Mojgan Sheikhpour - Pasteur Institute of Iran, Tehran, Iran
Erfan Rahimi - Pasteur Institute of Iran, Tehran, Iran
Vahid Amiri - Pasteur Institute of Iran, Tehran, Iran

Background: Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosisand mainly affects the lungs. Tuberculosis has the second highest mortality rate in the world.Latent tuberculosis infection in people usually does not have symptoms for years, in which case itis referred to as latent tuberculosis. Some factors may be effective in the occurrence of activetuberculosis and bring it out of the latent state. These factors include: immunodeficiency, aging,smoking, diseases of the immune system, improper nutrition, stress and addiction to injectabledrugs. Although tuberculosis alone can be a big problem for human health, it is more worrying toknow that this disease can be closely related to lung cancer. Lung cancer is one of the mostimportant causes of death in the world. Several studies have shown that the risk of lung cancerincreases several times in people who get tuberculosisMethods: In this study on ۶۰ patients with active tuberculosis and ۶۰ patients with lung cancer,smoking history was investigated.Results: The results showed that ۳۵% of the patients with tuberculosis used cigarettes or tobacco.Also, about ۶۰% of lung cancer patients were smokers and ۳۵% of them had drug addiction.Conclusion: Smoking can increase the sensitivity and risk of developing active tuberculosis andcan lead to lung cancer. Almost every year, ۸۰ to ۹۰ percent of millions of deaths in the world dueto lung cancer are caused by smoking and tobacco use, which can be prevented by quitting.However, there are a small percentage of patients who have never smoked in their lifetime. TBinfection before lung cancer increases the mortality rate and is significantly related to lung cancermortality, and this figure is much higher in smokers than in non-smokers.

Tuberculosis, Lung Cancer, Smoking, Addiction, Cigarettes.