The gold standard for finding lung cancer early is computed tomography (CT) lung cancer screening.
However, this is limited to people who have smoked.
Available laboratory tests may help diagnose lung cancer, though this is more likely with advanced tumors.
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Blood tests are often done to rule out other conditions or to provide information about your overall health.
In 2024, researchers developed a panel of sensors that can detect certain enzymes associated with lung cancer.
The test was able to identify cancer in 90% of the lung cancer patients involved in the study.
One is if cancer has spread to other organs, such as the liver.
The second occurs with the paraneoplastic syndromes that occur with some cancers.
Hence, there is a lower incidence of paraneoplastic syndromes than in the past.
Withbone metastases, alkaline phosphatase (ALP) is often elevated.
Current Screening Methods
Screening for a condition refers to looking for and finding a conditionbeforesymptoms are present.
That said, when used appropriately, screening can reduce lung cancer deaths.
While chest X-rays can find some lung cancers, screening chest X-rays do not appear to save lives.
Even after alung cancer diagnosisis made, a chest X-ray can remain normal.
Low-dose CT is similar to conventional CT of the chest but involves roughly 90% less radiation.
Low-dose CT is designed to screen people who do not have any symptoms of lung cancer.
False Positives
The major drawback to CT screening is false positives.
One study found that the false positive rate for CT lung cancer screening was 28.9%.
Bronchoscopy
Early lung cancers can sometimes be detected on a bronchoscopy.
Unfortunately, bronchoscopy is primarily of use in identifying cancers that occur in or near the large airways.
In one study, bronchoscopy was able to detect 69% of cancers.
At the current time, the test may still have some uses.
Even then, however, it doesn’t indicate where the cancer may be in the lungs.
But if the test is negative, it means very little.
In one study, sputum cytology was normal in 42% of people who had lung cancer.
So which of these indeterminate nodules should be biopsied?.
Biomarkers and Cancer Risk
Biomarkers are used commonly in medicine to guide diagnosis in treatment.
A well-known example is theA1C testused with diabetes.
Biomarkers to assist in evaluating some cancers (tumor markers) have also been used for a long time.
Protein Biomarkers
Protein biomarkers may be nonspecific or specific to cancer.
Nonspecific biomarkersare proteins that aren’t specific to a tumor but are often markers of inflammation.
They may be increased in the blood when cancer is present.
Several have been studied alone or in combination or panels.
Examples include C-reactive protein (CRP), carcinoembryonic antigen (CEA), and alpha-1-antitrypsin.
A 2018 study was promising.
Tumor-specific biomarkersalso hold some promise when combined with CT lung cancer screening.
The lymphocytes then make antibodies (autoantibodies since they are essentially “against self”) against these antigens.
The antibodies can then be measured in a blood sample.
A panel of 13 autoantibodies that were isolated were found to detect around 50% of lung cancers.
The test was able to detect between 40% and 70% of early stage lung cancers.
It could play a role as a primary screening test for those who decline CT screening.
Cell-free DNA Fragmentomes
Another new approach has been to test for cell-free DNA in a different way.
In a 2021 study, researchers looked at DNA fragmentation features (fragmentomes).
American Cancer Society.Cancer facts and figures 2021.
2024;4(1):37. doi:10.1038/s43856-024-00461-7
National Health Service.Lung cancer diagnosis.
2021;12(1):5060. doi:10.1038/s41467-021-24994-w
