As the disease continues to impact lives, learn about the advancements in screening and treatment that offer new hope and improved care.
Lung cancer, the third most common cancer in Singapore for both men and women, is also the leading cause of cancer-related deaths among men.1 “Up to 70% of lung cancer patients are diagnosed only at Stages 3 and 4,” says Dr Lim Hui Fang, Respiratory Physician at The Respiratory Practice. “Unfortunately, late diagnosis is associated with low survival — only about one-fifth of patients survive after five years of diagnosis.”
Lung cancer occurs when abnormal cells in the lungs grow uncontrollably, often starting in the cells lining the air passages. Early stages of lung cancer usually show no symptoms, and even in advanced stages, the symptoms can be vague, such as a prolonged cough, slight sputum with blood or mild breathlessness that may be mistaken for bronchitis, explains Dr Lim.
Recognising Symptoms and Risk Factors
While early lung cancer may not present symptoms, as the cancer grows, patients might experience:
- Persistent cough
- Coughing up blood
- Ongoing breathlessness
- Unexplained fatigue
- Chest pain
- Weight loss
Several risk factors can increase the likelihood of developing lung cancer, including:
- Smoking, the primary cause of lung cancer
- Exposure to second-hand smoke
- Exposure to harmful substances such as radon, asbestos, chromium and nickel
- Previous radiation therapy to the chest
- If you have had lung cancer, you have an increased chance of developing another lung cancer
- Family history of lung cancer, particularly among first-degree relatives
Interestingly, due to Singapore’s effective smoking cessation campaigns, half of lung cancer patients locally are non-smokers, Dr Lim points out. “However, non-smokers generally have a better median survival rate compared to smokers,” she adds.
Who Should Consider Screening?
Lung cancer screening is most effectively done with low-dose computed tomography (CT) scans, which can detect small and faint nodules early without emitting much radiation. Standard chest X-rays, by contrast, may only detect lung cancer at more advanced stages and are less useful for early detection.
However, Dr Lim highlights that lung cancer screening is not encouraged for all. “It exposes the patient to unnecessary radiation and invasive procedures,” she says.
Lung cancer screening is mainly recommended for individuals aged 50 to 80 years old with a significant smoking history — defined as someone who has been smoking about a pack a day for the past 20 years, or those who have quit within the last 15 years.
“Before opting for screening, consider the potential harms and benefits, and consult with an oncologist or lung cancer specialist who can advise whether low-dose CT screening is appropriate for you,” Dr Lim advises.
Getting a Biopsy
If a suspicious mass is detected during a low-dose CT scan, the next step is to obtain a tissue sample from the tumour, which can be done in a number of ways:
- CT-guided Biopsy: Using a needle inserted through the chest wall to collect tissue samples
- Transbronchial Lung Biopsy: Inserting a flexible tube into the throat to gather tissue samples
- EBUS-TBNA: Utilising special scopes and ultrasound to obtain tissue samples
Types of Lung Cancer
Lung cancer is categorised into small cell lung cancer and non-small cell lung cancer. “Small cell lung cancer accounts for about 10% of lung cancers we encounter — it’s typically very aggressive and almost exclusively found in smokers,” says Dr Tanujaa Rajasekaran, Senior Consultant, Medical Oncology at Parkway Cancer Centre (PCC).
Most patients in Singapore have non-small cell lung cancer, which includes subtypes such as adenocarcinoma, squamous cell carcinoma and large cell carcinoma. Treatment options vary depending on the specific subtype. “Our goal is to provide optimal treatment based on the subtype,” emphasises Dr Tanujaa.
Treatment: Stages 1 & 2
At Stage 1, patients usually have a small tumour confined to the lung. At Stage 2, the tumour is slightly larger, or lymph nodes on the same side as the affected lung may be involved. At these early stages, the goal is curative, and patients often undergo surgery to remove part, a segment or a lobe of the lung. “The type of surgery needed depends on your existing lung function, tumour size and extent,” explains Dr Tanujaa. For those who cannot undergo surgery, such as frail or elderly patients, radiation therapy is a potential alternative.
Surgery is typically followed by preventive chemotherapy (also known as adjuvant chemotherapy), targeted therapy or immunotherapy to eliminate any remaining cancer cells and reduce the risk of recurrence.
Treatment: Stages 3 & 4
At Stage 3, the tumour may be larger or have spread to lymph nodes on one or both sides of the chest. Treatment options at this stage are varied and decided by a multidisciplinary tumour board, including medical oncologists, surgeons, radiation oncologists and respiratory physicians. Treatment plans may involve a combination of chemotherapy, radiation therapy and surgery, with the potential addition of immunotherapy or targeted therapy.
At Stage 4, the cancer has spread to other organs such as the brain, liver or bones. While a cure is unlikely at this stage, treatment focuses on prolonging and improving the quality of life. Treatment is personalised based on the specific characteristics of the cancer. For instance, in non-small cell lung cancer, molecular profiling helps identify the gene mutation driving the cancer, allowing for targeted treatment.
Advances in Lung Radiation Therapy
Most lung cancer patients will require radiation therapy (also known as radiotherapy) at some point during their treatment journey. Radiation therapy is often combined with surgery and other treatments like chemotherapy to manage the disease.
Dr Ivan Tham, Senior Consultant, Radiation Oncology at PCC, highlights the growing use of Stereotactic Body Radiation Therapy (SBRT), which delivers precise radiation beams to treat lung cancer. Targeting a lung tumour is challenging due to movement as the patient breathes. To ensure accuracy and safety, radiation oncologists measure the tumour’s movement and adjust their approach accordingly.
Strategies to reduce movement include using a band around the patient’s abdomen to restrict breathing or employing a breath-hold technique, where the patient holds their breath for 20 seconds during treatment administration.
SBRT enables high-dose treatments with fewer sessions, typically three to eight depending on the patient’s needs. SBRT is particularly effective for smaller tumours and offers high-dose treatment to the tumour, while minimising exposure to healthy tissues. “For patients who are more frail or decline surgery, SBRT is a viable option for treating early-stage lung cancer,” says Dr Tham. SBRT has also shown positive outcomes in treating metastatic tumours.
Proton therapy is another option for lung cancer patients. This relatively new treatment in Singapore delivers radiation precisely to the tumour, minimising damage to surrounding healthy tissue. This makes proton therapy suitable for patients with tumours near sensitive organs or for those particularly sensitive to radiation.
