[Gatsky]

That's a good point, I am not a lawyer so I can't really comment. But perhaps there is a material difference between saying you developed a disease that could have been caused by smoking (as lung cancer occurs in non-smokers), and saying you were definitely harmed by smoking.

Other avenues could be:

- Smoking is also associated with other cancers, such as esophageal cancer and bladder cancer. Generally the warnings don't mention this however. By examining the mutation patterns in an esophageal cancer, you could relate it more conclusively to smoking, and could therefore claim you were not warned about that specific risk.

- Tissue samples from lung cancers diagnosed 20 or 30 years ago are sitting in archival storage. You could sequence the whole genome or exome of these tumours for about $1000 - $2000. Statute of limitations aside, sequencing these tumours could reveal the tobacco signature as a basis for a claim from a time when it was less clear or less public what the risks were.

- Passive smokers could have a case if their cancer shows a tobacco signature.

[gozur88]

I don't see how you can prove particular mutations are tobacco related. DNA can be damaged by viruses, solar radiation, various industrial chemicals, and naturally occurring replication errors. How would you prove this particular mutation was the result of smoking?

I don't see how this research changes anything from a legal perspective. We already knew smoking causes genetic mutations, but we also know people who've never been exposed to tobacco can develop lung cancer.

[Gatsky]

The aim is to prove that the pattern of mutations in the tumour (which typically contains several hundred mutations in coding regions, more in the whole genome) are caused by smoking.

[umanwizard]

Lung cancer is caused by smoking 85-90% of the time. Probably more if you add in secondhand smoke. I think it already meets any sort of "preponderance of evidence" sort of bar to just assume anyone with lung cancer got it from smoking.

[wallyhs]

Suppose that I live in an apartment with a wood stove, second-hand smoke from a room mate, and radon. If I get lung cancer, which one is to blame? How do you know?

[ghurtado]

Citation / reference needed.

[umanwizard]

I googled it and the same stat on a couple different reputable sites, like that of the American Lung Association and the American Cancer Society.