Micronodules Detected on CT during the NLST: Prevalence and Relation to Positive Studies and Lung Cancer

July 8, 2019

Micronodules are very small round areas of tissue in the lungs that show up on a CT scan as a white spot or shadow and can be an early sign of lung cancer.  

Oncologists have struggled with establishing clear screening guidelines for this population as there is insufficient scientific data regarding the malignant potential of micronodules and the impact on the lung screening process.

In the National Lung Screening Trial (NLST), researchers sought to determine if low-dose CT screening was effective in reducing the risk of mortality from lung cancer. The study enrolled 53,452 participants and 26,722 received a low-dose CT screening. In the NLST, all cases with a 4-mm nodule (micronodule) and no other findings of lung cancer were classified as a negative study.  

Now, in the Journal of Thoracic Oncology, researchers led by Reginald F. Munden MD, DMD, Wake Forest Baptist Health and School of Medicine analyzed a subset of those patients with micronodules to understand if the negative classification was appropriate. This subset included 11,326 (42%) of participants who had at least one CT with a micronodule. Of these cases, 5,560 (49%) had at least one positive CT examination of which 409 (3.6%) subsequently were diagnosed with lung cancer.

Media Contact: 

Marguerite Beck, marbeck@wakehealth.edu336-716-2415