Human kallikrein 11: an indicator of favorable prognosis in ovarian cancer patients

Clin Biochem. 2004 Sep;37(9):823-9. doi: 10.1016/j.clinbiochem.2004.04.009.


Objectives: Human kallikrein 11 (hK11) is a secreted serine protease, highly expressed in hormonally regulated tissues, including the prostate and the ovary. Our preliminary studies indicate that hK11 may represent a diagnostic and prognostic biomarker for ovarian cancer. The aim of the present study was to examine the prognostic value of hK11 expression in ovarian tumors.

Methods: Using our established immunofluorometric assay, hK11 levels were quantified (ng per mg of total protein) in 134 ovarian tumor extracts and correlated with various clinicopathological variables and outcome [progression-free survival (PFS), overall survival (OS)], over a median follow-up period of 42 months.

Results: hK11 concentration in ovarian tumor cytosols ranged from 0 to 155 ng/mg of total protein, with a median of 1.45 ng/mg. An optimal cutoff value of 6.3 ng/mg was selected to categorize tumors as hK11-positive or negative. hK11-positive tumors were most often of early stage (Stage I/II) and grade (G1/G2) (P < 0.05). Univariate analysis revealed that patients with hK11-positive tumors had a significantly longer PFS (HR of 0.39, P = 0.005) and OS (HR of 0.44, P = 0.033). Cox multivariate analysis indicated that hK11 was an independent prognostic indicator of PFS (HR of 0.47, P = 0.042). Kaplan-Meier survival curves further confirmed that women with hK11-positive tumors have longer PFS and OS (P = 0.003 and P = 0.028, respectively). Also, a weak positive correlation was found between the expression levels of tissue hK11 and tissue CA125 (rs = 0.508; P < 0.001).

Conclusions: These results further validate our initial findings that hK11 is an independent marker of favorable prognosis in ovarian cancer patients.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Chi-Square Distribution
  • Female
  • Follow-Up Studies
  • Humans
  • Middle Aged
  • Multivariate Analysis
  • Ovarian Neoplasms / diagnosis*
  • Ovarian Neoplasms / metabolism*
  • Prognosis
  • Proportional Hazards Models
  • Serine Endopeptidases / analysis*
  • Serine Endopeptidases / biosynthesis*
  • Statistics, Nonparametric


  • trypsin-like serine protease
  • Serine Endopeptidases