title: Prognostic importance of Gleason 7 disease among patients treated with external beam radiation therapy for prostate cancer: results of a detailed biopsy core analysis.
abstract: OBJECTIVE
  To analyze the effect of primary Gleason (pG) grade among a large cohort of Gleason 7 prostate cancer patients treated with external beam radiation therapy (EBRT).
  
  
  METHODS
  From May 1989 to January 2011, 1190 Gleason 7 patients with localized prostate cancer were treated with EBRT at a single institution. Of these patients, 613 had a Gleason 7 with a minimum of a sextant biopsy with nonfragmented cores and full biopsy core details available, including number of cores of cancer involved, percentage individual core involvement, location of disease, bilaterality, and presence of perineural invasion. Median follow-up was 6 years (range, 1-16 years). The prognostic implication for the following outcomes was analyzed: biochemical recurrence-free survival (bRFS), distant metastasis-free survival (DMFS), and prostate cancer-specific mortality (PCSM).
  
  
  RESULTS
  The 8-year bRFS rate for pG3 versus pG4 was 77.6% versus 61.3% (P<.0001), DMFS was 96.8% versus 84.3% (P<.0001), and PCSM was 3.7% versus 8.1% (P=.002). On multivariate analysis, pG4 predicted for significantly worse outcome in all parameters. Location of disease (apex, base, mid-gland), perineural involvement, maximum individual core involvement, and the number of Gleason 3+3, 3+4, or 4+3 cores did not predict for distant metastases.
  
  
  CONCLUSIONS
  Primary Gleason grade 4 independently predicts for worse bRFS, DMFS, and PCSM among Gleason 7 patients. Using complete core information can allow clinicians to utilize pG grade as a prognostic factor, despite not having the full pathologic details from a prostatectomy specimen. Future staging and risk grouping should investigate the incorporation of primary Gleason grade when complete biopsy core information is used.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York, USA.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Spratt
authors.forename: Zach
authors.initials: Z
authors.lastname: Zumsteg
authors.forename: Pirus
authors.initials: P
authors.lastname: Ghadjar
authors.forename: Misha
authors.initials: M
authors.lastname: Pangasa
authors.forename: Xin
authors.initials: X
authors.lastname: Pei
authors.forename: Samson W
authors.initials: SW
authors.lastname: Fine
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Yamada
authors.forename: Marisa
authors.initials: M
authors.lastname: Kollmeier
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zelefsky
mesh_terms: D000230:Adenocarcinoma / Q000097:blood / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D011379:Prognosis; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*; D020266:Radiotherapy, Conformal; D050397:Radiotherapy, Intensity-Modulated; D012189:Retrospective Studies
chemical_list: D017430:Prostate-Specific Antigen