Frequency and distribution of incidental findings deemed appropriate for S modifier designation on low-dose CT in a lung cancer screening program.

PURPOSE: To describe the frequency, distribution and reporting patterns of incidental findings receiving the Lung-RADS S modifier on low-dose chest computed tomography (CT) among lung cancer screening participants. METHODS: This retrospective investigation included 581 individuals who received baseline low-dose chest CT for lung cancer screening between October 2013 and June 2017 at a single center. Incidental findings resulting in assignment of Lung-RADS S modifier were recorded as were incidental abnormalities detailed within the body of the radiology report only. A subset of 60 randomly selected CTs was reviewed by a second (blinded) radiologist to evaluate inter-rater variability of Lung-RADS reporting. RESULTS: A total of 261 (45%) participants received the Lung-RADS S modifier on baseline CT with 369 incidental findings indicated as potentially clinically significant. Coronary artery calcification was most commonly reported, accounting for 182 of the 369 (49%) findings. An additional 141 incidentalomas of the same types as these 369 findings were described in reports but were not labelled with the S modifier. Therefore, as high as 69% (402 of 581) of participants could have received the S modifier if reporting was uniform. Inter-radiologist concordance of S modifier reporting in a subset of 60 participants was poor (42% agreement, kappa = 0.2). CONCLUSIONS: Incidental findings are commonly identified on chest CT for lung cancer screening, yet reporting of the S modifier within Lung-RADS is inconsistent. Specific guidelines are necessary to better define potentially clinically significant abnormalities and to improve reporting uniformity.

Evaluating efficacy of current lung cancer screening guidelines.

Objective Current lung cancer screening criteria based primarily on outcomes from the National Lung Screening Trial may not adequately capture all subgroups of the population at risk. We aimed to evaluate the efficacy of lung cancer screening criteria recommended by the United States Preventive Services Task Force, Centers for Medicare and Medicaid Services, and the National Comprehensive Cancer Network in identifying known cases of lung cancer. Methods An investigation of the Stony Brook Cancer Center Lung Cancer Evaluation Center's database identified 1207 eligible, biopsy-proven lung cancer cases diagnosed between January 1996 and March 2016. Age at diagnosis, smoking history, and other known risk factors for lung cancer were used to determine the proportion of cases that would have met current United States Preventive Services Task Force, Centers for Medicare and Medicaid Services, and National Comprehensive Cancer Network eligibility requirements for lung cancer screening. Results Of the 1046 ever smokers in the study, 40% did not meet the National Lung Screening Trial age requirements, 20% did not have a ≥30 pack year smoking history, and approximately one-third quit smoking >15 years before diagnosis, thus deeming them ineligible for screening. Applying the United States Preventive Services Task Force, Centers for Medicare and Medicaid Services, and National Comprehensive Cancer Network eligibility criteria to the Stony Brook Cancer Center's Lung Cancer Evaluation Center cases, 49.2, 46.3, and 69.8%, respectively, would have met the current lung cancer screening guidelines. Conclusions The United States Preventive Services Task Force and Centers for Medicare and Medicaid Services eligibility criteria for lung cancer screening captured less than 50% of lung cancer cases in this investigation. These findings highlight the need to reevaluate the efficacy of current guidelines and may have major public health implications.