PROGNOSTIC ROLE OF SOLID, SUBSOLID, AND PURE GROUND GLASS OPACITY (GGO) NODULES OF THE LUNG: A RETROSPECTIVE OBSERVATIONAL STUDY.

Introduction. A GGO nodule is a radiological finding characterized by a faded opacity hiding a pre-invasive or invasive adenocarcinoma. GGO can be: 1) pure, or 2) subsolid. The transformation of GGO nodules into solid is a strong indicator of malignancy. Current guidelines suggest 5-years follow-up for pure or subsolid GGOs. This study highlights a similar overall survival (OS) trend for subsolid GGO and solid nodules, compared to pure GGO. Methods. This is a retrospective observational study. 133 patients underwent lobectomy between 2010-2021 were analyzed. Density was evaluated by chest CT. Consolidation tumor ratio (CTR) was divided into three groups: pure GGO (Group 1, CTR < 0.5, n = 30), subsolid nodule (Group 2, 0.5 > CTR < 1, n = 37), solid nodule (Group 3, CTR = 1, n = 66). Pearson's chi-square test was used for categorical variables. Overall survival was estimated by Kaplan-Meier, log-rank test for univariate analysis, and Cox’s regression for multivariate analysis. Results. Overall survival (OS) was related to the nodule density for the three groups: Group 1 = 96% (IC 95%, 73–99%), Group 2 = 76% (IC 95%, 56–88%), and Group 3 = 78% (IC 95%, 62–88%). Mean survival time was 95 months. Multivariate analysis showed that for Group 2 vs. Group 1, the HR was 8.37 (IC 95%, 1.03–68.12), and for Group 3 vs. Group 1, the HR was 8.66 (IC 95%, 1.06–70.90). A similar trend was observed for Group 2 vs. Group 3. Conclusions. Patients with pure GGO showed the highest survival rate. Moreover, for Groups 2 and 3, a similar OS trend was observed. Therefore, for pure GGO, a long-term follow-up may be justified, although, for subsolid nodules, surgery should be considered as the first option. This needs to be analyzed in detail in further multicentric studies.