title: Preoperative therapy for lower rectal cancer and modifications in distance from anal sphincter.
abstract: OBJECTIVE
  To assess the frequency and magnitude of changes in lower rectal cancer resulting from preoperative therapy and its impact on sphincter-saving surgery. Preoperative therapy can increase the rate of preserving surgery by shrinking the tumor and enhancing its distance from the anal sphincter. However, reliable data concerning these modifications are not yet available in published reports.
  
  
  METHODS
  A total of 98 cases of locally advanced cancer of the lower rectum (90 Stage uT3-T4N0-N+ and 8 uT2N+M0) that had undergone preoperative therapy were studied by endorectal ultrasonography. The maximal size of the tumor and its distance from the anal sphincter were measured in millimeters before and after preoperative therapy. Surgery was performed 6-8 weeks after therapy, and the histopathologic margins were compared with the endorectal ultrasound data.
  
  
  RESULTS
  Of the 90 cases, 82.5% showed tumor downsizing, varying from one-third to two-thirds or more of the original tumor mass. The distance between the tumor and the anal sphincter increased in 60.2% of cases. The median increase was 0.73 cm (range, 0.2-2.5). Downsizing was not always associated with an increase in distance. Preserving surgery was performed in 60.6% of cases. It was possible in nearly 30% of patients in whom the cancer had reached the anal sphincter before the preoperative therapy. The distal margin was tumor free in these cases.
  
  
  CONCLUSIONS
  The results of our study have shown that in very low rectal cancer, preoperative therapy causes tumor downsizing in >80% of cases and in more than one-half enhances the distance between the tumor and anal sphincter. These modifications affect the primary surgical options, facilitating or making sphincter-saving surgery possible.
authors.affiliation: Divisione di Chirurgia II, Nuovo Ospedale Civile S. Agostino-Estense, Modena, Italy. gavioli.margherita@libero.it
authors.forename: Margherita
authors.initials: M
authors.lastname: Gavioli
authors.forename: Lorena
authors.initials: L
authors.lastname: Losi
authors.forename: Gabriele
authors.initials: G
authors.lastname: Luppi
authors.forename: Francesco
authors.initials: F
authors.lastname: Iacchetta
authors.forename: Sandra
authors.initials: S
authors.lastname: Zironi
authors.forename: Federica
authors.initials: F
authors.lastname: Bertolini
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Falchi
authors.forename: Filippo
authors.initials: F
authors.lastname: Bertoni
authors.forename: Gianni
authors.initials: G
authors.lastname: Natalini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal / Q000000981:diagnostic imaging / Q000473:pathology*; D000970:Antineoplastic Agents / Q000627:therapeutic use; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011300:Preoperative Care; D011879:Radiotherapy Dosage; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy*
chemical_list: D000970:Antineoplastic Agents