title: An objective measure of architectural complexity and proliferative index in Gleason pattern 3 prostate cancer.
abstract: OBJECTIVE
  To objectively characterize the architectural spectrum of Gleason pattern 3 prostate cancer (PCA) in a biologically meaningful manner.
  
  
  METHODS
  We define an objective architectural feature of PCA, "pinch point density" (PPD), and explore its relationship to proliferative index (PI). A pinch point (PP) is a site where the epithelium of two neighboring glandular structures is contiguous in one histologic section but not in an adjacent serial section. Seventeen radical prostatectomy specimens with areas of pure Gleason pattern 3 were studied. PPD was measured with computer aid using digital images of serial sections. PI was measured by computer-aided counting of Ki-67-positive cells.
  
  
  RESULTS
  PPD correlated inversely with PI (PPD vs. log [PI], P < .004). Characteristics not significantly correlated with PI included total number of malignant glands, PP per gland and total number of malignant cells. Subjectively, tumors with high PPD and low PI tended to contain a larger number of smaller glands as compared to tumors with low PPD and high PI. This impression was confirmed analytically.
  
  
  CONCLUSIONS
  PPD is an objective architectural feature of possible biologic significance. This is an early step toward identifying objective features of growth pattern in Gleason pattern 3 PCA that may be clinically meaningful.
authors.affiliation: Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Weinstein
mesh_terms: D002455:Cell Division; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D018715:Microscopy, Video / Q000379:methods*; D011471:Prostatic Neoplasms / Q000737:chemistry / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: D019394:Ki-67 Antigen