II. Types

  1. Basal Cell Carcinoma
  2. Actinic Keratoses (Squamous Cell Carcinoma precursor)
  3. Squamous Cell Carcinoma
    1. Represents 30% of Nonmelanoma Skin Cancer cases (related to cummulative UV light exposure)

III. Epidemiology

  1. Lifetime Risk >20% (>30% in white patients)

IV. Risk Factors: Both Basal Cell Carcinoma and Squamous Cell Carcinoma

  1. Very High Risk (10 fold or greater Relative Risk)
    1. Current immunosuppressive therapy after organ Transplantation (especially related to SCC)
    2. Personal history of skin cancer
    3. Melanoma in 2 or more first degree relatives
    4. Nevi numbering 100 or more, or 5 or more atypical or Dysplastic Nevi
      1. Basal Cell Skin Cancer risk increases 40% with >15 extremity nevi
        1. Nan (2019) J Am Acad Dermatol 80(4): 970-8 [PubMed]
    5. PUVA therapy for Psoriasis for more than 250 treatments
  2. Radiation exposure and other local skin damage
    1. Cummulative Sun Exposure
    2. Gamma radiation for Psoriasis or malignancy
    3. Ultraviolet Radiation exposure (esp. before age <14, esp. childhood Sunburns)
    4. Prior burn scars
    5. Tanning device use
      1. Increases SCC risk by 2.5 fold and BCC risk by 1.5 fold
      2. Risk increases with younger age of first tanning device exposure
  3. Genitourinary skin
    1. Human papilloma virus (HPV) infection
    2. Uncircumcised male
  4. Miscellaneous
    1. Tobacco Abuse
    2. Prior Nonmelanoma Skin Cancer

VI. Prognosis

  1. Metastasis risk
    1. Basal Cell Carcinoma does not metastasize
    2. Squamous Cell Carcinoma metastasizes in 3-4% of cases
      1. Recurrence or metastases occur in first 2 years in >70% of cases and first 5 years in 95% of cases
  2. Subsequent skin cancer risk (new skin cancer following previously treated skin cancer)
    1. Prior Nonmelanoma Skin Cancer increases risk of subsequent skin cancer by factor of 10 over general population
      1. Three year risk: 35%
      2. Five year risk: 40% after first diagnosis (82% after more than one diagnosis)
      3. Malignant Melanoma risk doubles after non-Melanoma skin cancer diagnosis
    2. Risk factors for subsequent skin cancer
      1. Male gender
      2. Age over 60 years
      3. Higher number of prior skin cancers
      4. Severe Actinic Keratosis involvement
      5. Tobacco Abuse
        1. Increases Squamous Cell Carcinoma risk by 2.0x for current smokers and 1.6x for prior smokers

VII. Prevention

  1. See Sun Exposure (lists general preventive measures)
  2. See Sunscreen
  3. See Self-skin examination
  4. Minimize significant Sun Exposure in age <24 years esp. with fair skin (and light eye color, red or blond hair, Freckles)
  5. Whole body skin examination
    1. USPTF: Not enough evidence
    2. ACS: Every 3 years for age 20 to 40 and every 1 year as of age 40 years
  6. Niacinamide 500 mg twice daily
    1. May be indicated in high risk patients with a history of Nonmelanoma Skin Cancer
    2. One fewer Nonmelanoma Skin Cancer lesion developed per year while on Niacinamide
    3. Chen (2014) Australas J Dermatol 55(3):169-75 +PMID:24635573 [PubMed]

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Related Studies

Ontology: Skin neoplasms malignant and unspecified (excl melanoma) (C0852525)

Concepts Neoplastic Process (T191)
Italian Tumori della cute, maligni e non specificati (melanoma escluso)
Japanese 悪性および詳細不明の皮膚新生物(黒色腫を除く), アクセイオヨビショウサイフメイノヒフシンセイブツコクショクシュヲノゾク
Czech Kožní novotvary maligní a blíže neurčené (kromě melanomu)
Hungarian Bőr neoplasmák, rosszindulatú és nem meghatározott (kizárva: melanoma)
English Skin neoplasms malignant and unspecified (excl melanoma), Skin neoplasms malignant and unspecified (excluding melanoma)
Portuguese Neoplasias malignas cutâneas e não especificadas (excl.melanoma)
Spanish Neoplasias de la piel malignas y no especificadas (excl melanoma)
Dutch huidneoplasmata maligne en niet-gespecificeerd (excl. melanoom)
French Tumeurs malignes et non précisées de la peau (excl mélanomes)
German Neubildungen der Haut boesartig und unspezifisch (ausschl. Melanome)