light-colored eyes are at higher risk.
• Age: The disease typically develops over many decades, making it more common in older adults, though it can occur in younger individuals in their 20s and 30s.
• Personal or Family History of Skin Cancer: Those with a history of basal cell carcinoma or a family history of skin cancer have a higher risk of recurrence.
• Immunosuppressive Medications: Medications that suppress immune function, such as those used in organ transplants or autoimmune diseases, can increase risk.
• Arsenic Exposure: Arsenic, a toxic metal found in the environment, is linked to a higher risk of basal cell carcinoma, especially with high levels in well water or occupational exposure.
• Genetic Syndromes: Certain genetic disorders, such as Gorlin-Goltz syndrome and xeroderma pigmentosum, increase the risk.

Symptoms

Basal cell carcinoma typically appears on sun-exposed skin, especially on the face and neck. Common signs include:

• Shiny, Pearl-like Nodules: These may be flesh-coloured or reddish and can be translucent with visible blood vessels. On darker skin, they may appear as shiny brown or black nodules.
• Brown, Black, or Blue Ulcers: These may have dark edges and a raised border.
• Flat, Scaly Plaques: These may enlarge over time.
• Scar-like Appearance: White, waxy, and poorly defined patches resembling scars.

Diagnosis

Diagnosis is confirmed through a skin biopsy, where a sample of skin is examined under a microscope to identify cancerous cells. Imaging tests, such as Magnetic Resonance Imaging (MRI), may be used to assess the spread of the cancer to surrounding tissues or organs.

Management

Treatment for basal cell carcinoma depends on the patient's age, sex, and the location, size, and type of the lesion. Methods include:

• Surgery: The primary treatment method is to remove the tumor entirely.
• Medications or Chemotherapy: Used when surgery is not feasible.
• Radiation Therapy: An alternative when surgery is not an option, though it is costlier and may have less favorable cosmetic outcomes.
• Cryotherapy: Freezing the cancerous tissue to destroy it.

Complications

While basal cell carcinoma is less likely to metastasize compared to other cancers, complications may include:

• Recurrence: The cancer often returns even after successful treatment.
• Increased Risk of Other Skin Cancers: Prior basal cell carcinoma raises the risk of developing other skin cancers, such as squamous cell carcinoma.
• Metastasis: Rarely, the cancer may spread to other organs, including lymph nodes, bones, and lungs.

Prevention

Preventive measures include:

• Avoiding Sun Exposure: Especially between 10 a.m. and 4 p.m., or scheduling outdoor activities during cloudy or winter months.
• Using Sunscreen: Apply sunscreen with SPF 30 or higher, reapplying every two hours or more frequently if swimming or sweating.
• Wearing Protective Clothing: Use long-sleeved clothing, and wide-brimmed hats, and avoid tanning beds.
• Regular Skin Checks: Monitor skin for changes and consult a doctor for any suspicious growths or non-healing sores.

When to see a doctor?

Consult a doctor if you notice changes in your skin, such as new growths, changes in existing skin lesions, or non-healing sores.

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