Evaluation of dynamic image progression of minimally invasive and preinvasive lung adenocarcinomas

BACKGROUND: The target of our study was to investigate if the size (greater than and less than 1 cm) of ground-glass opacities (GGOs) of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) of the lung influences the rate of their evolution. METHODS: We retrospectively analyzed patients with AIS and MIA who underwent surgery at Shanghai Chest Hospital, Shanghai Jiao Tong University between January 2018 and July 2019, focusing on histopathology, surgical procedure, epidermal growth factor receptor (EGFR) mutations, and computed tomography (CT) images. RESULTS: A total of 224 AIS (n=117) and MIA (n=107) tumors were analyzed. The patients with a tumor diameter <1 cm were distinctly younger than those with tumors >1 cm in size (P<0.001). Pure ground-glass opacities (pGGO) occurred significantly more in patients with nodules <1 cm, while part-solid/mixed ground-glass opacities (mGGO) predominated in patients with nodules >1 cm (P=0.047). There was no significant difference in GGO evolution for GGOs of different sizes. Mutations of EGFR were more common in patients with MIA than in those with AIS (P<0.001). CONCLUSIONS: We found that GGO size and variation (pGGO or mGGO) did not correlate to tumor stability, therefore larger GGOs can undergo standard follow-up protocols to evaluate their evolution over time.