title: A risk scale for predicting extensive subclinical spread of nonmelanoma skin cancer.
abstract: BACKGROUND
  The clinical appearance of nonmelanoma skin cancer may represent only a portion of microscopic tumor invasion.
  
  
  OBJECTIVE
  To develop a scale based on high-risk characteristics for predicting the probability of extensive subclinical spread of nonmelanoma skin cancer.
  
  
  METHODS
  Retrospective analysis of 1095 Mohs micrographic surgical cases (MMS) yielded high-risk factors for extensive tumor spread, defined as requirement of greater-than-or-equal3 MMS layers. Predictive characteristics included: any BCC on the nose, morpheaform BCC on the cheek, neck tumors and recurrent BCC in men, location on the eyelid, temple, or ear helix, and size>10 mm. Multivariate logistic regression was applied to develop a risk index.
  
  
  RESULTS
  Tumor characteristics were assigned point values calculated from the respective odds of extension and categorized into six risk classes with probabilities of extensive subclinical spread ranging from 10% to 56%.
  
  
  CONCLUSIONS
  A risk scale simplifies and enhances prediction of extensive tumors. The associated probabilities can help to guide patient preparation and appropriate therapy.
authors.affiliation: Department of Dermatology, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: R Sonia
authors.initials: RS
authors.lastname: Batra
authors.forename: Larisa C
authors.initials: LC
authors.lastname: Kelley
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002280:Basal Cell Carcinoma / Q000453:epidemiology / Q000209:etiology / Q000556:secondary / Q000601:surgery; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000209:etiology / Q000556:secondary / Q000601:surgery; D005260:Female; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D015580:Mohs Surgery; D009362:Neoplasm Metastasis; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D012878:Skin Neoplasms / Q000453:epidemiology* / Q000209:etiology* / Q000473:pathology / Q000601:surgery