title: The relationship between proliferation activity and parathyroid hormone levels in parathyroid tumors.
abstract: OBJECTIVE
  This article examines as to whether the Ki-67 index may be useful as a marker for cell proliferation, as well as to whether Ki-67 immunohistochemical expression and parathyroid hormone (PTH) levels are useful in distinguishing between parathyroid carcinoma (PC) and adenoma.
  
  
  METHODS
  A retrospective analysis of 50 patients (10 with PC and 40 with adenoma) who had been previously diagnosed with primary hyperparathyroidism (PHPT) was conducted. Normal parathyroid glands served as the control group. Immunostaining of Ki-67 was estimated through image analysis and the results were statistically analyzed.
  
  
  RESULTS
  Ki-67 was higher in PC patients (median 785.15) compared to adenoma patients (median 297.41; Mann-Whitney U-test p<0.001). ROC analysis confirmed that Ki-67 has a positive predictive marker in diagnosing cancer. Mann-Whitney U-test confirmed a highly statistically significant difference in the preoperative PTH levels between the PC and adenoma group (p <0.001). The PTH serum preoperative level was higher in PC patients (median 1721) than in those with adenoma (median 189.5). A highly significant correlation was also found between Ki-67 and preoperative PTH levels (p <0.001).
  
  
  CONCLUSIONS
  A higher rate of cellular proliferation was noted in malignant tumors as compared to benign tumors. Moreover, the expression profile of Ki-67 and high PTH levels in this study indicates a role for them as potential markers of malignancy.
authors.affiliation: Institute for Oncology and Radiology of Serbia, Department of Surgery, Belgrade, Serbia.
authors.forename: Zorka
authors.initials: Z
authors.lastname: Inic
authors.forename: Momcilo
authors.initials: M
authors.lastname: Inic
authors.forename: Snezana
authors.initials: S
authors.lastname: Jancic
authors.forename: Ivan
authors.initials: I
authors.lastname: Paunovic
authors.forename: Svetislav
authors.initials: S
authors.lastname: Tatic
authors.forename: Katarina
authors.initials: K
authors.lastname: Tausanovic
authors.forename: Vladan
authors.initials: V
authors.lastname: Zivavljevic
authors.forename: Milan
authors.initials: M
authors.lastname: Zegarac
authors.forename: Ivana
authors.initials: I
authors.lastname: Inic
authors.forename: Dusko
authors.initials: D
authors.lastname: Dunjdjerovic
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D049109:Cell Proliferation; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D010282:Parathyroid Neoplasms / Q000097:blood / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: D019394:Ki-67 Antigen; D010281:Parathyroid Hormone