title: Independent radiologic review in metastatic colorectal cancer: systematic review and meta-analysis.
abstract: OBJECTIVE
  To perform a meta-analysis addressing evaluation bias in local radiologic assessment (LRA) of lesions when compared with independent radiologic review (IRR) in randomized controlled trials (RCTs) testing chemotherapy for metastatic colorectal cancer (CRC).
  
  
  METHODS
  MEDLINE, EMBASE, ClinicalTrials.gov, the Cochrane Library, and Web sites for major medical meetings were searched for RCTs of chemotherapy for metastatic CRC that reported response evaluation by both LRA and IRR. The risk ratios (RRs) of response in the experimental (RR(exp)) and control (RR(cont)) arms were calculated (response rate in LRA divided by response rate in IRR) for each selected study. The ratio of RR of response was calculated (RR of response of LRA divided by RR of response of IRR). The random-effects model was applied. Meta-regression was used to examine the effect of study characteristics on outcomes.
  
  
  RESULTS
  LRA and IRR results were concordant (13 studies; 7742 patients; ratio of RR of response = 0.97; 95% confidence interval [95% CI]: 0.90, 1.04; P = .35). However, LRA overestimated tumor response independently of therapy allocation (interaction test, P = .81) both in control (RR(cont), 1.163; 95% CI: 1.086, 1.246; P < .001) and experimental (RR(exp), 1.156; 95% CI: 1.093, 1.222; P < .001) therapies. Meta-regression did not show any effect of trial characteristics on effects.
  
  
  CONCLUSIONS
  LRA yields higher response rates in RCTs testing chemotherapy for metastatic CRC, although there was no sign of bias toward experimental therapy. The need for IRR to control evaluation bias must be reappraised.
authors.affiliation: Department of Medical Oncology, Barretos Cancer Hospital, Barretos, Brazil. jpsnlima@yahoo.com.br
authors.forename: João Paulo da Silveira Nogueira
authors.initials: JP
authors.lastname: Lima
authors.forename: Fabiano Hahn
authors.initials: FH
authors.lastname: de Souza
authors.forename: Diocésio Alves Pinto
authors.initials: DA
authors.lastname: de Andrade
authors.forename: José Barreto Campello
authors.initials: JB
authors.lastname: Carvalheira
authors.forename: Lucas Vieira
authors.initials: LV
authors.lastname: dos Santos
mesh_terms: D016009:Chi-Square Distribution; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000188:drug therapy* / Q000473:pathology; D003952:Diagnostic Imaging; D006801:Humans; D009362:Neoplasm Metastasis; D016032:Randomized Controlled Trials as Topic; D012044:Regression Analysis; D016019:Survival Analysis