title: Short-course preoperative radiotherapy with immediate surgery versus long-course chemoradiation with delayed surgery in the treatment of rectal cancer: a systematic review and meta-analysis.
abstract: BACKGROUND
  Long-course chemoradiotherapy (LCRT) with delayed surgery or short-course radiotherapy (SCRT) with immediate surgery is probably the most frequent regimen in the treatment of rectal cancer. Debate is still going on whether SCRT or LCRT is more effective. So we performed this meta-analysis to evaluate the safety and efficacy of SCRT with immediate surgery versus LCRT with delayed surgery for the management of rectal cancer.
  
  
  METHODS
  Literature were searched from PubMed, Embase, Web of science, Cochrane Library up to May, 2014. Quality of the randomized controlled trials (RCTs) was evaluated according to the Cochrane's risk of bias tool of RCT. RevMan 5.3 was used for statistical analysis. Pooled risk ratio (RR) and 95% confidence interval (CI) were calculated. Subgroup analysis and sensitivity analysis were employed to explore heterogeneity.
  
  
  RESULTS
  16 trials were included in the qualitative systematic review. 12 trials were included in meta-analyses. 4 of them were RCTs; other 8 were non-RCTs. Meta-analysis demonstrated that there were no significant differences in overall survival (OS), disease free survival (DFS), local recurrence rate (LRR), distant metastasis rate (DMR), sphincter preservation rate, R0 resection rate and late toxicity. Compared with SCRT, LCRT obviously increased pCR rate [RR=0.15, 95%CI (0.08, 0.28), P=0.003], while LCRT obviously increased the grade 3-4 acute toxicity [RR=0.13, 95%CI (0.06, 0.28), P<0.00001].
  
  
  CONCLUSIONS
  SCRT with immediate surgery is as effective as LCRT with delayed surgery for treatment of rectal cancer in terms of OS, DFS, LRR, DMR, Sphincter preservation rate, R0 resection rate and late toxicity. Though LCRT increased pCR rate, LCRT also increased acute toxicity compared with SCRT. SCRT is a better choice in centers with a long waiting list or lack of medical resources.
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, PR China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, PR China.
authors.forename: Zhi-Rui
authors.initials: ZR
authors.lastname: Zhou
authors.affiliation: Department of Radiation Oncology, Tumor Hospital of Jilin Province, No. 1018, Huguang Road, 130012 Changchun, PR China. Electronic address: liushixin1964@126.com.
authors.forename: Shi-Xin
authors.initials: SX
authors.lastname: Liu
authors.affiliation: Internal Medicine of Traditional Chinese Medicine Department, Jing'an District Central Hospital of Shanghai, No. 259, Xikang Road, 200040 Shanghai, PR China.
authors.forename: Tian-Song
authors.initials: TS
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedics, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin, PR China.
authors.forename: Ling-Xiao
authors.initials: LX
authors.lastname: Chen
authors.affiliation: Systematic Review Solutions Ltd, Nottingham NG72TU, UK.
authors.forename: Jun
authors.initials: J
authors.lastname: Xia
authors.affiliation: Department of Laboratory Medicine, General Hospital of Ji'nan Military Command Region, 250031 Ji'nan, PR China.
authors.forename: Zhi-De
authors.initials: ZD
authors.lastname: Hu
authors.affiliation: Department of Digestive System, Xiyuan Hospital, China Academy of Traditional Chinese Medicine, Xiyuan No.1, 100091 Beijing, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
mesh_terms: D001003:Anal Canal; D059186:Chemoradiotherapy, Adjuvant / Q000009:adverse effects; D002986:Clinical Trials as Topic; D018572:Disease-Free Survival; D006801:Humans; D020360:Neoadjuvant Therapy / Q000009:adverse effects / Q000379:methods*; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D018365:Neoplasm, Residual; D059351:Organ Sparing Treatments; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D012004:Rectal Neoplasms / Q000473:pathology* / Q000628:therapy*; D015996:Survival Rate; D013997:Time Factors
keywords: Chemoradiotherapy; Meta-analysis; Preoperative radiotherapy; Rectal cancer