Lung cancer is one of the top ten cancers that affect people in most parts of the world. Lung cancer incidence is higher in men than in women. However, it is observed that the incidence in women is on the rise.

What causes Lung Cancer?

• Most lung cancers are associated with cigarette smoking. Cigarette smoke contains many carcinogens (and chemicals that help carcinogens to cause more damage).
• The more the number of cigarettes smoked and the earlier the age of smoking the greater the risk of lung cancer.
• Passive smoking also increases the risk of getting cancer.
• Exposure to ionising radiation, high levels of pollution, chemicals like nickel ,chromium and asbestos.
• The risk following exposure to asbestos depends on the duration and the amount of exposure.
• Radon exposure plays a role in lung cancers. Radon is a radioactive gas that is found in the earth's rock and soil and is formed by the natural breakdown of radium. Radon exposure in smokers increases the chances of getting lung cancer.
• There is also a genetic predisposition in people who get cancer of the lung. Some smokers do not get lung cancer, though many do. Some non-smokers also get lung cancer.

Development of lung cancer is a slow and multifactorial process. The incidence is high in persons between ages 50 and 70.

Types of Lung Cancers

The common lung cancer symptoms are:

• Cough that persists for a long period
• Sputum with blood
• Chest pain
• Weight loss
• Loss of appetite
• Breathlessness
• Hoarseness of voice
• Wheezing

Other symptoms such as swallowing difficulty, speech difficulty, darkening of the skin, pallor, nail abnormalities, muscle atrophy, bone pain, joint pain and swelling and fever with chills may also be present.

Investigation

The doctor may want to perform the following tests to confirm the presence of lung cancer.

• Blood tests to check blood counts, liver function, serum calcium and bone specific alkaline phosphatase.
• Test the sputum coughed up by the patient
• An X ray or CT scan to detect abnormal growths or spots
• A bronchoscopy to view the bronchial tubes and lungs
• A biopsy of the lung tissue

Staging

The treatment to be followed and the outcome are determined by the stage to which the cancer has progressed in the patient. An international system called the TNM system defines the stages of cancer.
TNM takes into account the following;
T - Tumour,
N – The spread to the lymph Nodes
M – Metastasis or the spread to other parts of the body from the primary site.
Accurate staging is needed for deciding the treatment and for assessing the outcome.

TNM staging groups lung cancer into four stages.

Treatment:

Mode of treatment depends on the type of cancer and the extent of spread.
It also depends on the age and general health of the patient.
The treatment options available are surgery, chemotherapy, and radiotherapy.

Surgery can be done for cancer that has not spread beyond the lung. Pulmonary function tests are done as screening tools to identify patients with high risk. Surgery is the treatment of choice in most cases of non small cell carcinoma.

Radiation therapy uses high energy X rays to kill the cancer cells and to shrink the tumours. Post operative radiation is employed where tumour has not been fully removed. Radiation can also be used to reduce pain and other symptoms in advanced cases.

Chemotherapy is the recommended treatment for patients with stage II and stage III cancer. Combination chemotherapy is the recommended treatment of choice for small cell carcinoma.

Prevention

• The rule no: 1 is to avoid cigarette smoke. Both smokers and passive smokers are at risk.
• If you work in factories keep track of the radiation and pollution levels you are exposed to.
• Get yourself screened if symptoms persist. Early detection gives you a better chance of cure.