Lung cancer is the commonest cancer in the world with the highest incidence of death. There were approximately 2.09 million new cases reported worldwide and 1.76 million deaths caused by lung cancer in 2018 (International Agency for Research on Cancer, World Health Organization). According to the Malaysian National Cancer Registry (2007 – 2011), it was reported that there were 10,608 lung cancer cases out of the total 103,507 cancer cases, with 7,415 cases in male and 3,193 cases in females.
Lung cancer is caused by mutated cells in the lungs that grew out of control, forming a tumour. In many cases, these altered cells die or are attacked by the immune system. But some cells escape the immune system and grow out of control, forming a malignant tumour in the lung.
Types of Lung Cancer
There are two major types of lung cancer:
- Non-small cell lung cancer (NSCLC) (most common)
- Small cell lung cancer (SCLC)
Other types of cancer found in the lungs include:
- Neuroendocrine tumour/carcinoma
In the early stages, lung cancer may not cause any symptoms but typically occur when the disease advanced. The common symptoms include:
- Chest pain
- Persistent cough
- Excessive lethargy
- Shortness of breath
- Hoarseness of voice
- Recurrent chest infection
- Loss of appetite and weight
- Coughing out blood (haemoptysis)
Anybody can get lung cancer but most lung cancers are caused by:
- Smoking (90%) – active and second-hand smoke
Tobacco smoke contains more than 4,000 chemical substances, most of which have been identified to cause lung cancer. According to research, smoking 20 cigarettes per day increases the risk of lung cancer by 20-25 times compared to non-smokers. Vaping also consists of many detrimental chemical substances that can be linked to cancer.
Other causes of lung cancer include:
- Chronic obstructive pulmonary disease
- Air pollution from vehicles and factories
- Having lung diseases such as tuberculosis
- Exposure to asbestos and other carcinogens
- Occupational exposure to arsenic, chromium, nickel, aromatic hydrocarbon, ether etc.
Stages of Lung Cancer
Stage I : Cancer may be present in the underlying lung tissues, but the lymph nodes
Stage II : Cancer may have spread to nearby lymph nodes or into the chest wall.
Stage III : Cancer is continuing to spread from the lungs to the lymph nodes or to nearby structures and organs, such as the heart, trachea and oesophagus.
Stage IV : Cancer has metastasized, or spread, beyond the lungs into other areas
of the body.
Cancer screening in lung cancer is still controversial, although early detection at an early stage of lung cancer can lead to a more effective treatment. Low dose CT scan of the chest could be used for screening for high-risk patients.
To diagnose lung cancer, a doctor could perform a combination of tests including:
- Blood tests – Blood test may be done to rule out possible causes of your symptoms, such as chest infection.
- Sputum cytology – A sample of your sputum (phlegm) is taken to be examined under a microscope to see if cancer cells are present in your lungs.
- Imaging Scans
- Chest X-ray: Most lung tumours will appear on X-rays as a white-grey mass. X-rays is usually paired with other imaging scans, to get a better diagnosis for lung cancer.
- CT scan: X-rays and a computer is used to produce detailed pictures of the inside of your body. A special dye called contrast medium will be administered to you to help improve the quality of the pictures.
- PET-CT scan: PET-CT scan is an imaging test which a radioactive drug (radiotracer) is administered into the person to help reveal how the tissues and organs are functioning. The tracer will collect in the area that has higher levels of chemical activity, which corresponds to areas of disease, in this case, will be your lungs. PET-CT scan may sometimes spot lung cancer before it appears on other imaging tests.
- Bone scan: A bone scan may be done to determine whether the lung cancer has metastasized into the bones. During the bone scan, you will be injected with a minimal amount of low-level radioactive material into your bloodstream and will collect mainly in the metastasized area.
- Thoracentesis: Thoracentesis is done to determine if the fluid around the lungs is caused by cancer. During a thoracentesis, a needle is placed between the ribs to drain the fluids so that it can be examined for cancer cells.
- Thoracoscopy or video-assisted thoracoscopic surgery (VATS) biopsy: An incision is made in the chest, in which the surgeon will insert a thin, lighted tube connected to a video camera and screen to examine the space between the lungs and the chest wall. The surgeon will be able to see small tumours on the lung or the lining of the chest wall and remove pieces of tissue to be examined under the microscope.
- Mediastinoscopy and Mediastinotomy: Both of these tests let the surgeon look at and take samples of lymph nodes in the area between the lungs (mediastinum).
- Percutaneous needle biopsy: Non-invasive procedure which involves the insertion of a needle into an organ or suspected lesions to get tissues or cells for diagnosis.
- Endobronchial ultrasound (EBUS) – A bronchoscope (a thin, lighted, flexible tube) fitted with an ultrasound device, is passed down the trachea to inspect nearby lymph nodes and other parts of the chest. Numbing medicine (Local anaesthesia) and light sedation will be administered to you, then a hollow needle will be passed through the bronchoscope to take biopsy samples.
- Endoscopic oesophageal ultrasound (EUS) – EUS is similar to EBUS, except that an endoscope is used, and is passed down the throat and into the oesophagus.
Beacon Hospital offers comprehensive Cancer Screening Packages that are tailored made for individuals depending on the patient’s needs.
Treatment of lung cancer depends on the type of cancer, stage of cancer and patient clinical condition.
- Lung surgery – Surgery is typically used to treat localized lung cancer.
But lung surgery might not be appropriate for you if your cancer has metastasized or is very near any of the following structures:
- The heart
- The windpipe
- The food pipe (oesophagus)
- Major blood vessels
In these circumstances, your doctor might recommend other cancer treatments as an alternative of surgery, such as radiotherapy, chemotherapy or a combination of both, targeted therapy or immunotherapy.
- Radiotherapy – The primary radiotherapytreatment for lung cancer is External Beam Radiation Therapy (EBRT). It delivers high doses of radiation to lung cancer cells from outside the body to kill cancer cells. External Beam Radiation Therapy (EBRT), which is usually delivered by a machine called a linear accelerator that focuses high-energy X-rays from the outside of the body to the tumour.
Halcyon Radiotherapy System at Beacon Hospital enables:
- Fast and precise X-ray dose delivered to each tumour with high accuracy over a minimum number of treatment sessions
- Reduces unwanted radiation dose, thus, minimizing side effects
Unlike any other radiation delivery system, the Halcyon technology’s beam-on time could be as fast as 1-minute plus. Its gantry rotates 4 times faster than a standard linear accelerator and its multi-leaf collimator (MLC) can move twice faster than traditional MLCs. All of these features help in improving the time it takes to treat the patients. cancer cells from outside the body to kill cancer cells.
TrueBeam 2.7 Radiosurgery/Radiotherapy System at Beacon Hospital offers:
- HyperArc™ High-Definition Radiotherapy and Radiosurgery
HyperArc™ high-definition Radiotherapy system represents a significant step forward for high quality Linac-based Radiosurgery, with an easy delivery of non-coplanar Stereotactic Radiosurgery (SRS) treatments. HyperArc™ could irradiate multiple tumours at the same time without repositioning the patient, which provides better management of patient motions while saving time for the patient and the clinical team. HyperArc™ ensures the planners achieve extremely compact dose distributions consistently and efficiently while maintaining patient safety.
- Stereotactic Radiosurgery (SRS)
Stereotactic radiosurgery (SRS) is a non-surgical radiation therapy used to treat functional abnormalities and small tumours of the brain. It can deliver precisely-targeted radiation in fewer high-dose treatments than traditional therapy, which can help preserve healthy tissue.
- Stereotactic Body Radiotherapy (SBRT/SRT)
Stereotactic Radiotherapy (SBRT/SRT) gives radiotherapy from many different angles around the body. The beams meet at the tumour, this means the tumour receives a high dose of radiation and the tissues around it receive a much lower dose. This lowers the risk of side effects. Stereotactic Radiotherapy (SBRT/SRT) is mainly used to treat smaller size tumour in lung, liver, lymph nodes, spinal cord and brain.
- Chemotherapy – using drugs to kill cancer cells. It works by distressing the growth of cancer cells. Chemotherapy is the key treatment for small cell lung cancer. Doctors use it because:
- this type of cancer responds very well to chemotherapy
- small cell lung cancer tends to have spread beyond the lung when it is diagnosed
Chemotherapy drugs circulate in the bloodstream around the body. Thus, chemotherapy can treat cells that have spread away from the lung tumour and spread to other parts of the body.
Type of chemotherapy drugs:
– Alkylating agent is a type of chemo drug that is capable of damaging the DNA of a cancer cell to ensure that the cell doesn’t make more copies of them.
– Topoisomerase inhibitor is a compound that can block the human enzymes that contributes to the growth of cancer cells.
– Antitumor antibiotic is an anticancer drug that is capable of slowing down or stop the growth of cancer cells.
– Antimetabolites is a chemo drug that is capable of interfering more than one enzyme that’s necessary for the growth of DNA inside the cancer cell.
– Mitotic inhibitor is a type of chemo drug that is capable of stopping the body from producing the protein which contributes to the cancer cell growth.
– Corticosteroids is man-made steroids used to help reduce the side effects of chemotherapy.
- Immunotherapy – Immunotherapy stimulate the body’s immune system to recognize, attack and kill cancer cells. Immunotherapy may not be suggested for all patients, and responses to the treatment may vary widely. Immunotherapy may also be used in combination with other treatments such as radiotherapy or chemotherapy.
- Targeted therapy – For lung cancer, targeted therapy works in a way that it disrupts the way cancers cells signal or interact with each other, causing them to stop growing and dividing. This treatment often has fewer side effects because they focus on targeting what is exactly wrong with the cancer cell, instead of killing normal, healthy cells too. For example, EGFR inhibitors, an oral medication, can be used alone without chemotherapy as the first treatment to block the signal from EGFR that tells the cells to grow for advanced non-small cell lung cancer with EGFR gene mutations. However, it is only suitable for patients with certain specific mutations found in the tumour.