title: Short-course Versus Long-course Preoperative Radiotherapy plus Delayed Surgery in the Treatment of Rectal Cancer: a Meta-analysis.
abstract: BACKGROUND
  Short-course preoperative radiation (SCRT) with delayed surgery was found to increase pathologic complete response (pCR) rates in several trials. However, there was no clear answer on whether SCRT or long-course chemo-radiotherapy (LCRT) is more effective. Therefore we conducted this meta-analysis to evaluate the safety and efficacy of SCRT versus LCRT, both with delayed surgery, for treatment of rectal cancer.
  
  
  METHODS
  The literature was searched from PubMed, EMBASE, Web of Science, Cochrane Library and clinicaltrials.gov up to November, 2014. Quality of the randomized controlled trials (RCTs) was evaluated according to the Cochrane's risk of bias tool of RCT. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to rate the level of evidence. Review Manager 5.3 was employed for statistical analysis. Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated.
  
  
  RESULTS
  Three RCTs, with a total of 357 rectal cancer patients, were included in this systematic review. Meta- analysis results demonstrated there were no significantly differences in sphincter preservation rate, local recurrence rate, grade 3~4 acute toxicity, R0 resection rate and downstaging rate. Compared with SCRT, LCRT was associated with significant increase in the pCR rate [RR=0.49, 95%CI (0.31, 0.78), P=0.003].
  
  
  CONCLUSIONS
  In terms of sphincter preservation rate, local recurrence rate, grade 3~4 acute toxicity, R0 resection rate and downstaging rate, SCRT with delayed surgery is as effective as LCRT with delayed surgery for management of rectal cancer. LCRT significantly increased pCR rate compared with SCRT. Due to risk of bias and imprecision, further multi-center large sample RCTs were needed to confirm this conclusion.
authors: Department of Radiation Oncology, Tumor Hospital of Jilin Province, Changchun, China E-mail : liushixin1964@126.com.
authors: Shi-Xin
authors: SX
authors: Liu
authors: Zhi-Rui
authors: ZR
authors: Zhou
authors: Ling-Xiao
authors: LX
authors: Chen
authors: Yong-Jing
authors: YJ
authors: Yang
authors: Zhi-De
authors: ZD
authors: Hu
authors: Tian-Song
authors: TS
authors: Zhang
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D006801:Humans; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000628:therapy*; D011300:Preoperative Care; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D016032:Randomized Controlled Trials as Topic; D012004:Rectal Neoplasms / Q000473:pathology / Q000628:therapy*; D012307:Risk Factors; D013997:Time Factors