title: Late adverse effects of radiation therapy for rectal cancer - a systematic overview.
abstract: OBJECTIVE
  The use of radiation therapy (RT) together with improvement in the surgical treatment of rectal cancer improves survival and reduces the risk for local recurrences. Despite these benefits, the adverse effects of radiation therapy limit its use. The aim of this review was to present a comprehensive overview of published studies on late adverse effects related to the RT for rectal cancer.
  
  
  METHODS
  Meta-analyses, reviews, randomised clinical trials, cohort studies and case-control studies on late adverse effects, due to pre- or postoperative radiation therapy and chemo-radiotherapy for rectal cancer, were systematically searched. Most information was obtained from the randomised trials, especially those comparing preoperative short-course 5 x 5 Gy radiation therapy with surgery alone.
  
  
  RESULTS
  The late adverse effects due to RT were bowel obstructions; bowel dysfunction presented as faecal incontinence to gas, loose or solid stools, evacuation problems or urgency; and sexual dysfunction. However, fewer late adverse effects were reported in recent studies, which generally used smaller irradiated volumes and better irradiation techniques; although, one study revealed an increased risk for secondary cancers in irradiated patients.
  
  
  CONCLUSIONS
  These results stress the importance of careful patient selection for RT for rectal cancer. Improvements in the radiation technique should further be developed and the long-term follow-up of the randomised trials is the most important source of information on late adverse effects and should therefore be continued.
authors.affiliation: Department of Surgery, University Hospital, University of Uppsala, Uppsala, Sweden. helgi.birgisson@surgsci.uu.se
authors.forename: Helgi
authors.initials: H
authors.lastname: Birgisson
authors.forename: Lars
authors.initials: L
authors.lastname: Påhlman
authors.forename: Ulf
authors.initials: U
authors.lastname: Gunnarsson
authors.forename: Bengt
authors.initials: B
authors.lastname: Glimelius
mesh_terms: D005244:Fecal Impaction / Q000209:etiology*; D005242:Fecal Incontinence / Q000209:etiology*; D006801:Humans; D010384:Pelvic Bones / Q000293:injuries; D011788:Quality of Life; D011878:Radiotherapy / Q000009:adverse effects*; D012004:Rectal Neoplasms / Q000532:radiotherapy*; D012735:Sexual Dysfunction, Physiological / Q000209:etiology*; D013923:Thromboembolism / Q000209:etiology