LUNG CANCER
Lung cancer is the leading cause of mortality due to malignancies, both for men and women. International Agency for Research on Cancer (IARC), reported that cancers are among the most important causes of morbidity and mortality worldwide, with approximately 14 million new cases and 8.2 million cancer-related deaths in 2012. 
The number of new cases is expected to increase by about 70% over the next two decades. In 2012 among the population, the 5 sites of cancer, the most common diagnoses were: lung, prostate, colorectum, stomach, and liver cancer. In 2012 was reported 1.59 million deaths / worldwide by lung cancers cases. The main etiological factor involved in causing the disease is smoking. About a third of cancer deaths are due to the 5 most important behavioral and dietary risks: high body mass index, low fruit and vegetable intake, physical inactivity, tobacco, alcohol.
Tobacco is the most important risk factor for cancer that causes about 20% of cancer deaths worldwide and about 70% of global deaths from lung cancer. The prevalence of cancer is second only to prostate and breast cancer, but lung cancer mortality is still not surpassed by any other malignancy. 
Due to late discovery, often in stages outdated therapeutically, only 14% of patients get diagnosed survive a longer period of time (five years). The incidence of developing lung cancer depends greatly on the time in which the individual start smoking, the number of years spent smoking or number of cigarettes in the period that is exposed to other risk factors. Probability of ​​developing lung cancer is relatively low until age 39 (for both sexes), but then begins to grow as an individual gets older. The peak incidence is around 70 years.

WHAT IS LUNG CANCER?

Lung cancer is a disease that is characterized, like other cancers, through uncontrolled growth of cells inside the lungs. These cells eventually form a tumor mass that is different from the surrounding healthy parenchyma. Such tumors are dangerous in that they determine ”theft" chronic oxygen and nutrients, the body despoiled by them, but the most important fact is that they exert compression on surrounding healthy structures. In addition, cancer cells can metastasize; leading to cancer will be spread to distant structures of the main office.
The most common etiologic agent involved in lung cancer is the smoking (active, but sometime
Lung cancer types, smoking lung cancer
Lung cancer
s passive). However, lung cancer occur in individuals smoking in these situations is correlated with chronic exposure to dusts such as asbestos (asbestos cancer), excessive air pollution in industrial areas or even genetic factors. Lung cancer can be primary or secondary. Primary cancer is one that originates in the lung structures, while the secondary form occurs in metastasis of other malignancies. The lunge is one of the most common organs that is localized metastases, with bone, liver and brain.


 LUNG CANCER TYPES

1  Non-small cell lung cancers NSCLC:
a.  Adenocarcinoma lung: This is the most frequently diagnosed type of cancer, accounting for over 30-40% of all cases;
b.   Squamous cell carcinoma lung is No. 2 in the order of frequency of lung cancer, been diagnosed in 30% of cases;
c.    Large cell lung cancer represents 10% of all lung cancers;
d.    Small cell lung carcinoma occurs in 20% of patients;
e.    Carcinoid lung occurs in 1% of patients;
2  Other forms of cancer

 WHAT CAUSES LUNG CANCER - SMOKING LUNG CANCER,
 LUNG CANCER RISK FACTORS
Unlike most other cancers, whose causes are often unknown, the leading cause of lung cancer is represented in over 90% of patients smoking. The correlation between the two (smoking and cancer) has been discovered since 1950. Among men smokers, the risk of developing smoking lung cancer is 17%, while among women smokers is 12%. Experts estimate that an individual who smoke more than one pack of cigarettes per day has a risk of developing smoking lung cancer by 20 to 25 times higher than a nonsmoker. 
If a person quits smoking, the risk of cancer is reduced gradually over time, but difficult. It seems that only after 15 years of total abstinence from smoking risks of cancer are becoming similar to that of a nonsmoker, but they are reduced to 2% only after 30 years after quitting. In the first 10 years, but risks remain very high. Smoking cigars or pipe is also an important risk factor, but not as significantly as smoking regular cigarettes. Smoking pipe is commonly associated lip of smoking lung cancer. Approximately 85% of all lung cancers occur in smokers or smokers who meanwhile had abandoned smoking.
The most important lung cancer risk factors that influence the development of this type of smoking lung cancer are:
1.    The number of cigarettes smoked;
2.    The age at which the individual was started smoking;
3.    The time period in which smoking (or while smoking was allowed);
4.    Nicotine content of cigarettes smoked. 
Because not all patients diagnosed with lung cancer are smokers, researchers found other causes that can cause this neoplasia. Their role is relatively well established, but there are factors such as genetics, whose influence remains to be established. Passive smoking (a nonsmoker by chronic exposure to cigarette smoke) is criminalized in 25% of all lung cancer cases occurring in nonsmokers.
An individual smoker who lives with a person, who smokes, has a two-fold higher risk of developing lung cancer. Passive smokers are exposed mainly nitrosamines, studies demonstrating that these compounds are excreted in people nonsmoker, but exposed to cigarette smoke at the rate of 1-5% compared to those that determine the active smokers. New cancer treatments can be an solution alternative at chemotherapy treatment lung cancer or prevent lung cancer.