Lung cancer is a disease characterized by abnormal growths, or cancers, in the lungs. Most of the lung tumours are malignant, i.e. they spread throughout the body by destroying the healthy tissues around them. Because of this, lung cancer is a very life-threatening type of cancer and one of the most difficult cancers to treat.
Brief Outlook of Lung Cancer
SIGNS AND SYMPTOMS OF LUNG CANCER
People with lung cancer do not exhibit any symptoms when the cancer is diagnosed and until it has spread. Some of the most common symptoms of lung cancer are:
If cancer spreads to other parts of the body, it may cause the following symptoms and syndromes
Lung cancer is of two types, depending on the type of cells that constitute cancer: Small Cell Lung Cancer (SCLC) and Non-Small Cell Lung Cancer (NSCLC).
SMALL CELL LUNG CANCER (SCLC)
SCLC occurs in about 20 per cent of the cases of lung cancer and is the most aggressive and fastest-growing of all lung cancers. Often, by the time it is discovered, it would have already spread to other parts of the body. It is also known as Oat Cell Carcinomas. It is more likely to respond to chemotherapy, but less likely to be cured with treatment.
In Limited-stage SCLC, cancer cells are found in one lung and may be found in the tissues between the lungs and in nearby lymph nodes. If cancer is found in the other lung, in the lymph nodes of the other lung, or other parts of the body, it is called Extensive-stage.
Risk Factors and Causes:
The risk factors for SCLC are as follows:
NON-SMALL CELL LUNG CANCER (NSCLC):
NSCLC are the most common lung cancers, which can be divided into several main types based on the type of cells found in the tumour. There are different subtypes of NSCLC. They are:
DIAGNOSIS OF LUNG CANCER:
The diagnosis usually starts with the doctor asking a list of questions about the symptoms, medical and personal history, lifestyle etc. of the individual. Doctors use a wide range of diagnostic procedures and tests to diagnose lung cancer. Some of them are:
LUNG CANCER PROGRESSION AND STAGING:
The staging of lung cancer refers to the extent of the disease. In the case of the NSCLC, it is staged according to the size of the tumour and whether it has spread to the lymph nodes or other organs of the body.
In the Occult or Hidden Stage, cancer cells are found in the coughed-up mucus or in other lung fluids, but no tumour can be seen in the lungs.
Stage 0 is not considered invasive because the cancer cells are found in the innermost lining of the air passages, but have not grown through it.
Stage 1A is considered invasive cancer because the tumour has grown through the inner lining of the airways into the deep lung tissue. The size of the tumour doesn’t exceed 3 cm and has not spread to the bronchi, lymph nodes or distant sites.
In Stage 1B, the diameter of the tumour exceeds 3 cm, or has spread to the main bronchus, or has grown through the lung into the inner layer of the pleura.
In Stage 2A, the tumour is no more than 3 across, but it has spread to the nearby lymph nodes on the same side of the chest as the tumour.
In Stage 2B, there are two scenarios that can occur. One, where the cancer cells have not spread to nearby lymph nodes, but have spread to other parts of the body like the chest wall, diaphragm etc. In the second scenario, cancer has spread to the nearby lymph nodes on the same side of the chest as the tumour. Also the size of the tumour exceeds 3 cm.
In Stage 3A, the tumour may be of any size and cancer has spread to more lymph nodes on the same side of the chest and to other nearby structures, but not the trachea.
In Stage 3B, the tumour may be of any size, and has spread to the lymph nodes on the other side of the chest or above the collar bone, and may have spread to nearby structures like the heart, major heart vessels, diaphragm, chest wall, trachea, oesophagus, breastbone, or to more than one place in the same lung.
In Stage 4, cancer has spread to other lobes of the same lung and to other parts of the body such as the brain, liver, kidneys, adrenal glands or bones.
Treatment options include local therapies such as
The patient may receive one or a combination of the treatments. There are several surgical options depending on the type and stage of cancer. During a Wedge Resection, the tumour and a small margin of healthy tissue are removed. In a Lobectomy, one lobe of the lung is removed. During a Pneumonectomy, the surgeon removes the entire lung. In a Sleeve Resection, the diseased section of a large airway is removed, and the healthy ends are reattached. During any of these procedures, the surgeon may remove the lymph to check them for signs of cancer.
Radiation therapy is a local treatment that uses high energy rays to kill or shrink cancer cells to relieve symptoms. External Beam Radiation Therapy (EBRT) is directed at cancer’s location from a machine outside your body. Brachytherapy is used to help remove blockages of the large airways by cancer. Chemotherapy is a systemic treatment that uses drugs to stop the growth of cancer cells by either killing them or inhibiting their cell division. Targeted therapies are newer cancer treatments that work by focusing on specific genetic abnormalities of cancer cells.
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