title: Thickness of superficial basal cell carcinoma (sBCC) predicts imiquimod efficacy: a proposal for a thickness-based definition of sBCC.
abstract: BACKGROUND
  Basal cell carcinoma (BCC) is the most common malignancy in the white population. It is an important driver of healthcare costs and causes significant morbidity. Topical imiquimod is a good noninvasive treatment alternative for surgical excision in superficial BCC (sBCC). However, there are currently no uniform histological definitions of sBCC. A definition based on tumour thickness might be a good alternative.
  
  
  OBJECTIVE
  To determine whether tumour thickness in sBCC is a predictor of treatment failure.
  
  
  METHODS
  We retrospectively examined 127 histological biopsy specimens of sBCC treated primarily with imiquimod five times a week for 6 weeks. Mean follow-up was 34 months (range 3-91). Recurrence was evaluated clinically with histological verification.
  
  
  RESULTS
  Among nonrecurrent cases the median tumour thickness was 0·26 mm (range 0·09-0·61), while for recurrent cases the median tumour thickness was 0·57 mm (range 0·41-1·41, P < 0·0001). Among lesions ≤ 0·40 mm in thickness, none recurred, whereas for lesions > 0·40 mm the recurrence rate was 58% (P < 0·0001).
  
  
  CONCLUSIONS
  We recommend the use of tumour thickness to define the superficial pattern in pathology reports for BCC as this can help to determine treatment response of sBCC to imiquimod.
authors.affiliation: Departments of Dermatology and Pathology, The University of Alabama at Birmingham, Birmingham, AL, U.S.A.
authors.forename: K M
authors.initials: KM
authors.lastname: McKay
authors.forename: B L
authors.initials: BL
authors.lastname: Sambrano
authors.forename: P S
authors.initials: PS
authors.lastname: Fox
authors.forename: R L
authors.initials: RL
authors.lastname: Bassett
authors.forename: S
authors.initials: S
authors.lastname: Chon
authors.forename: V G
authors.initials: VG
authors.lastname: Prieto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000634:Aminoquinolines / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002280:Basal Cell Carcinoma / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D006801:Humans; D000077271:Imiquimod; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000473:pathology; D017211:Treatment Failure; D016896:Treatment Outcome
chemical_list: D000634:Aminoquinolines; D000970:Antineoplastic Agents; D000077271:Imiquimod