Lung cancer is one of the leading causes of cancer death worldwide, and in its early stages it often causes no symptoms at all — which is exactly why screening matters. By the time symptoms appear, the disease has frequently progressed to a later, harder-to-treat stage. This guide covers who’s at risk, who should consider lung cancer screening in Singapore, what the screening test involves, and how a diagnosis is actually confirmed.
Lung cancer begins in the cells of the lung and may spread to lymph nodes or other organs, such as the brain or liver, if left untreated. There are two main types:
Lung cancer found at an early, localised stage is generally more treatable than cancer found after it has spread, which is why early detection through screening or prompt investigation of symptoms can make a meaningful difference to outcomes. Unfortunately, because early-stage lung cancer often causes no noticeable symptoms, many cases are only found once the disease is more advanced. This gap between “no symptoms” and “found late” is the main reason targeted screening programmes exist for people at higher risk.
Cigarette smoking remains the leading risk factor for lung cancer globally and is linked to the majority of cases and deaths in many countries. Cigarette smoke contains numerous toxic and cancer-causing compounds.
Regular exposure to other people’s smoke, whether at home or work, is also linked to a higher risk of lung cancer in non-smokers.
Radon is a naturally occurring radioactive gas that can accumulate indoors. Long-term exposure is a recognised risk factor for lung cancer.
A family history of lung cancer, or inherited factors affecting how the body repairs DNA damage or clears cancer-causing substances, can raise individual risk.
Unlike many Western countries where the large majority of lung cancer cases occur in smokers, close to half of lung cancer patients in Singapore have never smoked. This means risk factors such as family history, occupational or environmental exposure (including secondhand smoke and possibly air pollution), and other still-being-studied causes matter here in a way that a smoking-only view of lung cancer risk would miss. If you have any of these risk factors, it’s worth discussing your personal risk with a doctor, even as a non-smoker.
Local guidelines (updated January 2025) recommend lung cancer screening for individuals aged 50 to 80 with a significant smoking history, specifically, at least 20 pack-years, who currently smoke or quit within the last 15 years. (A pack-year is calculated by multiplying the average number of packs smoked per day by the number of years smoked. For example, one pack a day for 20 years, or two packs a day for 10 years, both equal 20 pack-years.)
Screening decisions are individualised, and a doctor will weigh overall health, personal risk factors, and preferences before recommending it. For non-smokers with a strong family history or significant environmental/occupational exposure, the evidence for routine screening is still developing, and there’s currently no formal recommendation, this is a conversation to have directly with a doctor rather than something to self-initiate.
The recommended screening test is a low-dose computed tomography (LDCT) scan – currently the only screening test recommended internationally for high-risk individuals. It uses a lower radiation dose than a standard CT scan while still producing detailed images of the lungs, and does not require needles, contrast dye, or sedation. The scan itself typically takes only seconds, with the full appointment usually under 15 minutes.
Screening does not prevent lung cancer – its purpose is to catch it at an earlier, more treatable stage before symptoms develop. Screening intervals depend on individual risk factors and prior results, so this is something your doctor will tailor to you.
Screening isn’t without trade-offs, and it’s worth understanding these before deciding whether it’s right for you:
Early-stage lung cancer frequently causes no symptoms, which is why screening, not symptom-watching, is the main tool for early detection in high-risk groups. When symptoms do appear, they can include:
These symptoms have many possible causes, most of them not cancer — but persistent or worsening symptoms are a reason to see a doctor rather than wait.
If screening or symptoms raise concern, several steps are typically involved in reaching a confirmed diagnosis.
A standard or low-dose CT scan is usually the first step to get a clearer picture of any abnormal area (often called a nodule) in the lung – its size, shape, and location. A PET scan may also be used, particularly to help assess whether cancer may have spread.
Imaging alone can raise suspicion, but a biopsy – examining a tissue sample under a microscope – is the only way to confirm a lung cancer diagnosis. Common ways a biopsy sample is obtained include:
Once lung cancer is confirmed, further tests help determine its stage – how large it is and whether it has spread to lymph nodes or other parts of the body. Staging typically draws on imaging (CT, PET) and, where needed, sampling of nearby lymph nodes. This information is central to planning the most appropriate treatment approach, which is why it’s discussed directly with the treating specialist.
See a doctor if you notice:
And separately from symptoms: if you’re a current or former heavy smoker aged 50–80, it’s worth discussing your eligibility for lung cancer screening with a doctor – even if you feel completely well.
Yes. In Singapore specifically, close to half of lung cancer patients have never smoked. Non-smokers can still be affected by secondhand smoke, radon, occupational exposures, family history, and other factors that aren’t fully understood.
No. Screening doesn’t prevent cancer from developing – it aims to catch it earlier, when treatment tends to be more effective, compared with waiting for symptoms to appear.
No. A CT or PET scan can show an abnormal area and raise suspicion, but a biopsy – examining tissue under a microscope – is needed to actually confirm whether it’s cancer.
Current local guidelines focus on adults aged 50–80 with a significant smoking history (20+ pack-years, current smoker or quit within 15 years). If you don’t fit this profile but have other risk factors, such as a strong family history, it’s best to discuss your individual situation with a doctor rather than assume you either do or don’t need screening.
LDCT uses a lower radiation dose than a standard CT scan and is generally considered an appropriate screening option for people at high risk, though like any test involving radiation, it carries a small trade-off that’s worth discussing with your doctor, especially if you’re considering repeated annual screening.
Lung cancer is often silent in its early stages, which makes screening, not just symptom-watching, an important tool for people at higher risk, including many non-smokers in Singapore. If you’re wondering whether you should be screened, or have symptoms that concern you, consult a doctor through the MaNaDr App to discuss your risk and next steps.
