The evolving TNM classification has emphasized the tumor size's role in NSCLC prognosis, reclassifying stage IIIA patients from the previous edition as stage IIIB (T3-4N2M0, 8th edition). However, the prognostic implications of tumor size and survival in stage III NSCLC patients undergoing neoadjuvant therapy remain unexplored. Therefore, we investigated the association between tumor size and mortality in N2 non-small cell lung cancer (NSCLC) patients undergoing neoadjuvant concurrent chemoradiotherapy followed by surgery (trimodality therapy), considering the number of metastatic N2 stations and histology. We analyzed 756 patients with stage III (T1-3N2) NSCLC who underwent trimodality therapy, excluding those with T3 tumors with invasion components or additional nodules (2003-2019). Overall survival was compared using the Cox-proportional hazards model, while the tumor size-survival relationship was estimated using restricted cubic splines. Using 8th TNM edition, 32.1%, 48.5%, and 19.3% were clinical T1, T2, and T3. During a median follow-up of 53.5 months, 398 patients died. The adjusted hazard ratios for overall survival comparing T2 and T3 to T1 were 1.46 (95% confidence interval, 1.14-1.85) and 1.48 (1.10-1.99). For the extent of clinical N2, large tumor size increased the mortality risk in patients with N2b but not in N2a. Tumor size did not increase mortality risk in squamous cell carcinoma patients; however, the mortality risk was increased with larger tumors in adenocarcinoma. These findings raise the importance of considering tumor size in treatment planning and suggesting tailored strategies.

Contrast-enhanced chest CT (CECT) is more sensitive than non-contrast-enhanced chest CT (NCECT), but NCECT may have comparable efficacy in detecting new primary lung cancer among stage I NSCLC survivors after two years of surveillance. This study aimed to evaluate the efficacy of NCECT versus CECT for surveillance among stage I NSCLC patients surviving two years after curative resection without disease recurrence. We conducted a retrospective cohort study of patients with stage I NSCLC who underwent curative-intent lung resection between January 2009 and December 2017 using the Registry for Thoracic Cancer Surgery at the Samsung Medical Center, Seoul, Korea. Overall survival, recurrence-free survival, and cost effectiveness were compared between patients undergoing surveillance with CECT and NCECT. Among 3248 patients, 1002 (38.8%) patients underwent NCECT surveillance. During a median follow-up of 2.3 years (interquartile range, 1.5-3.9 years), a total of 208 deaths were observed. Although patients undergoing NCECT surveillance had 0.04 more deaths per 100 person-year compared with patients undergoing CECT surveillance (95% CI -0.36 to 0.44), this difference did not reach statistical significance (1.27 vs. 1.31 per 100 person-years; HR, 1.10; 95% CI 0.81-1.50). Regarding cost effectiveness, CECT group had a gain of 0.024 quality-adjusted life-year but $785 higher total cumulative cost per patient compared to NCECT. There was no difference in recurrence and mortality between NCECT and CECT for surveillance among stage I NSCLC patients who survived two years after surgery without disease recurrence. Further randomized clinical trials are required to confirm the findings.

In patients with non–small cell lung cancer, obesity was associated with improved overall survival after curative resection, particularly when CT-assessed skeletal muscle mass and radiodensity were preserved.

Background:This study aimed to evaluate the efficacy and safety of adjuvant pembrolizumab in patients with completely resected stage I lung adenocarcinoma with micropapillary or solid-pattern (MPSOL). Methods:This was a single-center, single-arm phase 2 study (ClinicalTrials.gov identifier: NCT03254004). Key eligibility criteria included patients with stage I lung adenocarcinoma (per the American Joint Committee on Cancer 8th edition; primary tumor of <4 cm and without nodal metastasis), characterized by MPSOL histological subtype upon postsurgical pathological examination Patients were treated with pembrolizumab 200 mg every 3 weeks for 1 year or until disease recurrence or intolerable toxicity. The primary endpoint was 3-year disease-free survival (DFS), defined as the time from surgery to recurrence or death from any cause. Secondary endpoints included overall survival and safety. Findings:Between September 17, 2018, and February 10, 2022, 70 patients were enrolled. At a median follow-up of 45·0 months, the 3-year disease-free survival (DFS) was 83·2%, meeting the survival endpoint of >80%. Patients with EGFR mutations showed significantly poorer DFS than those with EGFR wild-type (hazard ratio [HR]: 5·01 [95% confidence interval (CI): 1·11-22·70], P = 0·036), although no significant differences were noted according to age, smoking status, tumor size, and PD-L1 tumor proportion score. Grade 3 or 4 treatment-related adverse events (AEs) occurred in 6 patients (8·6%). Thirteen AEs led to treatment discontinuation and the majority of these AEs resolved upon discontinuation and subsequent steroid treatment. Interpretation:Adjuvant pembrolizumab exhibited promising clinical efficacy in patients with stage I lung MPSOL, particularly those with EGFR-wild type, and exhibited tolerable safety. Funding:Merk Sharp & Dohme (MSD). The funders had no role in study design, data collection, data analysis, interpretation, or writing of the report.

BACKGROUND:Lung cancer patients with stage III-N2 disease may benefit from the subclassification of nodal involvement before decision-making. We aimed to evaluate whether the clinical N descriptor subclassification predicts prognosis in patients undergoing trimodality therapy for stage III-N2 non-small cell lung cancer. METHODS:Using our institutional registry between 2003 and 2019, we analyzed 899 consecutive patients with stage III-N2 non-small cell lung cancer undergoing neoadjuvant concurrent chemoradiotherapy followed by surgery. We subclassified clinical N2 into cN2a and cN2b on the basis of imaging and histopathologic results. Recurrence-free survival and overall survival were compared by N2 subclassification and separately by histologic type, using competing risks models and Cox proportional hazards models. RESULTS:By the proposed N subclassification, 503 (56.0%) and 396 (44.0%) patients were assigned to cN2a and cN2b, respectively. During a median follow-up of 53.1 months, 492 patients had recurrence and 477 died. The hazard ratios for recurrence comparing cN2b with cN2a after adjustment for age, sex, comorbidities, clinical T category, and histologic type were 1.22 (95% CI, 1.03-1.46). The adjusted hazard ratios for mortality comparing cN2b to cN2a were 1.43 (1.19-1.71). When stratified by histologic type, cN2b had a higher risk of mortality compared with cN2a in both adenocarcinoma and squamous cell carcinoma. CONCLUSIONS:In our study evaluating the International Association for the Study of Lung Cancer's approach to subclassify the clinical N descriptor for stage III-N2 non-small cell lung cancer patients, cN2b had a higher risk of recurrence and mortality compared with cN2a, suggesting that clinical N subclassification may be a valuable predictor for stage III-N2 patients.

Background:Major pulmonary resection after neoadjuvant concurrent chemoradiation therapy (nCCRT) is associated with a substantial risk of postoperative complications. This study investigated postoperative complications and associated risk factors to facilitate the selection of suitable surgical candidates following nCCRT in stage IIIA-N2 non-small cell lung cancer (NSCLC). Methods:We conducted a retrospective analysis of patients diagnosed with clinical stage IIIA-N2 NSCLC who underwent surgical resection following nCCRT between 1997 and 2013. Perioperative characteristics and clinical factors associated with morbidity and mortality were analyzed using univariable and multivariable logistic regression. Results:A total of 574 patients underwent major lung resection after induction CCRT. Thirty-day and 90-day postoperative mortality occurred in 8 patients (1.4%) and 41 patients (7.1%), respectively. Acute respiratory distress syndrome (n=6, 4.5%) was the primary cause of in-hospital mortality. Morbidity occurred in 199 patients (34.7%). Multivariable analysis identified significant predictors of morbidity, including patient age exceeding 70 years (odds ratio [OR], 1.8; p=0.04), low body mass index (OR, 2.6; p=0.02), and pneumonectomy (OR, 1.8; p=0.03). Patient age over 70 years (OR, 1.8; p=0.02) and pneumonectomy (OR, 3.26; p<0.01) were independent predictors of mortality in the multivariable analysis. Conclusion:In conclusion, the surgical outcomes following nCCRT are less favorable for individuals aged over 70 years or those undergoing pneumonectomy. Special attention is warranted for these patients due to their heightened risks of respiratory complications. In high-risk patients, such as elderly patients with decreased lung function, alternative treatment options like definitive CCRT should be considered instead of surgical resection.

PURPOSE:Optimal treatment for stage IIIA/N2 non-small cell lung cancer (NSCLC) is controversial. We aimed to assess the efficacy and safety of adjuvant pembrolizumab for stage IIIA/N2 NSCLC completely resected after neoadjuvant concurrent chemoradiation therapy (CCRT). MATERIALS AND METHODS:In this open-label, single-center, single-arm phase 2 trial, patients with stage IIIA/N2 NSCLC received adjuvant pembrolizumab for up to 2 years after complete resection following neoadjuvant CCRT. The primary endpoint was disease-free survival (DFS). Secondary endpoints included overall survival (OS) and safety. As an exploratory biomarker analysis, we evaluated the proliferative response of blood CD39+PD-1+CD8+ T cells using fold changes in the percentage of proliferating Ki-67+ cells from days 1 to 7 of cycle 1 (Ki-67D7/D1). RESULTS:Between October 2017 and October 2018, 37 patients were enrolled. Twelve (32%) and three (8%) patients harbored EGFR and ALK alterations, respectively. Of 34 patients with programmed cell death ligand 1 assessment, 21 (62%), nine (26%), and four (12%) had a tumor proportion score of < 1%, 1%-50%, and ≥ 50%, respectively. The median follow-up was 71 months. The median DFS was 22.4 months in the overall population, with a 5-year DFS rate of 29%. The OS rate was 86% at 2 years and 76% at 5 years. Patients with tumor recurrence within 6 months had a significantly lower Ki-67D7/D1 among CD39+PD-1+CD8+ T cells than those without (p=0.036). No new safety signals were identified. CONCLUSION:Adjuvant pembrolizumab may offer durable disease control in a subset of stage IIIA/N2 NSCLC patients after neoadjuvant CCRT and surgery.

Purpose Recently, we developed allele-discriminating priming system (ADPS) technology. This method increases the sensitivity of conventional quantitative polymerase chain reaction up to 100 folds, with limit of detection, 0.01%, with reinforced specificity. This prospective study aimed to develop and validate the accuracy of ADPS epidermal growth factor receptor (EGFR) Mutation Test Kit using clinical specimens. Materials and Methods In total 189 formalin-fixed paraffin-embedded tumor tissues resected from patients with non-small cell lung cancer were used to perform a comparative evaluation of the ADPS EGFR Mutation Test Kit versus the cobas EGFR Mutation Test v2, which is the current gold standard. When the two methods had inconsistent results, next-generation sequencing-based CancerSCAN was utilized as a referee. Results The overall agreement of the two methods was 97.4% (93.9%-99.1%); the positive percent agreement, 95.0% (88.7%98.4%); and the negative percent agreement, 100.0% (95.9%-100.0%). EGFR mutations were detected at a frequency of 50.3% using the ADPS EGFR Mutation Test Kit and 52.9% using the cobas EGFR Mutation Test v2. There were 10 discrepant mutation calls between the two methods. CancerSCAN reproduced eight ADPS results. In two cases, mutant allele fraction was ultra-low at 0.02% and 0.06%, which are significantly below the limit of detection of the cobas assay and CancerSCAN. Based on the EGFR genotyping by ADPS, the treatment options could be switched in five patients. Conclusion The highly sensitive and specific ADPS EGFR Mutation Test Kit would be useful in detecting the patients who have lung cancer with EGFR mutation, and can benefit from the EGFR targeted therapy.

Background: This retrospective study aimed to determine the treatment patterns and the surgical and oncologic outcomes after completion lobectomy (CL) in patients with locoregionally recurrent stage I non-small cell lung cancer (NSCLC) who previously underwent sublobar resection. Methods: Data from 36 patients who initially underwent sublobar resection for clinical, pathological stage IA NSCLC and experienced locoregional recurrence between 2008 and 2016 were analyzed. Results: Thirty-six (3.6%) of 1,003 patients who underwent sublobar resection for NSCLC experienced locoregional recurrence. The patients' median age was 66.5 (range, 44-77) years at the initial operation, and 28 (77.8%) patients were men. Six (16.7%) patients underwent segmentectomy and 30 (83.3%) underwent wedge resection as the initial operation. The median follow-up from the initial operation was 56 (range, 9-150) months. Ten (27.8%) radiation, concurrent chemoradiation therapy), and 4 (11.1%) did not receive treatment or were lost to follow-up after recurrence. Patients who underwent CL experienced no significant complications or deaths. The median follow-up time after CL was 64.5 (range, 19-93) months. The 5-year overall survival (OS) and post-recurrence survival (PRS) were higher in the surgical group than in the non-surgical (p<0.001) and no-treatment groups (p<0.001). Conclusion: CL is a technically demanding but safe procedure for locoregionally recurrent stage I NSCLC after sublobar resection. Patients who underwent CL had better OS and PRS than patients who underwent non-surgical treatments or no treatments; however, a larger cohort study and long-term surveillance are necessary.

Aims Programmed death‐ligand 1 (PD‐L1) expression is a predictive biomarker for adjuvant immunotherapy and has been linked to poor differentiation in lung adenocarcinoma. However, its prevalence and prognostic role in the context of the novel histologic grade has not been evaluated. Methods We analysed a cohort of 1233 patients with resected lung adenocarcinoma where PD‐L1 immunohistochemistry (22C3 assay) was reflexively tested. Tumour PD‐L1 expression was correlated with the new standardized International Association for the Study of Lung Cancer (IASLC) histologic grading system (G1, G2, and G3). Clinicopathologic features including patient outcome were analysed. Results PD‐L1 was positive (≥1%) in 7.0%, 23.5%, and 63.0% of G1, G2, and G3 tumours, respectively. PD‐L1 positivity was significantly associated with male sex, smoking, and less sublobar resection among patients with G2 tumours, but this association was less pronounced in those with G3 tumours. PD‐L1 was an independent risk factor for recurrence (adjusted hazard ratio [HR] = 3.25, 95% confidence intervals [CI] = 1.93–5.48, P < 0.001) and death (adjusted HR = 2.69, 95% CI = 1.13–6.40, P = 0.026) in the G2 group, but not in the G3 group (adjusted HR for recurrence = 0.94, 95% CI = 0.64–1.40, P = 0.778). Conclusion PD‐L1 expression differs substantially across IASLC grades and identifies aggressive tumours within the G2 subgroup. This knowledge may be used for both prognostication and designing future studies on adjuvant immunotherapy.

BACKGROUND The prevalence of lymph node (LN) metastasis in small-sized lung cancer varies depending on the tumor size and proportion of ground-glass opacity. We investigated occult LN metastasis and prognosis in patients with small-sized non-small cell lung cancer (NSCLC), mainly focusing on the pure-solid tumor. METHODS We retrospectively reviewed patients with 52-cm clinical N0 NSCLC who underwent lung resection with curative intent from 2003 to 2017. Among them we analyzed patients who also underwent adequate complete systematic LN dissection. Pathologic results and disease-free survival of the radiologically mixed ground-glass nodule (mGGN) and pure-solid nodule (PSN) groups were analyzed. RESULTS Of 1329 patients analyzed, 591 had mGGNs and PSNs. As tumor size increased, patients in the mGGN group showed no difference in LN metastasis: <= 1 cm, 2.27%; 1.0 to 1.5 cm, 2.19%; and 1.5 to 2.0 cm, 2.18% (P [ .999). However the PSN group showed a significant difference in LN metastasis as the tumor size increased: <= 1 cm, 2.67%; 1.0 to 1.5 cm, 12.46%; and 1.5 to 2.0 cm, 21.31% (P < .001). In the multivariate analysis tumor size was a significant predictor of nodal metastasis in the PSN group but not in the mGGN group. In terms of 5-year disease-free survival, the mGGN group showed a better prognosis than the PSN group (94.4% vs 71.2%, P < .001). CONCLUSIONS We need to conduct a thorough LN dissection during surgery for small-sized NSCLC, especially for pure-solid tumors >= 1 cm. (Ann Thorac Surg 2024;117:586-93) (c) 2024 by The Society of Thoracic Surgeons. Published by Elsevier Inc.

Immune checkpoint blockades are actively adopted in diverse cancer types including metastatic melanoma and lung cancer. Despite of durable response in 20-30% of patients, we still lack molecular markers that could predict the patient responses reliably before treatment. Here we present a composite model for predicting anti-PD-1 response based on tumor mutation burden (TMB) and transcriptome sequencing data of 85 lung adenocarcinoma (LUAD) patients who received anti-PD-(L)1 treatment. We found that TMB was a good predictor (AUC = 0.81) for PD-L1 negative patients (n = 20). For PD-L1 positive patients (n = 65), we built an ensemble model of 100 XGBoost learning machines where gene expression, gene set activities and cell type composition were used as input features. The transcriptome-based models showed excellent accuracy (AUC > 0.9) and highlighted the contribution of T cell activities. Importantly, nonresponder patients with high prediction score turned out to have high CTLA4 expression, which suggested that neoadjuvant CTLA4 combination therapy might be effective for these patients. Our data and analysis results provide valuable insights into developing biomarkers and strategies for treating LUAD patients using immune checkpoint inhibitors.

Purpose This study aimed to develop a magnetic resonance imaging (MRI)-based radiomics model to predict high-risk pathologic features for lung adenocarcinoma: micropapillary and solid pattern (MPsol), spread through air space, and poorly differentiated patterns. Materials and Methods As a prospective study, we screened clinical N0 lung cancer patients who were surgical candidates and had undergone both 18 F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) and chest CT from August 2018 to January 2020. We recruited patients meeting our proposed imaging criteria indicating high-risk, that is, poorer prognosis of lung adenocarcinoma, using CT and FDG PET/CT. If possible, these patients underwent an MRI examination from which we extracted 77 radiomics features from T1-contrast-enhanced and T2-weighted images. Additionally, patient demographics, maximum standardized uptake value on FDG PET/CT, and the mean apparent diffusion coefficient value on diffusion-weighted image, were considered together to build prediction models for high-risk pathologic features. Results Among 616 patients, 72 patients met the imaging criteria for high-risk lung cancer and underwent lung MRI. The magnetic resonance (MR)-eligible group showed a higher prevalence of nodal upstaging (29.2% vs. 4.2%, p < 0.001), vascular invasion (6.5% vs. 2.1%, p=0.011), high-grade pathologic features (p < 0.001), worse 4-year disease-free survival (p < 0.001) compared with non-MR-eligible group. The prediction power for MR-based radiomics model predicting high-risk pathologic features was good, with mean area under the receiver operating curve (AUC) value measuring 0.751-0.886 in test sets. Adding clinical variables increased the predictive performance for MPsol and the poorly differentiated pattern using the 2021 grading system (AUC, 0.860 and 0.907, respectively). Conclusion Our imaging criteria can effectively screen high-risk lung cancer patients and predict high-risk pathologic features by our MR-based prediction model using radiomics.

Background:Contralateral pulmonary resection after pneumonectomy presents considerable challenges, and few reports in the literature have described this procedure.Methods:We retrospectively reviewed the medical records of all patients who underwent contralateral lung resection following pneumonectomy for any reason at our institution between November 1994 and December 2020.Results:Thirteen patients (9 men and 4 women) were included in this study. The median age was 57 years (range, 35-77 years), and the median preoperative forced expiratory volume in 1 second was 1.64 L (range, 1.17-2.12 L). Contralateral pulmonary resection was performed at a median interval of 44 months after pneumonectomy (range, 6-564 months). Surgical procedures varied among the patients: 10 underwent single wedge resection, 2 were treated with double wedge resection, and 1 underwent lobectomy. Diagnoses at the time of contralateral lung resection included lung cancer in 7 patients, lung metastasis from other cancers in 3 patients, and tuberculosis in 3 patients. Complications were observed in 4 patients (36%), including acute kidney injury, pneumothorax following chest tube removal, pneumonia, and prolonged air leak. No cases of operative mortality were noted.Conclusion:In carefully selected patients, contralateral pulmonary resection after pneumonectomy can be accomplished with acceptable operative morbidity and mortality.

Occult lymph node metastasis (OLNM) is frequently found in patients with resectable non-small cell lung cancer (NSCLC), despite using diagnostic methods recommended by guidelines. To evaluate the risk of OLNM in NSCLC patients using the radiologic characteristics of the primary tumor on computed tomography (CT). We retrospectively reviewed clinicopathologic features of 2042 clinical T1-4N0 NSCLC patients undergoing curative intent pulmonary resection. Unique radiological features (i.e., air-bronchogram throughout the whole tumor, heterogeneous ground-glass opacity (GGO), mainly cystic appearance, endobronchial location), percentage of solid portion, and shape of tumor margin were analyzed via a stepwise approach. We used multivariable logistic regression to assess the relationship between OLNM and tumor characteristics. Compared with the other unique features, endobronchial tumors were associated with the highest risk of OLNM (OR = 3.9, 95

Background: Several studies have reported the predictive and prognostic value of novel transcriptional factor-based molecular subtypes in small-cell lung cancer (SCLC). We conducted an in-depth analysis using multi-omics data to elucidate the underlying characteristics that lead to differences in clinical outcomes between subtypes. Patients and Methods: Immunohistochemistry (IHC, n=252), target exome sequencing (n=422), and whole transcriptome sequencing (WTS, n=189) data generated from 427 patients with SCLC patients were comprehensively analyzed. The differences in the mutation profile, gene expression profile were analyzed according to the IHC-based molecular subtype. Clinical implication was evaluated based on treatment outcomes of individual patients. Results: IHC based molecular subtyping revealed a high incidence of ASCL1 subtype (SCLC-A, 56.3%) followed by ASCL1/NEUROD1 co-expressed (SCLC-trans, 17.9%), NEUROD1 (SCLC-N, 12.3%), POU2F3 (SCLC-P, 9.1%), triple-negative (SCLC-TN, 4.4%) subtypes showing high concordance with WTS-based subtyping. We delineated the SCLC-trans subtype resembling SCLC-A rather than SCLC-N in terms of both gene expression profiles and clinical outcomes. SCLC-TN type was defined as non-significant expression of A, N, P. Favorable overall survival (OS) was observed in SCLC-A compared to SCLC-N (adjusted HR 2.4, 95% CI 1.5-3.9, p < 0.001) and SCLC-P (adjusted HR 1.7, 95% CI 0.9-2.9, p = 0.087). SCLC-TN showed a similar OS with SCLC-A (adjusted HR 1.2, 95% CI 0.6 -2.7, p = 0598). The clinical outcome based on inflamed phenotype, clustered by effector cell gene expression profile which are only found in 5% of SCLC-N but 60% of SCLC-P, was more likely to benefit from first-line immunotherapy treatment than non-inflamed phenotype (p = 0.013). Inflammed phenotype demonstrated longer progression-free survival to the first line immunotherapy compared to the non-inflammed phenotype. (10.5 vs 4.3, p = 0.013) Conclusions: This study provides fundamental data, including the incidence and basic demographics of molecular subtypes of SCLC using both IHC and WTS from a comparably large cohort including potential differences in the distribution of subtypes based on ethnicity. Additionally, our results reveal differences in the underlying biological pathway activities and immunogenicity based on molecular subtype, possibly related to the difference in clinical outcomes, including immunotherapy response. Citation Format: Sehhoon Park, Tae Hee Hong, Soohyun Hwang, Hyun-Ae Jung, Jong-Mu Sun, Jin Seok Ahn, Myung-Ju Ahn, Jong Ho Cho, Yong Soo Choi, Jhingook Kim, Young Mog Shim, Hong Kwan Kim, Yoon-La Choi, Se-hoon Lee, Keunchil Park. Comprehensive analysis using transcriptional factor based molecular subtypes and correlation to clinical outcomes in small-cell lung cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4546.

Summary Background Lung cancer diagnostic guidelines advocate for invasive mediastinal nodal staging (IMNS), but the survival benefits of this approach in patients with non-small cell lung cancer (NSCLC) without radiologic evidence of lymph node metastasis (rN0) remain uncertain. We aimed to investigate the impact of IMNS in patients with rN0 NSCLC by comparing the long-term survival between patients who underwent IMNS and those who did not (non-IMNS). Methods In this retrospective cohort study, we included patients with NSCLC but without radiologic evidence of lymph node metastasis from the Registry for Thoracic Cancer Surgery and the clinical data warehouse at the Samsung Medical Centre, Republic of Korea between January 2, 2008 and December 31, 2016. We compared the 5-year overall survival (OS) rate as the primary outcome after propensity score matching between the IMNS and non-IMNS groups. The age, sex, performance statue, tumor size, centrality, solidity, lung function, FDG uptake in PET-CT, and histological examination of the tumor before surgery were matched. Findings A total of 4545 patients (887 in the IMNS group and 3658 in the non-IMNS group) who received curative treatment for NSCLC were included in this study. By the mediastinal node dissection, the overall incidence of unforeseen mediastinal node metastasis (N2) was 7.2% (317/4378 patients). Despite the IMNS, 67% of pathological N2 was missed (61/91 patients with unforeseen N2). Based on propensity score matching, 866 patients each for the IMNS and non-IMNS groups were assigned. There was no significant difference in 5-year OS and recurrence-free survival (RFS) between two groups: 5-year OS was 73.9% (95% confidence interval, CI: 71%–77%) for IMNS and 71.7% (95% CI: 68.6%–74.9%; p = 0.23), for non-IMNS (hazard ratio, HR 0.90, 95% CI: 0.77–1.07), while 5-year RFS was 64.7% (95% CI: 61.5%–68.2%) and 67.5% (95% CI: 64.3%–70.9%; p = 0.35 (HR 1.08, 95% CI: 0.92–1.27), respectively. Moreover, the timing and locations of recurrence were similar in both groups. Interpretation IMNS might not be required before surgery for patients with NSCLC without LN suspicious of metastasis. Further randomised trials are required to validate the findings of the present study. Funding None.

Limited information is available regarding the association between preoperative lung function and postoperative pulmonary complications (PPCs) in patients with esophageal cancer who undergo esophagectomy. This is a retrospective cohort study. Patients were classified into low and high lung function groups by the cutoff of the lowest fifth quintile of forced expiratory volume in 1 s (FEV1) %predicted (%pred) and diffusing capacity of the carbon monoxide (DLco) %pred. The PPCs compromised of atelectasis requiring bronchoscopic intervention, pneumonia, and acute lung injury/acute respiratory distress syndrome. Modified multivariable-adjusted Poisson regression model using robust error variances and inverse probability treatment weighting (IPTW) were used to assess the relative risk (RR) for the PPCs. A joint effect model considered FEV1%pred and DLco %pred together for the estimation of RR for the PPCs. Of 810 patients with esophageal cancer who underwent esophagectomy, 159 (19.6%) developed PPCs. The adjusted RR for PPCs in the low FEV1 group relative to high FEV1 group was 1.48 (95% confidence interval [CI] = 1.09–2.00) and 1.98 (95% CI = 1.46–2.68) in the low DLco group relative to the high DLco group. A joint effect model showed adjusted RR of PPCs was highest in patients with low DLco and low FEV1 followed by low DLco and high FEV1, high DLco and low FEV1, and high DLco and high FEV1 (Reference). Results were consistent with the IPTW. Reduced preoperative lung function (FEV1 and DLco) is associated with post-esophagectomy PPCs. The risk was further strengthened when both values decreased together.