title: Is it time to rethink the rule of total mesorectal excision? A prospective radiological and pathological study in 49 consecutive patients with mid-rectal cancer.
abstract: OBJECTIVE
  Total mesorectal excision (TME) after neoadjuvant chemoradiotherapy is the standard treatment for T3-T4 and/or N+ mid-rectal tumours, regardless of the exact tumour level. This leads to optimal oncological results but possible impaired functional results. Reducing rectal excision could reduce the functional drawbacks. This study prospectively assessed the risk of N+ or other mesorectal tumour deposit (OTD) below the tumour level by magnetic resonance imaging (MRI) performed after chemoradiotherapy and pathological examination of the TME specimen.
  
  
  METHODS
  Consecutive patients with mid-rectal cancer who underwent TME after chemoradiotherapy were included. A prospective evaluation by postchemoradiotherapy MRI and pathological examination was performed to assess the location of N+ nodes and/or OTDs.
  
  
  RESULTS
  Of 49 consecutive patients, 27 (55%) presented with nodes on postchemoradiotherapy MRI. However, only 12 nodes (size 2-4 mm) in 9 patients (18%) were under the tumour level. On pathological examination, 717 total lymph nodes were found, with 37 N+ and 22 OTD. According to the tumour level: (i) above tumour level, 21/453 nodes were N+ and 6 OTD; (ii) at tumour level, 16/166 nodes were N+ and 15 OTD; (iii) below tumour level, 0/98 nodes (0%) was N+ and only 1 OTD (2%) was noted at 2 cm below tumour level.
  
  
  CONCLUSIONS
  After chemoradiotherapy, N+ and/or OTD located under the level of the rectal cancer seems to be a very rare event. A postchemoradiotherapy MRI could help detect such patients. For others patients, conservation of the lower rectum with only a subtotal mesorectal excision could possibly improve function.
authors.affiliation: Department of Pathology, Beaujon Hospital, Université Paris VII, Clichy, France.
authors.forename: N
authors.initials: N
authors.lastname: Guedj
authors.affiliation: Department of Radiology, Beaujon Hospital, Université Paris VII, Clichy, France.
authors.forename: M
authors.initials: M
authors.lastname: Zappa
authors.affiliation: Department of Colorectal Surgery, Beaujon Hospital, Université Paris VII, Clichy, France.
authors.forename: L
authors.initials: L
authors.lastname: Maggiori
authors.affiliation: Department of Radiology, Beaujon Hospital, Université Paris VII, Clichy, France.
authors.forename: C
authors.initials: C
authors.lastname: Bertin
authors.affiliation: Department of Oncology and Radiotherapy, Saint Louis Hospital, Université Paris VII, Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Hennequin
authors.affiliation: Department of Colorectal Surgery, Beaujon Hospital, Université Paris VII, Clichy, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Panis
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy; D013505:Digestive System Surgical Procedures / Q000379:methods*; D005260:Female; D006801:Humans; D008197:Lymph Node Excision / Q000379:methods*; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008643:Mesentery / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D012007:Rectum / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome
keywords: Rectal cancer; lymph node; radiochemotherapy; total mesorectal excision