Lung cancer can be caused by risk factors other than smoking cigarettes, pipes, or cigars. Examples include exposure to other people’s smoke (called secondhand smoke), radon, air pollution, a family history of lung cancer, and asbestos.
In the United States, about 10% to 20% of lung cancers, or 20,000 to 40,000 lung cancers each year, happen in people who never smoked or smoked fewer than 100 cigarettes in their lifetime. Researchers estimate that secondhand smoke contributes to about 7,300 and radon to about 2,900 of these lung cancers.
Not to mention metastatic lung cancer that’s spread from other sites.
Also a blow to the head could be a result of violent or high risk tendencies, not the cause. Like x% of violent criminals have had head injuries because they are the sort of people who get into fist fights.
Anecdotes abound; my own father died of lung cancer at age 34, having never smoked nor been (much*) exposed to asbestos.
* he was not a miner, did not work with it, etc, but it was fairly ubiquitous, particularly in roofing, during his life. He was not a roofer either, he was a mild mannered English teacher.
Very few people develop primary cancer in their lungs if they never smoked, unless they lived with a heavy smoker for many years. From what I learned of oncology after seeing both my parents through death from cancer (not lung, in either case-- albeit, they had both been smokers, but quit c. 1964 when the “big” surgeon’s general report linking smoking to cancer came out; they died in 1997 & 2017), primary lung cancer that is not connected to smoking looks different under a microscope than cancer related to smoking.
You can develop smoking-related cancer (and other diseases) after having been a smoker, even if you quit years before. Every year after quitting improves your odds of not getting ill, but if you were a heavy or long-time smoker, you may never get back to the odds of a “never smoked” person.
Also, occasionally, something diagnosed in a living person as primary lung cancer turns out on autopsy to have originated elsewhere in some obscure place-- but not everyone is autopsied, so those cases all still go down statistically as lung cancer.
A fairly large fraction of natural deaths that aren’t autopsied are reported as “heart attack”. Both my father and my husband’s uncle’s death certificates says, “heart attack”. My dad was later autopsied (pulmonary embolism) but the death certificate didn’t change. And my husband’s uncle had a lot of health conditions that could have killed him, none involving the heart. He wasn’t autopsied. My husband thinks the death certificate was just written up that way in laziness by the police officer who found him. (He died alone, at home.)
It’s enough of a board that i don’t trust the official “prevalence of cause of death” statistics.
It’s true that lung cancer was rare until smoking became common, and then ballooned into a common cause of death. But it was just “very rare”, lung cancer wasn’t newly described when smoking caught on.
Just as a point of note, police don’t write death certificates. A medical examiner, county coroner, or treating physician will issue a (cause of) death certificate. You are right to question death statistics based upon death certificates alone because most corpses are not autopsied, and many county coroners are not actually medical pathologists or even medically trained at all. Unless a death occurred in a patient under treatment, the body was autopsied, or it was due to an obvious trauma, the cause of death is often just speculation, and the default assumption is typically heart failure or stroke.
Lung cancers (and COPV) can also be caused by a variety of environmental contaminants and is more common in certain occupations or women in developing countries cooking over wood fires without adequate ventilation, but smoking tobacco (or chronic smoking of marijuana) is basically inhaling a cocktail of carcinogens by the dose so it is by far the largest single contributor toward lung cancers.
Thank you for the details on who fills out death certificates. I know where the national mortality stats come from, and they are (mostly) from death certificates.
My father was autopsied, and the ME listed his cause of death as “complications of heart disease”. I found that unsatisfying enough to call the ME. He said there was no evidence of heart attack. But there was also no other evidence for a cause of death.
