Outcome in patients with lung cancer invisible on chest roentgenograms but detected only by helical computed tomography

Abstract

The aim of this study was to evaluate the prognosis for patients with lung cancer detected by helical CT but not by CXR. One hundred and thirty-seven asymptomatic patients with lung cancer diagnosed by annual mass screening of the chest were enrolled over a 7-year period. Five-year survival rates in patients with lung cancer detected only by helical CT (n = 19: CT-only detection group) and in patients with lung cancer visible by both CXR and helical CT (n = 118: control group) were evaluated, and clinical variables were examined as possible predictors of survival time using the Cox proportional-hazards model. There was a significant difference between the 5-year survival rates in the CT-only detection group and in the control group (80% vs. 39%, log rank: P = 0.0171). The risk of death decreased 77% in CT-only detectable lung cancer (hazard ratio: 0.219, 95% confidence interval: 0.057-0.845, P = 0.0275). Lung cancer could not be seen by CXR because nodules were small or faint (n = 11) or overlapping a shadow of thoracic components (n = 8). The percentage of subsolid nodules (classified as either part-solid or non-solid nodules) was higher in the subgroup with small or faint nodules (82% vs. 25%, P = 0.0423). Helical CT has the ability to detect early lung cancer before the small or faint nodules increase to a size visible on CXR, and patients with lung cancer detected only by helical CT have a better prognosis.

Turning Gray: The Natural History of Lung Cancer Over Time

“…Studies have reported an average tumor diameter of 33 mm among cancers detected during routine care, [33][34][35][36][37] 30 mm in patients undergoing CXR screening, 38 -40 and 16 mm in patients undergoing CT screening (all scans). 1,16,17,37,38,[41][42][43][44][45] For patients detected purely by an incidence scan during the course of CT screening the average size is approximately 13 mm. 1,42,44 Table 6 tabulates results of calculations based on reported average tumor sizes and doubling times according to the method of detection using the exponential growth model.…”

Comparison between a Case-Matched Analysis of Left Upper Lobe Trisegmentectomy and Left Upper Lobectomy for Small Size Lung Cancer Located in the Upper Division

“…The increase in advanced diagnosis techniques such as high resolution computed tomography (HRCT), which can detect small size or light density lung cancers [4], may be the main reason for the increase in limited resections [5]. Furthermore, some reports have shown that patients with lung cancer detected only by helical CT have a better prognosis than patients with lung cancer invisible on chest roentgenograms [6]. The situation appears to be gradually changing with respect to segmentectomy procedures.…”

Respirology year‐in‐review 2006: Clinical science

“…are under study. A study of 137 patients with lung cancer showed that those ( n = 19) with early disease detected only on CT, but not on CXR, had significantly better prognosis (5‐year survival 80% vs. 39%, respectively) than those with lung cancer visible on both CT and chest radiographs 9 . However, Shaipanich et al .…”

“…A study of 137 patients with lung cancer showed that those (n = 19) with early disease detected only on CT, but not on CXR, had significantly better prognosis (5-year survival 80% vs. 39%, respectively) than those with lung cancer visible on both CT and chest radiographs. 9 However, Shaipanich et al believed that no single modality will achieve sufficient accuracy as a sole screening tool, and combination with additional biomarkers may be more likely to succeed. 10 PET-CT is increasingly employed in the work-up of patients with lung cancer.…”