Background: In the US, Lung cancer is the second most common malignancy, but the most common cause of cancer deaths. In 2010, the National Lung Screening Trial described a 20.3% reduction in lung cancer mortality in high-risk patients screened by low-dose spiral CT (LDCT). In 2012, multiple groups established screening guidelines. The National Comprehensive Cancer Network recommended yearly screening for patients aged 55 to 75 years, ≥30 packyears of smoking, or smoking cessation within 15 years. In late 2013, LDCT screening for lung cancer was initiated at the Providence VA Medical Center. It was anticipated that over time there would be a rise in early stage cancers and decrease in late stage cancers. We submitted preliminary data at AVAHO in 2015 with increased earlier detection as anticipated. We have now completed 5 years of screening and are presenting data from 2014 through 2018.
Results: The number of screening CTs has increased almost every year (1929, 1875, 1916, 2201, 2336 respectively), and the number with cancer decreased from 1.34% (2014) to 0.008% (2018). The majority of NSCLCs found have been early stage, but with Small Cell Lung Cancer, 50% had limited and 50% extensive disease. Yearly screening is not likely to increase early detection of Small Cell Lung Cancer. Percentages of stage I & II for NSCLC prior to screening were 30% and 27% in 2012 and 2013 respectively. In 2014 – 2018 percentages were 69%, 60%, 50%, 83% and 50%. In 2016 and 2018, several veterans came to the VA to establish care with a known nodule, or had their first screening CT here, and they were found to have late stage disease. When we subtracted those first time screens the percentages of stage I & II were 69%, 60%, 78%, 83%, and 56%.
Discussion: As expected, for NSCLC yearly LDCT screening increased “pickup” of early stage disease. Unanswered questions include: How long should annual screening continue; What is the financial, emotional and radiation exposure impact of frequent screening, especially for those who need to be followed at more frequent intervals.
