Short-Course Radiotherapy in Neoadjuvant Treatment for Rectal Cancer: A Systematic Review and Meta-analysis

Background: To assess whether preoperative short-course radiotherapy (PSRT) could be the treatment of choice compared to preoperative long-course chemoradiotherapy (PLCRT) METHODS: The PubMed, Embase, and Web of Science Databases were searched to conduct a systematic review and meta-analysis. Perioperative and survival outcomes between PSRT and PLCRT were selected as end points for our meta-analysis. In addition, health-related quality-of-life outcomes were also systematically reviewed between PSRT and PLCRT. Finally, we also reviewed evidence of optimized regimens of PSRT (with delayed surgery or adding consolidation chemotherapy).

Results: PLCRT showed a better pathologic complete response (pCR) rate (odds ratio = 0.05, 95% confidence interval = 0.02-0.18, P < .01), but this benefit did not translate into a higher sphincter preservation rate (odds ratio = 1.62, 95% confidence interval = 0.72-3.67, P = .25) or other perioperative outcome differences. In terms of survival outcomes, adding either PLCRT or PSRT both showed obvious advantages for local control compared to surgery alone, and PSRT and PLCRT had similar long-term outcomes irrespective of pairwise or network meta-analyses. Moreover, on the basis of health-related quality-of-life scores, PSRT and PLCRT also had no overall differences. Systematic review of current evidence indicates that the insufficiency of PSRT on pCR might be improved by delayed surgery or adding consolidation chemotherapy.

Conclusions: PSRT could be the treatment of choice compared to PLCRT when pCR is not the primary aim. PSRT with delayed surgery or adding consolidation may provide further possibilities for the future evolution of neoadjuvant therapies.