Ryutaro Kakinuma1, Masayuki Noguchi2, Kazuto Ashizawa3, Keiko Kuriyama4, Akiko Miyagi Maeshima5, Naoya Koizumi6, Tetsuro Kondo7, Haruhisa Matsuguma8, Norihisa Nitta9, Hironobu Ohmatsu10, Jiro Okami11, Hiroshi Suehisa12, Taiki Yamaji13, Ken Kodama14, Kiyoshi Mori15, Kouzo Yamada7, Yoshihiro Matsuno16, Sadayuki Murayama17, Kiyoshi Murata9. 1. Cancer Screening Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan; Cancer Screening Center, National Cancer Center Hospital, Tokyo, Japan; Department of Pulmonology, Tokyo General Hospital, Tokyo, Japan. Electronic address: rkaki@ncc.go.jp. 2. Department of Pathology, University of Tsukuba, Faculty of Medicine, Tsukuba, Japan. 3. Department of Clinical Oncology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. 4. Department of Radiology, Osaka National Hospital, Osaka, Japan. 5. Department of Pathology, National Cancer Center Hospital, Tokyo, Japan. 6. Department of Radiology, Niigata Cancer Center, Niigata, Japan. 7. Department of Thoracic Oncology, Kanagawa Cancer Center, Yokohama, Japan. 8. Department of Thoracic Surgery, Tochigi Cancer Center, Utsunomiya, Japan. 9. Department of Radiology, Shiga University of Medical Science, Otsu, Japan. 10. Department of Thoracic Oncology, National Cancer Center Hospital East, Kashiwa, Japan. 11. Department of General Thoracic Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan. 12. Department of Thoracic Surgery, Shikoku Cancer Center, Matsuyama, Japan; Department of Thoracic Surgery, Iwakuni Clinical Center, Iwakuni, Japan. 13. Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan; Division of Epidemiology, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan. 14. Department of General Thoracic Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan; Department of Thoracic Surgery, Yao Municipal Hospital, Yao, Japan. 15. Department of Thoracic Oncology, Tochigi Cancer Center, Utsunomiya, Japan; Department of Pulmonology, Tsuboi Cancer Center Hospital, Koriyama, Japan. 16. Department of Surgical Pathology, Hokkaido University Hospital, Sapporo, Japan. 17. Department of Radiology, University of the Ryukyus, Faculty of Medicine, Okinawa, Japan.
Abstract
INTRODUCTION: The purpose of this study was to evaluate the natural course of the progression of pulmonary subsolid nodules (SSNs). MATERIALS AND METHODS: Eight facilities participated in this study. A total of 795 patients with 1229 SSNs were assessed for the frequency of invasive adenocarcinomas. SSNs were classified into three categories: pure ground-glass nodules (PGGNs), heterogeneous GGNs (HGGNs) (solid component detected only in lung windows), and part-solid nodules. RESULTS: The mean prospective follow-up period was 4.3 ± 2.5 years. SSNs were classified at baseline as follows: 1046 PGGNs, 81 HGGNs, and 102 part-solid nodules. Among the 1046 PGGNs, 13 (1.2%) developed into HGGNs and 56 (5.4%) developed into part-solid nodules. Among the 81 HGGNs, 16 (19.8%) developed into part-solid nodules. Thus, the SSNs at the final follow-up were classified as follows: 977 PGGNs, 78 HGGNs, and 174 part-solid nodules. Of the 977 PGGNs, 35 were resected (nine minimally invasive adenocarcinomas [MIAs], 21 adenocarcinomas in situ [AIS], and five atypical adenomatous hyperplasias). Of the 78 HGGNs, seven were resected (five MIAs and two AIS). Of the 174 part-solid nodules, 49 were resected (12 invasive adenocarcinomas, 26 MIAs, 10 AIS, and one adenomatous hyperplasia). For the PGGNs, the mean period until their development into part-solid nodules was 3.8 ± 2.0 years, whereas the mean period for the HGGNs was 2.1 ± 2.3 years (p = 0.0004). CONCLUSION: This study revealed the frequencies and periods of development from PGGNs and HGGNs into part-solid nodules. Invasive adenocarcinomas were diagnosed only among the part-solid nodules, corresponding to 1% of all 1229 SSNs.
INTRODUCTION: The purpose of this study was to evaluate the natural course of the progression of pulmonary subsolid nodules (SSNs). MATERIALS AND METHODS: Eight facilities participated in this study. A total of 795 patients with 1229 SSNs were assessed for the frequency of invasive adenocarcinomas. SSNs were classified into three categories: pure ground-glass nodules (PGGNs), heterogeneous GGNs (HGGNs) (solid component detected only in lung windows), and part-solid nodules. RESULTS: The mean prospective follow-up period was 4.3 ± 2.5 years. SSNs were classified at baseline as follows: 1046 PGGNs, 81 HGGNs, and 102 part-solid nodules. Among the 1046 PGGNs, 13 (1.2%) developed into HGGNs and 56 (5.4%) developed into part-solid nodules. Among the 81 HGGNs, 16 (19.8%) developed into part-solid nodules. Thus, the SSNs at the final follow-up were classified as follows: 977 PGGNs, 78 HGGNs, and 174 part-solid nodules. Of the 977 PGGNs, 35 were resected (nine minimally invasive adenocarcinomas [MIAs], 21 adenocarcinomas in situ [AIS], and five atypical adenomatous hyperplasias). Of the 78 HGGNs, seven were resected (five MIAs and two AIS). Of the 174 part-solid nodules, 49 were resected (12 invasive adenocarcinomas, 26 MIAs, 10 AIS, and one adenomatous hyperplasia). For the PGGNs, the mean period until their development into part-solid nodules was 3.8 ± 2.0 years, whereas the mean period for the HGGNs was 2.1 ± 2.3 years (p = 0.0004). CONCLUSION: This study revealed the frequencies and periods of development from PGGNs and HGGNs into part-solid nodules. Invasive adenocarcinomas were diagnosed only among the part-solid nodules, corresponding to 1% of all 1229 SSNs.