II. Types
III. Risk Factors: Both Basal Cell Carcinoma and Squamous Cell Carcinoma
- Very High Risk (10 fold or greater Relative Risk)
- Current immunosuppressive therapy after organ transplantation (especially related to SCC)
- Personal history of skin cancer
- Melanoma in 2 or more first degree relatives
- Nevi numbering 100 or more, or 5 or more atypical or Dysplastic Nevi
- PUVA therapy for Psoriasis for more than 250 treatments
- Radiation exposure and other local skin damage
- Cummulative Sun Exposure
- Gamma radiation for Psoriasis or malignancy
- Ultraviolet Radiation exposure (esp. before age <14)
- Prior burn scars
- Tanning device use
- Increases SCC risk by 2.5 fold and BCC risk by 1.5 fold
- Risk increases with younger age of first tanning device exposure
- Genitourinary skin
- Human papilloma virus (HPV) infection
- Uncircumcised male
- Miscellaneous
- Tobacco Abuse
- Prior Nonmelanoma Skin Cancer
IV. Signs
- See Sun Damaged Skin
- See Basal Cell Carcinoma
- See Squamous Cell Carcinoma
- See Actinic Keratoses
V. Prognosis
- Metastasis risk
- Basal Cell Carcinoma does not metastasize
- Squamous Cell Carcinoma metastasizes in 3-4% of cases
- Recurrence or metastases occur in first 2 years in >70% of cases and first 5 years in 95% of cases
- Subsequent skin cancer risk (new skin cancer following previously treated skin cancer)
- Prior Nonmelanoma Skin Cancer increases risk of subsequent skin cancer by factor of 10 over general population
- Three year risk: 35%
- Five year risk: 50%
- Risk factors for subsequent skin cancer
- Male gender
- Age over 60 years
- Higher number of prior skin cancers
- Severe Actinic Keratosis involvement
- Tobacco Abuse
- Increases Squamous Cell Carcinoma risk by 2.0x for current smokers and 1.6x for prior smokers
- Prior Nonmelanoma Skin Cancer increases risk of subsequent skin cancer by factor of 10 over general population
VI. Prevention
- See Sun Exposure (lists general preventive measures)
- See Sunscreen
- See Self-skin examination
- Whole body skin examination
- USPTF: Not enough evidence
- ACS: Every 3 years for age 20 to 40 and every 1 year as of age 40 years
-
Niacinamide 500 mg twice daily
- May be indicated in high risk patients with a history of Nonmelanoma Skin Cancer
- One fewer Nonmelanoma Skin Cancer lesion developed per year while on Niacinamide
- Chen (2014) Australas J Dermatol 55(3):169-75 +PMID:24635573 [PubMed]
VII. References
- Tavelli in Noble (2001) Primary Care, p. 771-2
- Firnhaber (2012) Am Fam Physician 86(2): 161-8 [PubMed]
- Nguyen (2002) Curr Treat Options Oncol 3:193-203 [PubMed]
- Stulberg (2004) Am Fam Physician 70:1481-8 [PubMed]
