title: Clinicopathological and immunohistochemical features of lung invasive mucinous adenocarcinoma based on computed tomography findings.
abstract: BACKGROUND
  We performed an analysis to clarify differences in clinicopathological and molecular features of lung invasive mucinous adenocarcinoma (IMA) based on computed tomography (CT) findings and their impact on prognosis.
  
  
  METHODS
  On the basis of CT findings, we divided lung IMA into three subtypes: solid, bubbling, and pneumonic. We then investigated differences in clinicopathological characteristics, prognosis, and the expressions of well-identified biomarkers, including cyclooxygenase-2 (Cox-2), excision repair cross-complementation group 1 (ERCC1), ribonucleotide reductase M1 (RRM1), class III beta-tubulin, thymidylate synthase (TS), secreted protein acidic and rich in cysteine (SPARC), programmed cell death-1 ligand-1 (PD-L1), andepidermal growth factor receptormutation, among the three subtypes.
  
  
  RESULTS
  A total of 29 patients with resected lung IMA were analyzed. Compared with the solid or bubbling type, the pneumonic type had a higher proportion of symptoms, a larger tumor size, a higher pathological stage, and a significantly worse prognosis. The immunohistochemical findings tended to show high expression of RRM1, class III beta-tubulin, and Cox-2 in the tumor and of SPARC in the stroma, but not of ERCC1, TS, and PD-L1 in the tumor. None of the biomarkers with high expression levels in the tumor were prognostic biomarkers, but the expression of SPARC in the stroma was correlated with a poor outcome.
  
  
  CONCLUSIONS
  Clinical and pathological features, in conjunction with molecular data, indicate that IMA should be divided into different subgroups. In our results, the pneumonic type was correlated with a significantly worse outcome. Further studies should be performed to confirm our conclusion and to explore its molecular implications.
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Okayama, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Shimizu
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Okayama, Japan.
authors.forename: Riki
authors.initials: R
authors.lastname: Okita
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Okayama, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Saisho
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Okayama, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Maeda
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Okayama, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nojima
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Okayama, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Nakata
keywords: SPARC; computed tomography finding; invasive mucinous adenocarcinoma; non-small cell lung cancer; prognostic biomarker; secreted protein acidic and rich in cysteine