Comparison of video-assisted mediastinoscopy and video-assisted mediastinoscopic lymphadenectomy for lung cancer

Rotation aiding technique for endobronchial ultrasound-guided transbronchial needle aspiration biopsy of intrathoracic lymph nodes: A complementary approach to the conventional jabbing method

Background

This study aimed to compare the lymph node core tissue lengths obtained via mediastinal or hilar lymphadenopathy using the complementary “rotation aiding” and conventional Jab technique.

Methods

We prospectively measured the lymph node core tissue length in patients who sequentially underwent the Jab and rotation aiding (RA) techniques between October 2012 and December 2014. Wilcoxon signed‐rank test was used to compare the core tissue length and grade of diagnostic cells obtained by each technique. McNemar's test was used to compare the proportion of adequate cellularity (≥grade 2) between the aspiration techniques.

Results

The core tissue length of 61 lymph nodes from 43 patients (mean age: 63 years, range: 16–86 years) was analyzed. Pathological findings were consistent with malignant lesions in 25 (41%) patients and benign lesions in 36 (59%). The most common diagnosis in benign lymph nodes was reactive, followed by tuberculosis and sarcoidosis. We obtained longer core tissue with RA technique than with the Jab technique (83.2 ± 12.7 vs. 60.1 ± 10.1 mm; p = 0.02). There was a significant increase in cellularity grade and proportion of ≥grade 2 cells with the RA technique than with the Jab technique (2.39 ± 1.08 vs. 1.84 ± 1.14; p < 0.001, 78.7% vs. 52.5%; p = 0.002), regardless of the pathological diagnosis.

Conclusions

RA technique facilitated more lymph node samples in terms of core tissue length and cellularity than the Jab technique.

Controversies in Mediastinal Staging for Nonsmall Cell Lung Cancer

Mediastinal lymph nodal involvement in nonsmall cell lung cancer plays a crucial role in deciding treatment strategy. Survival falls markedly with increasing involvement of mediastinal nodal stations. Hence, accurate staging of the mediastinum with lowest morbidity is of utmost importance. A wide array of invasive and noninvasive modalities that complement each other in assessing the nodes are available at our disposal. Guidelines recommend noninvasive imaging as the initial step in the staging algorithm for all tumors, followed by invasive staging. No single modality has proven to be the ideal method to stage the mediastinum when used alone. In the present decade, minimally invasive endobronchial ultrasound (EBUS) has challenged the position of surgical mediastinoscopy, which has been the gold standard, historically. However, a negative EBUS needs to be confirmed by surgical mediastinoscopy. Video-assisted mediastinoscopic lymphadenectomy has also come to the forefront in last two decades and has shown exceptional results, when performed in experienced centers. This review details the various modalities of mediastinal staging and the controversies surrounding the optimal method of staging, restaging after neoadjuvant therapy, and the most cost-effective strategy.

Surgical mediastinal lymph node staging for non-small-cell lung carcinoma

Background

The current preferred approach for surgical mediastinal staging of non-small-cell lung carcinoma is video-assisted mediastinoscopy. An alternative technique in which lymph nodes are resected instead of biopsied is video-assisted mediastinoscopic lymphadenectomy (VAMLA) that is suggested to be superior in detecting N2 disease. Yet, evidence is conflicting and furthermore limited by sample size. The objective was to compare mediastinal staging through VAMLA and video-assisted mediastinoscopy.

Methods

A single-center cohort study was conducted. All consecutive patients that underwent surgical mediastinal staging of non-small-cell lung carcinoma by VAMLA (2011 to 2018) were compared to historic video-assisted mediastinoscopy controls (2007 to 2011). Patients with negative surgical mediastinal staging underwent subsequent anatomical resection with systematic regional lymphadenectomy. Primary outcome was the sensitivity and negative predictive value for detecting N2 disease.

Results

Two-hundred-sixty-nine video-assisted mediastinoscopic lymphadenectomies and 118 video-assisted mediastinoscopies were performed. The prevalence of N2 disease was 20% and 26% respectively in the VAMLA and video-assisted mediastinoscopy group, while the rate of unforeseen pN2 resulting from lymph node dissection during anatomical resection was 4% and 11%, respectively. Invasive staging using VAMLA demonstrated superior sensitivity of 0.82 and a negative predictive value of 0.96 when compared to video-assisted mediastinoscopy (0.62 and 0.89, respectively), offering a 64% decrease in risk of unforeseen pN2 following anatomical resection. However, VAMLA is also associated with a 75% risk increase on complications (P=0.36).

Conclusions

We conclude that performing invasive mediastinal lymph node assessment for staging of non-small-cell lung carcinoma, VAMLA should be the preferred technique with superior sensitivity and negative predictive value in detecting N2 disease. Though, VAMLA is also associated with an increased risk of complications.

Mediastinal lymph node staging for lung cancer

Mediastinal lymph node staging is crucial in deciding the treatment strategy for lung carcinoma. The diagnosis rate of computed tomography is not high; however, it is a standard examination. Although the contrast computed tomography is necessary for an accurate diagnosis, images from the positron emission tomography are excellent, and these two technologies are independent and complementary. Positron emission tomography has a disadvantage of false positives and false negatives, but it should also be used in cases where lymph node diameters are 1 cm or more. However, image-based diagnostic methods are not an alternative to histological examination. The results of a transbronchial needle biopsy are extremely dependent on the inspection method, the diagnostic ability of the physician, and the staging of the case. The transesophageal ultrasound endoscope is useful for reaching parts inaccessible by a mediastinoscope. Although its employment requires technical training, it is becoming popular as a minimally invasive method of obtaining cell and the tissue samples. A thoracoscopic biopsy is considered as a last resort for mediastinal lymph node diagnosis. Carefully-chosen invasive procedures are necessary to diagnose swollen lymph nodes. Although mediastinoscopy is still considered as the gold standard, most procedures will be replaced by a comparatively minimally invasive method in the future.

Lung cancer staging: a concise update

Diagnosis and clinical staging of lung cancer are fundamental to planning therapy. The techniques for clinical staging, i.e anatomic and metabolic imaging, endoscopies and minimally invasive surgical procedures, should be performed sequentially and with an increasing degree of invasiveness. Intraoperative staging, assessing the magnitude of the primary tumour, the involved structures, and the loco-regional lymphatic spread by means of systematic nodal dissection, is essential in order to achieve a complete resection. In resected tumours, pathological staging, with the systematic study of the resected specimens, is the strongest prognostic indicator and is essential to make further decisions on therapy. In the present decade, the guidelines on lung cancer staging of the American College of Chest Physicians and the European Society of Thoracic Surgeons are based on the best available evidence and are widely followed. Recent advances in the classification of the adenocarcinoma of the lung, with the definition of adenocarcinoma in situ, minimally invasive adenocarcinoma and lepidic predominant adenocarcinoma, and the publication of the eighth edition of the tumour, node and metastasis classification of lung cancer, have to be integrated into the staging process. The present review complements the latest guidelines on lung cancer staging by providing an update of all these issues.

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

OBJECTIVE

The European Society of Thoracic Surgeons (ESTS) has proposed a revised preoperative lymph node staging guideline for patients with potentially resectable non-small cell lung cancer (NSCLC). We aimed to assess the validity of this revised ESTS guideline and survival results in our patient cohort.

METHODS

A total of 571 patients with potentially resectable NSCLC seen between January 2004 and November 2013 were included in the study. The preoperative mediastinal staging was performed by video-assisted cervical mediastinoscopy or video-assisted mediastinoscopic lymphadenectomy in all patients except those with peripheral cT1N0 nonadenocarcinoma tumors. Resection via thoracotomy or video-assisted thoracoscopic surgery was done in patients with no mediastinal lymph node metastasis. Surgical pathological results were compared with the ESTS staging guideline, and the validity of the guideline was tested.

RESULTS

In this series, mediastinal lymph node metastasis was revealed preoperatively in 266 patients (46.6%). A total of 305 patients underwent anatomic lung resection. The sensitivity, specificity, positive and negative predictive values, and accuracy of the guidelines were calculated as 95.0%, 100%, 100%, 94.6%, and 97.2%, respectively.

CONCLUSIONS

The ESTS revised preoperative lymph node staging guidelines for patients with NSCLC seem to be effective and valid, and may provide high survival following resectional surgery.

The incidence of hoarseness after mediastinoscopy and outcome of video-assisted versus conventional mediastinoscopy in lung cancer staging

Objectives Theoretically, video-assisted mediastinoscopy (VM) should provide a decrease in the incidence of hoarseness in comparison with conventional mediastinoscopy (CM). Methods An investigation of 448 patients with the NSCLC who underwent mediastinoscopy (n = 261 VM, n = 187 CM) between 2006 and 2010. Results With VM, the mean number of sampled LNs and of stations per case were both significantly higher (n = 7.91 ± 1.97 and n = 4.29 ± 0.81) than they were for CM (n = 6.65 ± 1.79 and n = 4.14 ± 0.84) (p < 0.001 and p = 0.06). Hoarseness was reported in 24 patients (5.4%) with VM procedures resulting in a higher incidence of hoarseness than did CM procedures (6.9% and 3.2%) (p = 0.08). The incidence of hoarseness was observed to be more frequent in patients with left-lung carcinoma who had undergone a mediastinoscopy (p = 0.03). Hoarseness developed in 6% of the patients sampled at station 4L, whereas this ratio was 0% in patients who were not sampled at 4L (p = 0.07). A multivariate analysis showed that the presence of a tumor in the left lung is the only independent risk factor indicating hoarseness (p = 0.09). The sensitivity, NPV, and accuracy of VM were calculated as to be 0.87, 0.95, and 0.96, respectively. The same staging values for CM were 0.83, 0.94, and 0.95, respectively. Conclusion VM, the presence of a tumor in the left-lung, and 4L sampling via mediastinoscopy are risk factors for subsequent hoarseness. Probably due to a wider area of dissection, VM can lead to more frequent hoarseness.

Comparison of Endobronchial Ultrasound-Guided Fine Needle Aspiration and Video-Assisted Mediastinoscopy for Mediastinal Staging of Lung Cancer

Video-assisted mediastinoscopy (VAM) and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) are the two most commonly used invasive methods for mediastinal staging of lung cancer. The objective of this review is to assess and compare the overall diagnostic values of VAM and EBUS-TBNA. PubMed, Embase, Web of Science and the Cochrane Library were searched for studies that evaluated EBUS-TBNA or VAM accuracy. Quantitative meta-analysis was used to pool sensitivity and specificity, and study quality was evaluated. Meta-regression was applied to indirectly compare EBUS-TBNA and VAM after adjusting quality score, study design, and station number. A total of ten studies with 999 EBUS-TBNA patients and seven studies with 915 VAM patients were included. Since the pooled specificity was 100% for both modalities, sensitivity was mainly analyzed. The pooled sensitivities for EBUS-TBNA and VAM were 0.84 (95% CI 0.79-0.88) and 0.86 (95% CI 0.82-0.90), respectively. Subgroup analyses of quality score, study design, station number and rapid on-site cytologic evaluation showed no significant influence on the overall sensitivity of the two modalities. After adjusting quality score, study design, and station number, the pooled sensitivities of VAM and EBUS-TBNA were not significantly different. However, more procedural complications and fewer false negatives (FN) were found with VAM than EBUS-TBNA. VAM and EBUS exhibited equally high diagnostic accuracy for mediastinal staging of lung cancer. Due to lower morbidity with EBUS-TBNA and fewer FN with VAM, EBUS-TBNA should be performed first, followed by VAM in the case of a negative needle result.

Staging lung cancer: role of endobronchial ultrasound

Accurate staging is the first step in the management of lung cancer. Nodal staging is quite important for physicians to be able to judge the primary operability of patients harboring no distant metastasis. For many years, mediastinoscopy has been considered a "gold standard" modality for nodal staging. Mediastinoscopy is known to be a highly sensitive procedure for mediastinal staging and has been performed worldwide, but is invasive. Because of this, clinicians have sought a less invasive modality for nodal staging. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive modality for diagnosis and staging of lung cancer. EBUS-TBNA is a needle biopsy procedure that has accessibility compatible with the reach of the convex-probe EBUS scope, so N1 nodes are also assessable. The diagnostic yield is similar to that of mediastinoscopy, and the core obtained by the dedicated needle biopsy can be used for histological assessment to determine the subtypes of lung cancer. The samples can also be used to test for various biomarkers using immunohistochemistry, polymerase chain reaction for DNA/complementary DNA, and in situ hybridization, and the technique is useful for selecting candidates for specific molecular-targeted therapeutic agents. According to the newly published American College of Chest Physicians guideline, EBUS-TBNA is now considered "the best first test" for nodal staging in patients with radiologically suspicious nodes. Appropriate training and thorough clinical experience is required to be able to perform correct nodal staging using this procedure.

Methods for staging non-small cell lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Correctly staging lung cancer is important because the treatment options and prognosis differ significantly by stage. Several noninvasive imaging studies and invasive tests are available. Understanding the accuracy, advantages, and disadvantages of the available methods for staging non-small cell lung cancer is critical to decision-making.

METHODS

Test accuracies for the available staging studies were updated from the second iteration of the American College of Chest Physicians Lung Cancer Guidelines. Systematic searches of the MEDLINE database were performed up to June 2012 with the inclusion of selected meta-analyses, practice guidelines, and reviews. Study designs and results are summarized in evidence tables.

RESULTS

The sensitivity and specificity of CT scanning for identifying mediastinal lymph node metastasis were approximately 55% and 81%, respectively, confirming that CT scanning has limited ability either to rule in or exclude mediastinal metastasis. For PET scanning, estimates of sensitivity and specificity for identifying mediastinal metastasis were approximately 77% and 86%, respectively. These findings demonstrate that PET scanning is more accurate than CT scanning, but tissue biopsy is still required to confirm PET scan findings. The needle techniques endobronchial ultrasound-needle aspiration, endoscopic ultrasound-needle aspiration, and combined endobronchial ultrasound/endoscopic ultrasound-needle aspiration have sensitivities of approximately 89%, 89%, and 91%, respectively. In direct comparison with surgical staging, needle techniques have emerged as the best first diagnostic tools to obtain tissue. Based on randomized controlled trials, PET or PET-CT scanning is recommended for staging and to detect unsuspected metastatic disease and avoid noncurative resections.

CONCLUSIONS

Since the last iteration of the staging guidelines, PET scanning has assumed a more prominent role both in its use prior to surgery and when evaluating for metastatic disease. Minimally invasive needle techniques to stage the mediastinum have become increasingly accepted and are the tests of first choice to confirm mediastinal disease in accessible lymph node stations. If negative, these needle techniques should be followed by surgical biopsy. All abnormal scans should be confirmed by tissue biopsy (by whatever method is available) to ensure accurate staging. Evidence suggests that more complete staging improves patient outcomes.