title: Clinical implication of negative conversion of predicted circumferential resection margin status after preoperative chemoradiotherapy for locally advanced rectal cancer.
abstract: OBJECTIVE
  To evaluate the prognostic implication of the negative conversion of predicted circumferential resection margin status before surgery in patients with locally advanced rectal cancer with predicted circumferential resection margin involvement.
  
  
  METHODS
  Thirty-eight patients (28 men, 10 women; median age, 61 years; age range, 39-80 years) with locally advanced rectal cancer with predicted circumferential resection margin involvement who underwent preoperative chemoradiotherapy followed by radical surgery were analyzed. Involvement of the circumferential resection margin was predicted on the basis of pre- and post-chemoradiotherapy magnetic resonance imaging. The primary endpoints were 3-year local recurrence-free survival and overall survival.
  
  
  RESULTS
  The median follow-up time was 41.1 months (range, 13.9-85.2 months). The negative conversion rate of predicted circumferential resection margin status after preoperative chemoradiotherapy was 65.8%. Patients who experienced negative conversion of predicted circumferential resection margin status had a significantly higher 3-year local recurrence-free survival rate (100.0% vs. 76.9%; P=0.013), disease-free survival rate (91.7% vs. 59.3%; P=0.023), and overall survival rate (96.0% vs. 73.8%; P=0.016) than those who had persistent circumferential resection margin involvement.
  
  
  CONCLUSIONS
  The negative conversion of the predicted circumferential resection margin status as predicted by magnetic resonance imaging will assist in individual risk stratification as a predictive factor for treatment response and survival before surgery. These findings may help physicians determine whether to administer more intense adjuvant chemotherapy or change the surgical plan for patients displaying resistance to preoperative chemoradiotherapy.
authors.affiliation: Department of Radiation Oncology, Korea University Medical Center, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Nam Kwon
authors.initials: NK
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Korea University Medical Center, Korea University College of Medicine, Seoul, Republic of Korea. Electronic address: kcyro@korea.ac.kr.
authors.forename: Chul Yong
authors.initials: CY
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Korea University Medical Center, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young Je
authors.initials: YJ
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, Korea University Medical Center, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Dae Sik
authors.initials: DS
authors.lastname: Yang
authors.affiliation: Department of Radiation Oncology, Korea University Medical Center, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Won Sup
authors.initials: WS
authors.lastname: Yoon
authors.affiliation: Division of Colorectal Surgery, Department of Surgery, Korea University Medical Center, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Seon Hahn
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Division of Colorectal Surgery, Department of Surgery, Korea University Medical Center, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jin
authors.initials: J
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care / Q000379:methods*; D011379:Prognosis; D012004:Rectal Neoplasms / Q000473:pathology* / Q000628:therapy*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015996:Survival Rate; D016896:Treatment Outcome
keywords: Circumferential resection margin; Magnetic resonance imaging; Preoperative chemoradiotherapy; Rectal neoplasms