About 90% of the screening-detected pure ground-glass opacity lung nodules did not grow during long-term follow-up in subjects with no history of malignancy and most of growing nodules had an indolent clinical course.
Background: Although focal ground-glass opacity lung nodules are generally reported to grow slowly, their natural course is unclear. The purpose of this study was to elucidate the natural course of screening-detected pure ground-glass opacity lung nodules in patients with no history of malignancy.
Methods: We retrospectively reviewed the database of subjects who had undergone screenings involving low-dose computed tomography scans. We included patients with pure ground-glass opacity lung nodules who were followed for more than two years after the initial screening.
Results: Between June 1997 and September 2006, 122 pure ground-glass opacity nodules were found in 89 patients. The median nodule size was 5.5 (3–20) mm in the largest diameter on initial low-dose computed tomography scan. The median follow-up period per patient was 59 months. On a per-person basis, the frequency of growth was 13.5% (12/89). On a per-nodule basis, the frequency of growth was 9.8% (12/122).Nodule growth was significantly associated with initial size and new development of an internal solid portion. The median volume doubling time was 769 for growing pure ground-glass opacity nodules. A total of 11 growing nodules were surgically validated and all lesions were confirmed as primary lung cancer.
Conclusions: About 90% of the screening-detected pure ground-glass opacity lung nodules did not grow during long-term follow-up in subjects with no history of malignancy and most of growing nodules had an indolent clinical course. A strategy of long-term follow-up and selective surgery for growing nodules should be considered for pure ground-glass opacity lung nodule.