Can lung cancer be detected by chest X-ray during routine physical examination

The answer is yes, but only part of it can be found, and the missed diagnosis rate is not low. To put it bluntly, a chest X-ray is like pressing the lungs, heart, ribs, blood vessels and other organs in the chest into a pancake and taking a group photo. All the structures are stacked together. If the lesion grows behind the heart, next to the spine, or is less than 1 cm in size, it will be easily blocked by the surrounding tissue, and no abnormality will be seen at all.

I met a 38-year-old Internet salesperson when I was on duty in the respiratory department. The chest X-ray result of the annual physical examination at the work unit said "no obvious abnormality". He had been coughing intermittently for almost two months that year, and he didn't get better after taking cough medicine, so he came to the hospital. During follow-up consultation, a low-dose CT was performed, and it was discovered that there was a 1.2-centimeter malignant nodule in the lower lobe of the right lung near the thoracic spine. Looking back at his chest X-rays from the previous two years, that location was so tightly blocked by the heart and thoracic spine that no trace of it could be seen.

There are actually different opinions in the industry on the value of chest X-rays for lung cancer screening. Many public health doctors in primary medical institutions believe that for ordinary people without high-risk factors, chest X-rays are cheap and have low radiation. However, most oncology and respiratory specialists would recommend that high-risk groups who smoke all year round, have a family history of lung cancer, or are exposed to oil fumes or industrial dust for a long time should not just rely on chest X-rays for lung cancer screening. It is best to do low-dose CT once a year. The radiation dose is only 1/5 of conventional CT. It is very safe. It can also detect millimeter-level early lesions, and the missed diagnosis rate is much lower than that of chest X-rays.

This does not mean that chest X-rays are completely useless. Last year, I met a 62-year-old aunt who had free physical examinations every year after her retirement. The result that year showed that there was a spiky mass in the upper lobe of the right lung. I rushed to the hospital for further puncture biopsy and was diagnosed with very early-stage lung adenocarcinoma. After minimally invasive surgery, she recovered very well and did not even need follow-up chemotherapy. If she had waited for symptoms to be checked, it might have been delayed to the mid-to-late stage.

In fact, there is no need to forcibly remove chest X-rays from the routine physical examination items. After all, different groups of people have different screening needs and budgets. It is perfectly fine for ordinary healthy people to take a chest X-ray every year for basic screening.