title: Exploratory Decision-Tree Modeling of Data from the Randomized REACTT Trial of Tadalafil Versus Placebo to Predict Recovery of Erectile Function After Bilateral Nerve-Sparing Radical Prostatectomy.
abstract: Understanding predictors for the recovery of erectile function (EF) after nerve-sparing radical prostatectomy (nsRP) might help clinicians and patients in preoperative counseling and expectation management of EF rehabilitation strategies.
  
  
  
  To describe the effect of potential predictors on EF recovery after nsRP by post hoc decision-tree modeling of data from A Study of Tadalafil After Radical Prostatectomy (REACTT).
  
  
  
  Randomized double-blind double-dummy placebo-controlled trial in 423 men aged <68 yr with adenocarcinoma of the prostate (Gleason ≤7, normal preoperative EF) who underwent nsRP at 50 centers from nine European countries and Canada.
  
  
  
  Postsurgery 1:1:1 randomization to 9-mo double-blind treatment with tadalafil 5mg once a day (OaD), tadalafil 20mg on demand, or placebo, followed by a 6-wk drug-free-washout, and a 3-mo open-label tadalafil OaD treatment.
  
  
  
  Three decision-tree models, using the International Index of Erectile Function-Erectile Function (IIEF-EF) domain score at the end of double-blind treatment, washout, and open-label treatment as response variable. Each model evaluated the association between potential predictors: presurgery IIEF domain and IIEF single-item scores, surgical approach, nerve-sparing score (NSS), and postsurgery randomized treatment group.
  
  
  
  The first decision-tree model (n=422, intention-to-treat population) identified high presurgery sexual desire (IIEF item 12: ≥3.5 and <3.5) as the key predictor for IIEF-EF at the end of double-blind treatment (mean IIEF-EF: 14.9 and 11.1), followed by high confidence to get and maintain an erection (IIEF item 15: ≥3.5 and <3.5; IIEF-EF: 15.4 and 7.1). For patients meeting these criteria, additional non-IIEF-related predictors included robot-assisted laparoscopic surgery (yes or no; IIEF-EF: 19.3 and 12.6), quality of nerve sparing (NSS: <2.5 and ≥2.5; IIEF-EF: 14.3 and 10.5), and treatment with tadalafil OaD (yes and no; IIEF-EF: 17.6 and 14.3). Additional analyses after washout and open-label treatment identified high presurgery intercourse satisfaction as the key predictor.
  
  
  
  Exploratory decision-tree analyses identified high presurgery sexual desire, confidence, and intercourse satisfaction as key predictors for EF recovery. Patients meeting these criteria might benefit the most from conserving surgery and early postsurgery EF rehabilitation. Strategies for improving EF after surgery should be discussed preoperatively with all patients; this information may support expectation management for functional recovery on an individual patient level.
  
  
  
  Understanding how patient characteristics and different treatment options affect the recovery of erectile function (EF) after radical surgery for prostate cancer might help physicians select the optimal treatment for their patients. This analysis of data from a clinical trial suggested that high presurgery sexual desire, sexual confidence, and intercourse satisfaction are key factors predicting EF recovery. Patients meeting these criteria might benefit the most from conserving surgery (robot-assisted surgery, perfect nerve sparing) and postsurgery medical rehabilitation of EF.
  
  
  
  ClinicalTrials.gov, NCT01026818.
authors.affiliation: Department of Urology, Vita Salute San Raffaele University, Milan, Italy. Electronic address: napoli.patrizia@hsr.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Montorsi
authors.affiliation: Department of Urology and Urological Oncology, Hanover Medical School, Hanover, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Oelke
authors.affiliation: Global Statistical Sciences, EU Statistics, Lilly Deutschland GmbH, Bad Homburg, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Henneges
authors.affiliation: Department of Surgery, Division of Urology, University of Western Ontario, London, Ontario, Canada.
authors.forename: Gerald
authors.initials: G
authors.lastname: Brock
authors.affiliation: Department of Urology, Vita Salute San Raffaele University, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Salonia
authors.affiliation: Therapeutic Area Men's Health, Eli Lilly SpA, Florence, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: d'Anzeo
authors.affiliation: Therapeutic Area Men's Health, Eli Lilly SpA, Florence, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Rossi
authors.affiliation: Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: John P
authors.initials: JP
authors.lastname: Mulhall
authors.affiliation: Biomedicines BU, Lilly Deutschland GmbH, Bad Homburg, Germany.
authors.forename: Hartwig
authors.initials: H
authors.lastname: Büttner
mesh_terms: D000230:Adenocarcinoma / Q000601:surgery*; D000368:Aged; D003075:Coitus; D003663:Decision Trees; D004311:Double-Blind Method; D007172:Erectile Dysfunction / Q000188:drug therapy* / Q000209:etiology / Q000523:psychology; D006801:Humans; D008297:Male; D008875:Middle Aged; D059351:Organ Sparing Treatments; D010410:Penile Erection / Q000187:drug effects*; D058986:Phosphodiesterase 5 Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D057234:Preoperative Period; D011468:Prostatectomy / Q000009:adverse effects / Q000379:methods*; D011471:Prostatic Neoplasms / Q000601:surgery*; D020127:Recovery of Function; D065287:Robotic Surgical Procedures; D020377:Self Efficacy; D012720:Severity of Illness Index; D019529:Sexuality; D000068581:Tadalafil / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D058986:Phosphodiesterase 5 Inhibitors; D000068581:Tadalafil
keywords: Clinical trials; Decision-tree analysis; Erectile dysfunction; Nerve-sparing radical prostatectomy; Phosphodiesterase type 5 inhibitors; Predictors; Prostate cancer; Rehabilitation; Tadalafil