What Is Lung Cancer?
The lungs are two large sponge-like organs in our chest that enable us to breathe. We take in oxygen-rich air through our nose, via the windpipe (trachea) into air sacs where gaseous exchange takes place. Oxygen is taken into the body and carbon dioxide escapes into the air. Toxic substances in cigarette smoke damage both the windpipe and lungs. When these cells become abnormal, cancer can develop.

As the cancer grows, it invades neighbouring organs such as the heart and chest wall. It also spreads to lymph glands around the airway and to other parts of the body.

How Common Is Lung Cancer?
Lung cancer is the most common cancer in men and the 3rd most common cancer in women in Singapore. Men have a 3 times higher risk of lung cancer than women. Among the 3 major ethnic groups, the Chinese have the highest risk.

Lung cancer is also the No. 1 cancer killer with 700 deaths per year. Only 14% of lung cancer patients survive 5 years.

Risk Factors

	Smoking: The most important risk factor is cigarette smoking. 90% of lung cancer in men and 79% in women are due to tobacco smoking. A smoker has a 15 times higher risk of lung cancer!
	Pipe and cigar smoking. The risk of lung cancer is also increased for this group of smokers.
	Occupational hazards. Exposure to certain workplace chemicals and minerals increases the risk of lung cancer, e.g. asbestos, coal gas, chromates, nickel, arsenic, vinyl chloride, mustard gas and radon.
	Passive smokers. Non-smoking wives who inhale their husbands' smoke have a 35% higher risk of lung cancer.

Signs & Symptoms
Lung cancer is more common in male smokers above 50. The main symptoms are: