The Natural Growth Rate of Growing Malignant Pulmonary Nodules with Ground-Glass Opacity and Association of Clinic Features With It

Abstract Objective The objective of the study was to investigate the volume (VDT) and mass doubling time (MDT) of growing malignant ground-glass opacity(GGO) and explore the relationships between doubling times and clinical-pathological features. Methods We collected 37 GGO cases (18 male & 19 female with age between 43- and 82-year-old) between 2016 and 2020 and all of these cases were along with growing malignant pulmonary nodules. The duration of follow-up and the variation in GGOs volume and mass were recorded. The morphologic changes and three-dimensional segmentation of GGO nodules were used to calculate the VDT and MDT based on a modified Schwartz model. The independent sample t-test was used to investigate the relationship between doubling times and their features. Logistic regression was used to evaluate the risk factors of growing malignant GGOs. Results The median follow-up time was 725 days (31-1507 days). The averaged VDT and MDT of the GGOs were 973 days and 671 days, respectively. Both VDT and MDT were significantly different among the three different groups of solid components of GGO(p<0.05). The vacuole sign and lepidic-predominant lung adenocarcinoma (LPA) also made an important role in changing the VDTs and MDTs (p<0.05). In addition, the growth of malignant pulmonary nodules was significantly associated with air bronchus sign (OR 6.667; 95% CI of 1.126-39.470; p=0.037). Multivariate analysis showed that LPA declined the GGOs growth (odds ratio 0.093, 95% CI of 0.011-0.765, p = 0.027). Conclusions The solid component of GGOs and vacuole sign were closely associated with the growth rate of GGOs. The GGOs with air bronchus sign was more dangerous in terms of growth rate than other GGO cases. However, the appearance of LPA could inhibit GGO growth. Further studies are still required to verify the obtained results.