THE HEALTHY LUNG The air we breathe in enter the lungs through the trachea and then the right and left bronchi. The bronchi are airways that branch into smaller airways and finally the air sacs. Oxygen is absorbed and carbon dioxide expelled via the surface area of the air sacs. The average lung has more than 300 million of these air sacs.

Mucus produced by the cells in the airways trap the foreign material that enter the airway. Tiny hair-like structures called cilia sweep the mucus toward the throat where it can be coughed out. 

THE SMOKED-DAMAGED LUNG
Consistent insult eg. due to smoking, to the cell lining of the airway will cause an increase in the production of mucus. The tiny-hair in the air passages become worn away and are unable to sweep foreign particles out of the throat. Very often the smoker try to cough out the mucus. Chronic smokers have been heard to cough frequently in the morning. In more advanced cases, the air sacs become destroyed and abnormal growth patterns leading to cancer may develop. 

THE CANCEROUS LUNG
Lung cancer can take 10 to 30 years to develop. Hence it is frequently seen in middle-aged and elderly persons. In lung cancer, the cells lining the airways grow and divide without control so that an abnormal mass is formed. The cancer cells grow and spread to the other parts of the body. Lung cancers tend to spread more quickly because the lungs are supplied richly by blood vessels and lymphatic vessels. When the cancer spreads through the lymph channels, it can cause enlarged lymph glands. When it spreads through the blood stream, the cancer cells spread to the liver, bone, brain or the other lung. 

WHAT CAUSES LUNG CANCER?

CIGARETTE SMOKING is the main cause of lung cancer. It is responsible for 90% of lung cancer deaths. With the increasing number of years of smoking, the number of cigarettes smoked each day and the tar and nicotine contents of the cigarettes; the risks of developing lung cancer will be increased. 

PIPE AND CIGAR SMOKING - The risk of lung cancer is also increased in pipes and cigars smokers though less than those who smoke cigarette. 

INDUSTRIAL HAZARDS - Exposure to certain workplace chemical and minerals increase the risk of lung cancer eg. asbestos, coal gas, chromates, nickel, arsenic, vinyl chloride, mustard gas, radon by-products of uranium mining and processing. Asbestos workers who also smoke increase their risks of developing lung cancer 60 times. 

PASSIVE SMOKING - Non-smoking wives who inhale their husbands smoke have a 35% higher risk of developing lung cancer. 

SYMPTOMS
Persistent cough and shortness of breath. If you have a cough that does not improve with treatment, a chest x-ray should be done especially when there is associated shortness of breath. 

Blood in the sputum.  Chest pain - Chest pain may occur in association with a chronic cough.  Recurrent chest infection, fever and weight loss.  In many cases, the cancer has spread to the other parts of the body causing secondary changes such as liver enlargement, pallor (lack of blood causing the patient to look pale), lymph node enlargement etc.

DIAGNOSIS?
History and physical examination
As in any disease, before the doctor diagnoses, he will first take the medical history and exam the patient. Subsequent investigations will be taken to confirm the diagnosis. 

Chest x-rays are valuable in the diagnoses of lung cancer. 

Sputum cytology 
In some cases, examination of the sputum under the microscope may reveal cancer cells. Cancer cells may be coughed up from the lungs or airways. 
Bronchoscopy
A fibre-optic tube is passed through the nose or mouth into the trachea to the airways or bronchi. Suspicious-looking growth can be biopsied (a small piece of tissue is taken for examination under the microscope) to confirm cancer. 
C.T. scans
Computerized tomography scans are x-ray beams that rotate around the body to produce series of x-rays taken from different angles. The information is then processed by a computer to produce a complete picture or a cross-section of a part of the body. 
MRI
Magnetic Resonance Imaging can build composite 3-dimensional images of sections of the body. 
Thoracotorny
An operation is done when the surgeon believes that the cancer is present and investigations cannot locate the site of the cancer. 

TREATMENTS 
Surgery, radiation and chemotherapy are the three main methods of cancer treatment. The type of treatment depends on the size, extent of the disease, the type of lung cancer and the general health of the patient. 

SURGERY
Part of the lung or the whole lung may be removed in the treatment of lung cancer. Before surgery, the patient will undergo a lung function test to assess the functional capacity of the existing lung. After surgery, these patients may require assisted ventilation for a short period. Physical activities may also be limited for a short period. If the remaining lung function is good, the patient will be able to continue a normal life. 

CHEMOTHERAPY
Certain type of lung cancer are sensitive to chemotherapy treatment. This form of treatment is increasingly being used in combination with surgery or with radiation. As newer drugs are discovered and their range of efficacy increased, the use of chemotherapy will increase. Side-effects of chemotherapy such as nausea, vomiting and diarrhoea can be overcome with medications. 

RADIATION
Radiation or the use of x-rays to treat lung cancer may be in conjunction with surgery or as a palliative treatment to relieve the pressure symptoms or pain caused by the lung cancer. Side-effects of radiation such as tiredness, skin rash or sore throat are transient. 

Cancer Facts 

Back to top | Questions & Answers