title: Paradigm-shifting new evidence for treatment of rectal cancer.
abstract: BACKGROUND
  Treatment of rectal cancer has dramatically evolved during the last three decades shifting toward a tailored approach based on preoperative staging and response to neoadjuvant combined modality therapy (CMT).
  
  
  METHODS
  A literature search was performed using PubMed/Medline electronic databases.
  
  
  RESULTS
  Selected patients with T1 N0 rectal cancer are best treated with local excision by transanal endoscopic microsurgery (TEM). Satisfactory results have been reported after CMT and TEM for the treatment of highly selected T2 N0 rectal cancers. CMT followed by rectal resection and total mesorectal excision is considered the standard of care for the treatment of locally advanced rectal cancer. However, a subset of stage II and III patients may not require neoadjuvant radiation treatment. Finally, there are mounting data supporting a "watch and wait" approach or local excision in patients with complete clinical response after neoadjuvant CMT.
  
  
  CONCLUSIONS
  Current evidence shows that selected T1 N0 rectal cancers can be managed by TEM alone, while locally advanced cancers should be treated by CMT followed by radical surgery. Studies are underway to identify patients that do not benefit from neoadjuvant radiation therapy. A non-operative approach in case of complete clinical response must be validated by large prospective studies.
authors.affiliation: Department of Surgery, University of Washington Medical Center, 1959 NE Pacific St, Box 356410, Seattle, WA, 98195, USA, afichera@uw.edu.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Fichera
authors.forename: Marco E
authors.initials: ME
authors.lastname: Allaix
mesh_terms: D001003:Anal Canal; D059186:Chemoradiotherapy, Adjuvant; D016099:Endoscopy, Gastrointestinal; D006801:Humans; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D018714:Radiotherapy, Adjuvant; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery / Q000628:therapy*; D057832:Watchful Waiting