-Kaohsiung Medical University Gangshan Hospital-

Ms. Lin (pseudonym), a 50-year-old woman, maintained a regular lifestyle and healthy diet. She had never smoked and experienced none of the common symptoms of lung cancer, such as a persistent cough, coughing up blood, or unexplained weight loss. Her chest X-ray showed no abnormalities, and a blood test revealed a carcinoembryonic antigen (CEA) level of only 2.8 ng/mL, which was entirely within the normal range. Based solely on her clinical presentation and routine health examination results, Ms. Lin appeared to be a perfectly healthy middle-aged woman.

However, Ms. Lin’s father had previously been diagnosed with lung cancer, meaning she had a family history of the disease. As she met the eligibility criteria for government-funded screening, her physician arranged a low-dose computed tomography (LDCT) scan for early lung cancer detection. Subsequent examinations and surgery revealed that Ms. Lin had early-stage lung adenocarcinoma. Fortunately, it was detected before the cancer had spread, and the tumor was completely removed through surgery. She continues to receive regular outpatient follow-up care, has recovered well, and shows no signs of recurrence.

Dr. Ying-Ming Tsai, Director of the Division of Pulmonary and Critical Care Medicine at Kaohsiung Medical University Gangshan Hospital, stated that Taiwan’s Ministry of Health and Welfare expanded the eligibility criteria for government-funded LDCT screening on January 1, 2025. For individuals with a family history of lung cancer among first-degree relatives—including parents, children, and siblings—the eligible age range was lowered to 40–74 years for women and 45–74 years for men. For heavy smokers aged 50–74, the smoking-history threshold was relaxed to 20 pack-years or more.

Dr. Jui-Yang Ma of the Division of Pulmonary and Critical Care Medicine at Kaohsiung Medical University Gangshan Hospital explained that LDCT is currently the only evidence-based screening tool capable of detecting lung cancer at an early stage. It does not require the injection of contrast media, and its radiation dose is only approximately one-fifth to one-tenth that of a conventional CT scan. Despite the lower radiation exposure, LDCT produces high-resolution, three-dimensional cross-sectional images that can clearly identify lung nodules only a few millimeters in size.

By comparison, a conventional chest X-ray produces a two-dimensional projection image and cannot fully display the lungs’ three-dimensional structure. Tumors smaller than one centimeter, low-density lesions such as ground-glass nodules, or abnormalities concealed behind the heart, beneath the diaphragm, or where bones overlap are nearly impossible to detect on an X-ray.

There is also currently no medical evidence that blood-based tumor markers such as CEA can diagnose lung cancer earlier or improve patient outcomes. Elevated tumor marker levels are more commonly observed in intermediate- or advanced-stage cancer and may also result from non-cancerous factors such as inflammation or smoking. Conversely, many patients with early-stage lung cancer have completely normal tumor marker levels. Excessive reliance on serum tumor markers may therefore create a false sense of security and delay diagnosis and treatment.

Dr. Tsai again emphasized that lung cancer has long been the leading cause of cancer-related death in Taiwan. Because early-stage lung cancer often causes no symptoms at all, many patients are already in an advanced stage when they seek medical attention for persistent coughing, blood-streaked sputum, chest pain, or unexplained weight loss. Proactive screening is the only way to accurately identify small lesions before symptoms appear.

Following surgical treatment, the five-year survival rate for patients with stage 0 or stage I lung cancer can exceed 90%. If you are eligible for government-funded LDCT screening, please bring your National Health Insurance card and schedule an examination at a designated contracted hospital. Protect your lung health—take the initiative and get screened without delay.



Figure. CT scan showing a tumor in the right upper lung.