title: Evaluation of Tumor Response after Short-Course Radiotherapy and Delayed Surgery for Rectal Cancer.
abstract: OBJECTIVE
  Neoadjuvant therapy is able to reduce local recurrence in rectal cancer. Immediate surgery after short course radiotherapy allows only for minimal downstaging. We investigated the effect of delayed surgery after short-course radiotherapy at different time intervals before surgery, in patients affected by rectal cancer.
  
  
  METHODS
  From January 2003 to December 2013 sixty-seven patients with the following characteristics have been selected: clinical (c) stage T3N0 ≤ 12 cm from the anal verge and with circumferential resection margin > 5 mm (by magnetic resonance imaging); cT2, any N, < 5 cm from anal verge; and patients facing tumors with enlarged nodes and/or CRM+ve who resulted unfit for chemo-radiation, were also included. Patients underwent preoperative short-course radiotherapy with different interval to surgery were divided in three groups: A (within 6 weeks), B (between 6 and 8 weeks) and C (after more than 8 weeks). Hystopatolgical response to radiotherapy was measured by Mandard's modified tumor regression grade (TRG).
  
  
  RESULTS
  All patients completed the scheduled treatment. Sixty-six patients underwent surgery. Fifty-three of which (80.3%) received a sphincter saving procedure. Downstaging occurred in 41 cases (62.1%). The analysis of subgroups showed an increasing prevalence of TRG 1-2 prolonging the interval to surgery (group A-16.7%, group B-36.8% and 54.3% in group C; p value 0.023).
  
  
  CONCLUSIONS
  Preoperative short-course radiotherapy is able to downstage rectal cancer if surgery is delayed. A higher rate of TRG 1-2 can be obtained if interval to surgery is prolonged to more than 8 weeks.
authors.affiliation: Colorectal Surgical Oncology, Istituto Nazionale per lo Studio e la Cura dei Tumori-"Fondazione Giovanni Pascale" IRCCS, Naples, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Rega
authors.affiliation: Division of Radiotherapy, Department of Diagnostic Imaging, Radiant and Metabolic Therapy, Istituto Nazionale per lo Studio e la Cura dei Tumori-"Fondazione Giovanni Pascale" IRCCS, Naples, Italy.
authors.forename: Biagio
authors.initials: B
authors.lastname: Pecori
authors.affiliation: Colorectal Surgical Oncology, Istituto Nazionale per lo Studio e la Cura dei Tumori-"Fondazione Giovanni Pascale" IRCCS, Naples, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Scala
authors.affiliation: Division of Gastrointestinal Medical Oncology, Istituto Nazionale per lo Studio e la Cura dei Tumori-"Fondazione Giovanni Pascale" IRCCS, Naples, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Avallone
authors.affiliation: Colorectal Surgical Oncology, Istituto Nazionale per lo Studio e la Cura dei Tumori-"Fondazione Giovanni Pascale" IRCCS, Naples, Italy.
authors.forename: Ugo
authors.initials: U
authors.lastname: Pace
authors.affiliation: Division of Radiology, Department of Diagnostic Imaging, Radiant and Metabolic Therapy, Istituto Nazionale per lo Studio e la Cura dei Tumori-"Fondazione Giovanni Pascale" IRCCS, Naples, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Petrillo
authors.affiliation: Nuclear Medicine Unit, Istituto Nazionale per lo Studio e la Cura dei Tumori-"Fondazione Giovanni Pascale" IRCCS, Naples, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Aloj
authors.affiliation: Pathology Unit, Istituto Nazionale per lo Studio e la Cura dei Tumori-"Fondazione Giovanni Pascale" IRCCS, Naples, Italy.
authors.forename: Fabiana
authors.initials: F
authors.lastname: Tatangelo
authors.affiliation: Colorectal Surgical Oncology, Istituto Nazionale per lo Studio e la Cura dei Tumori-"Fondazione Giovanni Pascale" IRCCS, Naples, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Delrio
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011879:Radiotherapy Dosage; D012004:Rectal Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D012189:Retrospective Studies; D061665:Time-to-Treatment; D016896:Treatment Outcome