Physician challenges lung cancer statistic


By Don Setliff, M.D.

As a practicing ENT physician of 30-plus years, I must object to Maria Connor’s article in the April 30 edition of your publication. She states, “Almost two-thirds of people who get lung cancer don’t smoke.” This is simply untrue.

About 85 percent of lung cancer is directly smoking related, while only 24 percent or so of all adults smoke. That is no coincidence. When I was a resident at UCSD, I reviewed 430 patient charts of patients with squamous cell carcinoma (by far the most common type of respiratory tract cancer), and 96 percent of the charts documented a history of cigarette smoking, at least one pack per day for at least 20 years. Many patients diagnosed with squamous cell cancer (SCC) are ex-smokers, but the carcinogenic effects of smoking for 20 years or more do not cease when they quit smoking. The odds of contracting SCC slowly decrease over many years after the person stops smoking, but it is very common to diagnose SCC in people who quit smoking as much as seven to eight years earlier. The histologic type of cancer that non-smokers most often get is adenocarcinoma, the cause of which remains obscure, as it does for most other solid tissue cancers and for leukemias.

The most disturbing part of Maria’s misstatement is that it gives the impression that cigarette smoking is not the main cause of lung cancer, an impression that may even encourage taking up the habit, especially young readers. This attempts to undo the progress that has been made in our society in educating the public that lung cancer is mainly caused by smoking cigarettes — not exclusively, but mainly. Not to mention emphysema, chronic bronchitis, oral cancer (also almost always SCC), throat and voicebox cancer (SCC), bladder cancer. That smoking contributes heavily to cardiovascular disease is well established in the medical literature.

It is one thing to point out that not all lung cancer is caused by cigarettes. It is quite another to claim that two-thirds of lung cancer is not smoking-related. Smoking cigarettes remains the single greatest cause of preventable human death and disability; nothing else even comes close. You should publish a prominent correction to this completely erroneous assertion.