Validity of the updated European Society of Thoracic Surgeons staging guideline in lung cancer patients

Video-assisted mediastinoscopic lymphadenectomy (VAMLA): Mature results for staging non-small cell lung cancer with normal mediastinum

OBJECTIVES

The aim of this study is to analyze the accuracy of video-assisted mediastinoscopic lymphadenectomy (VAMLA) and the unsuspected (u) N2/3 rates in patients with non-small cell lung cancer (NSCLC) and normal mediastinum by integrated positron emission tomography-computed tomography.

METHODS

Prospective observational single-center study of 603 consecutive VAMLAs from 2010 to 2022.

EXCLUSION CRITERIA

other indications (n = 32), tumors different from NSCLC (n = 91), and clinical (c) N2/3 tumors by positron emission tomography-computed tomography (n = 46). Systematic nodal dissection was the gold standard to validate negative VAMLAs. Those patients with negative VAMLA and missing reference standard test were excluded. uN2/3 rates were analyzed in the global series and in the subgroups of tumors according to their clinical nodal and tumor categories. Pathologic findings were reviewed, and staging values were calculated.

RESULTS

Three hundred eighty-three patients with cN0/1 NSCLC underwent VAMLA. Staging values of VAMLA were: sensitivity, 0.98 (95% CI, 0.92-0.99); negative predictive value, 0.99 (95% CI, 0.98-1); and diagnostic accuracy, 0.99 (95% CI, 0.98-1). The uN2/3 rate for the whole series (N = 383) was 18.8%. The uN2/3 rates according to presurgical nodal and tumor categories determined by positron emission tomography computed tomography were: 3.6% (4 out of 111) in cT1N0; 16.3% (18 out of 110) in cT2N0; 10.25% (4 out of 39) in cT3N0; and 32% (7 out of 22) in cT4N0. Forty-two percent (39 out of 93) in cN1; complication rate was 7%.

CONCLUSIONS

This series of NSCLC with normal mediastinum staged by VAMLA demonstrates a high accuracy of this technique and a high rate of uN2/3 disease (specially in cN1 and cT4N0). VAMLA could be considered the reference staging procedure for staging cN0/1 NSCLC.

Lymph node micrometastasis in non-small cell lung cancer

Lung cancer has some of the highest morbidity and mortality rates of all cancers, and an important risk factor for mortality in patients with lung cancer is tumor metastasis. Even if a tumor is completely removed at an early stage of the disease, quite a number of patients still have the risk of recurrence. With the advent of molecular diagnostic and therapeutics, more and more studies have found that a poor prognosis may be related to lymph node micrometastasis. However, clinicians still find that predicting the prognosis and choosing the type of surgery and postoperative adjuvant chemotherapy are still challenging. Thus, this article reviews the current research status of lymph node micrometastasis in non-small cell lung cancer, envision to provide some updates and insights in this area.

Confirmatory Mediastinoscopy after Negative EBUS-TBNA for Mediastinal Staging of Lung Cancer: Systematic Review and Meta-analysis

RATIONALE

Current guidelines of non-small cell lung cancer (NSCLC) mediastinal staging recommend starting invasive staging with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). However, the indication to confirm a negative result of EBUS-TBNA by means of video-assisted mediastinoscopy (VAM) prior to resection differs in every guideline.

OBJECTIVE

Our aim was to evaluate the current evidence regarding the added value of confirmatory VAM after a negative EBUS-TBNA for mediastinal staging in patients with NSCLC.

METHODS

Systematic searches of studies on EBUS-TBNA for NSCLC mediastinal staging with or without confirmatory VAM but with surgical confirmation of negative results were conducted in accordance with PRISMA statement in PubMed, SCOPUS, Cochrane and Guidelines from 2005 through November 2021. In the meta-analysis the sensitivity of confirmatory VAM after a negative EBUS-TBNA, the sensitivity and negative predictive value (NPV) of the combination EBUS-TBNA plus confirmatory VAM, alongside the number of confirmatory VAM required to detect additional N2/3 disease (number needed to treat [NNT]), in patients with a previous negative EBUS-TBNA were estimated.

RESULTS

5412 articles were found, of which 29 studies were included. Random effects meta-analysis showed a sensitivity of 66.9% (95% CI: 55.8%-77.1%) for confirmatory VAM, and 96.7% (95% CI: 95.1%- 98%) for the combination EBUS-TBNA plus confirmatory VAM. NPV in studies with confirmatory VAM increased of 79.2% (95% CI: 71.4%-86.1%) for EBUS-TBNA alone to 91.8% (95% CI: 87.1%-95.5%) for EBUS-TBNA plus confirmatory VAM. The NNT of confirmatory VAM in patients with a previous negative EBUS-TBNA was 23.8 (95% CI: 19.3-31.2) CONCLUSIONS: Confirmatory VAM after negative EBUS-TBNA reduces the rate of unforeseen N2/3 disease, but with a high NNT, and should be recommended only to certain cases yet to be defined.

How We Do It: Mediastinal Staging for Lung Cancer

Mediastinal lymph node staging in the setting of known or suspected lung cancer is supported by multiple professional societies as standard for high-quality care, yet proper mediastinal staging often is lacking. Neglecting pathologic lymph node sampling can understage or overstage the patient and lead to inappropriate treatment. Although some cases of nodal disease are radiographically obvious, others are not as apparent, and both situations require pathologic proof to allow for appropriate treatment selection. This article discusses the nuances of mediastinal staging and emphasizes the usefulness of a multidisciplinary approach and dialog to address lung cancer staging and treatment. We summarize the relevant guidelines and literature and provide a case scenario to illustrate the approach to mediastinal staging from our viewpoints as a thoracic surgeon and pulmonologist.

Preoperative staging of the mediastinum is an essential and multidisciplinary task

Mediastinal staging is a crucial step in the management of patients with NSCLC. With the recent development of novel techniques, mediastinal staging has evolved from an activity of interest mainly for thoracic surgeons to a joint effort carried out by many specialists. In this regard, the debate of cases in MDT sessions is crucial for optimal management of patients. Current evidence-based clinical guidelines for preoperative NSCLC staging recommend that mediastinal staging should be performed with increasing invasiveness. Image-based techniques are the first approach, although they have limited accuracy and findings must be confirmed by pathology in almost all cases. In this setting, the advent of radiomics is promising. Invasive staging depends on procedural factors rather than diagnostic performance. The choice between endoscopy-based or surgical procedures should depend on the local expertise of each centre. As the extension of mediastinal disease in terms of number of involved lymph nodes and nodal stations affects prognosis and the choice of treatment, systematic samplings are preferred over random targeted samplings. Following this approach, a diagnosis of single mediastinal nodal involvement can be unreliable if all reachable mediastinal nodal stations have not been assessed. The performance of confirmatory mediastinoscopy after a negative endoscopy-based procedure is controversial but currently recommended. Current indications of invasive staging in patients with radiologically normal mediastinum have to be re-evaluated, especially for central tumour location.

Minimizing residual occult nodal metastasis in NSCLC: recent advances, current status and controversies

Introduction: Nodal involvement in lung cancer is a significant determinant of prognosis and treatment management. New evidence exists regarding the management of occult lymph node metastasis and residual disease in the fields of imaging, mediastinal staging, and operative management.Areas covered: This review summarizes the latest body of knowledge on the identification and management of occult lymph node metastasis in NSCLC. We focus on tumor-specific characteristics; imaging modalities; invasive mediastinal staging; and operative management including, technique, degree of resection, and lymph node examination.Expert opinion: Newly identified risk-factors associated with nodal metastasis including tumor histology, location, radiologic features, and metabolic activity are not included in professional societal guidelines due to the heterogeneity of their reporting and uncertainty on how to adopt them into practice. Imaging as a sole diagnostic method is limited. We recommend confirmation with invasive mediastinal staging. EBUS-FNA is the best initial method, but adoption has not been uniform. The diagnostic algorithm is less certain for re-staging of mediastinal nodes after neoadjuvant therapy. Mediastinal node sampling during lobectomy remains the gold-standard, but evidence supports the use of minimally invasive techniques. More study is warranted regarding sublobar resection. No consensus exists regarding lymph node examination, but new evidence supports reexamination of current quality metrics.

Nodal size ranking as a predictor of mediastinal involvement in clinical early-stage non-small cell lung cancer

In non-small cell lung cancer (NSCLC) patients, the recommended minimum requirement for an endoscopy-based mediastinal staging procedure is sampling the largest lymph node (LN) in right and left inferior paratracheal, and subcarinal stations. We aimed to analyze the percentage of cases where the largest LN in each mediastinal station was malignant in a cohort of NSCLC patients with mediastinal metastases diagnosed in the lymphadenectomy specimen. Furthermore, we investigated the sensitivity of a preoperative staging procedure in a hypothetical scenario where only the largest LN of each station would have been sampled.Prospective data of patients with mediastinal nodal metastases diagnosed in the lymphadenectomy specimens were retrospectively analyzed. The long-axis diameter of the maximal cut surface of all LNs was measured on hematoxylin and eosin-stained sections.Seven hundred seventy five patients underwent operation and 49 (6%) with mediastinal nodal disease were included. A total of 713 LNs were resected and 119 were involved. Sixty seven nodal stations revealed malignant LNs: in these, the largest LN was malignant in 39 (58%). In a "per patient" analysis, a preoperative staging procedure that sampled only the largest LN would have attained a sensitivity of 0.67; and if the largest and the second largest were sampled, sensitivity would be 0.87.In patients with NSCLC, nodal size ranking is not reliable enough to predict malignancy. In clinical practice, regardless of the preoperative staging method, systematic thorough sampling of all visible LNs is to be recommended over selective random samplings.

Methylation Assessment for the Prediction of Malignancy in Mediastinal Adenopathies Obtained by Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration in Patients with Lung Cancer

The evaluation of mediastinal lymph nodes is critical for the correct staging of patients with lung cancer (LC). Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive technique for mediastinal staging, though unfortunately lymph node micrometastasis is often missed by cytological analysis. The aim of this study was to evaluate the predictive capacity of methylation biomarkers and provide a classification rule for predicting malignancy in false negative EBUS-TBNA samples. The study included 112 patients with a new or suspected diagnosis of LC that were referred to EBUS-TBNA. Methylation of p16/INK4a, MGMT, SHOX2, E-cadherin, DLEC1, and RASSF1A was quantified by nested methylation-specific qPCR in 218 EBUS-TBNA lymph node samples. Cross-validated linear regression models were evaluated to predict malignancy. According to EBUS-TBNA and final diagnosis, 90 samples were true positives for malignancy, 110 were true negatives, and 18 were false negatives. MGMT, SHOX2, and E-cadherin were the methylation markers that better predicted malignancy. The model including sex, age, short axis diameter and standard uptake value of adenopathy, and SHOX2 showed 82.7% cross-validated sensitivity and 82.4% specificity for the detection of malignant lymphadenopathies among negative cytology samples. Our results suggest that the predictive model approach proposed can complement EBUS-TBNA for mediastinal staging.

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.

Progress in the Management of Early-Stage Non-Small Cell Lung Cancer in 2017

The landscape of care for early-stage non-small cell lung cancer continues to evolve. While some of the developments do not seem as dramatic as what has occurred in advanced disease in recent years, there is a continuous improvement in our ability to diagnose disease earlier and more accurately. We have an increased understanding of the diversity of early-stage disease and how to better tailor treatments to make them more tolerable without impacting efficacy. The International Association for the Study of Lung Cancer and the Journal of Thoracic Oncology publish this annual update to help readers keep pace with these important developments. Experts in the care of early-stage lung cancer patients have provided focused updates across multiple areas including screening, pathology, staging, surgical techniques and novel technologies, adjuvant therapy, radiotherapy, surveillance, disparities, and quality of life. The source for information includes large academic meetings, the published literature, or novel unpublished data from other international oncology assemblies.