Common lung cancer screening tool superior to alternatives

A newly published study that compared the accuracy of two commonly used lung cancer screening algorithms found that the American College of Radiology Lung-RADs screening tool is more accurate in detecting cancerous nodules in patients with a history of lung cancer than NELSON, a Dutch clinical trial that measures nodule volume and growth rate instead of linear measurement of nodule size as done in Lung-RADs.

The study, published in the American Journal of Roentgenology on Nov. 10, 2021,was a retrospective study of 185 patients (100 women, 85 men; mean age, 66 years) who underwent lung cancer screening at a single health care system between July 2015 and August 2018. Using Lung-RADS, seven cancers were downgraded to category 2. The weighted cancer risk was 5% for new nodules, 1% for stable existing nodules, and 44% for growing existing nodules.

“Lung-RADS scores exhibited excellent sensitivity and specificity for cancer in existing nodules and excellent sensitivity in new nodules, though low specificity in new nodules,” wrote the authors, led by Mark M. Hammer, MD, a radiologist with Brigham and Women’s Hospital in Boston.

CT scans are increasingly used for lung cancer screening, so accuracy is essential in devising an appropriate treatment plan for patients. Nearly all centers in the United States use the American College of Radiology’s Lung-RADS for lung cancer screening. In Europe, many centers use the volumetric-based approach of NELSON.

Several studies have compared the performance of nodule risk assessment algorithms, but the findings are inconsistent. Lung-RADS was found to be inferior to the Vancouver risk calculator in predicting malignancy in the National Lung Screening Trial for total nodules. Dr. Hammer previously reported that subsolid nodules classified as Lung-RADS categories 2 and 3 have a higher risk of malignancy than reported. Meanwhile, a study that followed 13,195 men and 2,594 women at high risk of lung cancer found that lung cancer mortality was lower among participants who underwent volume CT screening than among those who underwent no screening.

The authors cited the retrospective design and the small sample size as study limitations. They added that pathological proof was not obtained from benign nodules, which may represent undiagnosed cancer.

The authors declared no conflict of interest.