Lung cancer is one of the most common cancers in the world. It is a leading cause of cancer death in men and women in the United States. Cigarette smoking causes most lung cancers. The more cigarettes you smoke per day and the earlier you started smoking, the greater your risk of lung cancer. High levels of pollution, radiation and asbestos exposure may also increase risk.
Cancer of the lung, like all cancers, results from an abnormality in the body’s basic unit of life, the cell. Normally, the body maintains a system of checks and balances on cell growth so that cells divide to produce new cells only when new cells are needed. Disruption of this system of checks and balances on cell growth results in an uncontrolled division and proliferation of cells that eventually forms a mass known as a tumor
Tumors can be benign or malignant; when we speak of “cancer,” we are referring to those tumors that are malignant. Benign tumors usually can be removed and do not spread to other parts of the body. Malignant tumors, on the other hand, often grow aggressively locally where they start, but tumor cells also can enter into the bloodstream or lymphatic system and then spread to other sites in the body. the areas of tumor growth at these distant sites are called metastases. Since lung cancer tends to spread or metastasize very early after it forms, it is a very life-threatening cancer and one of the most difficult cancers to treat. While lung cancer can spread to any organ in the body, certain locations — particularly the adrenal glands,liver, brain, and bones — are the most common sites for lung cancer metastasis.
The lung also is a very common site for metastasis from malignant tumors in other parts of the body. Tumor metastases are made up of the same types of cells as the original (primary) tumor. For example, if prostatecancer spreads via the bloodstream to the lungs, it is metastatic prostate cancer in the lung and is not lung cancer.
The principal function of the lungs is to exchange gases between the air we breathe and the blood. Through the lung, carbon dioxide is removed from the bloodstream and oxygen enters the bloodstream. The right lung has three lobes, while the left lung is divided into two lobes and a small structure called the lingula that is the equivalent of the middle lobe on the right. The major airways entering the lungs are the bronchi, which arise from the trachea, which is outside the lungs. The bronchi branch into progressively smaller airways called broinchoiles that end in tiny sacs known as alveoli where gas exchange occurs. The lungs and chest wall are covered with a thin layer of tissue called the pleura.
symptoms for lung cancer:-
- Lung cancer is the number one cause of cancer deaths in both men and women in the U.S. and worldwide.
- cigarette smoking is the principal risk factor for development of lung cancer.
- Passive exposure to tobacco smoke also can cause lung cancer.
- The two types of lung cancer, which grow and spread differently, are small cell lung cancers (SCLC) and non-small cell lung cancers (NSCLC).
- The stage of lung cancer refers to the extent to which the cancer has spread in the body.
- The general prognosis of lung cancer is poor because doctors tend not to find the disease until it is at an advanced stage. Five-year survival is around 54% for early stage lung cancer that is localized to the lungs but only around 4% in advanced, inoperable lung cancer.
- smoking sessation is the most important measure that can prevent the development of lung cancer.
When should one consult a doctor?
One should consult a health-care professional if he or she develops the symptoms associated with lung cancer, in particular, if they have
- a new persistent cough
- blood in the sputum,
- persistent bronchitis or repeated respiratory infections,
- chest pain
- unexplained weight loss
- breathing difficulties such as shortness of breath or wheezing.
Treatment for lung cancer
Treatment for lung cancer primarily involves surgical removal of the cancer, chemotherapy, or radiation therapy, as well as combinations of these treatments. Targeted therapies and immunotherapy are becoming more common, as well. The decision about which treatments will be appropriate for a given individual must take into account the location and extent of the tumor, as well as the overall health status of the patient
Surgery: Surgical removal of the tumor is generally performed for limited-stage NSCLC and is the treatment of choice for cancer that has not spread beyond the lung. About 10%-35% of lung cancers can be removed surgically, but removal does not always result in a cure, since the tumors may already have spread and can recur at a later time. Among people who have an isolated, slow-growing lung cancer removed, 25%-40% are still alive five years after diagnosis. It is important to note that although a tumor may be anatomically suitable for resection, surgery may not be possible if the person has other serious conditions (such as severe heart or lung disease) that would limit their ability to survive an operation.
Experimental therapies: Since no therapy is currently available that is absolutely effective in treating lung cancer, patients may be offered a number of new therapies that are still in the experimental stage, meaning that doctors do not yet have enough information to decide whether these therapies should become accepted forms of treatment for lung cancer. New drugs or new combinations of drugs are tested in so-called clinical trials which are studies that evaluate the effectiveness of new medications in comparison with those treatments already in widespread use. Lung cancer treatment vaccine are being studied in clinical trials.
Is it possible to prevent lung cancer?
Cessation of smoking and eliminating exposure to tobacco smoke is the most important measure that can prevent lung cancer. Many products, such as nicotine gum, nicotine sprays, or nicotine inhalers, may be helpful to people trying to quit smoking. Minimizing exposure to passive smoking also is an effective preventive measure. Using a home radon test kit can identify and allow correction of increased radon levels in the home. Methods that allow early detection of cancers, such as the helical low-dose CT scan, also may be of value in the identification of small cancers that can be cured by surgical resection and prevented from becoming widespread, incurable, metastatic cancer.