What tests are used to diagnose lung cancer?
The best test to diagnose lung cancer is a computed tomography (CT) scan, but it comes with its own risks.
Routine blood tests are not used to diagnose lung cancer specifically. For example, if cancer has spread to the bones, blood tests might show an abnormal increase in the levels of calcium and alkaline phosphatase. A certain tumor marker may be checked using blood tests. These can help classify the tumor and which drug will be more effective against it. Chest X-ray is also not a reliable test for diagnosing lung cancer.
The U.S. Preventive Services Task Force (USPSTF) recommends taking a screening test with a low-dose CT scan provided you fulfill the following specified criteria:
- You should be between 50 and 80 years of age.
- You should be asymptomatic, which means you should not have any of the signs and symptoms of lung cancer as mentioned earlier.
- You should
- Be currently smoking or have quit smoking during the last 15 years.
- Have a tobacco smoking history of 20 pack-years (smoking an average of 20 packets a day).
This noninvasive test can be covered by Mediclaim and other insurance companies. Read your insurance policy carefully.
Doctors recommend only low-dose CT scans for screening. There are some risks associated with a CT scan and not everyone should be screened for lung cancer. The risk is of getting exposed to some amount of radiation. Schedule an appointment with your doctor and ask them if you can and if you should undergo the screening test for lung cancer. Your doctor will weigh the benefits against the risks and help you reach the right decision.
You may need to have additional tests and procedures if the CT scan detects any abnormality in your lung, particularly pointing toward a lung cancer diagnosis. Your doctor will direct you toward a team of experts who will explain the report to you and about the number of follow-ups you might need to have after the initial screening.
Other factors that put you at an increased risk of lung cancer include
- Exposure to
- Secondhand smoke
- Radon gas
- Air pollution
- Previous radiation to the lungs
- Personal or family history of lung cancer
- Arsenic in drinking water
If you have been exposed to the above risk factors and are worried but do not fulfill the USPSTF criteria for screening, do not hesitate to discuss the same with your doctor. Get all your doubts cleared. If your doctor examines you and rules out the possibility of lung cancer, you may feel relaxed. They may ask you to go through a few routine tests such as X-rays. Your follow-ups, if necessary, will be scheduled accordingly. They may also advise one or more of the additional tests that include
- Magnetic resonance imaging (MRI)
- Positron emission tomography (PET) scan
- Bone scans
- Sputum cytology
- Bronchoscopy and bronchoalveolar lavage
- Needle biopsy
- Major surgical procedures
- Molecular testing