Many people in the lung cancer world consider the National Lung Screening Trial (NLST) that demonstrated a 20% improvement in survival from CT-screening higher risk people for lung cancer as a major advance in the field, befitting coverage in Dr. Weiss’s summary of lung cancer highlights from 2011, but this hasn’t yet led to wholesale adoption of the practice. Why not? Some people say that it’s just one study and that we need more evidence, but it’s hard not to believe that implications for health care resource utilization (i.e., cost and practical implementation) aren’t a big part of the challenge. Annual CT scans will/would add a lot of cost when applied for the millions of people just in the US who would be appropriate candidates by the definition of the study (age 55-75 and with a 30 pack-year smoking history). In addition, we know that CT screening detects a lot of nodules that require plenty of follow-up scans and cause significant anxiety but ultimately prove to not be cancer. What if we could add another factor that could raise or lower our suspicion and potentially enable us to modify the frequency of scanning and/or our enthusiasm for escalating the workup?
I’ve covered one such approach in a prior post describing a test analyzing chemical compounds in the exhaled breath of patients, and this research is ongoing. But another strategy is to analyze the blood of patients in search of preliminary evidence of cancer that might be detectable at the time of or even before the earliest imaging findings suggestive of cancer. The EarlyCDT-Lung test is designed to do this by looking for immuno-biomarkers (“auto-antibodies” created by the body in reaction to a protein detected within), any of a panel of 6-7 that could signify early cancer if one or more of these is elevated.