title: Long-term anorectal dysfunction after postoperative radiotherapy for rectal cancer.
abstract: OBJECTIVE
  Adjuvant radiotherapy in the treatment of rectal cancer has been shown to increase long-term morbidity causing severe anorectal dysfunction with physiologic changes whose interaction remains poorly understood. This study examines long-term anorectal morbidity from adjuvant postoperative radiotherapy.
  
  
  METHODS
  In a prospective study, patients with Dukes B or C rectal carcinoma were randomized to postoperative radiotherapy or no adjuvant treatment after anterior resection. The long-term effect of radiotherapy on anorectal function in a subset of surviving patients was assessed from a questionnaire on subjective symptoms and from physiology laboratory evaluation and flexible sigmoidoscopy.
  
  
  RESULTS
  Twelve of 15 patients (80 percent) treated with radiotherapy had increased bowel frequency compared with 3 of the 13 patients (23 percent) who did not have radiation therapy (P = 0.003). The former group had loose or liquid stool more often (60 vs. 23 percent, P = 0.05), had fecal incontinence more often (60 vs. 8 percent, P = 0.004), and wore pad more often (47 vs. 0 percent, P = 0.004). They also experienced fecal urgency and were unable to differentiate stool from gas more often. Endoscopy revealed a pale and atrophied mucosa and telangiectasias in the irradiated patients. Anorectal physiology showed a reduced rectal capacity (146 vs. 215 ml, P = 0.03) and maximum squeeze pressure (59 vs. 93 cm H2O, P = 0.003) in the radiotherapy group. Impedance planimetry demonstrated a reduced rectal distensibility in these patients (P < 0.0001).
  
  
  CONCLUSIONS
  Adjuvant postoperative radiotherapy after anterior resection causes severe long-term anorectal dysfunction, which is mainly the result of a weakened, less sensitive anal sphincter and an undistensible rectum with reduced capacity.
authors.affiliation: Surgical Research Unit, Department of Surgery L, Aarhus University Hospital, Section TGH, Aarhus, Denmark. Lilli@dadlnet.dk
authors.forename: Lilli
authors.initials: L
authors.lastname: Lundby
authors.forename: Klaus
authors.initials: K
authors.lastname: Krogh
authors.forename: Vagn J
authors.initials: VJ
authors.lastname: Jensen
authors.forename: Per
authors.initials: P
authors.lastname: Gandrup
authors.forename: Niels
authors.initials: N
authors.lastname: Qvist
authors.forename: Jens
authors.initials: J
authors.lastname: Overgaard
authors.forename: Soren
authors.initials: S
authors.lastname: Laurberg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000714:Anastomosis, Surgical; D003131:Combined Modality Therapy; D016099:Endoscopy, Gastrointestinal; D019160:Endosonography; D005242:Fecal Incontinence / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D005772:Gastrointestinal Transit / Q000502:physiology; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D011446:Prospective Studies; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects*; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000601:surgery*; D012189:Retrospective Studies; D012812:Sigmoidoscopy; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D016896:Treatment Outcome