title: Interval between surgery and neoadjuvant chemoradiation therapy for distal rectal cancer: does delayed surgery have an impact on outcome?
abstract: BACKGROUND
  The optimal interval between neoadjuvant chemoradiation therapy (CRT) and surgery in the treatment of patients with distal rectal cancer is controversial. The purpose of this study is to evaluate whether this interval has an impact on survival.
  
  
  METHODS
  Patients who underwent surgery after CRT were retrospectively reviewed. Patients with a sustained complete clinical response (cCR) 1 year after CRT were excluded from this study. Clinical and pathologic characteristics and overall and disease-free survival were compared between patients undergoing surgery 12 weeks or less from CRT and patients undergoing surgery longer than 12 weeks from CRT completion and between patients with a surgery delay caused by a suspected cCR and those with a delay for other reasons.
  
  
  RESULTS
  Two hundred fifty patients underwent surgery, and 48.4% had CRT-to-surgery intervals of 12 weeks or less. There were no statistical differences in overall survival (86% vs. 81.6%) or disease-free survival rates (56.5% and 58.9%) between patients according to interval (< or =12 vs. >12 weeks). Patients with intervals of 12 weeks or less had significantly higher rates of Stage III disease (34% vs. 20%; p = 0.009). The delay in surgery was caused by a suspected cCR in 23 patients (interval, 48 +/- 10.3 weeks). Five-year overall and disease-free survival rates for this subset were 84.9% and 51.6%, not significantly different compared with the remaining group (84%; p = 0.96 and 57.8%; p = 0.76, respectively).
  
  
  CONCLUSIONS
  Delay in surgery for the evaluation of tumor response after neoadjuvant CRT is safe and does not negatively affect survival. These results support the hypothesis that shorter intervals may interrupt ongoing tumor necrosis.
authors.affiliation: Habr-Gama Research Institute, São Paulo, SP, Brazil. gamange@uol.com.br
authors.forename: Angelita
authors.initials: A
authors.lastname: Habr-Gama
authors.forename: Rodrigo Oliva
authors.initials: RO
authors.lastname: Perez
authors.forename: Igor
authors.initials: I
authors.lastname: Proscurshim
authors.forename: Rafael Miyashiro
authors.initials: RM
authors.lastname: Nunes Dos Santos
authors.forename: Desiderio
authors.initials: D
authors.lastname: Kiss
authors.forename: Joaquim
authors.initials: J
authors.lastname: Gama-Rodrigues
authors.forename: Ivan
authors.initials: I
authors.lastname: Cecconello
mesh_terms: D001938:Brazil / Q000453:epidemiology; D017024:Chemotherapy, Adjuvant / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000517:prevention & control*; D012004:Rectal Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery*; D012189:Retrospective Studies; D016019:Survival Analysis; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome