Lung cancer has been the most common and fatal type of cancer; indeed worldwide incidence of lung cancer is alarming. It is considered a leading cause of cancer- related deaths among males and females due to environmental pollution, occupational exposure, genetic susceptibility, increasing number of smokers and others.

Lung cancer has been the most common and fatal type of cancer; indeed worldwide incidence of lung cancer is alarming. It is considered a leading cause of cancer- related deaths among males and females due to environmental pollution, occupational exposure, genetic susceptibility, increasing number of smokers and others.

Moreover, a large proportion of people living in low and middle income countries are exposed to secondhand smoke (SHS) in their homes, workplaces, and other public places.

Although, lung cancer had become one of fatality causes of the 20th century due to an increasing life span combined with exposures to various etiologic factors, it is one of the leading causes of preventable deaths.

There are various important risk factors other than tobacco smoking that can contribute substantially to the lung cancer mortality in never smokers; these other lung carcinogens often act in an additive or synergistic manner in individuals who smoke tobacco products.

Inclusion Criteria:

• All female patients presented with bronchogenic carcinoma patients and diagnosed at chest diseases department, Oncology Center Mansoura University (OCMU) in last 10 years.

Exclusion Criteria:

• lung metastasis ( not primary bronchogenic carcinoma)

A retrospective cohort study will be conducted on bronchogenic carcinoma patients who had been presented to and diagnosed at chest diseases department, Oncology Center Mansoura University (OCMU) in last 10 years as smoking is a major risk factor and it is more common in males than females.

A retrospective cohort study will be conducted on bronchogenic carcinoma patients who had been presented to and diagnosed at chest diseases department, Oncology Center Mansoura University (OCMU) in last 10 years.