title: Gleason grade grouping of prostate cancer is of prognostic value in Asian men.
abstract: OBJECTIVE
  The International Society of Urological Pathology made recommendations for the use of Grade Groups (GG) originally described by Epstein and colleagues over Gleason score (GS) alone in 2014, which was subsequently adopted by the WHO classification in 2016. The majority of studies validating this revision have been in Caucasian populations. We therefore asked whether the new GG system was retrospectively associated with biochemical disease-free survival in a mixed-ethnicity cohort of Asian men.
  
  
  METHODS
  A total of 680 radical prostatectomies (RPs) from 2005 to 2014 were included. GS from initial biopsy and RP were compared and used to allocate cases to GG, defined as: 1 (GS≤6); 2 (GS 3+4=7); 3 (GS 4+3=7); 4 (GS 4+4=8/5+3=8/3+5=8) and 5 (GS 9-10). Biochemical recurrence was defined as two consecutive post-RP prostate-specific antigen (PSA) levels of >0.2 ng/mL after post-RP PSA reaching the nadir of <0.1 ng/mL.
  
  
  RESULTS
  Our data showed that Kaplan-Meier analysis revealed significant differences in biochemical recurrence within Gleason GG based on either biopsy or prostatectomy scoring. Multivariate analysis further confirmed that a higher GG was significantly associated with risk of biochemical recurrence. This GG system had a higher prognostic discrimination for both initial biopsy and RP than GS.
  
  
  CONCLUSIONS
  Our study validates the use of the revised and updated GG system in a mixed-ethnicity population of Asian men. Higher GG was significantly associated with increased risk of biochemical recurrence. We therefore recommend its use to inform clinical management for patients with prostate cancer.
authors.affiliation: Department of Anatomical Pathology, Singapore General Hospital, Singapore, Singapore.|Singapore Immunology Network (SIgN), Agency of Science, Technology and Research (A*STAR), Singapore, Singapore.
authors.forename: Joe
authors.initials: J
authors.lastname: Yeong
authors.affiliation: DUKE-NUS Medical School, Center For Quantitative Medicine, Singapore, Singapore.
authors.forename: Rehena
authors.initials: R
authors.lastname: Sultana
authors.affiliation: Department of Urology, Singapore General Hospital, Singapore, Singapore.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Teo
authors.affiliation: Department of Urology, Singapore General Hospital, Singapore, Singapore.
authors.forename: Hong Hong
authors.initials: HH
authors.lastname: Huang
authors.affiliation: Department of Urology, Singapore General Hospital, Singapore, Singapore.
authors.forename: John
authors.initials: J
authors.lastname: Yuen
authors.affiliation: Division of Pathology, Singapore General Hospital, Singapore, Singapore.
authors.forename: Puay Hoon
authors.initials: PH
authors.lastname: Tan
authors.affiliation: Department of Anatomical Pathology, Singapore General Hospital, Singapore, Singapore.
authors.forename: Li Yan
authors.initials: LY
authors.lastname: Khor
mesh_terms: D000368:Aged; D019540:Area Under Curve; D044466:Asian People; D001706:Biopsy; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D006801:Humans; D007610:Kallikreins / Q000378:metabolism; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000378:metabolism; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000208:ethnology* / Q000473:pathology* / Q000601:surgery; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D012846:Singapore; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: C549870:KLK3 protein, human; D007610:Kallikreins; D017430:Prostate-Specific Antigen
keywords: CANCER; DIAGNOSIS; HISTOPATHOLOGY; PROSTATE