BACKGROUND: Current guidelines support the use of adjuvant chemotherapy (CT) following neoadjuvant chemoradiotherapy (CTRT) and surgery to treat @entity5 , although clinical trials have provided little evidence that it is effective. We performed a systematic review of published studies to assess whether adjuvant CT improves outcome after neoadjuvant therapy and radical surgery in cases of @entity5 . MATERIALS AND METHODS: We conducted an electronic database search for randomized and nonrandomized studies in PubMed, EMBASE, Web of Science, Scopus and the Cochrane Register of Controlled Trials. We then carried out a meta-analysis by using the fixed- or random-effects models. The primary endpoint was 5-year @entity1349 ( @entity1349 ) reported as odds ratios (ORs) and 95  % confidence intervals (CIs). RESULTS: Two randomized controlled trials (RCTs), one pooled analysis of five RCTs and 10 retrospective studies that included a total of 5,457 @entity1 matched our selection criteria. Meta-analysis showed that for @entity5 @entity1 treated with surgery and neoadjuvant CTRT, adjuvant CT improves 5-year @entity1349 (OR, 0.64; 95  % CI, 0.46-0.88; p   =   0.006) and 5-year disease-free survival (DFS) (OR, 0.71; 95  % CI, 0.6-0.83; p   <   0.0001). The 5-year @entity1349 benefit was significantly larger in downstaged @entity1 and in retrospective series. A better DFS was instead noted in all studies due to a reduced risk of local relapse. CONCLUSIONS: Amongst @entity5 @entity1 treated with neoadjuvant therapy and surgery, adjuvant CT seems to improve the 5-year DFS and @entity1349 rates and may be discussed with @entity1 . However, the benefit derives mainly from retrospective evidence.

A systematic review and meta-analysis of adjuvant chemotherapy after neoadjuvant treatment and surgery for XXXX .

@entity5 :: ('MESH:D009369', 'Disease') :: ['rectal cancer'] @entity1 :: ('9606', 'Species') :: ['patients'] @entity1349 :: ('MESH:D011475', 'Disease') :: ['overall survival', 'OS']
@entity5 :: (MESH:D009369,Disease) :: ['rectal cancer']
