Survival of Patients With Unsuspected pN2 Non-Small Cell Lung Cancer After an Accurate Preoperative Mediastinal Staging

Clinical Effect of Endosonography on Overall Survival in Patients with Radiological N1 Non-Small Cell Lung Cancer

PURPOSE

It is unclear whether performing endosonography first in non-small cell lung cancer (NSCLC) patients with radiological N1 (rN1) has any advantages over surgery without nodal staging. We aimed to compare surgery without endosonography to performing endosonography first in rN1 on the overall survival (OS) of patients with NSCLC.

MATERIALS AND METHODS

This is a retrospective analysis of patients with rN1 NSCLC between 2013 and 2019. Patients were divided into 'no endosonography' and 'endosonography first' groups. We investigated the effect of nodal staging through endosonography on OS using propensity score matching (PSM) and multivariable Cox proportional hazard regression analysis.

RESULTS

In the no endosonography group, pathologic N2 occurred in 23.0% of patients. In the endosonography first group, endosonographic N2 and N3 occurred in 8.6% and 1.6% of patients, respectively. Additionally, 51 patients were pathologic N2 among 249 patients who underwent surgery and mediastinal lymph node dissection (MLND) in endosonography first group. After PSM, the 5-year OSs were 68.1% and 70.6% in the no endosonography and endosonography first groups, respectively. However, the 5-year OS was 80.2% in the subgroup who underwent surgery and MLND of the endosonography first group. Moreover, in patients receiving surgical resection with MLND, the endosonography first group tended to have a better OS than the no endosonography group in adjusted analysis using various models.

CONCLUSION

In rN1 NSCLC, preoperative endosonography shows better OS than surgery without endosonography. For patients with rN1 NSCLC who are candidates for surgery, preoperative endosonography may help improve survival through patient selection.

EBUS-TBNA for mediastinal staging of centrally located T1N0M0 non-small cell lung cancer clinically staged with PET/CT

BACKGROUND AND OBJECTIVE

To evaluate the diagnostic accuracy and clinical usefulness of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for mediastinal staging of centrally located T1N0M0 non-small cell lung cancer (NSCLC) clinically staged with positron emission tomography/computed tomography (PET/CT).

METHODS

We conducted a study that included patients with centrally located T1N0M0 NSCLC, clinically staged with PET/CT who underwent EBUS-TBNA for mediastinal staging. Patients with negative EBUS-TBNA underwent mediastinoscopy, video-assisted mediastinoscopic lymphadenectomy (VAMLA) and/or lung resection with systematic nodal dissection, that were considered the gold standard. The sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), overall accuracy of EBUS-TBNA for diagnosing mediastinal metastases (N2 disease) and the number needed to treat (NNT: number of patients needed to undergo EBUS-TBNA to avoid a case of pathologic N2 disease after resection) were calculated.

RESULTS

One-hundred eighteen patients were included. EBUS-TBNA proved N2 disease in four patients. In the remaining 114 patients who underwent mediastinoscopy, VAMLA and/or resection there were two cases of N2 (N2 prevalence 5.1%). The sensitivity, specificity, NPV, PPV and overall accuracy for diagnosing mediastinal metastases (N2 disease) were of 66%, 100%, 98%, 100% and 98%, respectively. The NNT was 31 (95% CI: 15-119).

CONCLUSION

EBUS-TBNA in patients with central clinically staged T1N0M0 NSCLC presents a good diagnostic accuracy for mediastinal staging, even in a population with low prevalence of N2 disease. Therefore, its indication should be considered in the management of even these early lung cancers.

True Prevalence of Unforeseen N2 Disease in NSCLC: A Systematic Review + Meta-Analysis

Patients with unforeseen N2 (uN2) disease are traditionally considered to have an unfavorable prognosis. As preoperative and intraoperative mediastinal staging improved over time, the prevalence of uN2 changed. In this review, the current evidence on uN2 disease and its prevalence will be evaluated. A systematic literature search was performed to identify all studies or completed, published trials that included uN2 disease until 6 April 2023, without language restrictions. The Newcastle-Ottawa Scale (NOS) was used to score the included papers. A total of 512 articles were initially identified, of which a total of 22 studies met the predefined inclusion criteria. Despite adequate mediastinal staging, the pooled prevalence of true unforeseen pN2 (9387 patients) was 7.97% (95% CI 6.67-9.27%), with a pooled OS after five years (892 patients) of 44% (95% CI 31-58%). Substantial heterogeneity regarding the characteristics of uN2 disease limited our meta-analysis considerably. However, it seems patients with uN2 disease represent a subcategory with a similar prognosis to stage IIb if complete surgical resection can be achieved, and the contribution of adjuvant therapy is to be further explored.

Histology of the Primary Tumor Correlates with False Positivity of Integrated 18F-FDG-PET/CT Lymph Node Staging in Resectable Lung Cancer Patients

This study aimed to evaluate the diagnostic accuracy and false positivity rate of lymph node (LN) staging assessed by integrated 18F-fluorodeoxyglucose positron emission computed tomography (18F-FDG-PET/CT) in patients with operable lung cancer to the tumor histology. In total, 129 consecutive patients with non-small-cell lung cancer (NSCLC) undergoing anatomical lung resections were included. Preoperative LN staging was evaluated in the relationship to the histology of the resected specimens (group 1: lung adenocarcinoma/LUAD; group 2: squamous cell carcinoma/SQCA). Statistical analysis was performed by the Mann-Whitney U-test, the chi² test, and binary logistic regression analysis. To establish an easy-to-use algorithm for the identification of LN false positivity, a decision tree including clinically meaningful parameters was generated. In total, 77 (59.7%) and 52 (40.3%) patients were included in the LUAD and SQCA groups, respectively. SQCA histology, non-G1 tumors, and tumor SUVmax > 12.65 were identified as independent predictors of LN false positivity in the preoperative staging. The corresponding ORs and their 95% CIs were 3.35 [1.10-10.22], p = 0.0339; 4.60 [1.06-19.94], p = 0.0412; and 2.76 [1.01-7.55], and p = 0.0483. The preoperative identification of false-positive LNs is an important aspect of the treatment regimen for patients with operable lung cancer; thus, these preliminary findings should be further evaluated in larger patient cohorts.

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Overview of Challenges and Opportunities in Revising the Nodal Classification of Lung Cancer

The status of lymph node involvement is a major component of the TNM staging system. The N categories for lung cancer have remained unchanged since the fourth edition of the TNM staging system, partly because of differences in nodal mapping nomenclature, partly because of insufficient details to verify possible alternative approaches for staging. In preparation for the rigorous analysis of the International Association for the Study of Lung Cancer database necessary for the ninth edition TNM staging system, members of the N-Descriptors Subcommittee of the International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee reviewed the evidence for alternative approaches to categorizing the extent of lymph node involvement with lung cancer, which is currently based solely on the anatomical location of lymph node metastasis. We reviewed the literature focusing on NSCLC to stimulate dialogue and mutual understanding among subcommittee members engaged in developing the ninth edition TNM staging system for lung cancer, which has been proposed for adoption by the American Joint Committee on Cancer and Union for International Cancer Control in 2024. The discussion of the range of possible revision options for the N categories, including the pros and cons of counting lymph nodes, lymph node stations, or lymph node zones, also provides transparency to the process, explaining why certain options may be discarded, others deferred for future consideration. Finally, we provide a preliminary discussion of the future directions that the N-Descriptors Subcommittee might consider for the 10th edition and beyond.

Rate and Predictors of Unforeseen PN1/PN2-Disease in Surgically Treated cN0 NSCLC-Patients with Primary Tumor > 3 cm: Nationwide Results from Italian VATS-Group Database

Background. Since no robust data are available on the real rate of unforeseen N1-N2 disease (uN) and the relative predictive factors in clinical-N0 NSCLC with peripheral tumours > 3 cm, the usefulness of performing a (mini)invasive mediastinal staging in this setting is debated. Herein, we investigated these issues in a nationwide database. Methods. From 01/2014 to 06/2020, 15,784 thoracoscopic major lung resections were prospectively recorded in the “Italian VATS-Group” database. Among them, 1982 clinical-N0 peripheral solid-type NSCLC > 3 cm were identified, and information was retrospectively reviewed. A mean comparison of more than two groups was made by ANOVA (Bonferroni correction for multiple comparisons), while associations between the categorical variables were estimated with a Chi-square test. The multivariate logistic regression model and Kaplan–Meyer method were used to identify the independent predictors of nodal upstaging and survival results, respectively. Results. At pathological staging, 229 patients had N1-involvement (11.6%), and 169 had uN2 disease (8.5%). Independent predictors of uN1 were SUVmax (OR: 1.98; CI 95: 1.44–2.73, p = 0.0001) and tumour-size (OR: 1.52; CI: 1.11–2.10, p = 0.01), while independent predictors of uN2 were age (OR: 0.98; CI 95: 0.96–0.99, p = 0.039), histology (OR: 0.48; CI 95: 0.30–0.78, p = 0.003), SUVmax (OR: 2.07; CI 95: 1.15–3.72, p = 0.015), and the number of resected lymph nodes (OR: 1.03; CI 95: 1.01–1.05, p = 0.002). Conclusions. The unforeseen N1-N2 disease in cN0/NSCLCs > 3 cm undergoing VATS resection is observable in between 12 and 8% of all cases. We have identified predictors that could guide physicians in selecting the best candidate for (mini)invasive mediastinal staging.

Clinical utility of EBUS-TBNA of hilar, interlobar, and lobar lymph nodes in patients with primary lung cancer

Background

Endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA) is used to evaluate hilar/interlobar/lobar lymph nodes. This study aimed to assess the clinical utility of EBUS‐TBNA for station 10/11/12 lymph nodes (LNs) in patients with primary lung cancer.

Methods

This was a retrospective analysis of a prospectively collected database of patients with primary lung cancer who underwent EBUS‐TBNA for station 10/11/12 LNs from January 2015 to December 2019. Patients with benign results from EBUS‐TBNA who did not undergo surgical sampling/clinical follow‐up or who received radiotherapy/chemotherapy were excluded.

Results

The analyses were conducted on 889 LNs from 797 patients. The overall diagnostic sensitivity, specificity, accuracy, negative predictive value (NPV), and positive predictive value of EBUS‐TBNA were 95.7, 100, 97.3, 93.2, and 100%, respectively. Diagnostic sensitivity was significantly lower for LNs <10 mm than ≥10 mm in size (90.1% vs. 97.8%; p < 0.001). There was no significant difference in diagnostic performance according to the nodal station (10 vs. 11/12) and left‐ versus right‐sided LNs. The diagnostic sensitivity (100 vs. 95.5%; p = 0.221) and specificity (100 vs. 100%) of N3 LNs was not significantly different from those of N1 LNs. In this study, eight (8/91, 8.8%) patients with cN1 NSCLC received neoadjuvant treatment based on the results of EBUS‐TBNA.

Conclusion

EBUS‐TBNA accurately evaluates station 10/11/12 LNs of both N1 and N3 disease. The diagnostic performances of EBUS‐TBNA for station 10/11/12 LNs seem to be comparable to those of EBUS‐TBNA for mediastinal LNs.

Results in mediastinal lymph node staging of surgical lung cancer: Data from the prospective cohort of the Spanish Video-Assisted Thoracic Surgery Group

OBJECTIVES

The objective of this study was to assess the diagnostic performance of combined computerised tomography (CT) and positron emission tomography (PET) in mediastinal staging of surgical lung cancer based on data obtained from the prospective cohort of the Spanish Group for Video-Assisted Thoracic Surgery (GEVATS).

METHODS

A total of 2782 patients underwent surgery for primary lung carcinoma. We analysed diagnostic success in mediastinal lymph node staging (cN2) using CT and PET. Bivariate and multivariate analyses were performed of the factors involved in this success. The risk of unexpected pN2 disease was analysed for cases in which an invasive testing is recommended: cN1, the tumour centrally located or the tumour diameter >3 cm.

RESULTS

The overall success of CT together with PET was 82.9% with a positive predictive value of 0.21 and negative predictive value of 0.93. If the tumour was larger than 3 cm and for each unit increase in mediastinal SUVmax, the probability of success was lower with OR 0.59 (0.44-0.79) and 0.71 (0.66-0.75), respectively. In the video-assisted thoracic surgery (VATS) approach, the probability of success was higher with OR 2.04 (1.52-2.73). The risk of unexpected pN2 increased with the risk factors cN1, the tumour centrally located or the tumour diameter >3 cm: from 4.5% (0 factors) to 18.8% (3 factors) but did not differ significantly as a function of whether invasive testing was performed.

CONCLUSIONS

CT and PET together have a high negative predictive value. The overall success of the staging is lower in the case of tumours >3 cm and high mediastinal SUVmax, and it is higher when VATS is performed. The risk of unexpected pN2 is higher if the disease is cN1, the tumour centrally located or the tumour diameter >3 cm but does not vary significantly as a function of whether patients have undergone invasive testing.

The Value of a Systematic Protocol Using Endobronchial Ultrasound and Endoscopic Ultrasound in Staging of Lung Cancer for Patients with Imaging iN0–N1 Disease

<b><i>Introduction:</i></b> We hypothesize that systematic, combined, and multidisciplinary study of the mediastinum (endobronchial ultrasound [EBUS] and endoscopic ultrasound [EUS]) in patients with NSCLC with radiologically normal mediastinum improves the results of mediastinal staging obtained with EBUS alone. <b><i>Material and Methods:</i></b> A retrospective study of the prospective database collected on the patients with NSCLC with a radiologically normal mediastinum and an indication for systematic staging with EBUS and EUS. EBUS staging was followed by EUS in patients in which the results from the pathological analysis of EBUS were negative. <b><i>Results:</i></b> Forty-five patients were included in the analysis. The combination of EBUS followed by EUS provided better results than EBUS alone: sensitivity (S) 95% versus 80%, negative predictive value (NPV) 96.15% versus 86.21%, negative likelihood ratio 0.05 versus 0.20, and post-test probability 3.8% versus 13.8%. This represents an increase in S (15%), the validity index (6.6%), and NPV (9.9%) compared to EBUS alone. There were 4 false negatives (FNs) (8.8%) with the EBUS test alone. After adding EUS, 3 more cases were positive (6.6%) and only 1 FN (2.2%). <b><i>Conclusions:</i></b> In patients with NSCLC and a radiographically normal mediastinum, a systematic and combined staging with EBUS and EUS show higher sensitivity in the detection of mediastinal metastasis than with the use of EBUS alone. The high accuracy of the test means that the use of mediastinoscopy is not necessary to confirm the results in these patients. Since the availability of EUS is low, it may be advisable for the interventional pulmonologist to receive training in EUS-b.

Evaluation of mediastinoscopy in mediastinal lymph node staging for non-small-cell lung cancer

OBJECTIVES

The purpose of this study was to assess the quality of video-assisted cervical mediastinoscopy (VACM) in the staging of non-small-cell lung cancer (NSCLC) at the Antwerp University Hospital with a focus on test effectiveness indicators, morbidity and unforeseen pN2 results.

METHODS

All consecutive VACM workups of cases of NSCLC performed between January 2010 and December 2015 were included to assess overall test quality and effectiveness. Quality assurance was performed in accordance with the recommendations of the European Society of Gastrointestinal Endoscopy and European Society of Thoracic Surgeons (ESTS) where appropriate.

RESULTS

A total of 168 video-assisted cervical mediastinoscopies were included. A total of 91.7% of the procedures were performed in accordance with the ESTS guideline. An unforeseen pN2 staging was identified in 10 anatomical lung resections (8.6%). Statistical analysis showed no significant association between VACM performed in accordance with the ESTS guideline and the presence of pN2 positive lymph nodes [χ2 (1) = 0.61; P = 0.57] and no association between VACM performed in accordance with the ESTS guideline and overall futile thoracotomy [χ2 (1) = 0.76; P = 0.50]. Calculations revealed a sensitivity of 81.8 [95% confidence interval (CI) 69.1-90.9], specificity of 100%, positive predictive value of 100%, negative predictive value of 91.9% (95% CI 86.6-95.2) and diagnostic accuracy of 94.1% (95% CI 89.33-97.11).

CONCLUSIONS

Overall, 91.7% of the VACM were performed in accordance with the ESTS guideline. This process resulted in a sensitivity of 81.8%, a negative predictive value of 91.9% and an unforeseen pN2 rate of 8.6%.

Differential outcomes of residual disease in surgically-resected non-small cell lung cancer and the importance of guideline-concordant adjuvant therapy

Background

Positive mediastinal lymph nodes, a marker for systemic disease, and positive margins, a marker for local disease, following resection of non-small cell lung cancer (NSCLC) are forms of residual disease. The objective of this study is to compare survival of patients with residual disease and to study the effect of receipt of guideline vs. non-guideline concordant care.

Methods

The National Cancer Database (NCDB) was used to identify patients who underwent treatment naïve surgical resection with clinical stage T1-3N0-1M0 NSCLC between 2006–2016 and had pN2 disease, positive surgical margins, or both. Concordant care was determined based on form of chemotherapy and radiation, dosage, volume, modality, and duration. Kaplan-Meier survival curves and log-rank tests were used to compare five-year survival. Multivariable analysis using Cox proportional hazards modeling identified factors that contributed to worse overall survival.

Results

There were 8,189 patients included: pN2 (5,416), positive margins (2,386), and both (387). Five-year survival rates for all patients were pN2 (35.8%), positive margins (33.9%), and both (22.9%) (P<0.0001). On multivariable analysis, positive margins were an independent predictor of better survival relative to pN2 disease (HR =0.729, CI: 0.676, 0.787, P<0.0001). Receipt of non-guideline concordant treatment was an independent predictor of worse survival compared to receipt of guideline-concordant treatment (HR =1.61, CI: 1.504, 1.725, P<0.0001).

Conclusions

In upfront surgical patients, guideline-concordant treatment in the setting of residual disease is associated with better overall survival compared with non-guideline concordant treatment. Pathologic N2 disease is associated with a lower survival rate than positive resection margins, possibly reflecting the systemic nature of pN2 disease.

Trends in mediastinal nodal staging and its impact on unforeseen N2 and survival in lung cancer

INTRODUCTION

Guidelines for invasive mediastinal nodal staging in resectable nonsmall cell lung cancer (NSCLC) have changed over the years. The aims of this study were to describe trends in invasive staging and unforeseen N2 (uN2) and to assess a potential effect on overall survival.

METHODS

A nationwide Dutch cohort study included all clinical stage IA-IIIB NSCLC patients primarily treated by surgical resection between 2005 and 2017 (n=22 555). We assessed trends in invasive nodal staging (mediastinoscopy 2005-2017; endosonography 2011-2017), uN2 and overall survival and compared outcomes in the entire group and in clinical nodal stage (cN)1-3 patients with or without invasive staging.

RESULTS

An overall increase in invasive nodal staging from 26% in 2005 to 40% in 2017 was found (p<0.01). Endosonography increased from 19% in 2011 to 32% in 2017 (p<0.01), while mediastinoscopy decreased from 24% in 2011 to 21% in 2017 (p=0.08). Despite these changes, uN2 was stable over the years at 8.7%. 5-year overall survival rate was 41% for pN1 compared to 37% in single node uN2 (p=0.18) and 26% with more than one node uN2 (p<0.01). 5-year overall survival rate of patients with cN1-3 with invasive staging was 44% versus 39% in patients without invasive staging (p=0.12).

CONCLUSION

A significant increase in invasive mediastinal nodal staging in patients with resectable NSCLC was found between 2011 and 2017 in the Netherlands. Increasing use of less invasive endosonography prior to (or as a substitute for) surgical staging did not lead to more cases of uN2. Performance of invasive staging indicated a possible overall survival benefit in patients with cN1-3 disease.

Optimal Adjuvant Therapy in Resected Stage IIIA-N2 Non-Small-Cell Lung Cancer Harboring EGFR Mutations

BACKGROUND

Some non-small-cell lung cancer (NSCLC) patients are unexpectedly diagnosed with stage IIIA-N2 disease at the time of thoracoscopy or thoracotomy. Because of the limited statistical evidence of induction chemotherapy for these patients, it is necessary to develop more profound treatment strategies.

METHODS

The demographic and clinical characteristics of patients with stage IIIA-N2 NSCLC harboring epidermal growth factor receptor (EGFR) mutations after radical resection were retrospectively reviewed. The patients were divided into 3 groups based on treatment: EGFR tyrosine kinase inhibitors (EGFR-TKIs, erlotinib or gefitinib), adjuvant chemotherapy (docetaxel plus cisplatin), and combination treatment (chemotherapy plus EGFR-TKIs). The effect of adjuvant therapy on survival rate was assessed using univariate and Cox regression analyses.

RESULTS

Patients receiving EGFR-TKIs alone showed significantly improved disease-free survival (DFS; p = 0.025) when compared to those receiving chemotherapy alone. Compared to chemotherapy alone, the combination of chemotherapy and EGFR-TKIs resulted did not significantly improve DFS (p < 0.001) and overall survival (OS p < 0.001). The combination of EGFR-TKIs with chemotherapy as adjuvant therapy led to improvements in both DFS (p = 0.116) and OS (p = 0.039) compared to patients receiving a EGFR-TKI monotherapy. Toxicities were mild in the 3 treatment groups.

CONCLUSIONS

Our study demonstrated that adjuvant EGFR-TKI treatment significantly increased the DFS of patients with stage IIIA-N2 NSCLC when compared with cisplatin-based chemotherapy. The use of EGFR-TKIs and chemotherapy is recommended in the setting of combined-modality therapy.

Is invasive mediastinal staging necessary in intermediate risk patients with negative PET/CT?

Background

Tumor involvement of mediastinal lymph nodes is of high importance in non-small cell lung cancer (NSCLC). Invasive mediastinal staging is recommended in selected patients without evidence of mediastinal involvement on staging by imaging. In the present study we aimed to evaluate the effectiveness of invasive mediastinal staging in reducing pN2, its impact on survival and the risk factors for occult pN2.

Methods

Patients with NSCLC tumors larger than 3 cm, central tumors or cN1 cases treated in our institution between 2013 and 2018 were prospectively included in the study. Incidence of pN2 and overall survival was compared among invasively staged (IS) and non-invasively staged groups (NIS). Multivariate analysis was performed to identify risk factors of pN2.

Results

A total of 201 patients were included in the study, 79 (39.3%) of whom were not invasively staged (NIS group) and 122 (60.7%) were invasively staged (IS group). Incidence of cN1 and mean PET/CT uptake was different among both groups. Prevalence of pN2 was similar in both groups (7.6% in NIS vs. 12.6% in IS; P>0.05). Median survival in IS-pN2 patients was 11 months longer than in NIS-pN2 group (33.6 vs. 22.5 months; P=0.245). cN1 emerged as the only a risk factor for pN2.

Conclusions

Invasive staging does not reduce the incidence of pN2. However, this finding could be biased because in our series cN1 patients were more often staged and cN1 has been detected as a risk factor for pN2. In addition patient better selection after invasive staging might have an impact on overall survival. To conclude, invasive mediastinal staging in intermediate risk patients for positive mediastinal nodes is justified.

Adherence to the mediastinal staging guideline and unforeseen N2 disease in patients with resectable non-small cell lung cancer: Nationwide results from the Dutch Lung Cancer Audit - Surgery

OBJECTIVES

Invasive mediastinal staging is advised by guidelines in patients with resectable non-small cell lung cancer (NSCLC) and suspicious lymph nodes (cN1-3) or for central, FDG-non-avid or peripheral tumours >3 cm. Our objective was to assess current guideline adherence and consequent unforeseen N2 disease (uN2) in NSCLC patients having various indications for mediastinal staging.

MATERIALS AND METHODS

We analysed the Dutch Lung Cancer Audit - Surgery data of all patients who underwent a primary lung resection with lymph node dissection for NSCLC in 2017-2018. Based on the 2015 ESTS-ERS-ESGE guideline we assessed the use of initial endosonography and confirmatory mediastinoscopy as well as uN2 rates.

RESULTS

A total of 2238 patients were analysed. 43 % (95 %-CI: 41-45) underwent initial endosonography followed by a confirmatory mediastinoscopy in 44 % (95 %-CI:40-47) of them, resulting in a 19 % (95 %-CI: 17-20) rate of properly staged patient according to the guidelines. uN2 was demonstrated in 12.5 % (95 %-CI: 9.7-16.0) of correctly staged patients compared to 10.9 % (95 %-CI: 9.6-12.4) who were not (p = .36). The highest uN2 rate was found in cN1-3 patients who were not staged (23.0 %, 95 %-CI: 16.4-31.2) compared to 13.0 % (95 %-CI: 9.7-17.1) who were (p = .01).

CONCLUSION

Guideline adherence in Dutch NSCLC patients with an indication for invasive mediastinal staging is poor. The highest uN2 rate was found in unstaged cN1-3 patients, suggesting that this subgroup may benefit from an appropriate staging conform guidelines.

Lobectomy does not confer survival advantage over segmentectomy for non-small cell lung cancer with unsuspected nodal disease

OBJECTIVE

Conversion to lobectomy is typically performed when positive lymph nodes are found during intentional segmentectomy. Our objective was to evaluate survival after lobectomy and segmentectomy in patients with unsuspected nodal metastases.

METHODS

The National Cancer Database was queried for patients with clinical T1N0, pathological N1/N2 non-small cell lung cancer (NSCLC) who underwent either lobectomy or segmentectomy. Survival differences between the 2 groups were evaluated using a propensity score model. Cox regression analysis was used to evaluate predictors of overall survival, including adjuvant treatment. Statistical analysis was done using SPSS version 21.0 (IBM Corp, Armonk, NY).

RESULTS

Between 2004 and 2015, unsuspected pathological N1 disease for clinical T1N0M0 NSCLC was found in 2.5% (228/9118) and 6.7% (8915/132,604) of patients who underwent segmentectomy and lobectomy, respectively. The incidence of unsuspected pathological N2 disease for clinical T1N0M0 NSCLC was 2.4% (224/9118) after segmentectomy and 3.9% (5192/132,604) after lobectomy. Using propensity matched pairs (227 pairs for N1 and 215 for N2), segmentectomy showed equivalent 5-year survival compared with lobectomy for the N1 group (41.9% vs 44.3%; P = .35), and N2 group (41.6% vs 37.2%; P = .99). In a multivariable model, adjuvant chemotherapy was associated with better survival of patients with unsuspected N1 (hazard ratio, 0.613; 95% confidence interval, 0.536-0.700; P < .001) and N2 (hazard ratio, 0.684; 95% confidence interval, 0.583-0.802; P < .001) nodal metastases.

CONCLUSIONS

Survival is similar between lobectomy and segmentectomy for clinical T1N0 and unsuspected pathological N1/N2 nodal metastases. The use of adjuvant chemotherapy significantly improves survival in patients with lymph node metastasis (N1/N2) independent of the type of anatomic lung resection.

[Correlation between Lymph Node Ratio and Clinicopathological Features and Prognosis of IIIa-N2 Non-small Cell Lung Cancer]

BACKGROUND

IIIa-N2 non-small cell lung cancer was significant different in survival, although N stage of lung cancer based on anatomic location of metastasis lymph node. Lymph node ratio considered of prognostic factor might be the evaluation index for IIIa-N2 non-small cell lung cancer prognosis. Therefore, the aim of the study was to evaluate the correlation between lymph node ratio and clinicopathological features and prognosis of IIIa-N2 non-small cell lung cancer prognosis.

METHODS

A total of 288 cases of pathological IIIa-N2 non-small cell lung cancer were enrolled who received radical resection at the Department of Thoracic Surgery II, Peking University Cancer Hospital from January 2006 to December 2016. The univariate analysis between clinicopathological variables and lymph node ratio used Pearson's chi-squared test. Cox regression was conducted to identify the independent prognosis factors for IIIa-N2 non-small cell lung cancer.

RESULTS

There were 139 cases in the lower lymph node ratio group, another 149 cases in the higher lymph node ratio group. Adenocarcinoma (χ²=5.924, P=0.015), highest mediastinal lymph node metastasis (χ²=46.136, P<0.001), multiple-number N2 metastasis (χ²=59.347, P<0.001), multiple-station N2 metastasis (χ²=77.387, P<0.001) and skip N2 lymph node metastasis (χ²=61.524, P<0.001) significantly impacted lymph node ratio. The total number of lymph node dissection was not correlated with the lymph node ratio (χ²=0.537, P=0.464). Cox regression analysis confirmed that adenocarcinoma (P=0.008), multiple-number N2 metastasis (P=0.025) and lymph node ratio (P=0.001) were the independent prognosis factors of disease free survival. The 5-year disease free survival was 18.1% in the higher lymph node ratio group, and 44.1% in the lower. Lymph node ratio was the independent prognosis factor of overall survival (P<0.001). The 5-year overall survival was 36.7% in the higher lymph node ratio group, and 64.1% in the lower.

CONCLUSIONS

Lymph node ratio was correlative with the pathology, highest mediastinal lymph node metastasis, multiple-number N2 metastasis, multiple-station N2 metastasis and skip N2 lymph node metastasis. Lymph node ratio was the independent prognosis factor for IIIa-N2 non-small cell lung cancer.

Induction Therapies Plus Surgery Versus Exclusive Radiochemotherapy in Stage IIIA/N2 Non-Small Cell Lung Cancer (NSCLC)

In spite of the growing body of data from prospective randomized clinical trials (PRCTs) and meta-analyses, the optimal treatment approach in patients with stage IIIA non-small cell lung cancer remains unknown. This review focuses on the available data directly confronting induction chemotherapy or induction radiochemotherapy (RT-CHT) when followed by surgery with exclusive RT-CHT. Seven PRCTs and 4 meta-analyses investigated this issue. In addition, numerous retrospective studies attempted to identify potential predictors and/or prognosticators that may have influenced the decision to offer surgery in a particular patient subgroup. Several retrospective studies also evaluated exclusive RT-CHT in this setting. There is not a single piece of the highest level of evidence (PRCT or MA) showing any advantage of induction therapies followed by surgery over exclusive RT-CHT with the former treatment option leading to significantly more morbidity and mortality. Although several studies attempted to identify patient subgroups favoring induction therapies followed by surgery, they have invariably been retrospective in nature, and their results have never been reproduced even in other retrospective setting. Furthermore, no PRCT investigated potential pretreatment patient and/or tumor-related predictors of surgical multimodality success. Exclusive RT-CHT achieves similar results to induction therapies followed by surgery but with less morbidity and mortality. This is accompanied with the finding that no pretreatment predictor exists to enable identification of even a subgroup of stage IIIA/pN2 patients benefiting from any surgical approach.

Present indications of surgical exploration of the mediastinum

Preoperative mediastinal staging is crucial in the management of patients with non-small cell lung cancer (NSCLC), especially to define prognosis and the most proper treatment. To obtain the highest certainty level before lung resection, the current American and European guidelines for preoperative mediastinal nodal staging for NSCLC recommend getting tissue confirmation of regional nodal spread in all cases except in patients with small (≤3 cm) peripheral carcinomas with no evidence of nodal involvement on computed tomography (CT) and positron emission tomography (PET). We have a wide variety of surgical methods for mediastinal staging that are well integrated in the current preoperative algorithms. Their main indication is the validation of negative results obtained by minimally invasive endoscopic techniques. However, recent studies have reported the superiority of mediastinoscopy over endosonography methods in terms of accuracy for those tumours classified as clinical (c) N0-1 by CT and PET or with intermediate risk of N2 disease (cN1 and central tumours). Apart from the exploration of the mediastinum, other surgical procedures [parasternal mediastinotomy, extended cervical mediastinoscopy (ECM) and video-assisted thoracoscopic surgery (VATS)] allow the completion of the staging process with the assessment of the primary tumour and metastasis, exploring the lung, pleural cavity, and pericardium when it is required. Transcervical lymphadenectomies represent the evolution of mediastinoscopy and they are already considered the most reliable method for mediastinal staging, mainly in the subgroup of patients in whom endosonography methods have a low sensitivity: tumours with normal mediastinum by CT and PET. In addition to their indication for staging, these procedures have also demonstrated to be feasible as preresectional lymphadenectomy in VATS lobectomy, improving the radicality of the number of lymph nodes and lymph node stations explored, mostly for left-sided tumours for which a complete mediastinal nodal dissection is not always possible by VATS approach.

MEDIASTinal staging of non-small cell lung cancer by endobronchial and endoscopic ultrasonography with or without additional surgical mediastinoscopy (MEDIASTrial): study protocol of a multicenter randomised controlled trial

Background

In case of suspicious lymph nodes on computed tomography (CT) or fluorodeoxyglucose positron emission tomography (FDG-PET), advanced tumour size or central tumour location in patients with suspected non-small cell lung cancer (NSCLC), Dutch and European guidelines recommend mediastinal staging by endosonography (endobronchial ultrasound (EBUS) and endoscopic ultrasound (EUS)) with sampling of mediastinal lymph nodes. If biopsy results from endosonography turn out negative, additional surgical staging of the mediastinum by mediastinoscopy is advised to prevent unnecessary lung resection due to false negative endosonography findings. We hypothesize that omitting mediastinoscopy after negative endosonography in mediastinal staging of NSCLC does not result in an unacceptable percentage of unforeseen N2 disease at surgical resection. In addition, omitting mediastinoscopy comprises no extra waiting time until definite surgery, omits one extra general anaesthesia and hospital admission, and may be associated with lower morbidity and comparable survival. Therefore, this strategy may reduce health care costs and increase quality of life. The aim of this study is to compare the cost-effectiveness and cost-utility of mediastinal staging strategies including and excluding mediastinoscopy.

Methods/design

This study is a multicenter parallel randomized non-inferiority trial comparing two diagnostic strategies (with or without mediastinoscopy) for mediastinal staging in 360 patients with suspected resectable NSCLC. Patients are eligible for inclusion when they underwent systematic endosonography to evaluate mediastinal lymph nodes including tissue sampling with negative endosonography results. Patients will not be eligible for inclusion when PET/CT demonstrates ‘bulky N2-N3’ disease or the combination of a highly suspicious as well as irresectable mediastinal lymph node. Primary outcome measure for non-inferiority is the proportion of patients with unforeseen N2 disease at surgery. Secondary outcome measures are hospitalization, morbidity, overall 2-year survival, quality of life, cost-effectiveness and cost-utility. Patients will be followed up 2 years after start of treatment.

Discussion

Results of the MEDIASTrial will have immediate impact on national and international guidelines, which are accessible to public, possibly reducing mediastinoscopy as a commonly performed invasive procedure for NSCLC staging and diminishing variation in clinical practice.

Trial registration

The trial is registered at the Netherlands Trial Register on July 6th, 2017 (NTR 6528).

Electronic supplementary material

The online version of this article (10.1186/s12893-018-0359-6) contains supplementary material, which is available to authorized users.

N2-IIIA non-small cell lung cancer: a plea for surgery!

Management of stage IIIA-N2 non-small cell lung cancer is still matter of ongoing controversy. The debate is flawed by the heterogeneity of this group of patients, lack of strong evidence from controlled trials, diverging treatment strategies, and hesitating estimation of prognosis. Surgery is credited a survival advantage in a trimodality setting. For many teams, N2 is by principle managed with induction chemotherapy, followed by surgery if the patient is down-staged. However, surgery remains a suitable option even in case of persistent N2. On the other hand, outcomes are comparable, regardless whether chemotherapy has been given as induction or adjuvant treatment. Hence, upfront surgery without invasive staging, followed by adjuvant therapies, appears reasonable in resectable single station N2 disease, simplifying patient care and reducing cost. We expect that molecular biomarkers will improve estimation of prognosis and patient selection in the future.

Mediastinal lymphadenectomy fulfilling NCCN criteria may improve the outcome of clinical N0-1 and pathological N2 non-small cell lung cancer

BACKGROUND

This retrospective study investigated whether mediastinal lymphadenectomy compliant with the National Comprehensive Cancer Network (NCCN) criteria will improve the oncological outcomes of clinical early-stage lung cancer.

METHODS

From 2003-2010, 712 consecutive cases of clinical N0/1 were included for retrospective analysis, including 152 confirmed cases of pN2 and 560 of pN0-1 disease following surgery. Group A was defined as the cases fulfilling NCCN lymphadenectomy criteria (≥ three stations of N2 nodes dissection) and group B included all other cases. The groups were stratified according to pN status and the outcomes were assessed.

RESULTS

Five-year overall survival (OS) and 5-year disease-free survival (DFS) were significantly different between group A versus B [72%±2% vs. 63%±4% (OS), P=0.014; 58.0%±2% vs. 49%±4% (DFS), P=0.038] in the whole cohort. After stratification by pN status, this difference was remained in pN2 subgroup [50%±5% vs. 25%±9% (OS), P=0.006; 31.0%±4% vs. 13%±7% (DFS), P=0.014], but not in pN0-1 subgroups. Cox regression analysis showed that performing a lymphadenectomy fulfilling NCCN criteria was a significant prognostic factor for OS either in the whole cohort [P=0.003, hazard ratio (HR): 0.598, 95% confidence interval (CI): 0.425-0.841] or in patients of pN2 status (P=0.038, HR: 0.559, 95% CI: 0.323-0.968). Cases with ≥4 N2 stations dissected did not achieve better survival benefit compared to those harvesting 3 stations in cN0/1-pN2 group (P=0.152).

CONCLUSIONS

Mediastinal lymphadenectomy fulfilling NCCN criteria appears to improve the survival of unexpected N2 group (cN0/1-pN2) among early-stage lung cancer patients. More extended N2 node dissection may not further improve the outcome in this group.

Long-term outcomes after lobectomy for non-small cell lung cancer when unsuspected pN2 disease is found: A National Cancer Data Base analysis

OBJECTIVE

There are few studies evaluating whether to proceed with planned resection when a patient with non-small cell lung cancer (NSCLC) unexpectedly is found to have N2 disease at the time of thoracoscopy or thoracotomy. To help guide management of this clinical scenario, we evaluated outcomes for patients who were upstaged to pN2 after lobectomy without induction therapy using the National Cancer Data Base (NCDB).

METHODS

Survival of NSCLC patients treated with lobectomy for clinically unsuspected mediastinal nodal disease (cT1-cT3 cN0-cN1, pN2 disease) from 1998-2006 in the NCDB was compared with "suspected" N2 disease patients (cT1-cT3 cN2) who were treated with chemotherapy with or without radiation followed by lobectomy, using matched analysis based on propensity scores.

RESULTS

Unsuspected pN2 disease was found in 4.4% of patients (2047 out of 46,691) who underwent lobectomy as primary therapy for cT1-cT3 cN0-cN1 NSCLC. The 5-year survival was 42%, 36%, 21%, and 28% for patients who underwent adjuvant chemotherapy (n = 385), chemoradiation (n = 504), radiation (n = 300), and no adjuvant therapy (n = 858), respectively. Five-year survival of the entire unsuspected pN2 cohort was worse than survival of 2302 patients who were treated with lobectomy after induction therapy for clinical N2 disease (30% vs 40%; P < .001), although no significant difference in 5-year survival was found in a matched-analysis of 655 patients from each group (37% vs 37%; P = .95).

CONCLUSIONS

This population-based analysis suggests that, in the setting of unsuspected pN2 NSCLC, proceeding with lobectomy does not appear to compromise outcomes if adjuvant chemotherapy with or without radiation therapy can be administered following surgery.

Diagnosing and staging lung cancer involving the mediastinum

The purpose of this article is to provide an update on evidence-based methods for mediastinal staging in patients with lung cancer. This is a review of the recently published studies and a summary of relevant guidelines addressing the role of CT scan, PET scan, endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA), and mediastinoscopy as pertinent to lung cancer staging and restaging. The focus is on how these diagnostic methods fit into the best algorithm for patients with chest imaging abnormalities suspected of malignant disease. Several studies, meta-analyses, and systematic reviews specifically targeted the role of PET scan, EBUS-TBNA, and mediastinoscopy for detecting mediastinal lymph node involvement in patients suffering from lung cancer. Based on the recommendations from the currently published guidelines, algorithms of care are proposed for staging and restaging of the mediastinum.