How Serious Is Basal Cell Skin Cancer?

A blue-black area on the skin may be a sign of basal cell skin cancer.

Basal cell carcinoma (BCC) is the most common type of skin cancer. It originates in the basal cells, which are cells found in the lower layer of the skin that are responsible for producing new skin as the old skin layers die off.

Basal cell carcinoma typically occurs on areas of the skin exposed to the sun, such as the face, around the eyes, ears, head and scalp, and neck. In rare cases, basal cell cancer may occur on the hands.

Characteristics of the tumors may include the following:

• A pearly white bump
• Translucent appearance
• Spider veins (telangiectases) visible on the surface
• Waxy skin growths with raised border and depression in the center
• Flat, scaly patches
• They may bleed, especially if injured.
• Oozing or crusting
• Ulcerations of the bumps
• Slow growing: 0.5 cm in 1-2 years
• Black-blue or brown areas

Environmental and genetic factors may predispose certain patients to develop basal cell carcinoma.

The main risk factor for developing basal cell carcinoma is exposure to ultraviolet (UV) rays from the sun or from tanning beds. Other risk factors for BCC include the following:

• Therapeutic exposure to psoralen plus ultraviolet A light (PUVA) for skin conditions such as psoriasis
• Drugs that cause photosensitivity (sensitivity of skin to sunlight), such as tetracycline antibiotics or thiazide diuretics
• Dietary factors, such as high intake (more than twice weekly) of citrus products that contain compounds called furocoumarins that are considered photocarcinogenic agents
• Chronic arsenic exposure
• Therapeutic ionizing radiation, such as that used to treat facial acne, psoriasis, or tinea capitis
• Having light skin, light hair, and light eye color, with poor tanning ability
• Personal history of basal cell carcinoma
• Certain genetic disorders
• Inherited disorders
• Nevoid basal cell carcinoma syndrome (Gorlin syndrome)
• Xeroderma pigmentosum
• Bazex-Dupré-Christol syndrome
• Oculocutaneous albinism
• Chronic immunosuppression (organ transplant recipients and patients who have human HIV)
• Smoking

A doctor will get a medical history and perform a physical examination and then perform a skin biopsy to confirm the diagnoses of basal cell carcinoma. There are two types of skin biopsies that may be indicated:

• Shave biopsy: A small tool resembling a razor scrapes off a small area of the skin. This may be all that is needed.
• Punch biopsy: A circular tool punches through the deeper layers of skin.

Imaging studies are usually unnecessary, but if the cancer is suspected to have spread to deeper structures such as bone, then your doctor may use computed tomography (CT) scans or X-ray.

For most cases of basal cell carcinoma, surgery is the recommended treatment. The following are recommended surgical techniques for BCC:

• Electrodesiccation and curettage
• Excisional surgery
• Mohs micrographically controlled surgery
• Cryosurgery

The following treatment options may also treat basal cell carcinoma:

• Radiation therapy
• Photodynamic therapy (PDT)
• Topical medications that treat superficial basal cell carcinomas:
  • Topical 5-fluorouracil 5% (5-FU, Carac, Efudex, Fluoroplex)
  • Imiquimod (Aldara)
  • Tazarotene (Tazorac)
• Oral medications:
  • Vismodegib (Erivedge)
  • Sonidegib (Odomzo)

Complications of basal cell carcinoma may include

• recurrence,
• increase risk of other types of skin cancer, such as squamous cell carcinoma, and
• metastasis (spread of the cancer beyond the skin) (rare).

Basal cell carcinomas rarely spread (metastasize) so they are not typically staged. If the tumor is large and it is suspected of spreading to other parts of the body, then staging may be used.

Staging for basal cell carcinomas is similar to the staging for another type of skin cancer called squamous cell carcinoma (SCC):

• Stage 0: Cancer involves only the epidermis (outermost layer of skin) and has not spread to the dermis (middle layer of skin).
• Stage I: Cancer is not large (for example, less than 2 cm) and has not spread to the lymph nodes or other organs.
• Stage II: Cancer is large (for example, greater than 2 cm) but has not spread to lymph nodes or other organs.
• Stage III: Cancer has spread to tissues beneath the skin such as muscle, bone, or cartilage, and/or to regional lymph nodes but not to other organs.
• Stage IV: Cancer can be any size and has spread to other organs.

The prognosis for patients with basal cell carcinoma is very good, and the 5-year recurrence rate is about 5%. The cancer rarely spreads (metastasizes) so patients can generally expect a normal life expectancy if doctors treat their cancer promptly.

Advanced basal cell carcinoma is rare, however, if the cancer is allowed to progress, it can cause significant illness.

The best way to prevent basal cell carcinoma and other skin cancers is to protect the skin from the sun.

• Wear sunscreen with an SPF of at least 30. Apply sunscreen at least 30 minutes prior to sun exposure, and reapply every 2 hours or more frequently if swimming or sweating.
• Wear protective clothing and a wide-brimmed hat.
• Avoid the midday sun, between the hours of 10 a.m. to 4 p.m., when the sun's rays are the strongest.
• Avoid tanning beds.
• Examine your skin regularly for new moles, spots, bumps, or growths, and inform your doctor of any skin changes.

In patients who are at higher risk for recurrence of basal cell carcinoma, certain medications may be used, however, studies on the effectiveness of these medications have had mixed results.

• Celecoxib (Celebrex), a type of nonsteroidal anti-inflammatory drug (NSAID), may offer modest risk reduction, but studies on its effectiveness for preventing tumors are mixed.
• Oral nicotinamide (vitamin B3) is a vitamin supplement available over the counter. Additional studies are needed to determine its effectiveness in preventing skin cancers. Consult your doctor before taking any supplements because of possible side effects or drug interactions.
• Topical fluorouracil (5-FU, Carac, Efudex, Fluoroplex) has been shown to help prevent other skin conditions and precursors to basal cell carcinoma, however, the data are mixed on whether it may help prevent BCC.