Basal Cell Carcinoma



Basal cell carcinoma (BCC) is the most common type of skin cancer, originating from the basal cell layer of the skin appendages.

  • Rarely metastasizes but is locally invasive and capable of local tissue destruction and disfigurement


Most common cancer in Europe, Australia, and the United States; the most common type of skin cancer


  • Over 2 million new cases each year in the United States; 2.5 times more common than squamous cell carcinoma (SCC)
  • Highest incidence in the world is in Australia.
  • White individuals have a 1 in 5 chance of developing BCC during their lifetime.
  • Most common skin cancer in Asian and Hispanic individuals; second most common skin cancer in African American/black individuals (1)
  • Predominant age: generally >60 years
  • Predominant sex: male > female (2:1 ratio)

Not well established

Etiology and Pathophysiology

UV radiation induces inflammation and cyclooxygenase activation in the skin.

Several genetic conditions increase the risk of developing BCC:

  • Albinism (recessive alleles)
  • Xeroderma pigmentosum (autosomal recessive)
  • Bazex-Dupré-Christol syndrome (rare, X-linked dominant)
  • Nevoid BCC syndrome/Gorlin syndrome (rare, autosomal dominant)
  • Cytochrome P450 CYP2D6 and glutathione S-transferase detoxifying enzyme gene mutations (especially in truncal BCC, marked by clusters of BCCs and a younger age of onset)
  • Mutations in the tumor suppressor gene patched, or activated mutations in smoothened, resulting in upregulation of hedgehog pathway signaling

Risk Factors

  • Chronic sun exposure (UV radiation); increased susceptibility in the following phenotypes:
    • Light complexion: skin type I (burns, but does not tan) and skin type II (usually burns, sometimes tans)
    • Red or blond hair
    • Blue or green eyes
  • Tendency to sunburn
  • Male sex, although increasing risk in women due to lifestyle changes, such as tanning beds
  • Previous history of nonmelanoma skin cancer
  • Family history of skin cancer
  • Chronic immunosuppression: transplant recipients (5 to 10 times higher incidence), patients with HIV (2 times higher incidence), or lymphomas
  • Arsenic exposure
  • Immunosuppression
  • UV radiation and/or use of tanning devices
  • Xeroderma pigmentosum

General Prevention

  • Use broad-spectrum sunscreens of at least SPF 30 daily at least 15 minutes before outdoor activity. Reapply every 2 hours, or immediately after swimming or sweating.
  • Avoid overexposure to the sun. Avoid tanning beds.
  • The USPSTF concludes the current evidence is insufficient to assess the balance of benefits and harms of visual skin examination by a clinician to screen for skin cancer in adults. The American Cancer Society recommends cancer-related checkups every 3 years in patients 20 to 39 years old and yearly in patients ≥40 years

Commonly Associated Conditions

  • Cosmetic disfigurement (head and neck most often affected)
  • Loss of vision with orbital involvement
  • Loss of nerve function due to perineural spread or extensive and deep invasion
  • Ulcerating neoplasms are prone to infections.

There's more to see -- the rest of this topic is available only to subscribers.