Cancer itself isn’t deterministic. This isn’t news. There is virtually nothing that is 100% guaranteed to produce cancer, but there are things that massively increase risk. Tobacco is one of them.
An estimated 72% of lung cancers in Canada are caused by tobacco (https://www.canada.ca/en/health-canada/services/health-conce...) Smokers are 25x more likely to die of lung cancer as nonsmokers. The US CDC estimates that smoking is linked to 80-90% of lung cancer deaths (https://www.cdc.gov/cancer/lung/basic_info/risk_factors.htm).
Saying “tobacco causes lung cancer” isn’t guaranteeing that smoking leads to lung cancer, but it sure as hell is the leading cause.
