Despite publicly admitting, to varying degrees, that cigarette smoking causes cancer, the industry has consistently dismissed these claims for people who have sued them, reveals an analysis of recent lawsuits, published in a supplement to Tobacco Control.
The authors looked at the opening and closing statements of the defence, witness statements, and depositions for 34 personal injury claims brought against major tobacco manufacturers between 1986 and 2003 in the US.
They used data archived in the Tobacco Deposition and Trial Testimony Archive (DATTA).
Each of the arguments put forward by the companies were categorised into seven different groups.
These included an absence of scientific proof that cigarette smoking causes cancer, denials that the plaintiff had lung cancer, or accepting that the plaintiff had lung cancer, but of a variety not caused by the particular product in question.
The defence also argued that the presence of other risk factors invalidated the claims that tobacco was solely responsible and that the plaintiff had exercised free will, despite knowing the risks to health of smoking.
The use of the 'no scientific proof to link cigarette smoking with cancer' defence declined as companies began to publicly admit that smoking causes disease, starting in the late 1990s.
But the defence of mitigating factors and the exercise of free will correspondingly increased over the same period.
The authors conclude: The cigarette companies, through their public admissions and courtroom arguments, seem to be saying: 'Yes, smoking causes lung cancer, but not in the people who sue us.'