title: Clinicopathologic correlates of postoperative N1 or N2 nodal upstaging in non-small cell lung cancer.
abstract: BACKGROUND
  Clinical and pathologic determinations of lymph node staging are critical in the treatment of lung cancer. However, up- or downstaging of nodal status frequently is necessitated by postsurgical findings. This study was conducted to evaluate clinicopathologic features that impact nodal upstaging in patients staged primarily via positron emission tomography/computed tomography (PET/CT) and chest CT prior to surgery.
  
  
  METHODS
  Between years 2011 and 2014, 634 patients underwent surgical treatment for non-small cell lung cancer (NSCLC) at our institution. Excluding 37 patients (given induction chemotherapy), 103 patients pathologically staged as N1 or N2 NSCLC. Nodal upstaging patients were classified into group A and non-upstaging patients into group B. We compared clinical characteristics and pathological results of group A with group B.
  
  
  RESULTS
  Ultimately, 59 patients (57.3%) were assigned to group A and 44 patients (42.7%) to group B. Patients in group A (vs. group B) were significantly younger (61.6 vs. 68.4 years; P<0.001) and more often were female (47.5% vs. 15.9%; P=0.001), with shorter smoking histories (12.2 vs. 28.8 pack years; P<0.001) and lower maximum standardized uptake values (SUVmax) (7.3 vs. 10.4; P=0.001). Most upstaged (group A) tumors (50/59, 84.7%) were adenocarcinomas, displaying micropapillary (MPC; n=36) and lepidic (n=35) component positivity with significantly greater frequency (both, P<0.001); and the frequency of epidermal growth factor receptor (EGFR) mutation (n=36) was significantly greater in this subset (P=0.001). Multivariate analysis (logistic regression) indicated a significant correlation between MPC positivity and nodal upstaging (P=0.013).
  
  
  CONCLUSIONS
  In patients upstaged postoperatively to N1 or N2 stage of NSCLC, occult lymph node metastasis and MPC positivity were significantly related.
authors.affiliation: 1 Department of Thoracic & Cardiovascular Surgery, 2 Department of Hospital Pathology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Youngkyu
authors.initials: Y
authors.lastname: Moon
authors.affiliation: 1 Department of Thoracic & Cardiovascular Surgery, 2 Department of Hospital Pathology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Kyo Young
authors.initials: KY
authors.lastname: Lee
authors.affiliation: 1 Department of Thoracic & Cardiovascular Surgery, 2 Department of Hospital Pathology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Kim
authors.affiliation: 1 Department of Thoracic & Cardiovascular Surgery, 2 Department of Hospital Pathology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Jae Kil
authors.initials: JK
authors.lastname: Park
keywords: Lung cancer; adenocarcinoma; lymph node