Background: Tobacco smoking remains the leading preventable cause of cancer worldwide. The World Health Organization (WHO) introduced the Framework Convention on Tobacco Control MPOWER policy package (Monitor, Protect, Offer, Warn, Enforce, and Raise) in 2008 to accelerate tobacco control measures and reduce smoking prevalence worldwide. While these measures have been successfully implemented in many high-income countries in Europe and North America, substantial gaps persist across other WHO regions.  
Objective: This study aimed to quantify the potential number of cancer cases that could be prevented in the Eastern Mediterranean Region (EMR) and East Asia under scenarios of full MPOWER implementation.
Methods: Using population-level data, we examined the association between changes in the national implementation of the MPOWER policy package and tobacco smoking prevalence through a fixed-effects linear regression model. The analysis was performed separately for EMR and East-Asia. Using the results of the regression model, we estimated gender-specific prevalence of tobacco smoking for each country under a hypothetical scenario of full implementation of MPOWER package and estimated the population attributable fraction (PAF) for 13 tobacco-related cancers based on the current smoking prevalence and alternative scenario of full MPOWER implementation. The number of preventable cases was estimated as the difference of number of attributable cases between the current and alternative scenario. We used GLOBOCAN (IARC) crude, sex-specific cancer incidence projections for 2025–2050.
Results: Between 2025 and 2050, an estimated 163 million tobacco-related cancer cases are projected to occur in East Asian countries, of which 44.5 million (PAF: 27.3%; 95% CI: 25.4–29.3) are attributable to tobacco smoking. Over the same period, we estimated 14.3 million tobacco-related cancer cases in the EMR, with more than 3 million cases attributable to current tobacco smoking prevalence (PAF= 21.3%, 95% CI: 18.4 – 24.6). The full implementation of MPOWER measures are estimated to prevent approximately 3.5 million tobacco-related cancer cases in East Asia (95% CI: 2.9–4.0 million) and 154,200 tobacco-related cancer cases in the EMR (95% CI: 92,200–208,000) over the next 25 years.
Conclusion: Comprehensive implementation of anti-tobacco policies could reduce a substantial number of projected cancers in both East-Asian and EMR countries.