title: The Emerging Non-operative Management of Non-metastatic Rectal Cancer: A Population Analysis.
abstract: OBJECTIVE
  Recent studies have piloted a nonoperative approach in patients with a complete clinical response to neoadjuvant chemoradiation for non-metastatic rectal cancer. This study evaluated these outcomes in the Surveillance, Epidemiology, and End Results (SEER) database.
  
  
  METHODS
  Using SEER database 8.1.5, we identified patients diagnosed with stage II-III rectal adenocarcinoma between 2004-2011, treated with radiation alone (RT), RT then surgery (RT-S), or surgery then RT (S-RT). Utilization patterns were investigated for all three groups and evaluated using the Chi-squared test. A secondary analysis was limited to current approaches (RT or RT-S). Overall survival (OS) was compared using the log-rank test. Predictors for nonoperative management were compared by multivariable analyses.
  
  
  RESULTS
  From 2004 to 2011, utilization of RT increased from 4% to 8%, RT-S from 57% to 75%, and S-RT decreased from 39% to 18% (p<0.001). In the secondary analysis, predictors for nonoperative management were lower T-stage and N-stage tumors, non-White race, and male sex. With 5,909 evaluable patients at a median follow-up of 35 months, the 5-year OS in the RT group was 56% vs. 80% in the RT-S group (log-rank p<0.001).
  
  
  CONCLUSIONS
  Nonoperative management of rectal cancer is increasing despite an apparent detriment in OS compared to a combined modality approach, that may reflect a selection bias in the SEER database.
authors.affiliation: Tufts University School of Medicine, Tufts Medical Center, Boston, MA, U.S.A. mabrams@tuftsmedicalcenter.org.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Abrams
authors.affiliation: Tufts University School of Medicine, Tufts Medical Center, Boston, MA, U.S.A.
authors.forename: Paul P
authors.initials: PP
authors.lastname: Koffer
authors.affiliation: The Warren Alpert School of Medicine, Brown University, Rhode Island Hospital, Providence, RI, U.S.A.
authors.forename: Kara L
authors.initials: KL
authors.lastname: Leonard
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy; D000328:Adult; D000368:Aged; D059248:Chemoradiotherapy / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D018714:Radiotherapy, Adjuvant / Q000379:methods; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D012074:Remission Induction / Q000379:methods; D018426:SEER Program; D016896:Treatment Outcome; D055815:Young Adult
keywords: Nonoperative management; SEER; rectal cancer