title: Effect of repeated prostate biopsies on erectile function in men on active surveillance for prostate cancer.
abstract: OBJECTIVE
  Active surveillance is becoming an increasingly common management strategy for low grade prostate cancer and involves repeat prostate biopsies over time. It has been hypothesized that serial biopsies can lead to reduced erectile function in patients on active surveillance and we explored this hypothesis in a longitudinally followed cohort.
  
  
  METHODS
  We identified 342 men on active surveillance whose first biopsy occurred between 2000 and 2009. We investigated erectile function using patient reported outcomes, namely the 6 erectile function questions from the IIEF-6 (International Index of Erectile Function). We estimated the change in erectile function with time using locally weighted scatterplot smoothing.
  
  
  RESULTS
  The median (IQR) patient age in this cohort was 64 years (58-68). Median followup on active surveillance was 3.5 years (2.3-5.0) and the median number of biopsies was 5 (3-6). During the first 4 years on active surveillance erectile function decreased 1.0 point per year (95% CI 0.2, 1.7) on the IIEF-6 (scale 1 to 30). When stratified by comorbidities or number of biopsies we see an almost identical decrease in erectile function with time. The use of phosphodiesterase-5 inhibitors increased from 5% to 27% from baseline to year 5 on active surveillance.
  
  
  CONCLUSIONS
  In this longitudinally followed active surveillance cohort we observed a small decrease in erectile function and an increase in the use of phosphodiesterase-5 inhibitors with time. While we cannot separate out the effect of multiple biopsies from that of the natural aging process on erectile function in this observational study, our data suggest that active surveillance related biopsies do not have a large impact on erectile function.
authors.affiliation: Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York; Department of Urology, University Hospital Ruhr University Bochum, Marienhospital Herne, Herne, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Braun
authors.affiliation: Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Youness
authors.initials: Y
authors.lastname: Ahallal
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Sjoberg
authors.affiliation: Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Tarek
authors.initials: T
authors.lastname: Ghoneim
authors.affiliation: Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Mario
authors.initials: M
authors.lastname: Dominguez Esteban
authors.affiliation: Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York; Department of Urology, Weill Medical College of Cornell University, New York, New York.
authors.forename: John
authors.initials: J
authors.lastname: Mulhall
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Andrew
authors.initials: A
authors.lastname: Vickers
authors.affiliation: Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York; Department of Urology, Weill Medical College of Cornell University, New York, New York.
authors.forename: James
authors.initials: J
authors.lastname: Eastham
authors.affiliation: Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York; Department of Urology, Weill Medical College of Cornell University, New York, New York.
authors.forename: Peter T
authors.initials: PT
authors.lastname: Scardino
authors.affiliation: Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York; Department of Urology, Weill Medical College of Cornell University, New York, New York. Electronic address: touijera@mskcc.org.
authors.forename: Karim A
authors.initials: KA
authors.lastname: Touijer
mesh_terms: D000368:Aged; D001706:Biopsy / Q000009:adverse effects*; D015897:Comorbidity; D007172:Erectile Dysfunction / Q000209:etiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011471:Prostatic Neoplasms / Q000473:pathology*; D011788:Quality of Life; D019233:Retreatment
keywords: biopsy; erectile dysfunction; prostate; questionnaires; watchful waiting