Lung Cancer

Lung cancer happens when a malignant tumour forms in the tissue of one or both lungs.

What is Lung Cancer?

Primary lung cancer begins in the lungs, while a secondary or metastatic cancer occurs elsewhere in the body and spreads to the lungs.

Our lungs are a part of the respiratory system made up of air-filled organs and tissues to help us breathe. The main function of the respiratory system is to extract oxygen from the atmosphere and transfer it into the bloodstream, and to release carbon dioxide from blood stream into the atmosphere. This process of gas exchange is essential for life.

Types of Lung Cancer

Non-small Cell Lung Cancer (NSCLC)

About 80% to 85% of lung cancers are NSCLCs, making it the most common type of lung cancer. The two main subtypes of NSCLC are squamous cell carcinoma and adenocarcinoma.

Small Cell Lung Cancer (SCLC)

About 10% to 15% of all lung cancers are SCLCs. This type of lung cancer tends to grow and spread faster than NSCLC. About 70% of people with SCLC will have cancer that has already spread at the time they are diagnosed. Since this cancer grows quickly, it tends to respond well to chemotherapy and radiotherapy.

Staging

If you or a loved one has unfortunately been diagnosed with lung cancer from a biopsy test, the next important step is to determine the stage and grade of the tumour, stage referring to the size of the tumour and how far it has spread. A number of tests (eg. CT scan, whole-body PET scan, bronchoscopy, MRI brain scan +/- bone scan) may be required to accurately establish the stage of the cancer. This will determine what the best treatment for you is.

There are 4 stages for lung cancer based on a complex TNM staging system that is used worldwide:

  • The ‘T’ refers to the size and location of the tumour.
  • The ‘N’ refers to whether surrounding lymph nodes are affected by the cancer cells.
  • The ‘M’ descriptor refers to whether the cancer has spread outside the affected lung or chest cavity to a distant location (eg. brain or bone) by a process known as metastasis.

Early stage lung cancer (stages 1A, 1B, 2A, 2B and some cases of stage 3A) are best treated by surgery. This offers the best chance of a cure and future long-term survival, provided the patient is fit enough for an operation. More advanced stages (stages 3B, 3C, 4A and 4B) are usually best treated with chemotherapy and/or radiotherapy/immunotherapy.
In some patients, successful treatment will require a combination of surgery and chemo/ radiotherapy. This is called multi-modality therapy.

Warning signs:

  • Persistent coughing or “smoker’s cough”
  • Coughing up blood or dark-coloured phlegm/ sputum
  • Noisy breathing or breathing difficulty [stridor]
  • Unexplained breathlessness
  • Hoarseness
  • Recurring chest infections such as bronchitis or pneumonia
  • Fatigue, loss of appetite and unexplained weight loss
  • Pain in the chest, shoulder or back

Am I at risk?

Yes, if you fit the following:

  • Tobacco smoke
  • Exposure to cancer-causing agents at the workplace (radioactive substances, carcinogenic chemicals, diesel)
  • Arsenic in drinking water

Unavoidable risk factors:

  • Previous radiation therapy to the lungs
  • Air pollution
  • Personal or family history of lung cancer
  • Gender and ethnicity

What can I do?

Beat the cancer. Cut your risk by taking these steps:

  • Avoid tobacco
  • Limit exposure to second hand ‘passive’ smoking
  • Limit exposure to cancer-causing chemicals or radiation
  • Consume a healthy diet
  • Exercise

I have a higher risk of getting lung cancer, can it still be prevented?

Take preventive measures to further lower the risk:

  • Changing lifestyle (ie. quit smoking) or eating habits
  • See a doctor to discuss screening with a low-dose CT scan to detect the cancer at a very early stage. This offers the best hope for high risk individuals

Lung Cancer Myths vs. Facts

Myth Fact
Only smokers are susceptible to getting lung cancer Ex-smokers make up the majority of lung cancer patients in Malaysia. On the contrary, 20 percent of female lung cancer patients are lifelong non-smokers.
Living in a polluted city is a greater risk than smoking. The risk of lung cancer does increase with exposure to diesel, exhaust and air pollution. However, the risk is small in comparison to smoking.
Surgery causes lung cancer to spread. There is a surprisingly common belief that if lung cancer cells are somehow exposed to air it will spread, making surgery procedures dangerous. Surgery does not cause lung cancer to spread.