Blood Test to Detect Lung Cancer
I recently saw a story on the news that a blood test can detect lung cancer early. Can you tell me more about this test?
Anil Vachani, MD, Pulmonologist at Penn Medicine, responds:
Unlike other blood tests typically used to detect cancer, this test does not look for substances produced by cancer cells as they grow (such as PSA for prostate cancer). Instead, the test you are referring to looks for the genetic signature of immune-system cells that are activated by encounters with tiny lung tumors. So, it cannot detect !0pre-cancer,!1 but it detects changes in white blood cells that have encountered lung cancer cells in the body. The goal of the test is to detect lung cancer early enough to improve outcomes for people. The diagnostic test, which uses peripheral blood mononuclear cells, is still in early development and will require several additional studies to be performed prior to any potential clinical use. If the test continues to show good rates of detection, it would still be several years away from prime time clinical use.
There are currently no available blood tests for monitoring patients for early detection of lunch cancer or evaluating for recurrence after lung cancer therapy. The most commonly used method for monitoring patients at high risk for developing lung cancer or after lung cancer therapy is to undergo periodic imaging studies, typically with CT scans. This should be done under the care of a surgeon, oncologist, or pulmonologist.