Preoperative Short-course Radiotherapy Versus Conventionally Fractionated Radio (Chemo) Therapy For Locally Advanced Rectal Cancer: A Meta-analysis

Aim There are2preoperative radiation regimens accepted as standard:short course (5fractions of5Gy delivered over1week) with surgeryperformed within the next week and conventionally fractionatedradio(chemo)therapy (25-30fractions of1.8or2Gy over5-6weeks) withsurgery performed4to8weeks after treatment completion.The implementof preoperative short-course radiotherapy(SCRT) in rectal cancer iscontentious nowadays.The aim of this meta-analysis was to comparepreoperative short-course radiotherapy(SCRT) with conventionallyfractionated radio(chemo)therapy(CRT) on short term and long termoutcomes.Methods We comprehensively searched Chinese databases and thefollowing English databases:Pubmed,Medline,Embase,Cochrane library andOvid, from1980until2012. The analysis included only randomizedcontrolled trials (RCTs) comparing the efficacy of SCRT and CRT as aneoadjuvant modality for locally advanced rectal cancer,which was clinically staged T2-4.Results Only three RCTs involving722patients qualified for thisreview according to our inclusion criteria.In the fixed effect model, SCRTand CRT were associated with equal local recurrence rate,distant metastasesrate and overall survival: OR0.91,95%CI（0.54,1.52）,P0.71;OR0.91,95%CI（0.66,1.26）,P0.23;OR1.11,95%CI（0.80,1.53）,P0.78.Conclusions Compared to CRT, SCRT performed similaroncological outcomes,such as local recurrence rate,distant metastasis rateand overall survival.Combined with better compliance to treatment,milderacute toxicity and the advantage of cost,SCRT is superior to CRT as aneoadjuvant modality for locally advanced rectal cancer,but multicentricRCTs with large sample size are still needed to further confirm the resultsdue to some limitations of this review.