title: Prediction of erectile function following treatment for prostate cancer.
abstract: BACKGROUND
  Sexual function is the health-related quality of life (HRQOL) domain most commonly impaired after prostate cancer treatment; however, validated tools to enable personalized prediction of erectile dysfunction after prostate cancer treatment are lacking.
  
  
  OBJECTIVE
  To predict long-term erectile function following prostate cancer treatment based on individual patient and treatment characteristics.
  
  
  METHODS
  Pretreatment patient characteristics, sexual HRQOL, and treatment details measured in a longitudinal academic multicenter cohort (Prostate Cancer Outcomes and Satisfaction With Treatment Quality Assessment; enrolled from 2003 through 2006), were used to develop models predicting erectile function 2 years after treatment. A community-based cohort (community-based Cancer of the Prostate Strategic Urologic Research Endeavor [CaPSURE]; enrolled 1995 through 2007) externally validated model performance. Patients in US academic and community-based practices whose HRQOL was measured pretreatment (N = 1201) underwent follow-up after prostatectomy, external radiotherapy, or brachytherapy for prostate cancer. Sexual outcomes among men completing 2 years' follow-up (n = 1027) were used to develop models predicting erectile function that were externally validated among 1913 patients in a community-based cohort.
  
  
  METHODS
  Patient-reported functional erections suitable for intercourse 2 years following prostate cancer treatment.
  
  
  RESULTS
  Two years after prostate cancer treatment, 368 (37% [95% CI, 34%-40%]) of all patients and 335 (48% [95% CI, 45%-52%]) of those with functional erections prior to treatment reported functional erections; 531 (53% [95% CI, 50%-56%]) of patients without penile prostheses reported use of medications or other devices for erectile dysfunction. Pretreatment sexual HRQOL score, age, serum prostate-specific antigen level, race/ethnicity, body mass index, and intended treatment details were associated with functional erections 2 years after treatment. Multivariable logistic regression models predicting erectile function estimated 2-year function probabilities from as low as 10% or less to as high as 70% or greater depending on the individual's pretreatment patient characteristics and treatment details. The models performed well in predicting erections in external validation among CaPSURE cohort patients (areas under the receiver operating characteristic curve, 0.77 [95% CI, 0.74-0.80] for prostatectomy; 0.87 [95% CI, 0.80-0.94] for external radiotherapy; and 0.90 [95% CI, 0.85-0.95] for brachytherapy).
  
  
  CONCLUSIONS
  Stratification by pretreatment patient characteristics and treatment details enables prediction of erectile function 2 years after prostatectomy, external radiotherapy, or brachytherapy for prostate cancer.
authors.affiliation: Urology Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Alemozaffar
authors.forename: Meredith M
authors.initials: MM
authors.lastname: Regan
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Cooperberg
authors.forename: John T
authors.initials: JT
authors.lastname: Wei
authors.forename: Jeff M
authors.initials: JM
authors.lastname: Michalski
authors.forename: Howard M
authors.initials: HM
authors.lastname: Sandler
authors.forename: Larry
authors.initials: L
authors.lastname: Hembroff
authors.forename: Natalia
authors.initials: N
authors.lastname: Sadetsky
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Saigal
authors.forename: Mark S
authors.initials: MS
authors.lastname: Litwin
authors.forename: Eric
authors.initials: E
authors.lastname: Klein
authors.forename: Adam S
authors.initials: AS
authors.lastname: Kibel
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Hamstra
authors.forename: Louis L
authors.initials: LL
authors.lastname: Pisters
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Kuban
authors.forename: Irving D
authors.initials: ID
authors.lastname: Kaplan
authors.forename: David P
authors.initials: DP
authors.lastname: Wood
authors.forename: Jay
authors.initials: J
authors.lastname: Ciezki
authors.forename: Rodney L
authors.initials: RL
authors.lastname: Dunn
authors.forename: Peter R
authors.initials: PR
authors.lastname: Carroll
authors.forename: Martin G
authors.initials: MG
authors.lastname: Sanda
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects; D007172:Erectile Dysfunction / Q000209:etiology*; D005544:Forecasting; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D017063:Outcome Assessment, Health Care; D010410:Penile Erection / Q000528:radiation effects; D011468:Prostatectomy / Q000009:adverse effects*; D011471:Prostatic Neoplasms / Q000503:physiopathology / Q000532:radiotherapy* / Q000601:surgery*; D011788:Quality of Life; D011832:Radiation Injuries