New Research Further Dispels Fear of Over Diagnosis in CT Screening

According to a new study based on the International Early Lung Cancer Action Program (I-ELCAP), lung cancers identified in low-dose CT screening programs are similar to those identified by non- screening means. The research results, which were released on March 27 in Radiology, further alleviate concerns that cancers detected through low- dose CT screening are less aggressive than those found through other means, and therefore demand less attention and resources.  In fact, the frequency of small-cell carcinoma and adenocarcinoma were similar for cancers detected through screening programs and outside the screening setting.

This study is another brick in the wall of evidence building for the value of low radiation dose CT lung cancer screening in high risk asymptomatic smokers. Regardless of whether nodules are solid or “ground glass” (non-solid), growth occurs that is similar in the screened populations and in those detected of having lung cancer due to symptoms.

While it is true we do not yet have a data-based analysis of costs versus quality life years saved, the evidence that screening is worthwhile continues to become stronger. “The CT scanners we have now are really phenomenal,” with resolution that continues to improve as the radiation dose falls, “so that the amount of information you can get out of them for emphysema, for coronary artery risks, and so on, continues to increase,” says Dr. Claudia Henschke, lead author of this study.

She goes on to point out that cancers detected via low dose CT screening “are real cancers that would kill you if they weren’t discovered early, so it kind of underscores again the data that we had shown in ELCAP and that NLST (National Lung Screening Trial) has shown — that screening for lung cancer saves lives.” And that is the key takeaway.