The Burden of Lip and Oral Cavity Cancer Among Women Across 204 Countries and Territories in the Context of the Framework Convention on Tobacco Control: An Interrupted Time Series Analysis

Background: Historically, lip and oral cavity cancer (LOC) has been more prevalent among men, largely due to higher tobacco use in this group. However, over the past decades, smoking rates among women have risen and, in some regions, are approaching those of men. This shift highlights the urgent need to analyze the burden of LOC specifically in women, as they may respond differently to tobacco control policies. This study assessed whether the World Health Organization Framework Convention on Tobacco Control (WHO-FCTC), launched in 2003, and the implementation of MPOWER measures have influenced LOC trends among women. Methods: A controlled interrupted time series was conducted from 1990 to 2021, with the launch of the WHO-FCTC considered the intervention point. A total of 204 countries and territories were initially categorized into two groups: those without (G1) and with (G2) MPOWER coverage. G2 was further subdivided based on the median MPOWER score from 2007 to 2020 into G2A (equal to or below the median) and G2B (above the median). Analyses were also stratified by Socio-Demographic Index (SDI) levels. Female LOC rates were obtained from the Global Burden of Disease Study 2021. Prais-Winsten segmented regression was applied to estimate annual percent changes (APCs) in LOC rates before and after the WHO-FCTC. Results: Prior to the WHO-FCTC, most trends for G1 and G2A were stable, while all trends for G2B were increasing. After 2003, LOC rates increased across all groups, especially in G2B. In high-SDI settings, rising trends in G2B remained unchanged post-intervention, whereas G1 and G2A shifted from stable to increasing. Among low-SDI groups, slopes were mostly not statistically significant. Conclusions: These findings suggest that the WHO-FCTC has had no measurable impact on reducing LOC burden among women so far. Instead, rates have continued to rise in many regions, signaling a concerning trend for women’s global health.