Basal Cell Carcinoma

Basal Cell Carcinoma is a topic covered in the 5-Minute Clinical Consult.

To view the entire topic, please or purchase a subscription.

Medicine Central™ is a quick-consult mobile and web resource that includes diagnosis, treatment, medications, and follow-up information on over 700 diseases and disorders, providing fast answers—anytime, anywhere. Explore these free sample topics:

Medicine Central

-- The first section of this topic is shown below --

Basics

Description

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

  • Rarely metastasizes but capable of local tissue destruction

Geriatric Considerations
Greater frequency in geriatric patients (Ages 55 to 75 years have 100 times the incidence when compared with those aged <20 years.)

Pediatric Considerations
  • Rare in children, but childhood radiation treatment is contributory, as are frequent or severe sunburns.
  • The Centers for Disease Control and Prevention recommends against using tanning beds and lamps in their guidelines for cancer prevention in school-age children.

Epidemiology

Worldwide, the most common form of cancer


Incidence
  • Incidence in the United States: 1.2 million cases each year; 4 to 5 times more common than squamous cell carcinoma; Australia has highest incidence in the world.
  • White people have a 1 in 5 chance of developing BCC during their lifetime.
  • Predominant age: generally >40 years, although incidence increasing in younger populations
  • Predominant sex: male > female (2:1 ratio)

Etiology and Pathophysiology

  • UV-induced inflammation and cyclooxygenase activation in skin
  • In chromosome 9q22, mutation of PTCH1 (patched homolog 1), a tumor-suppressor gene that inhibits the hedgehog signaling pathway
  • UV-induced mutations of the TP53 (tumor protein 53), a tumor-suppressor gene
  • Activation of BCL2, an antiapoptosis proto-oncogene

Genetics
  • Several genetic conditions increase the risk of developing BCC:
    • Albinism (recessive alleles)
    • Xeroderma pigmentosum (autosomal recessive)
    • Bazex 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); most common 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
  • History of nonmelanoma skin cancer
    • After initial diagnosis of skin cancer, 35% risk of new nonmelanoma skin cancer at 3 years and 50% at 5 years
  • Family history of skin cancer
  • 3 to 4 decades after chronic arsenic exposure
  • 2 decades after therapeutic radiation
  • Chronic immunosuppression: transplant recipients (10 times higher incidence), patients with HIV, or lymphomas
  • No significant association between age and recurrence rate, according to most studies

General Prevention

  • Use broad-spectrum sunscreens of at least SPF 30 daily and reapply after swimming or sweating.
  • Avoid overexposure to the sun by seeking shade between 10 AM and 4 PM and wearing wide-brimmed hats and long-sleeved shirts.
  • The American Cancer Society recommends cancer-related checkups every 3 years in patients 20 to 40 years old and yearly in patients >40 years.

Commonly Associated Conditions

  • Cosmetic disfigurement because 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.

-- To view the remaining sections of this topic, please or purchase a subscription --

Citation

* When formatting your citation, note that all book, journal, and database titles should be italicized* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Basal Cell Carcinoma ID - 116072 ED - Baldor,Robert A, ED - Domino,Frank J, ED - Golding,Jeremy, ED - Stephens,Mark B, BT - 5-Minute Clinical Consult, Updating UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/116072/all/Basal_Cell_Carcinoma PB - Wolters Kluwer ET - 27 DB - Medicine Central DP - Unbound Medicine ER -