Basal Cell Carcinoma

Cancer to most people is an ominous entity.  It is indeed a threatening condition. A reason to fear is that medical science is yet to decipher codes of its cause and prevention. There are plenty of researches still going on in the field of cancer. Today’s article is about one such cancer of the skin – Basal Cell Carcinoma or Basal Cell Cancer (BCC).

Basal cell carcinoma was first described by Sir Arthur Jacob, an Irish ophthalmologist in the year 1827.  Since its description, it accounts for more than two-third skin cancers amongst the European and American communities and there is clear indication that this number is gradually rising. It commonly affects men and women after the fourth decade; but recent trends show that the younger community of men and women are not sufficiently protected. Stats indicate that about 1 million new cases are diagnosed every year in the US; and the US is not the country with the highest incidence of basal cell carcinoma. Today, records show that incidence rates of basal cell carcinoma are highest in Australia when compared to the rest of the world.

Understanding its cause:
There is a definite association between UV light exposure and basal cell carcinoma. Therefore, UV light exposure is generally accepted as a major cause of basal cell carcinoma. However, the association between light and BCC is complex.

UV light exposure factors that play different and important roles in determining the chances of basal cell carcinoma are:

• Timing of exposure
• Pattern of exposure
• Duration of exposure
• Amount of exposure
• Increased recreational exposure to the sun’s UV light since childhood seems to carry an additional risk.

Physical factors considered as independent risk components are:

• Fair complexion
• Red blonde hair
• Light eye color
• Easy freckles

Environmental factors linked to basal cell carcinoma are:

• Exposure to arsenic
• Ionizing radiation
• Ultraviolet A radiation
• Psoralen taken orally

Immunity has some amount of protective function. A definite relationship between immune-compromised state and basal cell carcinoma is seen.

Medical conditions which may increase the risk of BCC are:

• Previous scars
• Burn sites
• Draining sinuses
• Old ulcers
• Moles

Skin disorders which may increase the risk of BCC are:

• Albinism
• Xeroderma pigmentosa
• Darier's disease and other skin related syndromes

A family history of BCC also carries independent risks of BCC.

Presentation:
BCC doesn’t have a definite presentation. Classically it was described as a rodent ulcer in view of its close association to non-healing and bleeding ulcer. It can otherwise also present initially as a sore, a mole, a scar or a lump with dilated blood vessel around the border (telangiectasia).  When left unattended the skin lesions can spread locally at a rate of 0.5 cm in 1-2 years.  Over the years, it causes significant disfigurement. The usual areas affected are sun exposed areas, the face (especially around eyes and nasal bridge) and limbs. However, the unexposed areas such as trunk and body are also not spared.

Histologically, the cancerous cells arise from the basal layer of the skin, also known as basal cells. The cancer tissues can invade and grow locally. However, metastasis to distant organs is exceedingly rare.

Diagnosis:
An experienced skin specialist might be able to identify basal cell carcinoma clinically, although a biopsy is always required to confirm BCC. The biopsy involves the physician taking a sample of skin from the suspected lesion / ulcer to study under a microscope. The nature of the cells, whether normal or malignant, is identified after histological stains are applied to the sample to reveal the diagnosis.

Treatment:
Basal cell carcinoma requires surgical treatment. Based on the size and the extent of the cancer, procedure can be done at the physician’s office, a clinic or in an operating theatre.

The different forms of surgery available are:

• Mohs micrographic surgery is a more widely used form of surgery where the cancer tissue is sequentially removed and studied under a microscope until their samples are clear.
• Excisional surgery is where the whole growth along with surrounding normal tissue is removed.
• Curettage and electrodesiccation is when heat is used to destroy surrounding normal tissue after the whole growth is excised using a curette.
• Cryosurgery is the freezing of the tissue until the malignant cells destruct.
• Laser - Carbon dioxide or erbium Yag laser is used to remove the cancer growth along with variable amounts of normal tissue.

Besides surgery, radiation, photodynamic therapy and topical medications are also used in practice to treat basal cell carcinoma. Further, oral medication called Vismodegib is a drug that has been recently approved in BCC treatment albeit it is used in limited circumstances when other treatments are not feasible.

The result of the treatment is based on how early the treatment is done.

Key points and prognosis:

• Basal cell carcinoma is the most common skin cancer prevalent among the mixed European race.
• It is described as a non melanoma skin cancer. However, lack of melanin has a definite risk to a variable extent.
• Sun and UV exposure also has a definite risk. Seeking shade, avoiding tanning and UV booths, regular use of sun screen have protective functions which can be used as preventive measures.
• It is a slow growing cancer which grows to almost 0.5cms in a year or two. However, when left unattended has the potential to locally invade and cause severe cosmetic disfigurement.
• Metastasis is extremely rare. Therefore, chances of life threatening complications are exceedingly low.
• Since early diagnosis and treatment has clear effects on the result of treatment, it is essential to see a doctor for all slow growing lumps, sores that bleed and non healing ulcers especially those involving the face, eyes and nose.