BACKGROUND-AIM:
Tobacco smoking is one of the most important modifiable risk factors for several cancers. While its association with respiratory tract malignancies is well established, smoking also plays a major role in the aetiology of digestive tract cancers. In Italy, these neoplasms account for a substantial proportion of cancer incidence and mortality, highlighting the need to quantify the burden attributable to cigarette smoking.

METHODS:
We applied an innovative individual-level approach to estimate the population attributable fraction (PAF) of digestive tract cancer cases (including oral cavity and pharynx, oesophagus, stomach, and colorectum) attributable to active smoking in Italy in 2022. This method incorporates both smoking status (current, former, or never smokers) and individual characteristics such as smoking intensity, duration, and time since cessation. Estimates were based on data from a nationally representative survey of smoking habits, relative risks estimated using meta-analytical techniques, and national cancer incidence statistics.

RESULTS:
In Italy, in 2022, cigarette smoking accounted for an estimated population attributable fraction (PAF) of 32.0% for oral and pharyngeal cancers, 26.2% for oesophageal cancers, 14.0% for gastric cancers, and 6.6% for colorectal cancers. Overall, smoking was responsible for approximately 8396 digestive tract cancer cases, corresponding to 10.8% of all digestive tract cancer cases in Italy in 2022.

CONCLUSIONS:
These findings reveal a substantial contribution of smoking to the burden of digestive tract cancers and emphasize the urgency of reinforcing tobacco control policies and awareness campaigns. Integrating primary prevention measures within existing screening programs could further reduce the impact of smoking-related cancers.