In order to test for cancer, people have to go through invasive and even risky procedures to remove and biopsy a tumor. With these risky procedures between 75 and 85 percent of people find out that the tumor in question is benign and they went through a terrifying surgery to learn they are healthy. Instead of going through this process, researchers at the Medical University of South Carolina have been evaluating a blood test for biomarkers, which are used to test for specific types of diseases, to determine the likelihood of a nodule being cancerous. It does this by measuring the amount of two proteins, LG3BP and C163A. LGBP3 is linked to the immune response in the body while C163A is a marker for white blood cells, the main cells in the immune system. Abnormal levels of the markers are then compared alongside factors that predict cancer including a patient’s age, the tumor size, as well as other tumor characteristics. When using this test, it has correctly identified benign and malignant tumors 98 percent of the time.
The test works by using the above proteins and calculating whether or not the patient has cancer. For example, if a patient is less than 50 percent likely to have cancer and the biomarker test is negative, the lung nodule is probably not cancer. Instead of a doctor trying to figure out if a nodule is cancerous before recommending a certain procedure, the test helps to calculate what the risk of cancer is and lets a doctor give the best recommendations and options to his or her patient. This gives the doctor more confidence in his or her decision for a specific patient’s treatment and improves the overall patient care.
Since doctors cannot definitively rule out cancer with a biomarker, a patient who tests negative for a specific biomarker still has to have ongoing CT scans in order to monitor the lung nodule in question. The likely non-cancerous tumor can be monitored and if it does not grow for two years, it can be determined to be not cancerous.
This biomarker test is part of the Pulmonary Nodule Plasma Proteomic Classifier (PANOPTIC) study where a clinical trial of 685 patients older than 40 years of age with newly discovered nodules were studied. If the patients were able to use the PANOPTIC study as intended, 40 percent less procedures would have needed to be done. This study has the potential to prevent patients from having unneeded invasive, costly, and risky procedures and can help advance patient care in the future.
The next step of this study is a clinical utility study where the biomarker test will be looked at to see what the benefit is for patients and how it affects lung cancer treatment in the future.
Medical University of South Carolina “Can a Simple Blood Test Rule Out Cancer?” Science Daily (April 16, 2018). [Link]