Will a chest X-ray show lung cancer?
Chest X-rays cannot definitively diagnose lung cancers at an early stage.
Pulmonary nodules are small round or oval-shaped growth in the lung. They can be either cancerous (malignant) or benign (non-cancerous).
Only one of every 500 chest X-rays and one out of every 100 chest computerized tomography (CT) scans will show pulmonary nodules. At least 60% of pulmonary nodules observed on chest X-rays are benign, and 99% of those on chest CT are benign.
About half the people who smoke and are over age 50 years will have nodules, many of them being noncancerous, on a CT scan of their chest.
What does lung cancer look like on a CT scan?
A CT scan shows detailed cross-sectional images of your lungs and hence, it can detect lung cancer more accurately than chest X-ray. It can show the size, shape, position, and depth of any lung tumor.
Lung cancer looks like a nodule on a CT scan, which can detect many more lung nodules than a chest X-ray.
Does lung cancer show up in routine blood work?
Routine blood tests are not used to diagnose lung cancer, but they can indicate if cancer has spread to other organs, such as the liver or kidneys. For example, if cancer has spread to the bones, it might be an abnormal increase in the levels of calcium and alkaline phosphatase.
Routine blood tests can help to get a sense of a person’s overall health. For example, they can be used to help determine if a person can have surgery for lung cancer.
- If you are anemic (due to a low count of red blood cells)
- If you could have trouble with bleeding (due to a low blood platelet count)
- If you are at increased risk for infections (due to a low count of white blood cells)
A CBC test could be repeated regularly during cancer treatment to check if the cancer drugs are affecting these normal blood cells.
Are there blood markers for lung cancer?
Yes, tumor marker tests are the blood tests used to diagnose lung cancer, but they are not definitive tests. These suggest a possibility of cancer and need a CT scan to confirm. The tumor markers include:
- Carcinoembryonic antigen (CEA)
- Squamous cell carcinoma antigen (SCC)
- Neuron-specific enolase (NSE)
- Cytokeratin 19 fragment (CYFRA)
- Pro-gastrin-releasing peptide (ProGRP)
A study published in the European Respiratory Journal in July 2020 shows that lung cancer could be detected around three months earlier using a biomarker blood test and CT scanning in high-risk patients.