Barrett’s oesophagus: Evidence from the current meta-analyses

Table 3 Meta-analyses comparing cancer risk in different groups of patients with Barrett’s oesophagus

Subject	Ref.	Comparison	Group	Studies	Results	Outcome
Medical vs surgical treatment of reflux	Corey et al[16]	Antireflux surgery vs medical treatment	Antireflux surgery	34	18 cancers/4678 patient-years (0.38% per annum)	No significant difference in cancer risk between medical and surgical antireflux therapy
			Medical therapy		26 cancers/4906 patient-years (0.53% per annum)
Endoscopic ablative therapy vs surveillance	Wani et al[25]	Non-dysplastic Barrett’s oesophagus	Surveillance	45	5.98/1000 patient-years	Endoscopic ablative therapy is effective in reducing adenocarcinoma risk in patients with non-dysplastic Barrett’s oesophagus, low-grade dysplasia and high-grade dysplasia compared to surveillance alone
			Endoscopic ablative therapy	49	1.63/1000 patient-years
		Low-grade dysplasia	Surveillance	16	16.98/1000 patient-years
			Endoscopic ablative therapy	21	1.58/1000 patient-years
		High-grade dysplasia	Surveillance	4	65.8/1000 patient-years
			Endoscopic ablative therapy	28	16.76/1000 patient-years
Demographic factors	Thomas et al[26]	Location	United Kingdom	13	7/1000 patient-years	Cancer incidence similar in all geographic areas
			United States	16	7/1000 patient years
			Europe	10	8/1000 patient-years
			Australia and New-Zealand	2	5/1000 patient-years
	Yousef et al[27]	Gender	Males	6	10.2/1000 patient-years	Cancer incidence in males is double the rate in females
			Females	5	4.5/1000 patient-years
Segment length	Thomas et al[26]	Segment length	Short segment	6	2.8/1000 patient-years	Trend for lower risk in short segment Barrett’s oesophagus (P = 0.25)
			Long segment	6	7.8/1000 patient-years
	Yousef et al[27]	Segment length	Short segment	6	6.1/1000 patient-years	Similar risk in short and long segment disease
			Long segment	26	6.7/1000 patient-years
Dysplasia	Thomas et al[26]	Low-grade dysplasia as a confounding factor	Presence of low-grade dysplasia at index endoscopy	15	P = 0.23	No significant confounding effect on cancer incidence in meta-regression analysis
Helicobacter pylori	Rokkas et al[30]	All Helicobacter pylori	Cases	10	253/757 (34.3%)	Helicobacter pylori associated with lower rate of oesophageal cancer OR, 0.52; (95%CI: 0.37, 0.73)
			Controls	10	1398/2788 (50.1%)
		Cag A Helicobacter pylori	Cases	6	120/462 (26%)	Cag A Helicobacter pylori associated with lower rate of oesophageal cancer OR, 0.51; (95%CI: 0.31, 0.82)
			Controls	6	774/1936 (40%)
Non-steroidal Anti-inflammatory drugs Statins	Wang et al[31]	Aspirin and NSAIDs vs controls		3	RR 0.64 (95%CI: 0.42, 0.96)	Lower risk of adenocarcinoma in patients taking aspirin or NSAIDs
	Alexandre et al[33]	Statins vs controls		2	RR, 0.53 (95%CI: 0.36, 0.78)	Protective effect of statins vs controls
	Singh et al[36]			5	RR, 0.57; (95%CI: 0.44, 0.75)
Statins and NSAIDs	Singh et al[36]	Combined statins and NSAIDs vs neither		2	0.28; (95%CI: 0.14, 0.56)	Protective effect of NSAIDs and statins higher than either individually

NSAIDs: Nonsteroidal antiinflammatory drugs; OR: Odds ratio; CI: Confidence interval.