Last week's story about University of Arizona medical student Derek Neal's battle with lung cancer attracted some inaccurate comments from readers.

Some readers decided, based on reading the story, that tobacco use does not cause lung cancer.

Here's a sample of what one "Tyler J." wrote:

"It is now coming to light that the laws taking away a smokers RIGHT to smoke in places around others and targeting smokes with outrageous TAXES was/is un-constitutional (sic) because of the lunacy in our nation of the politically correct ignorant people on the REAL CAUSES of cancer."

Tyler J. could not be more wrong. Cigarette smoking is the leading cause of preventable death in the U.S.

While Neal, 41, was never a smoker and has a type of lung cancer that's attributed to genetics, his case is relatively unusual.

To read the sidebar about non-smoker lung cancer click here.

Dr. Linda Garland of the University of Arizona Cancer Center says most of the patients she treats for lung cancer are current or former smokers.

"In my patient population, when I am looking at the newly diagnosed patients, probably somewhere between 60 and 75 percent of people who walk in the door with lung cancer are former smokers.

"They stopped smoking five to 30 years ago. They did the right thing, yet the damage they sustained in their lungs - they sustained permanent damage that put them at risk for lung cancer years after they stopped smoking.

"It is very tragic unfortunately....It's many, many years of this chronic exposure to the carcinogen. It's an older person's disease, I rarely see younger people with it, but it can happen."

Here are some facts about smoking and lung cancer from the Centers for Disease Control and Prevention:

  • The risk of developing lung cancer is about 23 times higher among men who smoke cigarettes and about 13 times higher among women who smoke cigarettes compared with never smokers.
  • Cigarette smoking increases the risk for many types of cancer, including cancers of the lip, oral cavity, pharynx, esophagus, pancreas, larynx (voice box), lung, uterine cervix, urinary bladder, and kidney.
  • Rates of cancers related to cigarette smoking vary widely among members of racial/ethnic groups but are highest among African-American men.