Is shift-work associated with increased risk of esophageal cancer for males? A meta-analysis.

Abstract

190 Background: Globally, more than 570,000 people are diagnosed of esophageal cancer each year. Shift-work involving circadian disruption was designated as a probable cause of cancer by The International Agency for Research on Cancer. Previous studies investigating the relationship between shift-work and esophageal cancer among showed controversial results. Thus, this meta-analysis was conducted. Methods: A comprehensive literature search on PubMed was conducted to identify all relevant studies published prior to September 2020 according to the established inclusion criteria. The quality assessment was performed by the Newcastle-Ottawa Scale (NOS). The pooled odds risk (OR) and 95% confidence intervals (CI) were calculated to estimate the association between the shift-work and esophageal cancer risk. Random-effect or fixed-effect model was used to calculate the pooled OR, based on heterogeneity significance. Subgroup analyses were conducted based on night-shift versus rotating-shift. Sensitivity analysis and publication bias detection were also performed. All statistical analyses were performed using RevMan software (version 5.3; Cochrane library) and STATA 12.0 statistical software (Stata Corp., College Station, TX), and all P values were two-tailed, the test level was 0.05. Results: 21 articles were obtained from database searching, and 9 articles were obtained from other sources. 3 articles involving 52,098 participants were included. All studies were considered moderate to high quality. All included studies investigated only males on the association between shift-work and esophageal cancer risk. A statistically significant association between shift-work and increased esophageal cancer risk among males was found (OR 2.09, 95%CI: 1.48, 2.94, P< 0.0001, I 2= 29%). In subgroup analyses, night-shift work was associated with a non-statistically significant increased risk of esophageal cancer (OR 1.56, 95%CI: 0.96, 2.53, P= 0.07, I 2= 0%). In contrast, Rotating-shift was associated with increased esophageal cancer risk (OR 2.80, 95%CI: 1.72, 4.57, P < 0.0001, I 2= 0%). Sensitivity analysis confirmed the stability of the result. Funnel plot, Egger's test, and Begg's test found no publication bias of analysis (P = 0.572). Conclusions: The current meta-analysis demonstrates that shift-work is associated with increased esophageal cancer risk for males. However, no association between night-shift work and esophageal cancer risk was found. In contrast, association between rotating-shift work and increased esophageal cancer risk was found. Original studies on females regarding shift-work and esophageal cancer risk are lacking. More original studies on this topic for both male and female are needed to further explore shift-work impacts on esophageal cancer risk.