Effect of biopsy protocol adherence vs non-adherence on dysplasia detection rates in Barrett's esophagus surveillance endoscopies: a systematic review and meta-analysis.

 Barrett's esophagus (BE) surveillance endoscopies are advised for early diagnosis of esophageal adenocarcinoma (EAC). Current guidelines recommend obtaining four-quadrant random biopsies every 2 centimeters of BE length alongside with targeted biopsies if visible lesions are present. Low adherence rates for this random biopsy protocol are widely reported. The aim of this systematic review and meta-analysis was to assess the effect of adherence versus non-adherence to the four-quadrant biopsy protocol on detection of dysplasia in BE patients.  We searched for studies that reported effects of adherence and non-adherence to the four-quadrant biopsy protocol on dysplasia detection rates in BE patients. Adherence was defined as taking a minimum of 4 quadrant random biopsies per 2 cm of BE segment. Studies with low risk of bias and without applicability concerns were included in a good quality synthesis. Pooled relative risks (RRs) with 95% confidence interval (CI) of dysplasia detection rates were calculated.  A total of 1,570 studies were screened and 8 studies were included. Four studies were included in the good quality synthesis. In the pooled good quality analysis, four-quadrant biopsy protocol adherence significantly increased detection of dysplasia compared to non-adherence (RR 1.90, 95 % CI = 1.36-2.64; I2 = 45 %). Pooled RRs for LGD and HGD/EAC were 2.00 (95 % CI = 1.49-2.69; I2 = 0 %) and 2.03 (95 % CI = 0.98-4.24; I2 = 28 %), respectively.  This systematic review and meta-analysis demonstrates that four-quadrant biopsy protocol adherence is associated with increased detection of dysplasia in BE patients. Efforts should be made to increase biopsy protocol adherence rates.