title: Does cumulative prostate cancer length (CCL) in prostate biopsies improve prediction of clinically insignificant cancer at radical prostatectomy in patients eligible for active surveillance?
abstract: OBJECTIVE
  To evaluate if cumulative prostate cancer length (CCL) on prostate needle biopsy divided by the number of biopsy cores (CCL/core) could improve prediction of insignificant cancer on radical prostatectomy (RP) in patients with prostate cancer eligible for active surveillance (AS).
  
  
  METHODS
  Patients diagnosed with prostate cancer on extended (≥10 cores) biopsy with an initial prostate-specific antigen (iPSA) level of <15 ng/mL, clinical stage (cT) ≤ 2a, and highest biopsy Gleason score 3 + 3 = 6 or 3 + 4 = 7 with <3 positive cores who underwent RP were included in the study. The CCL/core and presence of insignificant cancer (organ-confined, volume <0.5 mL, Gleason score at RP ≤6) were recorded. pT2 prostate cancer with RP Gleason score ≤3 + 4 = 7 and volume <0.5 mL were categorised as low-tumour-volume organ-confined disease (LV-OCD).
  
  
  RESULTS
  In all, 221 patients met the inclusion criteria: the mean age was 59 years and the median iPSA level was 4.5 ng/mL. The clinical stage was cT1 in 86% of patients; biopsy Gleason score was 3 + 3 = 6 in 67% (group 1) and 3 + 4 = 7 in 33% of patients (group 2). The maximum percentage of biopsy core involvement was <50 in 85%; the median CCL/core was 0.15 mm. Insignificant cancer was found in 27% and LV-OCD in 44% of patients. Group 2 was associated with higher number of positive cores, maximum percentage core involvement, total prostate cancer length, and CCL/core. Group 1 was more likely to have insignificant cancer (39%) or LV-OCD (54%) than group 2 (3% and 23%, respectively). Group 2 had significantly higher RP Gleason score and pathological stage. Univariate analysis of group 1 showed that the iPSA level, maximum percentage core involvement, prostate cancer length, and CCL/core were all significantly associated with insignificant cancer and LV-OCD. For group 2, the number of positive cores (1 vs 2) was also significantly associated with LV-OCD. On multivariate logistic regression analysis, maximum percentage core involvement of <50, and number of positive cores (1 vs 2) were independent predictors of insignificant cancer in group 1; biopsy Gleason score, maximum percentage core involvement of <50 and prostate cancer length of <3 mm or CCL/core of <0.2 mm were all independent predictors of LV-OCD in the whole population. The maximum percentage of core involvement of <50 and prostate cancer length of <3 mm or CCL/core of <0.2 mm were also independent predictors of LV-OCD in group 1 patients.
  
  
  CONCLUSIONS
  In patients eligible for AS, a CCL/core of <0.20 mm was significantly associated with insignificant cancer and LV-OCD. However, when parameters of cancer burden were considered, CCL/core did not independently add any additional value for predicting insignificant cancer in patients with biopsy Gleason score 6. The CCL/core was an independent predictor of LV-OCD in the whole population and in group 1 patients, although the model including prostate cancer length showed slightly higher area under the receiver operating characteristic curve.
authors: Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH, USA.
authors: Derrick J
authors: DJ
authors: Chen
authors: Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH, USA.
authors: Sara M
authors: SM
authors: Falzarano
authors: Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH, USA.|Glickman Urological and Kidney Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
authors: Jesse K
authors: JK
authors: McKenney
authors: Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH, USA.|Glickman Urological and Kidney Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
authors: Chris G
authors: CG
authors: Przybycin
authors: Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH, USA.
authors: Jordan P
authors: JP
authors: Reynolds
authors: Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH, USA.
authors: Andres
authors: A
authors: Roma
authors: Glickman Urological and Kidney Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
authors: J Stephen
authors: JS
authors: Jones
authors: Glickman Urological and Kidney Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
authors: Andrew
authors: A
authors: Stephenson
authors: Glickman Urological and Kidney Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
authors: Eric
authors: E
authors: Klein
authors: Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH, USA.|Glickman Urological and Kidney Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
authors: Cristina
authors: C
authors: Magi-Galluzzi
mesh_terms: D000368:Aged; D001707:Biopsy, Needle; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery
keywords: active surveillance; cumulative cancer length; insignificant cancer; needle biopsy; prostate cancer