All this talk about tobacco but nothing about alcohol, for which there is much stronger evidence of DNA damage? Does the BBC have a hidden conflict of interest?
Do you have a link supporting the DNA damage and alcohol relationship? That's interesting.
Lung cancers are particular in that they feature an incredible amount of somatic mutation. If I remember its at least 10x as much as the next high-mutation rate cancer. Probably more even. Smoking tobacco provides a melange of mutagens: complex aromatic DNA adducts that result from combustion, heavy oils, and radiation from potassium heavy fertilizer. These would be enough to cause problems alone, but to make things as bad as possible the active ingredient is a critical signaling molecule in the cell cycle, which after copious application is likely to induce the survival of cells unresponsive to it. These cells are less likely to play nice with others.
"Do you have a link supporting the DNA damage and alcohol relationship? That's interesting."
Not the op but alcoholics are likelier to develop e.g. pancreatic cancer. I believe the direct mechanism, though, is not explained. "About 7 out of 10 cases of chronic pancreatitis are due to long term heavy drinking":
