title: Does ground glass opacity-dominant feature have a prognostic significance even in clinical T2aN0M0 lung adenocarcinoma?
abstract: BACKGROUND
  Recent studies have demonstrated that ground glass opacity (GGO)-dominant tumors correspond to pathologically low-grade adenocarcinomas and that patients with resected tumors have an excellent prognosis. However, almost all of those studies were limited to tumors measuring ≤3.0cm. The purpose of this study was to characterize lung adenocarcinomas >3.0cm in diameter with GGO-dominant features and evaluate the prognosis of patients with such tumors.
  
  
  METHODS
  One hundred and thirteen patients with cT2aN0M0 lung adenocarcinoma underwent surgical resection between 2005 and 2011. Twenty-five had tumors with a ≥50% GGO component (GGO-dominant group) and the remaining had solid-dominant tumors (Solid-dominant group). The clinicopathological findings and prognosis of the two groups were evaluated.
  
  
  RESULTS
  The tumors in the GGO-dominant group rarely exhibited pathological invasiveness, such as lymphatic (n=1), vascular (n=0) and pleural invasion (n=5) or lymph node metastasis (n=0). On the other hand, the tumors in the solid-dominant group frequently exhibited pathological invasiveness, including lymphatic (n=26), vascular (n=16) and plural invasion (n=52) and lymph node metastasis (n=18). There were significant differences in all of the characteristics between the two groups (lymphatic; p=0.0026, vascular; p=0.0214, and pleural invasion; p=0.0004, and lymph node metastases; p=0.0086, respectively). In the GGO-dominant group, 24 patients were alive without recurrence, while the remaining died of another cancer. Recurrence occurred in 34 patients in the solid-dominant group, and 16 died of the disease. The 5-year survival rate was 96% in the GGO-dominant group, compared to 71% in the solid-dominant group (p=0.0120).
  
  
  CONCLUSIONS
  In the GGO-dominant group, the malignant potential was low and the patients had a favorable prognosis after surgery, similar to the patients with GGO-dominant tumors diagnosed as cT1a-bN0M0.
authors.affiliation: Department of Thoracic Surgery, and Biostatistics and Bioinformatics Section, Center for Advanced Medicine and Clinical Research, Nagoya University Graduate School of Medicine, Nagoya, Japan. Electronic address: shota197065@med.nagoya-u.ac.jp.
authors.forename: Shota
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Department of Thoracic Surgery, and Biostatistics and Bioinformatics Section, Center for Advanced Medicine and Clinical Research, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Fukui
authors.affiliation: Department of Thoracic Surgery, and Biostatistics and Bioinformatics Section, Center for Advanced Medicine and Clinical Research, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Kawaguchi
authors.affiliation: Department of Thoracic Surgery, and Biostatistics and Bioinformatics Section, Center for Advanced Medicine and Clinical Research, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Fukumoto
authors.affiliation: Department of Thoracic Surgery, and Biostatistics and Bioinformatics Section, Center for Advanced Medicine and Clinical Research, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hirakawa
authors.affiliation: Department of Thoracic Surgery, and Biostatistics and Bioinformatics Section, Center for Advanced Medicine and Clinical Research, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Yokoi
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000556:secondary* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001808:Blood Vessels / Q000473:pathology; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D042601:Lymphatic Vessels / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D009367:Neoplasm Staging; D010994:Pleura / Q000473:pathology; D011379:Prognosis; D011859:Radiography; D015996:Survival Rate; D047368:Tumor Burden
keywords: Adenocarcinoma; GGO-dominant tumor; Ground glass opacity; High-resolution computed tomography; Lepidic growth pattern; Lung cancer