An Overview of Basal Cell Carcinoma Skin Cancer

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Basal cell carcinoma (BCC) accounts for about 80% of all cases of skin cancer worldwide. Skin damage from UV light exposure from sunlight or tanning salons is the leading cause.

BCC can produce a characteristic appearance of lesions on the skin, but a biopsy is the most definitive way to verify the diagnosis. While it is not a common complication, this type of cancer can metastasize, (spread to other regions of the body) potentially causing serious health problems.

Surgical removal of the cancer is usually recommended, and other treatments may include chemotherapy if cancer spreads. Prevention is important when it comes to skin cancer, including BCC. Moderation in sun exposure, protective clothing, and sunscreen are among the most effective strategies for prevention.

Symptoms

Over one million people are diagnosed with BCC each year in the United States. While this type of cancer typically begins during middle-age or older, it can also affect young adults. In fact, experts warn that BCC is affecting people at younger and younger ages.

If you develop this type of lesion, it can appear suddenly on your skin. These cancers may start at a size of 1 cm and continue to grow in size after they initially appear, becoming more noticeable with time.

A basal cell lesion is often described as a pearly papule. It has a slight shine, which is why it is described as pearly. Papules are elevated (sometimes very slightly) above the surface of the skin. The lesions are generally the same color or slightly lighter than the surrounding skin.

Some different features may develop, including:

  • Telangiectasias, which are small dilated blood vessels, can form in areas affected by BCC. These lesions appear pink, red, or purplish.
  • The cancerous areas on the skin can appear dark or brownish, due to the presence of dead cells.
  • You may experience a sensation of itchiness around the lesion
  • The lesion can appear as a persistent non-healing wound

The lesions of BCC usually appear on areas of the body that have been exposed to sunlight, especially high levels of sunlight. For example, it can appear on the face, ears, arms, leg, back, or abdomen.

Causes

Excessive exposure to ultraviolet light from the sun or in tanning salons is believed to be at the root of 80% of BCC cases. People living in states closer to the equator (such as Florida) or with a history of sunburns during childhood are more prone to developing BCC, especially at a younger age. It can take 10 to 20 years after the causative UV light exposure for the condition to develop.

However, other types of skin cancer, such as squamous cell carcinoma are more closely correlated with UV light exposure and sunburns than BCC is.

While not common, BCC can also occur in areas that aren't exposed to UV at all, such as the scalp.

Risk Factors

Caucasians, especially those with blue eyes, a fair complexion, and red, blond, or light brown hair, have the highest risk of BCC.

African-Americans, Asians, and Hispanics can develop this type of cancer, but not commonly. Compared with Caucasians, African-Americans have a decreased risk of BCC on UV light-exposed skin areas, but the same incidence of BCC on the covered skin.

How BCC Develops

Like other types of cancer, BCC is caused by mutations, which are changes in the molecular structure of a cell's DNA. These changes result in cellular overgrowth, which causes the lesions to develop, grow, and potentially metastasize.

UV exposure can cause these mutations to occur. Several genetic mutations have been identified in association with BCC—including alterations in the PTCH1, SMO, PTPN14, LATS1, TERT, and DPH3-OXNAD1 genes.

Diagnosis

Your doctor may recognize your skin lesion as BCC. Based on their appearance, the lesions can be categorized into several different types of BCC.

Types of BCC

  • Nodular: About 60% of BCCs are nodular. They start out as flat, well-defined lesions, then often become small bumps, which eventually collapse in the middle, leaving a raised ring on the border. Most nodular BCCs are on the face and can be disfiguring if not treated promptly.
  • Pigmented: Pigmented BCCs are similar to the nodular type, but they can contain brown or black spots, which can give them an appearance that resembles certain types of melanoma.
  • Fibrosing or Sclerotic: These BCCs are usually found on the face and look similar to scars. They are usually firm, ill-defined at the border, flat or slightly depressed, yellowish in color, and the surface tends to be smooth and shiny.
  • Superficial: This type comprises about 15% of BCCs. They spread outward from a red, well-defined, scaly patch and are most commonly found on the trunk and limbs. They are easily confused with psoriasis or eczema.
  • Fibroepithelioma of Pinkus: This is a rare type of BCC. It tends to be a smooth, elevated, small nodule found on the back, extremities, groin, or sole of the foot. As those are not sun-exposed areas, this disease is probably not sun-related.

    Biopsy

    Regardless of the appearance of BCC, a biopsy is the only way to make a definitive diagnosis. A skin biopsy is a removal of skin tissue for examination under a microscope. There are several types of skin biopsies. The right procedure for you depends on a few factors, including whether the lesion is raised above your skin.

    • Shave biopsy: Using this type of biopsy, your doctor would take a sample of your tissue by using a thin surgical blade to shave off the top layers of skin. This is the most common method for diagnosing BCC.
    • Punch biopsy: This type of biopsy uses a round, small device that functions somewhat like a cookie-cutter. It is used to take a deeper skin sample.
    • Lymph node biopsy: If there is a concern that your cancer may have spread to a nearby lymph node, your doctor may take a sample of tissue from the lymph node for examination.

    Staging and Grading

    Tumor staging is a classification used to describe the size of a tumor and how much it has spread. The grading of a tumor describes how fast growing the cells are. Your physical examination and biopsy are both used for tumor staging and grading.

    Treatment

    Your treatment depends on the type, extent, and location of your lesion. Although BCC doesn't typically spread to distant organs (metastasize), the lesions can eventually cause disfigurement and should be removed as soon as possible. The treatment required to remove them is much simpler and less likely to cause significant scarring when they are small.

    Methods commonly used to treat BCC include:

    • Curettage and electrodesiccation: This procedure involves scraping the tumor and electrically burning it to remove the cancer cells.
    • Surgical excision (removal): Your whole lesion, and possibly metastasis, can be removed surgically.
    • Mohs surgery (micrographic surgery): This is a specialized procedure in which your doctor will remove the area that appears cancerous and send it for a microscopic evaluation to confirm whether all of the cancer has been removed. You may need to have a deeper area surgically removed until it is confirmed that the whole cancerous area has been resected.
    • Aldara (imiquimod) is a topical cream approved for treatment of BCC. It peels away the cancerous lesion.
    • Radiation therapy is an option for some tumors, especially if they are located in an area that is not optimal for surgery, such as the ear.

    If basal cell carcinoma is left untreated, the lesions can grow and may eventually ulcerate (break through the skin) or damage the surrounding tissue or bone. While it is rare—there are individuals who have lost an eye, nose, or ear due to untreated BCC.

    Lesions that have spread need to be treated with chemotherapy specific for BCC.

    A Word From Verywell

    Basal cell carcinoma is the most common — but also one of the most curable — of all cancers.

    However, even after effective treatment, a person with a history of BCC has about a 40% greater likelihood of developing a second BCC than someone with no history of the condition. You need to be especially vigilant about prevention if you have a history of BCC.

    Avoiding excessive sun or tanning bed exposure is an important part of preventing skin cancer. Wearing protective clothing and using sunscreen can help you enjoy the outdoor warm weather without excessive UV light exposure. This is important for children and adults.

    And regular skin self-exams can help you catch any lesions at an early stage before they grow or spread.

    Keep in mind that it isn't healthy to completely avoid the sun—not only is sunlight a source of vitamin D, a lack of sunlight is associated with seasonal affective disorder. Moderation is the key.

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