title: Solitary Pure Ground-Glass Nodules 5 mm or Smaller: Frequency of Growth.
abstract: OBJECTIVE
  To clarify the percentage of solitary pure ground-glass nodules (SPGGNs) 5 mm or smaller that grow and develop into invasive adenocarcinomas.
  
  
  METHODS
  This study was approved by the institutional review board, and informed consent was obtained from all people who were screened. From February 2004 through December 2007, 7294 participants underwent screening for lung cancer with computed tomographic (CT) imaging. The nodule database was reviewed to identify SPGGNs 5 mm or smaller. Growth of the SPGGNs was evaluated as of March 31, 2013. In cases of pathologic analysis-proven adenocarcinomas that developed from SPGGNs 5 mm or smaller, solid components were evaluated. Percentages, 95% confidence intervals, and means were calculated.
  
  
  RESULTS
  At baseline screening, 438 SPGGNs 5 mm or smaller were identified, and during the study period one SPGGN 5 mm or smaller developed de novo. Of the 439 SPGGNs, 394 were stable and 45 (10.3% [95% confidence interval: 7.5%, 13.7%]), including newly developed SPGGN, grew. Of the 45 SPGGNs that grew, 0.9% (four of 439 [95% confidence interval: 0.3%, 2.3%]) developed into adenocarcinomas (two minimally invasive [including the newly developed SPGGN] and two invasive). The mean period between baseline CT screening and the appearance of solid components in the four adenocarcinomas was 3.6 years.
  
  
  CONCLUSIONS
  Of SPGGNs 5 mm or smaller, approximately 10% will grow and 1% will develop into invasive adenocarcinomas or minimally invasive adenocarcinomas. SPGGNs 5 mm or smaller should be rescanned 3.5 years later to look for development of a solid component.
authors.affiliation: From the Research Center for Cancer Prevention and Screening, Division of Screening (R.K., Y.M., N.M.), Department of Diagnostic Radiology (R.K., M.K.), Department of Endoscopy, Respiratory Endoscopy Division (T.T.), Division of Pathology (K.T., A.M.M.), and Department of Thoracic Surgery (H.A.), National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0051 Japan; Department of Radiology, National Cancer Center Hospital East, Tokyo, Japan (M.K.); Department of General Thoracic Surgery, Keio University Hospital, Tokyo, Japan (H.A.); and Department of Radiology, Tokyo Midtown Medical Center, Tokyo, Japan (N.M.).
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Kakinuma
authors.affiliation: From the Research Center for Cancer Prevention and Screening, Division of Screening (R.K., Y.M., N.M.), Department of Diagnostic Radiology (R.K., M.K.), Department of Endoscopy, Respiratory Endoscopy Division (T.T.), Division of Pathology (K.T., A.M.M.), and Department of Thoracic Surgery (H.A.), National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0051 Japan; Department of Radiology, National Cancer Center Hospital East, Tokyo, Japan (M.K.); Department of General Thoracic Surgery, Keio University Hospital, Tokyo, Japan (H.A.); and Department of Radiology, Tokyo Midtown Medical Center, Tokyo, Japan (N.M.).
authors.forename: Yukio
authors.initials: Y
authors.lastname: Muramatsu
authors.affiliation: From the Research Center for Cancer Prevention and Screening, Division of Screening (R.K., Y.M., N.M.), Department of Diagnostic Radiology (R.K., M.K.), Department of Endoscopy, Respiratory Endoscopy Division (T.T.), Division of Pathology (K.T., A.M.M.), and Department of Thoracic Surgery (H.A.), National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0051 Japan; Department of Radiology, National Cancer Center Hospital East, Tokyo, Japan (M.K.); Department of General Thoracic Surgery, Keio University Hospital, Tokyo, Japan (H.A.); and Department of Radiology, Tokyo Midtown Medical Center, Tokyo, Japan (N.M.).
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kusumoto
authors.affiliation: From the Research Center for Cancer Prevention and Screening, Division of Screening (R.K., Y.M., N.M.), Department of Diagnostic Radiology (R.K., M.K.), Department of Endoscopy, Respiratory Endoscopy Division (T.T.), Division of Pathology (K.T., A.M.M.), and Department of Thoracic Surgery (H.A.), National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0051 Japan; Department of Radiology, National Cancer Center Hospital East, Tokyo, Japan (M.K.); Department of General Thoracic Surgery, Keio University Hospital, Tokyo, Japan (H.A.); and Department of Radiology, Tokyo Midtown Medical Center, Tokyo, Japan (N.M.).
authors.forename: Takaaki
authors.initials: T
authors.lastname: Tsuchida
authors.affiliation: From the Research Center for Cancer Prevention and Screening, Division of Screening (R.K., Y.M., N.M.), Department of Diagnostic Radiology (R.K., M.K.), Department of Endoscopy, Respiratory Endoscopy Division (T.T.), Division of Pathology (K.T., A.M.M.), and Department of Thoracic Surgery (H.A.), National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0051 Japan; Department of Radiology, National Cancer Center Hospital East, Tokyo, Japan (M.K.); Department of General Thoracic Surgery, Keio University Hospital, Tokyo, Japan (H.A.); and Department of Radiology, Tokyo Midtown Medical Center, Tokyo, Japan (N.M.).
authors.forename: Koji
authors.initials: K
authors.lastname: Tsuta
authors.affiliation: From the Research Center for Cancer Prevention and Screening, Division of Screening (R.K., Y.M., N.M.), Department of Diagnostic Radiology (R.K., M.K.), Department of Endoscopy, Respiratory Endoscopy Division (T.T.), Division of Pathology (K.T., A.M.M.), and Department of Thoracic Surgery (H.A.), National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0051 Japan; Department of Radiology, National Cancer Center Hospital East, Tokyo, Japan (M.K.); Department of General Thoracic Surgery, Keio University Hospital, Tokyo, Japan (H.A.); and Department of Radiology, Tokyo Midtown Medical Center, Tokyo, Japan (N.M.).
authors.forename: Akiko Miyagi
authors.initials: AM
authors.lastname: Maeshima
authors.affiliation: From the Research Center for Cancer Prevention and Screening, Division of Screening (R.K., Y.M., N.M.), Department of Diagnostic Radiology (R.K., M.K.), Department of Endoscopy, Respiratory Endoscopy Division (T.T.), Division of Pathology (K.T., A.M.M.), and Department of Thoracic Surgery (H.A.), National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0051 Japan; Department of Radiology, National Cancer Center Hospital East, Tokyo, Japan (M.K.); Department of General Thoracic Surgery, Keio University Hospital, Tokyo, Japan (H.A.); and Department of Radiology, Tokyo Midtown Medical Center, Tokyo, Japan (N.M.).
authors.forename: Hisao
authors.initials: H
authors.lastname: Asamura
authors.affiliation: From the Research Center for Cancer Prevention and Screening, Division of Screening (R.K., Y.M., N.M.), Department of Diagnostic Radiology (R.K., M.K.), Department of Endoscopy, Respiratory Endoscopy Division (T.T.), Division of Pathology (K.T., A.M.M.), and Department of Thoracic Surgery (H.A.), National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0051 Japan; Department of Radiology, National Cancer Center Hospital East, Tokyo, Japan (M.K.); Department of General Thoracic Surgery, Keio University Hospital, Tokyo, Japan (H.A.); and Department of Radiology, Tokyo Midtown Medical Center, Tokyo, Japan (N.M.).
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Moriyama
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000368:Aged; D002471:Cell Transformation, Neoplastic; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed