title: Heterogeneity of DNA content in laryngeal squamous cell carcinoma in relation to histopathological variables.
abstract: CONCLUSIONS
  Multivariate analysis showed age, lymph node status, proliferative index in transformation border, and DNA index in the center of laryngeal squamous cell carcinoma to be significant predictors for survival. By accessing distinctive areas of the tumor we were able to reduce the impact of intratumoral heterogeneity on prognostic factors.
  
  
  OBJECTIVE
  Laryngeal carcinomas are characterized by considerable histological variation within the tumor. The possible effects of this morphological heterogeneity on the estimation of tumor DNA content were investigated.
  
  
  METHODS
  We analyzed 92 cases of archived, paraffin-embedded laryngeal carcinoma. For each tumor, three different regions, defined microscopically (center of tumor, transformation border, invasive border), were analyzed. DNA content was measured by flow cytometry. Three parameters were evaluated: DNA ploidy, DNA index, and proliferative index.
  
  
  RESULTS
  DNA ploidy, DNA index, and proliferative index were higher in the tumor center than in the respective borders. Intratumoral differences in DNA ploidy were observed in 56 tumors (60.8%); DNA index heterogeneity was observed in 57.6% cases. Proliferative index varied greatly in morphologically different parts of the same carcinoma. DNA ploidy and DNA index of the transformation border correlated with tumor size and lymph node status. Proliferative index of the tumor center and of transformation border correlated with lymph node status, tumor size, and histological grade.
authors.affiliation: Department of Oncology and Nuclear Medicine, Clinical Hospital 'Sestre milosrdnice', Zagreb.
authors.forename: Blazenka
authors.initials: B
authors.lastname: Ladika-Davidovic
authors.forename: Marijana
authors.initials: M
authors.lastname: Coric
authors.forename: Miljenko
authors.initials: M
authors.lastname: Bura
authors.forename: Luka
authors.initials: L
authors.lastname: Brcic
authors.forename: Zvonko
authors.initials: Z
authors.lastname: Kusic
authors.forename: Sven
authors.initials: S
authors.lastname: Seiwerth