Annual lung cancer screening by chest X ray to avoid further examinations.

Abstract

e19124 Background: Chest X ray (CXR) has been the most common screen procedure for detection of lung cancer. However, if patients had old inflammatory shadows such as tuberculosis, calcification and fibrotic changes, it would become increasingly difficult to detect the lung cancer. In that case, a comparative review of the CXR to the previous one helps the detection of new shadows. We examined whether the repeat participants (pts) who received the medical checkup annually, may have a profit for the lung cancer detection screening. Methods: Our clinic “MedCity21” is a university outpatient clinic to undergo a complete medical checkup in private health screening program. The pts with abnormalities detected in CXR were announced by call request and invited to our specialty clinic for chest CT scan as further examination. We examined the varieties of abnormal shadows by CXR and CT scans, and compared the differences between the repeat and the first-time pts using the chi-square tests, in 2018 and 2019 respectively. Results: In 2018, a total of 12540 with repeat / first-time pts of 6898/5642 pts (55/45%) were enrolled. The CXR abnormalities requiring further examinations were a total of 335 (2.6%) with those of 138/188 pts (p < 0.01). After the call requests, a total of 239 (71.3%) with those of 109/130 pts in 2018 received chest CT scan in our specialty clinic. In 2019, a total of 13690 pts with those of 7748/5942 (56.6/43.4%) were enrolled. The CXR abnormalities requiring further examinations were a total of 323 (2.4%) with those of 137/186 pts (p < 0.01). After the call requests, a total of 224 (69.3%) pts with those of 104/120 pts received chest CT scan in our specialty clinic. The varieties of abnormal shadows by CT scans showed that 8.3/20.8% (p < 0.01) in 2018 and 11.5/21.7% (p = 0.04) in 2019 of old inflammatory shadows, 11.0/6.9% (p = 0.27) in 2018 and 14.4/1.7% (p < 0.01) in 2019 of acute inflammatory shadows, respectively. The nodule was detected in 11.9/11.5% in 2018 and 8.7/10.8% in 2019 with no significant differences. Lung cancer was detected in 3/3 pts in 2018, and 1/3 pts in 2019. Conclusions: The repeat pts in each year, had significantly lower rate of CXR abnormalities detection, and had lower rate of the detection of old inflammatory changes as significant. In private health screening program, the repeat pts may have higher profits for the avoidance of further examination for lung cancer detection than the first-time pts.