Squamous Cell Carcinoma, Cutaneous
Cutaneous squamous cell cancer is the second most common nonmelanoma skin cancer after basal cell carcinoma (1).
Nonmelanoma skin cancer is the most common malignancy worldwide. Historically, squamous cell carcinoma (SCC) has been thought to account for 20% of nonmelanoma skin cancers, thus being the second most common malignancy after basal cell carcinoma (2),(3). However, recent data indicate that the ratio of basal cell carcinoma to SCC is 1.0 in the U.S. Medicare population (1). An accurate incidence of cutaneous SCC is not known since this is not required to be reported to national cancer registries.
Etiology and Pathophysiology
Some of the hereditary disorders have genes that are associated with cutaneous squamous cell cancer (5). They include:
- Most SCCs arise in:
- Sun-damaged skin of elderly white individuals of European ancestry
- Gender (more common in men)
- Increasing age (average age of onset is the mid-60s)
- Background of preexisting lesions of actinic keratosis (AK) (2)
- UV radiation exposure (5),(6)
- Preexisting conditions
- Immunosuppression (5)
- Chronic skin conditions (5)
- Burn scars, hidradenitis suppurativa, chronic osteomyelitis, discoid lupus erythematosus, lichen planus, lichen sclerosus et atrophicus
- Inherited genetic conditions (5)
- Albinism, epidermolysis bullosa, xeroderma pigmentosum
- Ionizing radiation exposure (6)
- Arsenic exposure (5),(6)
- Ulcers (6)
- Bowen disease (SCC in situ) (6)
- Erythroplasia of Queyrat (SCC in situ of penis) (6)
- HPV infection (6, 11, 16, 18) (6)
- Treatment with BRAF inhibitors (vemurafenib and dabrafenib) (7)
Commonly Associated Conditions
Actinic keratosis is the precursor of cutaneous squamous cell cancer, Bowen disease, erythroplasia of Queyrat (4).
There's more to see -- the rest of this topic is available only to subscribers.