What is lung cancer?

Lung cancer is the uncontrolled growth of abnormal cells in one or both of the lungs. While normal lung tissue cells reproduce and develop into healthy lung tissue, these abnormal cells reproduce rapidly and never grow into normal lung tissue. Lumps of cancer cells (tumors) then form and disrupt the lung, making it difficult to function properly.More than 87% of lung cancers are smoking related. However, not all smokers develop lung cancer. Quitting smoking reduces an individual's risk significantly, although former smokers remain at greater risk for lung cancer than people who never smoked. Exposure to other carcinogens such as asbestos and radon gas also increases an individual's risk, especially when combined with cigarette or cigar smoking.

What is Cancer?

Cancer cells are very similar to cells of the organism from which they originated and have similar (but not identical) DNA and RNA. This is the reason why they are not very often detected by the immune system, in particular if it is weakened. Cancer cells usually have an increased ability to divide rapidly and their number of divisions is not limited by telomeres on DNA (a counter system to limit number of divisions to 40-60). This can lead to the formation of large masses of tissue and in turn may lead to disruption of bodily functions due to destruction of organs or vital structures.

How is Cancer formed?

Cancer cells are formed from normal cells due to a modification / mutation of DNA and/or RNA. These modifications / mutations can occur spontaneously (II Law of Thermodynamics - increase of entropy) or they may be induced by other factors such as: nuclear radiation, electromagnetic radiation (microwaves, X-rays, Gamma-rays, Ultraviolet-rays, etc.), viruses, bacteria and fungi, parasites (due to tissue inflamation/irritation), heat, chemicals in the air, water and food, mechanical cell-level injury, free radicals, evolution and ageing of DNA and RNA, etc. All these can produce mutations that may start cancer. Cancer can be called therefore "Entropic Disease" since it is associated with the increase of entropy of the organism to the point where the organism cannot correct this itself. External intervention is required to allow the organism to return to an stable entropic state.Cancer cells are formed continuously in the organism (it is estimated that there are about 10,000 cancer cells at any given time in a healthy person). The question is why some of these result in macroscopic-level cancers and some don't. First, not all damaged cells can multiply and many of them die quickly. Those which have the potential to divide and form cancer are effectively destroyed by the various mechanisms available to the immune system. This process takes place continuously. Therefore cancer develops if the immune system is not working properly and/or the amount of cells produced is too great for the immune system to eliminate. The rate of DNA and RNA mutations can be too high under some conditions such as: unhealthy environment (due to radiation, chemicals, etc.), poor diet (unhealthy cell environment), people with genetic predispositions to mutations and people of advanced age (above 80).