Basal cell carcinoma is the most common skin cancer in the United States and Australia. Incidence is also on the rise in the United Kingdom. The most significant causative factor that has been associated with basal cell carcinoma is excessive and long term exposure to ultraviolet light radiated by the sun.

Clinical symptoms of the cancer

More often than not, basal cell carcinoma is found in parts of the body that are more prone to sun exposure such as the face, ears, neck, scalp, shoulders, and back.

Basal cell carcinoma varies in appearance and lesions may present as an open sore, a growth with a raised border, a scar-like area, a reddish patch or a bump or nodule. People who are exposed to the sun are advised to look out for changes in the skin such as alterations in the appearance of a mole or freckle. A change in the size, color, texture and the presence of pain, itching or bleeding are all treated as suspicious.

Basal cell carcinoma is more common among individuals with fair skin, blue, green, or grey eyes and blonde or red hair. These individuals also have a 50% risk of getting another tumour in the five years following the first diagnosis of the cancer.

Other factors that may raise the risk of basal cell carcinoma include exposure to arsenic or radiation and the presence of scars, tattoos or burns. Once a person has developed a basal cell carcinoma, they are at an increased risk of developing the same cancer in other regions.

Diagnosis

Diagnosis is made based on the clinical appearance of a lesion and a biopsy. During biopsy, a tiny tissue sample is taken from the lesion after numbing the area with a local anesthetic agent. Shave biopsy is appropriate in the case of a raised lesion. For flat lesions, a punch biopsy may be performed if the lesion is large while the whole lesion may ne excised for examination if it is small.

The sample is then thinly sliced, fixed and stained with special dyes for microscopic viewing on a glass slide.

Low and high risk basal carcinoma

Basal cell cancers may be divided into low-and high-risk categories by determining certain prognostic factors that affect the outcome of the cancer. These factors include:

• Size of the tumor
• Location of the tumor
• The nature of the tumor's margins (whether they are clear cut or diffuse)
• Rate and pattern of tumor growth
• Whether tumors are recurrent
• Health status of immune system