title: Effect of preoperative radio(chemo)therapy on long-term functional outcome in rectal cancer patients: a systematic review and meta-analysis.
abstract: BACKGROUND
  Preoperative radio(chemo)therapy (pR(C)T) significantly reduces the local recurrence risk and is therefore recommended in stage II/III rectal cancer. However, this multimodal treatment approach may be associated with late adverse effects. To determine the impact of pR(C)T on long-term anorectal, sexual, and urinary function, we performed a systematic review and meta-analysis.
  
  
  METHODS
  PubMed, Embase, and the Cochrane Library were systematically searched for studies reporting on long-term functional outcome after rectal cancer resection with pR(C)T. Only studies that reported anorectal, sexual, and/or urinary function after rectal cancer resection in TME-technique with pR(C)T were eligible for inclusion.
  
  
  RESULTS
  Twenty-five studies, including 6,548 patients, were identified. Methodological quality of the eligible studies was low. The majority of studies reported higher rates of anorectal (14/18 studies) and male sexual dysfunction (9/10 studies) after pR(C)T. Few studies examined female sexual dysfunction (n = 4). Meta-analysis revealed that stool incontinence occurred more often in irradiated patients (risk ratio (RR) = 1.67; 95 % confidence interval (CI), 1.36, 2.05; p < 0.0001) and manometric results were significantly worse after pR(C)T (mean resting pressures (weighted mean difference (WMD) = 15.04; 95 % CI, 0.77, 29.31; p = 0.04) and maximum squeeze pressures (WMD = 30.39; 95 % CI, 21.48, 39.3; p < 0.0001)). Meta-analysis of erectile dysfunction revealed no statistical significance (RR = 1.41; 95 % CI, 0.74, 2.72; p = 0.3). Six of eight studies and meta-analysis demonstrated no negative effect of pR(C)T on urinary function (RR = 1.05; 95 % CI, 0.67, 1.65; p = 0.82).
  
  
  CONCLUSIONS
  Although quality of studies on long-term functional outcome is limited, current evidence demonstrates that pR(C)T negatively affects anorectal function after TME.
authors.affiliation: Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany, martin.loos@tum.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Loos
authors.forename: Philipp
authors.initials: P
authors.lastname: Quentmeier
authors.forename: Tibor
authors.initials: T
authors.lastname: Schuster
authors.forename: Ulrich
authors.initials: U
authors.lastname: Nitsche
authors.forename: Ralf
authors.initials: R
authors.lastname: Gertler
authors.forename: Andreas
authors.initials: A
authors.lastname: Keerl
authors.forename: Thomas
authors.initials: T
authors.lastname: Kocher
authors.forename: Helmut
authors.initials: H
authors.lastname: Friess
authors.forename: Robert
authors.initials: R
authors.lastname: Rosenberg
mesh_terms: D001003:Anal Canal / Q000503:physiopathology*; D059186:Chemoradiotherapy, Adjuvant; D016001:Confidence Intervals; D005242:Fecal Incontinence / Q000209:etiology; D006801:Humans; D008365:Manometry; D020360:Neoadjuvant Therapy / Q000009:adverse effects*; D012004:Rectal Neoplasms / Q000601:surgery / Q000628:therapy*; D012735:Sexual Dysfunction, Physiological / Q000209:etiology; D013997:Time Factors; D014555:Urination Disorders / Q000209:etiology