Comparison of short-course with long-course preoperative neoadjuvant therapy for rectal cancer: A meta-analysis.

Aim: This study attempted to compare the prognostic performance of short- and long-course preoperative treatments for neoadjuvant therapy of rectal cancer by meta-analysis.

Methods: Electronic databases of PubMed and Embase were searched for eligible studies updated to February 29, 2016. Studies were included based on several predefined inclusion criteria. Quality assessment was carried out according to the Cochrane Collaboration recommendations in Cochrane handbook. Outcomes such as 1-5 survival rates, death rate, recurrence rate, complication rate, and distant metastasis were evaluated. Odds ratio (OR) with the corresponding 95% confidence interval (CI) was used to calculate the pooled results. Subgroup analysis stratified by radiotherapy (RT) and chemoradiotherapy (CRT) was performed. Publication bias was detected based on Egger's test. Sensitive analysis was also performed.

Results: Eight studies were included, and they were randomized controlled trials or controlled clinical trials. The included studies involved a total of 1475 patients (short treatment: n = 665; long treatment: n = 810). No significant difference was detected in each outcome between the short- and long-course preoperative treatments. Subgroup analysis indicated that the outcome of distant metastasis was significantly higher in long-course RT, compared with the short-course RT (OR = 2.65, 95% CI: 1.05, 6.68). No significant publication bias was observed. Sensitive analysis did not show any reverse result.

Conclusion: Short- and long-course preoperative treatments seem comparable for management of rectal cancer, in terms of outcomes such as survival, recurrence, and complications. However, long-course RT might increase risk of distance metastasis, compared to short-course RT.