title: Clinicopathologic Factors Associated With Occult Lymph Node Metastasis in Patients With Clinically Diagnosed N0 Lung Adenocarcinoma.
abstract: BACKGROUND
  In some patients, clinical N0 (cN0) lung adenocarcinoma diagnosed by preoperative computed tomography scanning and positron emission tomography scanning was staged as pathologic N1 (pN1) or N2 (pN2) postoperatively. The aim of this study was to determine the preoperative and postoperative clinicopathologic factors related to nodal upstaging after a surgical operation.
  
  
  METHODS
  We conducted a retrospective chart review of 350 patients treated for cN0 lung adenocarcinoma by curative resection. We analyzed clinicopathologic findings, comparing pN0 patients with the nodal upstaging group.
  
  
  RESULTS
  Of 350 patients treated for cN0 tumors, 305 (87.1%) were confirmed postoperatively as having pN0 tumors, and 45 (12.9%) were confirmed as having pN1 or pN2 tumors. The mean maximum standardized uptake value (SUVmax) was higher in the nodal upstaging group than in the pN0 group (6.9 versus 3.8, p = 0.004); the upstaging group also included more cases in which SUVmax was greater than 5 (70.5% versus 24.8%, p < 0.001). Pleural invasion, lymphatic invasion, and vascular invasion were all more frequently seen in the nodal upstaging group than in the pN0 group (all p < 0.001). The presence of tumors with a micropapillary component was higher in the nodal upstaging group (p < 0.001). Multivariate logistic regression analysis identified SUVmax greater than 5, lymphatic invasion, vascular invasion, and a micropapillary component as significant risk factors for nodal upstaging.
  
  
  CONCLUSIONS
  In lung adenocarcinoma diagnosed as clinical N0 by chest computed tomography and positron emission tomography scanning, the possibility of occult lymph node metastasis increases with SUVmax greater than 5 and when lymphatic invasion, vascular invasion, and a micropapillary component are present.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, Korea.
authors.forename: Youngkyu
authors.initials: Y
authors.lastname: Moon
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, Korea.
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Kim
authors.affiliation: Department of Hospital Pathology, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, Korea.
authors.forename: Kyo Young
authors.initials: KY
authors.lastname: Lee
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, Korea.
authors.forename: Sook Whan
authors.initials: SW
authors.lastname: Sung
authors.affiliation: Department of Internal Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, Korea.
authors.forename: Young Kyoon
authors.initials: YK
authors.lastname: Kim
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, Korea. Electronic address: jaekpark@catholic.ac.kr.
authors.forename: Jae Kil
authors.initials: JK
authors.lastname: Park
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D000072078:Positron Emission Tomography Computed Tomography; D011379:Prognosis; D012189:Retrospective Studies