Start Your Search
ORAL 24 - CT Detected Nodules - Predicting Biological Outcome (ID 122)
- Event: WCLC 2015
- Type: Oral Session
- Track: Screening and Early Detection
- Presentations: 1
ORAL24.01 - Natural History of Pulmonary Subsolid Nodules: A Prospective Multicenter Study (ID 1245)
10:45 - 12:15 | Author(s): R. Kakinuma
The purpose of this prospective multicenter study was to evaluate the natural course of progression of pulmonary subsolid nodules.
Eight facilities participated in this prospective study. This study was conducted with the approval of the institutional review board of each of the participating institutions. Written informed consent was obtained from all the patients. A total of 845 patients with 1325 pulmonary subsolid nodules were registered, of whom 795 patients (341 men, 454 women; mean age, 62 years [range, 31-88]) with 1238 subsolid nodules were selected as being eligible for this study. In this study, the pulmonary subsolid nodules were classified into three categories: pure ground-glass nodules (hereafter abbreviated as PGGNs), heterogeneous GGNs (solid component detected only in the lung window setting; hereafter abbreviated as HGGN), and part-solid nodules (solid component also detected in the mediastinal window setting). The CT images of the nodules that showed progression were reviewed by an expert radiologists’ panel. Pathological specimens of the resected nodules were reviewed by an expert pathologists’ panel.
The mean prospective follow-up period was 4.3 ± 2.5 years (range, 0.2–12.1; median, 3.5 [IQR, 2.4–6.0]). After exclusion of 9 resected nodules (2 no-lung-cancer nodules and 7 lung cancers not reviewed by the expert pathologists’ panel), the pulmonary subsolid nodules were classified as follows at the baseline: 1046 PGGNs, 81 HGGNs, and 102 part-solid nodules. Among the 1047 PGGNs, 13 (13/1046; 1.2%) developed into HGGNs, and 56 (56/1046; 5.4%) developed into part-solid nodules. Among the 81 HGGNs, 16 (16/81; 19.8%) developed into part-solid nodules. Thus, the subsolid nodules were classified as follows at the time of the final follow-up: 977 PGGNs, 78 HGGNs and 174 part-solid nodules. Of the 977 PGGNs, 35 (3.6%) were resected; from the histopathologic standpoint, the 35 resected PGGNs consisted of 9 minimally invasive adenocarcinomas (MIAs), 21 adenocarcinomas in situ (AISs), and 5 atypical adenomatous hyperplasias (AAHs). Of the 78 HGGNs, 7 (9%) were resected; from the histopathologic standpoint, the 7 HGGNs consisted of 5 MIAs and 2 AISs. Of the 174 part-solid nodules, 49 (28.2%) were resected; from the histopathologic standpoint, the 49 part-solid nodules consisted of 12 invasive adenocarcinomas, 26 MIAs, 10 AISs, and 1 AAHs. In total, 12 (12/1229, 1%) invasive adenocarcinomas, 40 (40/1229; 3.3%) MIAs, 33 (33/1229; 2.7%) AISs, and 6 (6/1229; 0.5%) AAHs were resected as of December 31, 2013; For the PGGNs, the mean period to development into part-solid nodules was 3.8 ± 2.0 years (range, 0.5-8.7; median, 3.4 [IQR, 2.0–5.2]); for the HGGNs, the mean period to development into part-solid nodules was 2.1 ± 2.3 years (range, 0.2–8.8; median, 1.0 [IQR, 0.7–3.4]) (P=0.0004).
Our prospective multicenter study revealed the frequency and period of development from PGGNs and HGGNs into part-solid nodules. Invasive adenocarcinomas were only diagnosed in the part-solid nodules. The findings of the study may contribute to the development of guidelines for follow-up of pulmonary subsolid nodules.