Short-course Versus Long-course Preoperative Radiotherapy plus Delayed Surgery in the Treatment of Rectal Cancer: a Meta-analysis

Background: Short-course preoperative radiation (SCRT) with delayed surgery was found to increasepathologic complete response (pCR) rates in several trials. However, there was no clear answer on whetherSCRT or long-course chemo-radiotherapy (LCRT) is more effective. Therefore we conducted this meta-analysisto evaluate the safety and efficacy of SCRT versus LCRT, both with delayed surgery, for treatment of rectalcancer. Materials and
Methods: The literature was searched from PubMed, EMBASE, Web of Science, CochraneLibrary and clinicaltrials.gov up to November, 2014. Quality of the randomized controlled trials (RCTs) wasevaluated 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 wasemployed 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. Metaanalysisresults demonstrated there were no significantly differences in sphincter preservation rate, localrecurrence rate, grade 3~4 acute toxicity, R0 resection rate and downstaging rate. Compared with SCRT, LCRTwas 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 anddownstaging rate, SCRT with delayed surgery is as effective as LCRT with delayed surgery for management ofrectal 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.