BIOPSY OR NOT TO BIOPSY? OUTCOMES OF THE IRREGULAR Z-LINE: A SYSTEMATIC REVIEW AND META ANALYSIS

Introduction: Irregular Z-line, defined as < 1 cm segment of columnar mucosa in distal esophagus, is commonly encountered and frequently biopsied. Consensus guidelines recommend against biopsies of irregular z-line due to low risk of progression to esophageal cancer (EAC). Despite this, presence of irregular Z-line with or without intestinal metaplasia (IM), dysplasia or EAC is encountered in practice and clinical significance is unclear. The aim of this meta-analysis was to study the prevalence of Barrett’s esophagus (BE), dysplasia and EAC in patients with irregular Z-line.
Methods: Major multiple databases, such as MedLine, Embase, Scopus, were searched from inception through October 2023 to identify studies that reported prevalence of BE, dysplasia and EAC in patients with irregular z-line. Standard meta-analysis methods were employed using the random-effects model, and I2 statistics was used to study heterogeneity. Primary study outcomes were IM with and without dysplasia, IM with low grade dysplasia (LGD) and high grade dysplasia (HGD), and EAC.
Results: A total of 10 studies (17,573 patients with irregular Z-line) were included in the final analysis. 6 studies evaluated patients without IM, and four studies included patients with IM. Mean age was 58.2 years, 63.1% were male% and the majority were caucasian. In patients with irregular Z-line at index endoscopy, the Pooled prevalence rate of IM in patients with irregular Z-line was 29.4% (95% CI [24.8 - 34.4; I2=95%]), IM without dysplasia was 27.5% [23.1-32.5; I2=96%], IM with dysplasia was 0.8% [0.4-1.6; I2=80%], IM with LGD was 1.3%[1.1-1.5; I2=0%], IM with HGD was 0.2%[0.2-0.4; I2=0%] and EAC was 0.2%[0-1.1; I2=0%]. In patients with irregular Z-line with IM, the pooled prevalence of IM with dysplasia was 6.2%( 95% CI [1.1 -27.8, I2= 93%], IM with LGD was 5.9%[2.5 - 13.3; I2=68%], IM with HGD was 1.6%[.1 - 15.4; I2=81%] and EAC was 1.5%[0.2 - 11.2; I2=76%]. By pairwise comparison, patients with irregular Z-line and IM demonstrated significantly higher rates of dysplasia and LGD. Pooled rates are summarized in Table-1.
Conclusion: Based on this meta-analysis, in patients with irregular Z-line and IM, pooled rate of LGD was 5.9%, HGD was 1.6% and EAC was 1.5%. Corresponding pooled values in patients with irregular Z-line without IM were 1.3%, 0.2% and 0.2%. Our results seem to suggest that patients with irregular Z-line and IM might represent a high-risk population who might benefit from serial endoscopic surveillance. Future studies are warranted to establish the need to biopsy an index finding of irregular Z-line.