Abstract 1199: Global cancers attributable to modifiable risk factors: Current and former smoking prevalence

Abstract Purpose: This study aims to estimate the global population attributable fraction (PAF) of cancer incidence and mortality due to tobacco smoking, further stratified by country, human development index (HDI) categories, cancer types, gender, and smoking status (current versus former smokers). Methods: PAFs were estimated using the prevalence of cancer cases in 2022 and relative risks (RRs) derived from large-scale pooled analyses and comprehensive meta-analyses. Population estimates were sourced from the World Bank, and cancer incidence and mortality data for 2022 were obtained from the Global Cancer Observatory (GLOBOCAN), spanning various HDI groups. Smoking rates from 180 countries in the year 2000 were utilized to account for latency periods. Results: Cancers with the highest global PAFs in current and former smokers for incidence (I) and mortality (M) were laryngeal (75.4%, I: n=140,000; M: n=78,000), lung (70.2%, I: n=1,720,000; M: n=1,290,000), pharyngeal (66.3%, I: n=130,000; M: n=61,000), oral cavity ( 39.7%, I: n=150,000; M: n=75,000), and bladder cancers (37.9%, I: n=230,000; M: n=82,000), where n represents number of cases. Overall global cancer burden attributable to smoking was determined to be 18.8%, with an overall PAF of 28.3% in male cases and 8.4% in female cases. Total cancer burden in very high, high, medium, and low HDI countries was calculated to be 23.6%, 25.7%, 19.7%, and 10.4% respectively. Overall cancer burdens for current and former smokers were calculated to be 16.0% and 2.8%, respectively. The countries identified as the highest risk for tobacco-related cancer incidence and mortality included Bangladesh, Turkey, North Korea, Cuba, and Hungary, with total cancer burdens of 27.1%, 26.6%, 26.3%, 26.1%, and 25.8% respectively. Conclusions: Laryngeal, lung, pharyngeal, oral cavity, and bladder cancers had the highest cancer burden from tobacco smoking. Current smokers had higher cancer burdens than former smokers, while males had a greater cancer burden than females. Nations with higher HDI levels experience greater cancer incidence and mortality rates compared to lower HDI countries. Data-driven trends indicate that cultural norms, industry influence, and limited resources hinder tobacco control in low-HDI nations, while tailored, gender-sensitive programs and taxation in high-HDI countries demonstrate success but need reinforcement. These findings highlight the critical need for tailored smoking cessation efforts, cancer screening procedures, and reporting practices while considering HDI and gender disparities. Citation Format: Darshi Shah, Veer Shah, Karan Shah, Prachi Shah, Monireh Sadat Seyyedsalehi, Paolo Boffetta. Global cancers attributable to modifiable risk factors: Current and former smoking prevalence [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1199.