Basal cell carcinoma

Dr Nirasha Chiranjan, a radiation oncologist, unpacks the causes and warnings signs of basal cell carcinoma and the treatment and prevention thereof.

With summer upon us, it’s important to remember that overexposure to the sun may have harmful side effects, including increasing your risk of skin cancer.

Skin cancer is one of the most common cancers worldwide. Basal cell carcinoma (BCC) is a type of skin cancer that is locally invasive and causes destruction of the skin and underling bone. It has a low metastatic potential compared to the other types of skin cancers. 

The incidence of basal cell carcinoma increases with age and is more common in men. The majority of basal cell carcinomas occur on the face and trunk. 

On histopathology, basal cell carcinomas are divided into three groups: nodular, superficial and morpheaform. 

Risk factors

1. UV radiation 

• Sun exposure — Exposure to UV radiation from sunlight is the most important environmental cause of BCC, and most risk factors relate directly to a person’s sun exposure habits or susceptibility to solar radiation. These risk factors include having fair skin, light-coloured eyes, red hair, northern European ancestry, older age, childhood freckling, and an increased number of past sunburns. Childhood sun exposure appears to be more important than exposure during adult life. 
• Tanning beds — The use of tanning beds may increase the risk for early development of BCC.

2. Inherited disorders 

• Inherited disorders that are associated with a greatly increased risk of developing BCC at an early age are Gorlin syndrome, Rombo syndrome, xeroderma pigmentosum and oculocutaneous albinism.

3. Immunosuppression 

• Chronic immunosuppression, as occurs with solid organ transplantation and with HIV infection may increase risk for the development of BCC.

4. Lifestyle factors – Smoking

Warning signs 

Check for basal cell carcinomas where your skin is most exposed to the sun like the face, neck, scalp and chest. BCC can present as a:

• Non-healing sore which bleeds on contact 
• Red irritated patch of skin
• Nodule
• Scar-like area 
• Small pink growth 

Diagnosis

The diagnosis of basal cell carcinoma is made on clinical examination and biopsy. 

Treatment

Treatment options include:

• Surgical excision
• Mohs micrographic surgery
• Curettage and electrodesiccation
• Radiation therapy
• Topical agents
• Photodynamic therapy
• Cryotherapy

Tumour characteristics, such as size, location, and pathology, as well as treatment tolerability, cost, and patient preference influence the selection of treatment. The prognosis for most patients with primary, low-risk BCC is excellent. 

Prevention

The primary approach to the prevention of basal cell carcinoma is protection from sun exposure. The various techniques to minimise solar exposure are use of a broad-spectrum sunscreen SPF 30 or higher, sun-protective clothing including hats and sunglasses, staying in the shade and avoidance of outdoor activities when the sun is strongest (9am-3pm). 

Take home message

Basal cell carcinomas grow slowly, most are curable and cause minimal damage when caught and treated early. Understanding BCC causes, risk factors and warning signs can help you detect them early, when theyare easiest to treat and cure.

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