PT  - JOURNAL ARTICLE
AU  - Dimitris Lioumpas
AU  - Athanasios Kleontas
AU  - Evangelos Georgios Fergadis
AU  - Stylianos Zaragkas
AU  - Ioannis Stamatatos
AU  - Thrasyvoulos Michos
AU  - Nikolaos Eleptheroulis
AU  - Fragkiskos Tsagkarakis
AU  - Dimitrios Xekalakis
AU  - Kostantinos Bouboulis
AU  - Antonios Katsadonis
AU  - Periklis Tomos
TI  - Deeper into the mediastinum: Topographical distribution and histological patterns of occult pN2 disease in 18FDG PET/CT node-negative NSCLC patients
AID  - 10.1183/13993003.congress-2021.OA2638
DP  - 2021 Sep 05
TA  - European Respiratory Journal
PG  - OA2638
VI  - 58
IP  - suppl 65
4099  - http://erj.ersjournals.com/content/58/suppl_65/OA2638.short
4100  - http://erj.ersjournals.com/content/58/suppl_65/OA2638.full
SO  - Eur Respir J2021 Sep 05; 58
AB  - Backround: The aim of the study is to assess the incidence and predictor factors of occult N2 mediastinal lymph node involvement in NSCLC patients with negative FDG uptake on PET-CT.Methods: We completed a retrospective review of patient's data with NSCLC from 2010- 2019, with no 18FDG uptake on PET-CT and underwent anatomical surgical resection with curative intent. Multivariate statistical analysis was performed to evaluate any association between pathological variables and occult N2 involvement. No invasive mediastinal staging was carried out in the study population.Results: The pN2 incidence was 8.9% (n=89). The majority of patients were older than 57 years [ avg 61(16±30)]. Notably, there was a 4-fold male predominance (83%),while the most frequent histological type in both sexes was adenocarcinoma(53%). In univariate analysis, lesions of left upper lobe [LUL (39%)] and right upper lobe [RUL (32%)] were significant predictors of occult N2 disease (p=0.041 vs. p=0.048). Patients with poorly differentiated carcinoma (solid/micropapillary predominant type) had an 67% elevated risk of unforeseen N2 disease (Hazard Ratio 1.71, p=0.032), while location of the tumor (central vs peripheral), didn’t positively affect nodal involvement(p=0.28).Conclusions: Our results suggest that invasive mediastinal staging should be probably encouraged in NSLCL male patients, with poorly differentiated adenocarcinoma lesions of the upper lobes. Considering the current lack of well-designed randomized trials, further studies are warranted in order to validate these findings, thus eliminating occult N2 involvement that may influence treatment and survival.FootnotesCite this article as: European Respiratory Journal 2021; 58: Suppl. 65, OA2638.This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).