Predicting high-grade cancer at ten-core prostate biopsy using four kallikrein markers measured in blood in the ProtecT study Journal Article


Authors: Bryant, R. J.; Sjoberg, D. D.; Vickers, A. J.; Robinson, M. C.; Kumar, R.; Marsden, L.; Davis, M.; Scardino, P. T.; Donovan, J.; Neal, D. E.; Lilja, H.; Hamdy, F. C.
Article Title: Predicting high-grade cancer at ten-core prostate biopsy using four kallikrein markers measured in blood in the ProtecT study
Abstract: Background: Many men with elevated prostate-specific antigen (PSA) levels in serum do not have aggressive prostate cancer and undergo unnecessary biopsy. Retrospective studies using cryopreserved serum suggest that four kallikrein markers can predict biopsy outcome. Methods: Free, intact and total PSA, and kallikrein-related peptidase 2 were measured in cryopreserved blood from 6129 men with elevated PSA (≥3.0ng/mL) participating in the prospective, randomized trial Prostate Testing for Cancer and Treatment. Marker levels from 4765 men providing anticoagulated plasma were incorporated into statistical models to predict any-grade and high-grade (Gleason score ≥7) prostate cancer at 10-core biopsy. The models were corrected for optimism by 10-fold cross validation and independently validated using markers measured in serum from 1364 men. All statistical tests were two-sided. Results: The four kallikreins enhanced prostate cancer detection compared with PSA and age alone. Area under the curve (AUC) for the four kallikreins was 0.719 (95% confidence interval [CI] = 0.704 to 0.734) vs 0.634 (95% CI = 0.617 to 0.651, P <. 001) for PSA and age alone for any-grade cancer, and 0.820 (95% CI = 0.802 to 0.838) vs 0.738 (95% CI = 0.716 to 0.761) for high-grade cancer. Using a 6% risk of high-grade cancer as an illustrative cutoff, for 1000 biopsied men with PSA levels of 3.0ng/mL or higher, the model would reduce the need for biopsy in 428 men, detect 119 high-grade cancers, and delay diagnosis of 14 of 133 high-grade cancers. Models exhibited excellent discrimination on independent validation among men with only serum samples available for analysis. Conclusions: A statistical model based on kallikrein markers was validated in a large prospective study and reduces unnecessary biopsies while delaying diagnosis of high-grade cancers in few men. © 2015 The Author 2015. Published by Oxford University Press.
Keywords: adult; controlled study; human tissue; unclassified drug; major clinical study; validation process; cancer diagnosis; cancer grading; prostate specific antigen; prostate cancer; gleason score; cryopreservation; blood analysis; prostate biopsy; kallikrein; statistical model; kallikrein related peptidase 2; randomized controlled trial (topic); biochemical marker; human; male; priority journal; article
Journal Title: JNCI: Journal of the National Cancer Institute
Volume: 107
Issue: 7
ISSN: 0027-8874
Publisher: Oxford University Press  
Date Published: 2015-07-01
Start Page: djv095
Language: English
DOI: 10.1093/jnci/djv095
PROVIDER: scopus
PMCID: PMC4554254
PUBMED: 25863334
DOI/URL:
Notes: Export Date: 2 September 2015 -- Source: Scopus
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MSK Authors
  1. Peter T Scardino
    671 Scardino
  2. Hans Gosta Lilja
    343 Lilja
  3. Andrew J Vickers
    880 Vickers
  4. Daniel D. Sjoberg
    234 Sjoberg