title: Prognostic factors in localized invasive primary cutaneous malignant melanoma: results of a large population-based study.
abstract: BACKGROUND
  The prognostic impact of several histopathological prognostic features in cutaneous malignant melanoma (CMM) remains controversial.
  
  
  OBJECTIVE
  To assess the independent prognostic value of mitotic rate, regression, tumour-infiltrating lymphocytes (TILs) and growth phase in primary stage I and II CMMs.
  
  
  METHODS
  Clinicohistopathological data were obtained from the Stockholm-Gotland registry for 4237 patients diagnosed with an incident primary stage I or II CMM followed up to December 2011. The risk of CMM-specific death was evaluated by a Cox regression model.
  
  
  RESULTS
  A mitotic rate of 1-10 mitoses per mm(2) [hazard ratio (HR) 1·69, 95% confidence interval (CI) 1·16-2·45] and > 10 mitoses per mm(2) (HR 2·27, 95% CI 1·46-3·52) were significant; TILs and regression were not. A more detailed analysis of data assessed between 1989 and 1995 confirmed significantly increased HRs for the presence vs. absence of mitoses (HR1-5/mm² 2·25, 95% CI 1·36-3·76; HR6-10/mm² 2·34, 95% CI 1·23-4·44; HR> 10/mm² 2·64, 95% CI 1·39-4·99). Other prognosticators were increasing T-stage vs. T1, presence of ulceration and presence of vertical growth phase (VGP). In T1 CMMs, an increasing tumour thickness vs. < 0·7 mm (HR0·7-0·8 mm 2·24, 95% CI 1·24-4·04; HR>0·8 mm  2·92, 95% CI 1·57-5·43) and presence of ulceration were significantly associated with higher HRs; mitotic rate, TILs, regression and growth phase were not.
  
  
  CONCLUSIONS
  Determinants of increased risk of CMM death in stage I and II CMMs were increasing T-stage, presence of ulceration, presence of mitoses and VGP. This was not found for TILs or regression.
authors.affiliation: Department of Oncology-Pathology, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Eriksson
authors.forename: M
authors.initials: M
authors.lastname: Frohm-Nilsson
authors.forename: J
authors.initials: J
authors.lastname: Järås
authors.forename: L
authors.initials: L
authors.lastname: Kanter-Lewensohn
authors.forename: P
authors.initials: P
authors.lastname: Kjellman
authors.forename: E
authors.initials: E
authors.lastname: Månsson-Brahme
authors.forename: I
authors.initials: I
authors.lastname: Vassilaki
authors.forename: J
authors.initials: J
authors.lastname: Hansson
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000401:mortality* / Q000473:pathology; D008875:Middle Aged; D011379:Prognosis; D017678:Sex Distribution; D012878:Skin Neoplasms / Q000401:mortality* / Q000473:pathology; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult; D000096142:Cutaneous Malignant Melanoma