Pulmonary adenocarcinomas appearing as part-solid ground-glass nodules: is measuring solid component size a better prognostic indicator?

Abstract

To assess whether measuring the solid portion of adenocarcinomas appearing as part-solid ground-glass nodules (GGNs) can predict a patient's prognosis accurately and how the prognosis corresponds to that of solid nodules. 501 patients (solid nodule group, 304; part-solid GGN group, 197) underwent curative surgery for stage I adenocarcinomas. Maximal diameters of the whole lesion including ground-glass opacities (D whole ) and solid components only (D solid ) were measured on CT. Disease-free survival (DFS) and overall survival (OS) were calculated from the date of surgery. D solid was a significant prognostic factor in the part-solid GGN group, while D whole was not. Part-solid GGNs with D solid ≤2 cm showed significantly better DFS (P = 0.016) and OS (P = 0.004) than solid nodules; however, those with D solid >2 cm did not show a significant difference. Hazard ratio (HR) for increase in D solid was significantly greater in part-solid GGNs than in solid nodules (P = 0.009). For OS, HR for increase in D solid was greater in part-solid GGNs than in solid nodule, which was marginally not significant (P = 0.060). D solid was better than D whole for prognosis prediction of adenocarcinomas appearing as part-solid GGNs. In addition, the influence of D solid on prognosis in the part-solid GGN group was greater than in the solid nodule group. • Dsolid is a better prognosis indicator than Dsolid in part-solid GGN adenocarcinomas • Part-solid GGN adenocarcinoma show better prognosis than solid adenocarcinomas when Dsolid ≤2 cm • Dsolid has greater prognostic influence in part-solid GGN adenocarcinomas than solid adenocarcinomas.