Smoking has always been considered as the only cause of lung cancer, which means that as long as a person does not smoke, he/she will not be subjected to the lung cancer disease.

As a result, many nonsmokers, who develop lung cancer, have no chance of an early diagnosis and do not get the immediate help they need, leading to less chances of recovery. These patients would normally be treated from various diseases as pneumonia or asthma, but will not be treated for lung cancer.

10% of men and 20% of women, who suffer from lung cancer, has never smoked in their lives.

Dr. Michael Thun, an Epidemiologist at the American Cancer Society, stated, "Lung cancer is underfunded and a major reason is the idea that it's all related to smoking and it's the smoker's fault".

Recently-released studies showed that lung cancer might emerge from second-hand smoking, attacking nonsmokers as vigorously as smokers themselves. Moreover, smoke emitting from cars and factories, as well as gas inhalation, for any reason might cause lung cancer. Another reason is genetic susceptibility of some patients to lung cancer attacks.

Lung cancer is the most terminal cancer in the U. S., taking more lives than breast and prostate cancers.