DD 03-07-14 09-10am Skin Cancer slides - Dunnick Flashcards
Skin cancer - prevalence
= most common form of cancer in US
Each year…
- >3.5 million skin cancers Dxed in >2 million ppl
- More new cases of skin cancer than combined incidence of breast, prostate, lung & colon cancers
Common Skin Cancer Types
Basal cell
Squamous cell
Melanoma
Non-melanoma Skin Cancer - Risk Factors
- Fair skin + geographic areas w/ high UV exposure
- UV radiation is most common cause of BCC
- Ionizing radiation, arsenic or polycyclic hydrocarbon exposure
Basal Cell Carcinoma - prevalence, morbidity/mortality
= Most common malignancy in the US
- ~2.8 million are Dxed annually in US
- rarely fatal, but can be highly disfiguring if allowed to grow
Basal Cell Carcinoma - Subtypes & prevalence
Superficial (15%)
Nodular (75%)
- Micronodular
- Pigmented (6%)
Infiltrative (5%)
Sclerosing / Morpheaform / Desmoplastic (3%)
Superficial BCC
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Nodular BCC
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Desmoplastic/Sclerosing/Morpheaform BCC
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Pigmented BCC
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Hedgehog Alterations in BCC & Treatment
Most BCCs have loss of function of PTCH1
= normally acts to block smoothened (SMO), a transmembrane protein
Vismodegib
= inhibitor of smoothened
= approved in 2012 for treatment of advanced BCC
Actinic Keratosis (AK) - defn., prevalence, lead to…
= Intraepidermal neoplasia
= most common pre-cancer affecting >58 million Americans
- ~65% of all squamous cell carcinomas & ~36% of all basal cell carcinomas arise in lesions previously Dxed as AKs
Actinic Keratosis - Treatment
Cryosurgery
- Liquid nitrogen (boiling point of -196 C)
Topical…
- 5-fluoruracil
- Imiquimod
- Diclofenac
Photodynamic therapy
Sun protection
Squamous cell carcinoma - prevalence
- 2nd most common cutaneous malignancy
- More common in immunosuppressed, esp. organ transplant pts
Squamous cell carcinoma - Risk factors
- UV damage
- Thermal injury
- Radiation
- HPV
- Burn scars (Marjolin’s ulcer)
- Chronic injury (i.e. EB)
Squamous cell carcinoma - Subtypes
- SCC in situ (Bowen’s disease)
- Keratoacanthoma
- Invasive SCC
Keratoacanthoma - distribution, time of growth, appearance
= subtype of squamous cell carcinoma
Distribution- primarily sun-exposed skin
Rapid growth over 6-8 weeks
Size- 1-3 cm
Crateriform endophytic & exophytic nodule w/ central keratin plug
Keratoacanthoma - Complications
Deep invasion w/out regression in 10-20%
Squamous Cell Carcinoma - appearance & distribution
Hyperkeratotic papule w/ variable size & thickness
Typically found on chronically sun-damaged skin
Squamous Cell Carcinoma - complications
Metastasis occurs in 0.3-5%
= more common in SCC of the lip (10-30%)