Utility of mediastinoscopy in clinical stage I lung cancers at risk for occult mediastinal nodal metastases

Efficacy of Mediastinoscopy in Patients With Isolated Mediastinal Lymphadenopathy

Background

Since its introduction in 1959 by Carlens (1), Mediastinoscopy has been, for long, used for assessment of the mediastinum (superior and middle) for establishing a histological diagnosis of mediastinal masses of undefined cause, and for Lung carcinomas staging. The use of Mediastinoscopy has been decreasing lately due to the introduction of other less invasive techniques (e.g., endoscopic ultrasound-directed fine needle aspiration cytology), however, it is still a cheap and effective tool that can be utilized in underprivileged centers.

Objective

To emphasize how does Mediastinoscopy plays an important role in confirming the clinical diagnosis of isolated mediastinal lymphadenopathy and reviewing its utility.

Methods

These are a retrospective analysis of medical charts for patients who underwent diagnostic cervical mediastinoscopy during (2012 - 2018) at a University hospital in Saudi Arabia. The included patients are presented with an isolated mediastinal lymph node enlargement, in the absence of underlying cause and was found to be significant (>1cm in its short axis) by computed tomography. The patient who had a known cause (e.g., Sarcoidosis) or were diagnosed via other tools, was excluded.

Results

Mediastinoscopy was performed on 56 patients, 38 of them were males (68%) and 18 females (32%), with a mean age of (37.5 ± 10 years). The patients' most common presenting symptoms were persistent cough (49%), fever of unknown origin (38%) and weight loss (36%) with an average of 2 symptoms per patient, while in 4 patients (7%) lymphadenopathy was discovered incidentally during the CT scan for other reasons. In addition, the histopathological examination of specimens obtained confirmed the most common diagnoses, Sarcoidosis in 17 patients (30%), lymphoma in 12 patients (21%) and TB in 10 patients (18%). The mean hospital stay (calculated from the day of the procedure) was (2.5 ± 4 days) including work up, with only one mortality (2%) and 3 patients (5%) had experienced post-operative complications.

Conclusion

The diagnostic Mediastinoscopy is both safe and efficient in the diagnosis of patients with isolated mediastinal lymphadenopathy, requiring a minimal surgical setup and is considered cost-effective. Therefore, it is a valid choice of investigating such cases in other underprivileged centers, as it reaches a tissue-based diagnosis, while other techniques are used for staging purposes.

Utility of PET-CT in non-small cell lung cancer clinical stage IB-IIA according to AJCC 8th edition staging system: an alternative to invasive mediastinal staging?

Objective

Mediastinal nodal staging in lung cancer is essential to determine treatment strategy and prognosis. There are controversies as to whether a mediastinal negative result in PET-CT may spare the invasive staging of the mediastinum. The main endpoint is to evaluate the negative predictive value (NPV) of PET-CT in non-small cell lung cancer (NSCLC) clinical stage IB-IIA without clinical nodal involvement. The secondary endpoint is to evaluate the prevalence of mediastinal and hilar nodal affection in this population.

Methods

We performed an observational descriptive study from January 2010 to January 2020, including 76 patients with clinical stage IB-IIA, who underwent pulmonary resection with systematic nodal sampling (pre-determined lymph node stations based on tumour location) for primary NSCLC. Clinically, nodal involvement was defined as any lymph node greater than 1 cm in the short axis on a CT or with metabolic uptake greater than 2.5 SUV on PET-CT. The prevalence of nodal metastases was recorded.

Results

Fifty six patients had clinical stage IB and 20 had clinical stage IIA. Mean tumour size was 3.74 ± 0.5 cm. Lobectomy was the resection procedure most frequently performed. Of the 76 patients with clinical N0 by PET-CT who underwent surgical resection, 10 (13.1%) were upstaged to pN1 and none were upstaged to pN2. NPV of PET-CT for overall nodal metastasis was 87% (95% CI: 0.79-0.94). NPV of PET-CT for N2 metastasis was 100%.

Conclusion

PET-CT might be an alternative to invasive mediastinal staging in patients with NSCLC clinical stage IB-IIA who are surgical candidates. Further prospective multi-institutional studies are necessary to verify the external validity of our study.

Prediction of Unexpected N2 Disease Associated With Clinical T1-2N0-1M0 Non-Small-Cell Lung Cancer

BACKGROUND

Despite the recent development of radiologic mediastinal staging modality, unexpected mediastinal lymph node metastasis still occurs. Preoperative accurate nodal staging is important to determine the optimal treatment. Therefore, this study aimed to identify predictors of unexpected N2 disease in non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Data from a multicenter database of 2802 patients with clinical T1-2N0-1M0 NSCLC who underwent anatomical segmentectomy or lobectomy were retrospectively analyzed. Unexpected N2 disease was defined as pathologic N2 disease with clinical N0 or N1. The predictive criteria of unexpected N2 disease were established on the basis of the multivariable analysis results of a derivation cohort of 2019 patients, and the criteria were further tested in a validation cohort of 783 patients.

RESULTS

In multivariable analyses, maximum standardized uptake value (SUV_max) of the primary tumor on 18-fluoro-2-deoxyglucose positron emission tomography/computed tomography (odds ratio, 1.072; 95% confidence interval, 1.018-1.129; P = .008) and clinical N1 (vs. clinical N0) disease (odds ratio, 5.40; 95% confidence interval, 1.829-15.94; P = .002) were independent predictors of unexpected N2 disease. The predictive criteria of unexpected N2 disease was defined as tumors with SUV_max of ≥ 3.1, determined by receiver operating characteristic curves, and clinical N1 disease. This criterion showed diagnostic accuracy of 90.6% (sensitivity 32.0%, specificity 94.5%) in the derivation cohort and 91.3% (sensitivity 32.6%, specificity 94.7%) in the validation cohort.

CONCLUSION

The predictive criteria of unexpected N2 disease (tumors with SUV_max of ≥ 3.1 and clinical N1) can be used to select candidates for preoperative invasive mediastinal staging in patients with clinical T1-2N0-1M0 NSCLC.

Comparison of the outcomes of sublobar resection and stereotactic body radiotherapy for stage T1-2N0M0 non-small cell lung cancer with tumor size ≤ 5 cm: a propensity score matching analysis

Background

Surgery and stereotactic body radiotherapy (SBRT) are both suitable treatment options for early stage Non-small cell lung cancer (NSCLC), which accounts for the majority of lung cancer. This study compared the outcomes of sublobar resection (SLR) and SBRT in patients with stage T1-2N0M0 NSCLC with tumor size ≤5 cm.

Methods

Patients with T1-2N0M0 lung cancer who underwent SLR or SBRT between January, 2012 and December, 2016 were included in this retrospective study. The survival outcomes and toxicity of the SLR and SBRT cohorts were compared using Kaplan-Meier survival plots. In a second exploratory analysis, propensity score matching (PSM) was applied to reduce selection bias between the two groups of patients.

Results

A total of 121 SLR and 109 SBRT cases were included. The average follow-up was 49.4 months. Prior to PSM, the 5-year overall survival (OS) and cancer-specific survival (CSS) rates in the SLR group (82.8% and 89.0%, respectively) were superior to those in the SBRT group (67.0% and 75.3%; P=0.001 and P=0.013, respectively). There were no statistically significant differences in the five-year locoregional control and disease-free survival (DFS) rates between the groups. PSM identified 40 patients from each treatment group who shared similar characteristics. At 5 years, the OS rates in the SLR and SBRT groups were comparable (79.9% vs. 66.5%, respectively; P=0.154). After PSM, the rates of CSS, locoregional control, and DFS were also similar between the groups (P=0.458, 0.369, and 0.698, respectively). In the SBRT group, one patient developed grade 3 radioactive pneumonitis. No grade >3 toxicities or treatment-related deaths occurred in either group.

Conclusions

SBRT may be an alternative option to SLR for patients who cannot tolerate lobectomy because of medical comorbidities and has a similar level of effectiveness.

Cost-effectiveness of endoscopic mediastinal staging

Lung cancer is the first cause of cancer-related mortality. Mediastinal staging has a main role in the definition of the therapeutic strategy in early-stage and locally-advanced non-small cell lung cancer (NSCLC). Non-invasive mediastinal staging with CT or PET imaging has relatively limited accuracy, and nodal biopsy may be required to reach adequate staging results. In the last two decades endoscopic techniques have been increasingly used in the field of mediastinal staging thanks to a reduced invasiveness and to the possibility of obtaining a more thorough assessment in comparison with surgical techniques. However, the ideal staging strategy is still a matter for debate, particularly considering the cost-effectiveness of the different approaches. Complication-rate, costs, impact on quality of life, time delay to treatment and survival of the different staging techniques still have to be analyzed in detail. Other issues to be discussed are the optimal combination of staging approaches and the influence of factors as the prevalence of nodal disease on the cost-effectiveness of the different methods. Future issues of invasive staging concern the possibility of extending the definition of nodal status to N1 intrapulmonary nodes, in the light of the development of new oncological and surgical therapeutic approaches.

The association of robotic lobectomy volume and nodal upstaging in non-small cell lung cancer

Robotic lung resection for lung cancer has gained popularity over the last 10 years. As with many surgical techniques, there are improvements in outcomes associated with increased operative volume. We sought to investigate lymph-node harvest and upstaging rates for robotic lobectomies performed at hospitals with varying robotic experience. The National Cancer Data Base was queried for patients with early stage non-small cell lung cancer who received lobectomy between 2010 and 2015. Hospitals were stratified into volume categories based on the number of robotic resections performed, as a proxy for robotic experience: low at  ≤ 12, low-middle 13-26, middle-high 27-52, and high volume at greater than or equal to 53. Lymph-node counts and nodal upstaging were compared among these volume categories. 8360 robotic lobectomies were performed. Mean lymph-node counts were for low, low-middle, middle-high, and high-volume robotic lobectomies were 9.8, 11.4, 12.9, and 12.6, respectively (P  < 0.001), while nodal-upstaging rates were 10.3%, 10.2%, 12.8%, and 13.4%, respectively (P < 0.001). Compared to low-volume hospitals, on multivariable analysis, high-volume robotic centers had increased nodal harvest (P < 0.001) and nodal-upstaging rates (P < 0.001). Robotic lobectomies performed at high-volume hospitals have greater lymph-node harvest and upstaging than low-volume hospitals.

Patient-reported Outcomes After the Treatment of Early Stage Non-small-cell Lung Cancer With Stereotactic Body Radiotherapy Compared With Surgery

INTRODUCTION

As there is increasing evidence for comparable survival after either stereotactic body radiotherapy (SBRT) or surgery for patients with stage I non-small-cell lung cancer (NSCLC), treatment impact on the quality of life (QoL) is essential for well-informed decision-making. Our previous work evaluated health utility between surgery and SBRT in stage I NSCLC. The aim of this secondary analysis is to directly compare QoL in the first year after SBRT and surgery.

MATERIALS AND METHODS

QoL was assessed at baseline and 3, 6, and 12 months after treatment. Two prospectively collected databases of patients with clinically proven stage I NSCLC, from 2 large hospitals in the Netherlands, were pooled (n = 306; 265 patients were treated with SBRT and 41 patients with surgery). To correct for confounding, propensity scores were calculated, to be selected for surgical treatment. A mixed model analysis was used to study differences in QoL between the 2 treatments.

RESULTS

The 41 surgical patients were matched to 41 SBRT patients on propensity score with a 1:1 ratio. At baseline, patients in the surgery group report a lower QoL compared with patients in the SBRT group. However, during the first year after treatment, no clinical meaningful differences were observed, except for role functioning, between patients treated using either modality.

CONCLUSION

This study comparing a matched cohort revealed no clinically significant differences in QoL following either SBRT or surgery for early stage NSCLC. These results support the hypothesis that surgery and SBRT are comparable treatments.

Invasive mediastinal staging for resected non-small cell lung cancer in a population-based cohort

OBJECTIVES

Invasive mediastinal nodal staging is recommended before curative-intent resection in patients with non-small cell lung cancer deemed at risk for mediastinal lymph node involvement. We evaluated the use and survival effect of preoperative invasive mediastinal nodal staging in a population-based non-small cell lung cancer cohort.

METHODS

We analyzed all curative-intent resections for non-small cell lung cancer from 2009 to 2018 in 11 hospitals in 4 contiguous Dartmouth Hospital Referral Regions, comparing patients who did not have invasive mediastinal nodal staging with those who did.

RESULTS

Preoperative invasive nodal staging was used in 22% of 2916 patients, including mediastinoscopy only in 13%, minimally invasive procedures only in 6%, and both approaches in 3%. Sixty-three percent of patients at risk for nodal disease (tumor size ≥3.0 cm/T2-T4; N1-N3 by computed tomography or positron-emission tomography-computerized tomography criterion) did not undergo invasive staging; among those who did not have invasive testing, 47% had at least 1 of the 3 clinical indications. Mediastinoscopy yielded a median of 3 lymph nodes and 2 nodal stations; 17% of mediastinoscopies and 31% of endobronchial ultrasound procedures yielded no lymph node material. Patients not invasively staged were more likely to have no nodes (6% vs 2%; P < .0001) and no mediastinal nodes (20% vs 11%; P < .0001) examined at surgery. Invasive staging was associated with significantly better survival (P = .0157).

CONCLUSIONS

More than a decade after the 2001 American College of Surgeons Patient Care Evaluation report, preoperative invasive nodal staging remains underused and of variable quality, but was associated with survival benefit in high-risk patients.

Stereotactic body radiation therapy for non-small cell lung cancer: A review

Stereotactic body radiation therapy (SBRT) is the treatment of choice for medically inoperable patients with early stage non-small cell lung cancer (NSCLC). A literature search primarily based on PubMed electronic databases was completed in July 2018. Inclusion and exclusion criteria were determined prior to the search, and only prospective clinical trials were included. Nineteen trials from 2005 to 2018 met the inclusion criteria, reporting the outcomes of 1434 patients with central and peripheral early stage NSCLC. Patient eligibility, prescription dose and delivery, and follow up duration varied widely. Three-years overall survival ranged from 43% to 95% with loco-regional control of up to 98% at 3 years. Up to 33% of patients failed distantly after SBRT at 3 years. SBRT was generally well tolerated with 10%-30% grade 3-4 toxicities and a few treatment-related deaths. No differences in outcomes were observed between conventionally fractionated radiation therapy and SBRT, central and peripheral lung tumors, or inoperable and operable patients. SBRT remains a reasonable treatment option for medically inoperable and select operable patients with early stage NSCLC. SBRT has shown excellent local and regional control with toxicity rates equivalent to surgery. Decreasing fractionation schedules have been consistently shown to be both safe and effective. Distant failure is common, and chemotherapy may be considered for select patients. However, the survival benefit of additional interventions, such as chemotherapy, for early stage NSCLC treated with SBRT remains unclear.

Mediastinal Staging in Non-Small Cell Lung Cancer

In the absence of distant metastases, lung cancer treatment is determined by the results of mediastinal lymph node staging. Occult mediastinal lymph node metastases can be missed by radiologic and needle-based staging methods. Aggressive staging of mediastinal lymph nodes improves staging accuracy. Improved accuracy of mediastinal lymph node staging results in more appropriate lung cancer treatment. Improved accuracy of mediastinal lymph node staging can improve stage-specific survival from lung cancer.

Undetected lymph node metastases in presumed early stage NSCLC SABR patients

INTRODUCTION

Stereotactic body radiation therapy (SBRT, also called stereotactic ablative body radiation SABR) is the treatment of choice for many patients with early-stage non-small cell lung cancer (NSCLC), including those who are unfit for surgery or refuse surgery.

AREAS COVERED

In an effort to develop optimal staging for the evaluation of SBRT candidates, we review the performance of available lymph node staging methods, as well as risk factors for lymph node involvement. Pubmed was searched to identify relevant literature. Current staging methods for NSCLC, including Positron Emission Tomography/Computed Tomography(PET/CT) and endobronchial ultra sound (EBUS), have limited sensitivities. Expert commentary: There are several factors, including primary tumor location, tumor size, and histology that are possibly associated with the sensitivity of PET/CT to detect mediastinal lymph node metastasis. Small lymph node metastases typically remain undetected by PET/CT. Therefore invasive nodal staging procedures are indicated for most presumed early-stage NSCLC patients, but these also have limited sensitivity. Occult lymph node metastasis is associated with adverse outcome in NSCLC. Moreover, there is overwhelming evidence that certain patients who have lymph node metastases detected at the time of surgery derive an overall survival benefit from adjuvant therapies. It remains to be determined if improved detection of lymph node metastases in SABR candidates can indeed improve prognosis.

PET-CT limitations in early stage non-small cell lung cancer: to whom more aggressive approach in radiotherapy and surgery should be directed?

This editorial comments on the study by Paravati et al., which reported on the incidence of occult regional lymph node metastases in PET-CT T1T2N0 non-small cell lung cancer (NSCLC) patients. A central location and the size of the tumor were shown to be the strongest predictors of the risk of occult nodal disease. Authors comment that in view of limitations of modern imaging, as well as the reported negative predictive value (NPV) of invasive staging methods, the choice of therapeutic options as the extent of surgery (lobectomy or sublobar resection) or radiotherapy [stereotactic body radiation therapy (SBRT) or conformal radiotherapy (RT) with some forms of elective nodal irradiation (ENI)] should consider tumor's characteristics and not be based only on imaging and invasive staging modalities.

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.

Endobronchial ultrasound elastography strain ratio for mediastinal lymph node diagnosis

Background

Ultrasound elastography is an imaging procedure that can assess the biomechanical characteristics of different tissues. The aim of this study was to define the diagnostic value of the endobronchial ultrasound (EBUS) elastography strain ratio of mediastinal lymph nodes in patients with a suspicion of lung cancer. The diagnostic values of the strain ratios were compared with the EBUS brightness mode (B-mode) features of selected mediastinal lymph nodes and with their cytological diagnoses.

Patients and methods

This prospective, single-centre study enrolled patients with an indication for biopsy and mediastinal staging after a non-invasive diagnostic workup of a lung tumour. EBUS with standard B-mode evaluation and elastography with strain ratio measurement were performed before endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA).

Results

Thirty-three patients with 80 suspicious mediastinal lymph nodes were included. Malignant infiltration was confirmed in 34 (42.5%) lymph nodes. The area under the receiver operating characteristic curve for the strain ratio was 0.87 (p < 0.0001). At a strain ratio ≥ 8, the accuracy for malignancy prediction was 86.25% (sensitivity 88.24%, specificity 84.78%, positive predictive value [PPV] 81.08%, negative predictive value [NPV] 90.70%). The strain ratio is more accurate than conventional B-mode EBUS modalities for differentiating between malignant and benign lymph nodes.

Conclusions

EBUS-guided elastography with strain ratio assessment can distinguish malignant from benign mediastinal lymph nodes with greater accuracy than conventional EBUS modalities. This new method may reduce the number of mediastinal EBUS-TBNAs and thus reduce the invasiveness and expense of mediastinal staging in patients with non-small lung cancer (NSCLC).