Lung Cancer :The body has a system of checks and balances on cell growth so that the cells divide to produce new cells to replace the worn out cells.This is a continues process.When there is abnormality in this system of checks and balances,uncontrolled division and proliferation of cells happen which eventually lead to tumors.
When we speak of cancer,we refer to the malignant tumors.Since,Lung cancer tends to spread or metastasize very early in this case it is life threatening and the most difficult Cancers to treat.Lung Cancer can spread to any organ of the body most likely Liver,Brain,Bone and Adrenal gland.
The function of Lungs is ti exchange the gases between the air we breath and the blood.Corbandioxide is removed from the blood and the oxigen from the air enters the blood through the Lungs.
The Lungs are divided into three lobes.The airways entering into the Lungs are called Bronchi,which arrives from the trachea.The Bronchi further branch into Bronchioles that end into tiny scads called alveoly where the exchange of gases occur.A thin layer of tissue called pleura covers the Lungs and the chest valve.
Lung Cancer can affect any part of the Lung.It is responsible for the most Cancer deaths in men and women throughout the world.Lung cancer was not common prior to 1930’s but increased radically as tobacco smoking increased.Most of the Lung Cancer patients are over 65 years of age.
There are many causes which lead to Lung Cancer.They are:
Smoking :It is the most likely cause for Lung Cancer.The risk of Lung Cancer increases with the number of Cigarettes smoked.Tobacco smoke contains nearly four thousand chemical compounds, many of which are carcinogenic.
Passive Smoking :The inhalation of tobacco smoke from other smokers whom you live with or share your work place are highly at risk of Lung Cancer.
Radon Gas :The natural decay product of uranium is radon gas.It is a chemically innert gas which is a type of ionizing radiation.The risk of Lung Cancer increases with radon exposure as this gas can travel through soil and may contaminate the environment as it enters living areas through gaps in pipes,drains,foundation etc.To detect radon gas is difficult as it is colorless and odourless.
Asbestos Fibers :These fibers persist for a long time in Lung tissue following exposure to Asbestos.As this fibers are used in thermal and acaustic insulation,people working in such industries have to be careful.Now a days it is banned in many countries because of its carcinogenic properties.
Genetic or Hereditary: Though majority of Lung Cancers are linked with smoking,we cannot ignore the fact that Lung Cancer may occur more likely in relatives of those who already had Lung Cancer.This is because of the presence of a particular gene that increases the susceptibility to the development of Lung Cancer.
Pollution :Air pollution causes upto 1% of Lung Cancer deaths.The polluted air from the power plants ,industries and vehicles when inhaled frequently for a long time causes Lung Cancer.
Lung Diseases :Diseases related to the Lung like chronic obstructive pulmonary disease may cause Lung Cancer even after cigarette smoking is quit.
People with a prehistory of Lung Cancer have a greater risk of developing a second Lung Cancer.
Types of Lung Cancer :Depending on the microscopic appearince of the tumor cells ,Lung Cancer can be classified into small cell Lung Cancer(SCLC)and non-small cell Lung Cancer(NSCLC).These two spread in different ways and may have different treatment options.
SCLC are mostly caused because of Smoking.They metastasize rapidly to many sites and are often discovered after they have spread extensively.NSCLC are the most common Lung Cancers.Based on the type of cell found in the tumor,They are Adenocarcinomas :They mostly develop in the outer or peripheral areas of Lungs. Squamous cell carcinoma :They are also called epidemoid carcinomas and they affect the central chest area in the bronchi. Large cell carcinomas :Generally undifferentiated and are the least common type of NSCLC .Sometimes mixtures of different types of NSCLC are also seen. Bronchial carcinoids :Mostly occur in people under 40 years of age.Carcinoids grows and spreads slowly than bronchogenic Cancers.Metastatic Cancers from other primary tumors in the body often spread to the lung through blood stream,lymphatic system or directly from near by organs.They are generally concentrated in peripheral area rather than the central areas of the lung.