Introduction: Non-tobacco products (NTP) are increasingly popular as an alternative to traditional tobacco use, raising concerns about potential health risks. This systematic review and meta-analysis examine the association of NTP use with oral, esophageal, & pharyngeal cancer, and oral potentially malignant disorders (OPMD) in adults.
Methods: A comprehensive electronic search was conducted in PubMed, Embase, and Google Scholar, for observational studies that evaluated the association between NTP use, and oral, esophageal, & pharyngeal cancer and OPMD, published till December 2023 in the English language. The quality of the included studies was assessed using the Newcastle-Ottawa scale. Pooled odds ratio (OR) with a 95% Confidence Interval (CI) was obtained using a random effects model, heterogeneity was assessed using I2 statistic. Sub-group analysis was conducted based on the year of publication, a comparator for association, type of NTP user, and country.
Results: Forty-nine studies were included in the meta-analysis with a combined total of 1,32,390 participants, revealing a significant association between NTP use and increased risk of cancers- oral (OR:5.0, 95% CI 3.3-7.7), esophageal (OR:3.0, 95%CI 1.2-7.5), and OPMD (OR:15.3, 95%CI 8.8-26.7). The proportion of the annual burden of oral and esophageal cancers attributable to NTP was 33% (30,667 cancers), and 19% (8,025 cases) respectively in India.
Conclusion: This review provides strong evidence for the association between NTP use and increased risk of oral, and esophageal cancer and OPMD. The findings highlight the need for targeted interventions, firmer regulations, and awareness campaigns addressing NTP. Incorporating NTP as a separate category in national surveys can help reduce their burden, particularly in high-risk populations.
Keywords: non-tobacco products; oral cancer; risk factors.