What Exactly Is a Centrally Located Lung Tumor? Results of an Online Survey

Pulmonary endoscopy - central to an interventional pulmonology program

INTRODUCTION

Pulmonary endoscopy occupies a central role in Interventional Pulmonology and is frequently the mainstay of diagnosis of respiratory disease, in particular lung malignancy. Older techniques such as rigid bronchoscopy maintain an important role in central airway obstruction. Renewed interest in the peripheral pulmonary nodule is driving major advances in technologies to increase the diagnostic accuracy and advance new potential endoscopic therapeutic options.

AREAS COVERED

This paper describes the role of pulmonary endoscopy, in particular ultrasound in the diagnosis and staging of lung malignancy. We will explore the recent expansion of ultrasound to include endoscopic ultrasound - bronchoscopy (EUS-B) and combined ultrasound (CUS) techniques. We will discuss in detail the advances in the workup of the peripheral pulmonary nodule.We performed a non-systematic, narrative review of the literature to summarize the evidence regarding the indications, diagnostic yield, and safety of current bronchoscopic sampling techniques.

EXPERT OPINION

EBUS/EUS-B has revolutionized the diagnosis and staging of thoracic malignancy resulting in more accurate assessment of the mediastinum compared to mediastinoscopy alone, thus reducing the rate of futile thoracotomies. Although major advances in the assessment of the peripheral pulmonary nodule have been made, the role of endoscopy in this area requires further clarification and investigation.

Ultrathin Bronchoscopy Without Virtual Navigation for Diagnosis of Peripheral Lung Lesions

BACKGROUND

The increasing incidence of encountering lung nodules necessitates an ongoing search for improved diagnostic procedures. Various bronchoscopic technologies have been introduced or are in development, but further studies are needed to define a method that fits best in clinical practice and health care systems.

RESEARCH QUESTION

How do basic bronchoscopic tools including a combination of thin (outer diameter 4.2 mm) and ultrathin bronchoscopes (outer diameter 3.0 mm), radial endobronchial ultrasound (rEBUS) and fluoroscopy perform in peripheral pulmonary lesion diagnosis?

STUDY DESIGN AND METHODS

This is a retrospective review of the performance of peripheral bronchoscopy using thin and ultrathin bronchoscopy with rEBUS and 2D fluoroscopy without a navigational system for evaluating peripheral lung lesions in a single academic medical center from 11/2015 to 1/2021. We used a strict definition for diagnostic yield and assessed the impact of different variables on diagnostic yield, specifically after employment of the ultrathin bronchoscope. Logistic regression models were employed to assess the independent associations of the most impactful variables.

RESULTS

A total of 322 patients were included in this study. The median of the long axis diameter was 2.2 cm and the median distance of the center of the lesion from the visceral pleural surface was 1.9 cm. Overall diagnostic yield was 81.3% after employment of the ultrathin bronchoscope, with more detection of concentric rEBUS views (93% vs. 78%, p < 0.001). Sensitivity for detecting malignancy also increased from 60.5% to 74.7% (p = 0.033) after incorporating the ultrathin scope into practice, while bronchus sign and peripheral location of the lesion were not found to affect diagnostic yield. Concentric rEBUS view, solid appearance, upper/middle lobe location and larger size of the nodules were found to be independent predictors of successful achievement of diagnosis at bronchoscopy.

INTERPRETATION

This study demonstrates a high diagnostic yield of biopsy of lung lesions achieved by utilization of thin and ultrathin bronchoscopes. Direct visualization of small peripheral airways with simultaneous rEBUS confirmation increased localization rate of small lesions in a conventional bronchoscopy setting without virtual navigational planning.

Bronchial washing fluid sequencing is useful in the diagnosis of lung cancer with necrotic tumor

BACKGROUND

Early-stage lung cancers detected by low-dose computed tomography (CT) often require confirmation through invasive procedures due to the absence of endobronchial lesions. This study assesses the diagnostic utility of bronchial washing fluid (BW) sequencing, a less invasive alternative, aiming to identify patient characteristics most suited for this approach.

METHODS

From June 2017 to March 2018, we conducted a prospective cohort study by enrolling patients with incidental lung lesions suspected of early-stage lung cancer at two independent hospitals, and 114 were diagnosed with lung cancer while 50 were diagnosed with benign lesions. BW sequencing was performed using a targeted gene panel, and the clinical characteristics of patients detected with cancer through sequencing were identified.

RESULTS

Malignant cells were detected in 33 patients (28.9 %) through BW cytology. By applying specificity-focused mutation criteria, BW sequencing classified 42 patients (36.8 %) as having cancer. Among the cancer patients who were BW sequencing positive and BW cytology negative, 15 patients (75.0 %) showed necrosis on CT. The sensitivity of BW sequencing was particularly enhanced in patients with necrotic tumors, reaching 75 %.

CONCLUSIONS

BW sequencing presents a viable, non-invasive diagnostic option for early-stage lung cancer, especially valuable in patients with necrotic lesions. By potentially reducing the reliance on more invasive diagnostic procedures, this method could streamline clinical workflows, decrease patient burden, and improve overall diagnostic efficiency.

Clinical and Bronchoscopy Assessment in Diagnosing the Histopathology Type of Primary Central Lung Tumors

Background

The location and type of a tumor influence the prognosis of lung cancer. Primary Central Lung Tumors (PCLTs) are correlated with poor prognoses and certain histologic types. This study aimed to present a comprehensive exploration of clinical and bronchoscopic assessments for diagnosing the histopathology types of PCLTs and identified the factors associated with certain histologic types.

Methods

This was an observational cross-sectional study of PCLTs, defined as tumors in direct contact with hilar structures or located within the inner two-thirds of the hemithorax. We gathered demographic and clinical data, as well as data on bronchoscopy assessment and histopathology type. Tumor stage, symptoms of superior vena cava syndrome, and enlargement of lymph nodes in the paratracheal and subcarinal regions were also documented.

Results

Of the 895 patients, 37.87% had primary lung tumors, with 17.76% classified as PCLTs. Notably, PCLT cases exhibited a higher proportion of stage III (28.9% vs. 18.3%; p = 0.03) and Squamous Cell Carcinoma (SCC) histopathology (37.1% vs. 17.2%; p = 0.00) compared with non-PCLT cases. Bronchoscopic findings in PCLTs revealed a predilection for central airway masses (25.2%) and compressive distal airway stenosis (25.2%). Subgroup analysis of 159 PCLT cases identified 37.10% as SCC. Multivariate analysis underscored that intraluminal masses predict central SCC (odds ratio 2.075, 95% confidence interval 1.07-3.99; p = 0.028).

Conclusion

The proportion of stage III, SCC histopathological type, and intraluminal lesions was higher in patients with PCLT than in non-PCLT cases. The presence of intraluminal lesions can predict the histopathological type of SCC in patients with PCLTs.

Long-Term Follow-Up after Laser-Assisted Pulmonary Metastasectomy Shows Complete Lung Function Recovery

Preserving maximum lung function is a fundamental goal of parenchymal-sparing pulmonary laser surgery. Long-term studies for follow-up of lung function after pulmonary laser metastasectomy are lacking. However, a sufficient postoperative lung function is essential for quality of life and reduces potential postoperative complications. In this study, we investigate the extent of loss in lung function following pulmonary laser resection after three, six, and twelve months. We conducted a retrospective analysis using a prospective database of 4595 patients, focusing on 126 patients who underwent unilateral pulmonary laser resection for lung metastases from 1996 to 2022 using a 1318 nm Nd:YAG laser or a high-power pure diode laser. Results show that from these patients, a median of three pulmonary nodules were removed, with 75% presenting central lung lesions and 25% peripheral lesions. The median preoperative FEV1 was 98% of the predicted value, decreasing to 71% postoperatively but improving to 90% after three months, 93% after six months, and 96% after twelve months. Statistical analysis using the Friedman test indicated no significant difference in FEV1 between preoperative levels and those at six and twelve months post-surgery. The findings confirm that pulmonary laser surgery effectively preserves lung function over time, with patients generally regaining their preoperative lung function within a year, regardless of the metastases' location.

Reduction of Blood Loss by Means of the Cavitron Ultrasonic Surgical Aspirator for Thoracoscopic Salvage Anatomic Lung Resections

In centrally located lung tumors, salvage pulmonary resections pose challenges due to adhesions between the pulmonary parenchyma, chest wall, and hilum. This study aimed to investigate the surgical outcomes associated with Cavitron Ultrasonic Surgical Aspirator (CUSA) usage in thoracoscopic salvage pulmonary resections. Patients with centrally located advanced-stage lung tumors who underwent salvage anatomic resections following systemic or radiotherapy were included. They were categorized into CUSA and non-CUSA groups, and perioperative parameters and surgical outcomes were analyzed. Results: The study included 7 patients in the CUSA group and 15 in the non-CUSA group. Despite a longer median surgical time in the CUSA group (3.8 h vs. 6.0 h, p = 0.021), there was a significant reduction in blood loss (100 mL vs. 250 mL, p = 0.014). Multivariate analyses revealed that the use of CUSA and radiotherapy had opposing effects on blood loss (β: -296.7, 95% CI: -24.8 to -568.6, p = 0.034 and β: 282.9, 95% CI: 19.7 to 546.3, p = 0.037, respectively). In conclusion, while using CUSA in the salvage anatomic resection of centrally located lung cancer may result in a longer surgical time, it is crucial in minimizing blood loss during the procedure.

Spread through Air Spaces (STAS) in Solitary Pulmonary Metastases from Colorectal Cancer (CRC)

BACKGROUND

Spread through air spaces (STAS) is a recently described route of tumor invasion associated with poor prognosis in primary lung cancer. Aim of this study was to investigate the presence of STAS and to assess its prognostic significance in patients undergoing pulmonary metastasectomy (PM) for solitary metastases from colorectal cancer (CRC).

MATERIALS AND METHODS

All 49 CRC patients (30 male and 19 female, median age 66 years) who underwent PM between January 2008 and December 2015 were retrospectively analyzed.

RESULTS

STAS was identified in 26.5% (n = 13) of resected specimens. Location of pulmonary lesions (central vs. peripheral) was assessed based on the available computed tomography imaging (n = 47, 96%). STAS was detected in all five patients with central metastases (100%) versus 7 of 42 (17%) with peripheral metastases (p = 0.0001). Locoregional recurrence occurred in STAS-positive patients (n = 4 of 13 vs. n = 0 of 36), all STAS-negative patients remained recurrence-free (p = 0.003). Median number of alveoli with STAS involvement was four (range from 2 to 9). There was statistically positive relationship between the number of alveoli invaded with STAS and locoregional recurrence of metastases (p = 0.0001). The presence of STAS is not a factor affecting the 5-year overall survival rate (p = 0.6651).

CONCLUSION

We identified STAS as a frequent finding in resected CRC lung metastases and found insignificant association with outcome.

Prognostic significance of location index in resected T1-sized early-stage non-small cell lung cancer

BACKGROUND

While the central location is a known adverse prognostic factor in lung cancer, a precise definition of central lung cancer has not yet emerged.

PURPOSE

To determine the prognostic significance of central lung cancer (defined by location index) in resected T1-sized early-stage non-small cell lung cancer (NSCLC).

MATERIAL AND METHODS

Patients with resected T1-sized early-stage NSCLC between 2010 and 2015 at a single tertiary cancer center were retrospectively reviewed. Central lung cancer was defined by a location index of the second tertile or less. Kaplan-Meier analysis with log-rank test and multivariable Cox regression analysis were performed to analyze the relationship between central lung cancer and the prognosis of relapse-free survival (RFS) and overall survival (OS). Inter-observer agreement was assessed using Cohen's kappa value and intraclass correlation coefficient (ICC).

RESULTS

Overall, 289 patients (169 men; median age 65 years; interquartile range 58-70 years) were evaluated. Central lung cancer (defined by location index) was adversely associated with RFS (P = 0.005) and OS (P = 0.01). Multivariable Cox regression analysis showed that central lung cancer was independently associated with poor RFS (adjusted hazard ratio 1.91; 95% confidence interval [CI] 1.12-3.24; P = 0.017) and OS (adjusted hazard ratio 1.69; 95% CI 1.04-2.74; P = 0.033). Location index demonstrated excellent inter-observer agreement (Cohen's kappa value 0.88; 95% CI 0.82-0.93) with a high ICC (0.98; 95% CI 0.97-0.98).

CONCLUSION

Central lung cancer defined by a location index of the second tertile or lower is an independent adverse prognostic factor in resected T1-sized early-stage NSCLC.

LobE-Specific lymph node diSsectiON for clinical early-stage non-small cell lung cancer: protocol for a randomised controlled trial (the LESSON trial)

INTRODUCTION

Lung cancer was the most common malignancy and the leading cause of cancer-related death in China or worldwide, and surgery is still the preferred treatment for early-stage non-small cell lung cancer (NSCLC). The pattern of lymph node metastasis was found potentially lobe specific, and thus, lobe-specific lymph node dissection (L-SLND) was proposed to be an alternative to systematic lymph node dissection (SLND) for the treatment of early-stage NSCLC.

METHODS AND ANALYSIS

The LobE-Specific lymph node diSsectiON trial is a single-institutional, randomised, double-blind and parallel controlled trial to investigate the feasibility of L-SLND in clinically diagnosed stage IA1-2 NSCLC with ground-glass opacity components (≥50%). The intraoperative frozen section examination of surgical tissues confirms the histological type of NSCLC. We hypothesise that L-SLND (experimental group) is not inferior to SLND (control group) and intend to include 672 participants for the experimental group and 672 participants for the control group with a follow-up duration of 60 months. The primary outcomes are 5-year disease-free survival and 5-year overall survival. The secondary outcomes are metastatic lymph node ratio, postoperative complication incidence and mortality, duration of operation, duration of anaesthesia (min), the volume of bleeding (mL) and drainage volume. The intention-to-treat analysis would be performed in the trial.

ETHICS AND DISSEMINATION

This trial was approved by the ethics committee on biomedical research, West China Hospital of Sichuan University (2021-332). Informed consent would be obtained from all participants, and dissemination activities would include academic conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

This trial was registered in the Chinese Clinical Trial Registry, ChiCTR2100048415.

Percutaneous Image-Guided Biopsy for a Comprehensive Hybridization Capture-Based Next-Generation Sequencing in Primary Lung Cancer: Safety, Efficacy, and Predictors of Outcome

Introduction

To evaluate factors associated with successful comprehensive genomic sequencing of image-guided percutaneous needle biopsies in patients with lung cancer using a broad hybrid capture-based next-generation sequencing assay (CHCA).

Methods

We conducted a single-institution retrospective review of image-guided percutaneous transthoracic needle biopsies from January 2018 to December 2019. Samples with confirmed diagnosis of primary lung cancer and for which CHCA had been attempted were identified. Pathologic, clinical data and results of the CHCA were reviewed. Covariates associated with CHCA success were tested for using Fisher's exact test or Wilcoxon ranked sum test. Logistic regression was used to identify factors independently associated with likelihood of CHCA success.

Results

CHCA was requested for 479 samples and was successful for 433 (91%), with a median coverage depth of 659X. Factors independently associated with lower likelihood of CHCA success included small tumor size (OR = 0.26 [95% confidence interval (CI): 0.11-0.62, p = 0.002]), intraoperative inadequacy on cytologic assessment (OR = 0.18 [95% CI: 0.06-0.63, p = 0.005]), small caliber needles (≥20-gauge) (OR = 0.22 [95% CI: 0.10-0.45, p < 0.001]), and presence of lung parenchymal abnormalities (OR = 0.12 [95% CI: 0.05-0.25, p < 0.001]). Pneumothorax requiring chest tube insertion occurred in 6% of the procedures. No grade IV complications or procedure-related deaths were reported.

Conclusions

Percutaneous image-guided transthoracic needle biopsy is safe and has 91% success rate for CHCA in primary lung cancer. Intraoperative inadequacy, small caliber needle, presence of parenchymal abnormalities, and small tumor size (≤1 cm) are independently associated with likelihood of failure.

Partitioning the lung field based on the depth ratio in three-dimensional space

Background

To explore the feasibility of the depth ratio method partitioning the lung parenchyma and the depth distribution of lung nodules in pulmonary segmentectomy.

Methods

Based on the measurement units, patients were allocated to the chest group, the lobar group, and the symmetrical 3 sectors group. In each unit, the center of the respective bronchial cross-section was set as the starting point (O). Connecting the O point with the center of the lesion (A) and extending to the endpoint (B) on the pleural, the radial line (OB) was trisected to divide the outer, middle, and inner regions. The depth ratio and relevant regional distribution were simultaneously verified using 2-dimensional (2D) coronal, sagittal, and axial computed tomography images and 3-dimensional (3D) reconstruction images.

Results

Two hundred and nine patients were included in this study. The median age was 53 (IQR, 44.5–62) years and 64 were males. The intra-group consistency of the depth ratio region partition was 100%. The consistency of the inter-group region partition differed among the three groups (Kappa values 0.511, 0.517, and 0.923). The chest group, lobar group, and symmetrical 3 sectors group had 69.4%, 26.3%, and 4.8% mediastinum disturbance, respectively (P<0.001).

Conclusions

The depth ratio method in the symmetrical 3 sectors of the lung maximally eliminated the disturbance of the mediastinal structures and more accurately trisected the lung parenchymal in 3D space. Sublobar resection based on subsegments strategy is feasible for outer 2/3 pulmonary nodules when depth ratio is used as the measurement method.

Definitions of Central Tumors in Radiologically Node-Negative, Early-Stage Lung Cancer for Preoperative Mediastinal Lymph Node Staging: A Dual-Institution, Multireader Study

BACKGROUND

Definitions for central lung cancer (CLC) have been ambiguous in guidelines, causing difficulty in selecting candidates for invasive mediastinal staging among patients with radiologically node-negative, early-stage lung cancer.

RESEARCH QUESTION

What is the optimal definition for CLC that is robust to interreader and institutional variation to select candidates for invasive mediastinal staging among those with clinical T1N0M0 lung cancer?

STUDY DESIGN AND METHODS

Two retrospective cohorts were evaluated for the associations of central lung cancer according to 13 definitions based on chest CT scan with occult nodal metastasis. Univariate and multivariate ordinal logistic regression analyses were performed with the pathologic N category as an ordinal outcome. Robust definitions, which retained statistical significance across multireader, dual-institutional datasets, were identified. For these definitions, binary diagnostic performance and interreader agreement were investigated.

RESULTS

In the two cohorts, 807 patients (median age, 63 years; interquartile range [IQR], 56-71 years; 410 women; 33 pN1, 48 pN2, and 1 pN3) and 510 patients (median age, 65 years; IQR, 58-71 years; 267 women; 33 pN1, 20 pN2, and no pN3) were included, respectively. Three definitions robust to interreader variation and dataset heterogeneity were identified: definition 7 (concentric lines arising from the midline, inner one-third, medial margin; adjusted OR, 2.01; 95% CI, 1.13-3.51; P = .02), definition 10 (location index-based inner one-third, center; adjusted OR, 3.60; 95% CI, 1.49-8.25; P = .003), and definition 12 (location index-based inner one-third, medial margin; adjusted OR, 3.57; 95% CI, 1.91-6.52; P < .001). Definition 12 showed higher interreader agreement than definition 7 (Cohen κ, 0.80 vs 0.66; P = .005). Nevertheless, the sensitivity and positive predictive value of the three definitions were < 50%.

INTERPRETATION

Three definitions exhibited robust associations with occult nodal metastasis. However, selecting candidates for invasive mediastinal staging solely based on a central tumor location would be suboptimal.

Differences in detection patterns, characteristics, and outcomes of central and peripheral lung cancers in low-dose computed tomography screening

Background

Although low-dose computed tomography (LDCT) screening is known to be effective for the detection of lung cancers localized in peripheral lung regions at a curable stage, limited data is available regarding the characteristics and outcomes of central lung cancers diagnosed in a screening cohort. This study aimed to determine whether LDCT screening could effectively detect central lung cancers at an early stage and offer survival benefits.

Methods

We analyzed 52,615 adults who underwent lung cancer screening with LDCT between May 2003 and Dec 2019 at a tertiary center in South Korea. Characteristics and outcomes of those diagnosed with lung cancer, stratified by screen-detection status and cancer location, were evaluated.

Results

A total of 352 individuals (281 screen-detected, 71 non-screen-detected) were diagnosed with lung cancer. Compared to screen-detected cancers, non-screen-detected cancers tended to be centrally-located (11.4% vs. 64.8%, P<0.001). Most non-screen-detected central cancers (89.1%) had a negative result on prior LDCT screening. Multivariable regression analyses revealed that for peripheral cancers, screen-detection was associated with a significantly lower probability of diagnosis at an advanced stage [III/IV, odds ratio (OR) =0.15, 95% confidence interval (CI): 0.05-0.45] and mortality [hazard ratio (HR) =0.33, 95% CI: 0.13-0.84]; however, the association was insignificant for central cancers. For screen-detected cancers, central location, compared to peripheral location, was significantly associated with a higher risk of diagnosis at an advanced stage (OR =20.83, 95% CI: 6.67-64.98) and mortality (HR =4.98, 95% CI: 2.26-10.97).

Conclusions

Unlike for peripheral cancers, LDCT screening did not demonstrate an improvement in outcomes of central lung cancers, indicating an important limitation of LDCT screening and the need for developing novel modalities to screen and treat central lung cancer.

Quantification of the spatial distribution of primary tumors in the lung to develop new prognostic biomarkers for locally advanced NSCLC

The anatomical location and extent of primary lung tumors have shown prognostic value for overall survival (OS). However, its manual assessment is prone to interobserver variability. This study aims to use data driven identification of image characteristics for OS in locally advanced non-small cell lung cancer (NSCLC) patients. Five stage IIIA/IIIB NSCLC patient cohorts were retrospectively collected. Patients were treated either with radiochemotherapy (RCT): RCT1* (n = 107), RCT2 (n = 95), RCT3 (n = 37) or with surgery combined with radiotherapy or chemotherapy: S1* (n = 135), S2 (n = 55). Based on a deformable image registration (MIM Vista, 6.9.2.), an in-house developed software transferred each primary tumor to the CT scan of a reference patient while maintaining the original tumor shape. A frequency-weighted cumulative status map was created for both exploratory cohorts (indicated with an asterisk), where the spatial extent of the tumor was uni-labeled with 2 years OS. For the exploratory cohorts, a permutation test with random assignment of patient status was performed to identify regions with statistically significant worse OS, referred to as decreased survival areas (DSA). The minimal Euclidean distance between primary tumor to DSA was extracted from the independent cohorts (negative distance in case of overlap). To account for the tumor volume, the distance was scaled with the radius of the volume-equivalent sphere. For the S1 cohort, DSA were located at the right main bronchus whereas for the RCT1 cohort they further extended in cranio-caudal direction. In the independent cohorts, the model based on distance to DSA achieved performance: AUC_RCT2 [95% CI] = 0.67 [0.55–0.78] and AUC_RCT3 = 0.59 [0.39–0.79] for RCT patients, but showed bad performance for surgery cohort (AUC_S2 = 0.52 [0.30–0.74]). Shorter distance to DSA was associated with worse outcome (p = 0.0074). In conclusion, this explanatory analysis quantifies the value of primary tumor location for OS prediction based on cumulative status maps. Shorter distance of primary tumor to a high-risk region was associated with worse prognosis in the RCT cohort.

Radiological and clinical features of screening-detected pulmonary invasive mucinous adenocarcinoma

 

OBJECTIVES

The current understanding of pulmonary invasive mucinous adenocarcinoma is largely based on studies of advanced stage patients and data about early-stage invasive mucinous adenocarcinoma are sparse. We evaluated the radiological and clinical features of screening-detected early-stage invasive mucinous adenocarcinoma (SD-IMA).

METHODS

Data from 91 patients who underwent surgical treatment for SD-IMA (≤3 cm) from 2013 to 2019 were reviewed retrospectively. Data on radiological characteristics, clinicopathological findings, recurrence and survival were obtained. Disease-free survival rate was analysed.

RESULTS

Radiologically, SD-IMAs presented as a pure ground-glass nodule (6.6%), part-solid nodule (38.5%) or solid (54.9%). Dominant locations were both lower lobes (74.7%) and peripheral area (93.4%). The sensitivity of percutaneous needle biopsy was 78.1% (25/32). Lobectomy was performed in 70 (76.9%) patients, and sublobar resection in 21 (23.1%) patients. Seventy-three (80.2%), 15 (16.5%) and 3 (3.3%) patients had pathological stage IA, IB and IIB or above, respectively. Seven patients developed recurrence, and 3 died due to disease progression. Pleural seeding developed exclusively in 2 patients who underwent needle biopsy. The 5-year disease-free survival rate was 89.4%. The disease-free survival rates at 5 years were 86.3% in the lobectomy group and 100% in the sublobar resection group.

CONCLUSIONS

SD-IMAs were mostly radiologically invasive nodules. SD-IMAs showed favourable prognosis after surgical treatment.

Anatomic resection has superior long-term survival compared with wedge resection for second primary lung cancer after prior lobectomy

OBJECTIVES

The extent of surgical resection for early-stage second primary lung cancer (SPLC) in patients with a previous lobectomy is unclear. We sought to compare anatomic lung resections (lobectomy and segmentectomy) and wedge resections for small peripheral SPLC using a population-based database.

METHODS

The Surveillance, Epidemiology and End Results database was queried for all patients with ≤2 cm peripheral SPLC diagnosed between 2004 and 2015 who underwent prior lobectomy for the first primary and surgical resection only for the SPLC. American College of Chest Physicians guidelines were used to classify SPLC. Kaplan-Meier analysis and multivariable Cox regression were used to compare overall survival.

RESULTS

A total of 356 patients met the inclusion criteria with 203 (57%) treated with wedge resection and 153 (43%) treated with anatomic resection. Significantly better median survival was observed with anatomic resection than with wedge resection using a Kaplan-Meier analysis (124 vs 63 months; P < 0.001). With multivariable Cox regression, improved long-term survival was observed for anatomic resection (hazard ratio: 0.44, confidence interval: 0.27-0.70; P = 0.001). Improvement in survival was demonstrated with wedge resection when lymph node sampling was done. Lastly, we calculated the average treatment effect on the treated with inverse probability weighting for a subgroup of patients and found that those with wedge resection and lymph node sampling had shorter long-term survival times.

CONCLUSIONS

Anatomic resections may provide better long-term survival than wedge resections for patients with early-stage peripheral SPLC after prior lobectomy. Significant improvement in survival was observed with wedge resection for SPLC when adequate lymph node dissection was performed.

How do we Classify a Central Tumor? Results of a Multidisciplinary Survey from the SEPAR Thoracic Oncology Area

INTRODUCTION

In patients with non-small cell lung cancer (NSCLC) and normal mediastinal imaging tests, centrally located tumors have greater occult mediastinal involvement. Clinical guidelines, therefore, recommend invasive mediastinal staging in this situation. However, definitions of centrality in the different guidelines are inconsistent. The SEPAR Thoracic Oncology area aimed to evaluate the degree of familiarity with various concepts related to tumor site among professionals who see patients with NSCLC in Spain.

METHODS

A questionnaire was distributed to members of Spanish medical societies involved in the management of NSCLC, structured according to the 3 aspects to be evaluated: 1) uniformity in the definition of central tumor location; 2) uniformity in the classification of lesions that extend beyond dividing lines; and 3) ability to delineate lesions in the absence of dividing lines.

RESULTS

A total of 430 participants responded. The most voted definition of centrality was «lesions in contact with hilar structures» (49.7%). The lines most often chosen to delimit the hemitorax were concentric hilar lines (89%). Most participants (92.8%) classified tumors according to the side of the dividing line that contained most of their volume. Overall, 78.6% were able to correctly classify a central lesion in the absence of dividing lines.

CONCLUSIONS

In our survey, the most widely accepted definition of centrality is not one of the proposals specified in the clinical guidelines. The results reflect wide variability in the classification of tumor lesions.

Predicting Lymph Node Metastasis in Non-small Cell Lung Cancer: Prospective External and Temporal Validation of the HAL and HOMER Models

BACKGROUND

Two models, the Help with the Assessment of Adenopathy in Lung cancer (HAL) and Help with Oncologic Mediastinal Evaluation for Radiation (HOMER), were recently developed to estimate the probability of nodal disease in patients with non-small cell lung cancer (NSCLC) as determined by endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA). The objective of this study was to prospectively externally validate both models at multiple centers.

RESEARCH QUESTION

Are the HAL and HOMER models valid across multiple centers?

STUDY DESIGN AND METHODS

This multicenter prospective observational cohort study enrolled consecutive patients with PET-CT clinical-radiographic stages T1-3, N0-3, M0 NSCLC undergoing EBUS-TBNA staging. HOMER was used to predict the probability of N0 vs N1 vs N2 or N3 (N2|3) disease, and HAL was used to predict the probability of N2|3 (vs N0 or N1) disease. Model discrimination was assessed using the area under the receiver operating characteristics curve (ROC-AUC), and calibration was assessed using the Brier score, calibration plots, and the Hosmer-Lemeshow test.

RESULTS

Thirteen centers enrolled 1,799 patients. HAL and HOMER demonstrated good discrimination: HAL ROC-AUC = 0.873 (95%CI, 0.856-0.891) and HOMER ROC-AUC = 0.837 (95%CI, 0.814-0.859) for predicting N1 disease or higher (N1|2|3) and 0.876 (95%CI, 0.855-0.897) for predicting N2|3 disease. Brier scores were 0.117 and 0.349, respectively. Calibration plots demonstrated good calibration for both models. For HAL, the difference between forecast and observed probability of N2|3 disease was +0.012; for HOMER, the difference for N1|2|3 was -0.018 and for N2|3 was +0.002. The Hosmer-Lemeshow test was significant for both models (P = .034 and .002), indicating a small but statistically significant calibration error.

INTERPRETATION

HAL and HOMER demonstrated good discrimination and calibration in multiple centers. Although calibration error was present, the magnitude of the error is small, such that the models are informative.

Assessing Differences in Lymph Node Metastasis Based Upon Sex in Early Non-Small Cell Lung Cancer

BACKGROUNDS

Whether sex has any impact on the risk of lymph node (LN) metastasis (LNM) in patients with early-stage non-small cell lung cancer (NSCLC) remains controversial. Therefore, we aimed to objectively compared the risk of LNM between female and male patients with early-stage NSCLC so as to figure out whether sex-different extent of surgery may be justified for treating these patients.

METHODS

We retrospectively collected clinical data of patients undergoing lobectomy or segmentectomy with systematic hilar and mediastinal LN dissection for clinical stage IA peripheral NSCLC from June 2014 to April 2019. Both multivariate logistic regression analysis and propensity score-matched(PSM) analysis were applied to compare the risk of LNM between female and male patients.

RESULTS

We finally included a total of 660 patients for analysis. In the analysis of unmatched cohorts, there was no significant different rate of LNM (12.4% Vs 13.9%, P=0.556), hilar/intrapulmonary LNM (8.4% Vs 10.7%, P=0.318) and mediastinal LNM(7.9% Vs 7.5%, P=0.851) between female and male patients. In the multivariate analysis, sex was not found to be an independent predictor of LN in these patients. Moreover, in the analysis of well-matched cohorts generated by PSM analysis, there was still no significant different rate of LNM (13.8% Vs 13.4%, P=0.892), hilar/intrapulmonary LNM (9.1% Vs 11.2%, P=0.442) and mediastinal LNM (9.1% Vs 6.5%, P=0.289) between female and male patients.

CONCLUSIONS

Sex was not an independent predictor of LNM in early-stage NSCLC and there is no sufficient evidence justifying for sex-different extent of surgical resection for these patients.

Surgical Consideration Based on Lymph Nodes Spread Patterns in Patients with Peripheral Right Middle Non-small Cell Lung Cancer 3 cm or Less

BACKGROUND

The optimal extent of lung resection and lymph nodes dissection for peripheral early-stage right middle non-small cell lung cancer (NSCLC) still remains controversial. In this study, we analyzed the patterns of lymph nodes metastasis (LNM) of patients with peripheral right middle NSCLC ≤ 3 cm, aiming to provide evidences for surgical choice for early-stage peripheral right middle lobe NSCLC.

METHODS

We retrospectively investigated the clinical and pathological data of patients diagnosed with peripheral right middle lobe NSCLC ≤ 3 cm between January 2015 and December 2019. The LNM patterns were analyzed by tumor size.

RESULTS

A total of 60 patients were included for analysis. The tumor size was preoperatively divided as follows: ≤ 1 cm (13 patients); > 1 cm but ≤ 2 cm (36 patients); > 2 cm but ≤ 3 cm (11 patients). Fifty-four patients were categorized as N0 group, 1 patient as N1 group, and 5 patients as N2 group. In the upper zone, 3 patients were found to have LNM. In the subcarinal zone, another 3 patients had LNM. But the lymph nodes of all these patients were negative in the lower zone. In station 10, 1 patient (1.67%) was found to have LNM, while in station 11-13, 2 patients (3.33%) were found to have LNM.

CONCLUSION

For the right middle lobe peripheral NSCLC ≤ 1 cm, sublobar resection with lymph node sampling may be a feasible treatment. For cancers > 1 cm but ≤ 2 cm, lobectomy with lobe-specific lymph node dissection (especially station 2R and 4R) may be a preferred choice. For tumors > 2 cm but ≤ 3 cm, lobectomy with systematic lymph node dissection may still be the standard of care.

Central Tumor Location at Chest CT Is an Adverse Prognostic Factor for Disease-Free Survival of Node-Negative Early-Stage Lung Adenocarcinomas

Background The prognostic value of primary tumor location in the central lung is unclear because of heterogeneity in definitions of central lung cancer (CLC). Purpose To (a) validate the prognostic value of two recently proposed definitions of CLC by using a method designed to offset the shortcomings of existing evidence and (b) investigate the prognostic implications of a quantitative definition of CLC at chest CT. Materials and Methods Patients with pathologic stage T1a-bN0M0 lung adenocarcinomas resected between 2009 and 2015 at a single tertiary care center were retrospectively identified. The primary end point was disease-free survival. The associations of multiple definitions of central tumor location with survival were evaluated by using multivariable Cox regression. Time-dependent discrimination measures and interreader agreement were assessed for each definition. Results A total of 436 patients (median age, 62 years [interquartile range, 55-69 years]; 245 women) were evaluated. Tumor location at CT in the inner one-third of the lung defined by concentric lines arising from the hilum was adversely associated with survival (five events among 34 patients with CLC and 27 events among 402 patients with peripheral lung cancer; adjusted hazard ratio, 2.90 [95% CI: 1.06, 7.96; P = .04]) and showed moderate interreader agreement (Cohen κ = 0.52 [95% CI: 0.37, 0.68]). Quantitatively determined location in the inner two-thirds of the lung was also an independent prognostic factor (16 events among 130 patients with CLC and 16 events among 306 patients with peripheral lung cancer; adjusted hazard ratio, 2.77 [95% CI: 1.36, 5.65]; P = .005), with higher interreader agreement (Cohen κ = 0.86 [95% CI: 0.80, 0.91]; P < .001). The quantification-based definition exhibited higher time-dependent sensitivity (48.2% [14.27/29.61; 95% CI: 28.8, 67.6] vs 15.1% [4.47/29.61; 95% CI: 1.3, 28.9]; P < .001). Conclusion Central lung cancer at chest CT, defined qualitatively or quantitatively, is an independent adverse prognostic factor in patients with node-negative, early-stage lung adenocarcinomas. The quantification-based approach has advantages in terms of time-dependent sensitivity and reproducibility. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Wandtke and Hobbs in this issue.

Central location and risk of imaging occult mediastinal lymph node involvement in cN0T2-4 non-small cell lung cancer

BACKGROUND

Appropriate pre-operative staging is a cornerstone in the treatment of non-small cell lung cancer (NSCLC). Central location and size greater than 3 cm are amongst indications for pre-operative invasive mediastinal staging but the quality of the evidence behind this recommendation is low.

METHODS

We retrospectively reviewed all cases of cT2-4N0M0 NSCLCL after CT and TEP-CT which underwent surgical resection with lymph node dissection or had a positive invasive pre-operative mediastinal staging in our institution from 2014 to 2018.

RESULTS

Three hundred and ten patients met inclusion criteria, 79 (25.5%) central and 231 (74.5%) peripheral tumors. Central tumor location was associated with a higher prevalence of pN2-3 disease (17.7% vs. 6.1%, P<0.001). In a multivariate analysis, central tumor location remained the only factor statistically associated with imaging occult mediastinal disease (OR 3.23, 95% CI: 1.45-7.18). NPV of PET-CT for occult mediastinal disease was 0.83 (95% CI: 0.72-0.90) in central and 0.94 (95% CI: 0.90-0.97) in peripheral tumor. Central location was also associated with a higher prevalence of occult N1 to N3 disease (43.0% vs. 15.2%, P<0.001).

CONCLUSIONS

This study suggests that invasive mediastinal staging is required in central cT2-4N0 NSCLC but can be questioned in peripheral one, especially in cT2N2 subgroup if the patient is a candidate for lobar resection.

Video-Assisted Thoracoscopic Sleeve Lobectomy for Centrally Located Non-small Cell Lung Cancer: A Meta-analysis

BACKGROUND

Whether video-assisted thoracoscopic surgery (VATS) sleeve lobectomy could be an alternative to traditional thoracotomy sleeve lobectomy in treating centrally located non-small cell lung cancer (NSCLC) remains unclear. Therefore, we conducted the first meta-analysis to compare the effects of VATS sleeve lobectomy with thoracotomy sleeve lobectomy.

METHODS

We systematically searched relevant studies from Pubmed, Embase, and Web of Science on May 12, 2020. Data for analysis included short-term outcomes (blood loss, lymph node dissected, operation time, hospital stay, complications) and long-term outcomes (3-year overall survival (OS) and progression-free survival (PFS) rates). We calculated the weighted mean differences (WMDs) for continuous data and risk ratio (RR) for pooling categorical data.

RESULTS

We finally included 5 retrospective cohort study consisting of 436 patients. VATS sleeve lobectomy yielded significantly less blood loss (WMD =  -37.83; 95% confidence intervals (CIs) = [-58.56, -17.11]; P < 0.001) than thoracotomy sleeve lobectomy and comparable total number of dissected lymph node to thoracotomy sleeve lobectomy (WMD =  - 0.07; 95%CI = [-1.14, 0.99]; P = 0.89). However, VATS sleeve lobectomy consumed significantly more operation time than thoracotomy sleeve lobectomy (WMD = 49.00; 95%CI = [14.67, 83.34]; P = 0.005). VATS sleeve lobectomy yielded significantly less postoperative hospital stay time than thoracotomy sleeve lobectomy (WMD =   -1.68; 95%CI = [-2.98, -0.39]; P = 0.011) and comparable postoperative complication rate to thoracotomy sleeve lobectomy (RR = 0.84; 95%CI = [0.49, 1.44]; P = 0.52). Moreover, VATS sleeve lobectomy yielded comparable 3-year OS (RR = 1.08; 95%CI = [0.95, 1.22]; P = 0.23) and PFS (RR = 1.15; 95%CI = [0.96, 1.37]; P = 0.13) rates to thoracotomy sleeve lobectomy. No significant heterogeneities were observed.

CONCLUSIONS

VATS sleeve lobectomy yielded less surgical trauma than thoracotomy sleeve lobectomy and improved postoperative recovery without compromising oncological prognosis. Even though VATS sleeve lobectomy may consume more operation time, it could be recommended as an alternative to thoracotomy sleeve lobectomy for treating centrally located NSCLC in carefully selected cases.

Is Biopsy of Contralateral Hilar N3 Lymph Nodes With Negative PET-CT Scan Findings Necessary When Performing Endobronchial Ultrasound Staging?

BACKGROUND

Systematic endobronchial ultrasound (EBUS)-guided lung cancer staging starts with hilar N3 nodes, proceeding sequentially to mediastinal N3, N2, and N1 nodes, with sampling of all enlarged nodes (size, ≥ 5 mm) by EBUS. However, procedure time is limited by patient comfort when moderate sedation is used. It is unclear if EBUS staging should start with hilar N3 nodes or whether starting with mediastinal N3 nodes suffices. Knowing the probability of hilar N3 nodes with PET-CT scan negative findings harboring occult metastasis can inform this decision.

RESEARCH QUESTION

What proportion of patients with hilar N3 nodes showing negative PET-CT scan findings have malignancy by EBUS?

STUDY DESIGN AND METHODS

This retrospective observational, single-center cohort study included consecutive patients with clinical-radiographic T1-3, N0-3, M0 non-small cell lung cancer undergoing systematic EBUS staging with biopsy of hilar N3 nodes with negative PET-CT scan findings. The primary outcome was the proportion of patients with malignant hilar N3 nodes showing negative PET-CT scan findings. Based on expert opinion, a threshold probability of malignancy of less than 5% was considered sufficient to skip hilar N3 nodes. We used the binomial exact test to compare the observed proportion vs threshold probability of 5%.

RESULTS

Of 1,737 consecutive patients undergoing EBUS staging, 1,567 showed negative PET-CT scan findings of the hilar N3 nodes. These nodes were enlarged by EBUS and were sampled in 739 patients. Malignancy was found in the hilar N3 nodes of 5 of 739 patients (0.68%; 95% CI, 0.22%-1.57%). The proportion was significantly less than the threshold probability (P < .001). Patients with positive PET scan results of the mediastinal N3 nodes were at higher risk of having occult hilar N3 nodal metastasis (P = .003), found in 3 of 46 patients (6.5%; 95% CI, 1.4%-17.9%) with positive PET scan results of the mediastinal N3 nodes.

INTERPRETATION

When using moderate sedation, because time is limited, it is reasonable to start with the mediastinal N3 nodes if the hilar and mediastinal N3 nodes show negative PET scan results. Patients with positive PET scan findings of the mediastinal N3 nodes probably should undergo hilar N3 node sampling.

Geometrical Measurement of Central Tumor Location in cT1N0M0 NSCLC Predicts N1 but Not N2 Upstaging

BACKGROUND

In patients with non-small cell lung cancer (NSCLC) and normal mediastinum, the central tumor location predicts occult nodal disease (both N1 and N2). We evaluated a novel definition of central location based on a geometrical measurement of the tumor location within the lung that could predict N2, N1, or both.

METHODS

This retrospective study included patients with confirmed NSCLC, radiologically and metabolically staged T1 N0 M0, who underwent invasive mediastinal staging and/or lung resection. The central tumor location was measured considering 2 ratios. The inner margin ratio (IMR) and outer margin ratio (OMR) were both calculated as the distance from the inner margin of the lung to both margins of the tumor (inner [IMR], outer [OMR]) divided by the lung width. Optimal cutoffs for IMR and OMR were calculated. Tumors with values lower than the cutoffs were considered central. Prevalences of N1 and N2 upstaging were estimated and bivariate logistic regression analysis was performed to predict the odds of N1 and N2 upstaging using IMR and OMR cutoffs.

RESULTS

A total of 209 patients were included. The prevalence of N1 and N2 upstaging was 11% and 5.3%, respectively. Cutoffs of 0.5 for IMR and 0.64 for OMR were estimated. Both ratios predicted N1 upstaging (adjusted odds ratio [95% confidence interval]: 4.2 [1.5-12]; P < .007; area under the curve, 0.65) but did not predict N2 upstaging.

CONCLUSIONS

Central tumor location can be assessed by means of IMR and OMR and predicts N1 upstaging in patients with radiologically and metabolically T1 N0 M0 tumors. This is important for the selection of patients for therapies that require N0 tumors.

Evidence for Expanding Invasive Mediastinal Staging for Peripheral T1 Lung Tumors

BACKGROUND

Guidelines recommend invasive mediastinal staging for patients with non-small cell lung cancer and a "central" tumor. However, there is no consensus definition for central location. As such, the decision to perform invasive staging largely remains on an empirical foundation.

RESEARCH QUESTION

Should patients with peripheral T1 lung tumors undergo invasive mediastinal staging?

STUDY DESIGN AND METHODS

All participants with a screen-detected cancer with a solid component between 8 and 30 mm were identified from the National Lung Screening Trial. After translation of CT data, cancer location was identified and the X, Y, Z coordinates were determined as well as distance from the main carina. A multivariable logistic regression model was constructed to evaluate for predictors associated with lymph node metastasis.

RESULTS

Three hundred thirty-two participants were identified, of which 69 had lymph node involvement (20.8%). Of those with lymph node metastasis, 39.1% were N2. There was no difference in rate of lymph node metastasis based on tumor size (OR, 1.03; P = .248). There was also no statistical difference in rate of lymph node metastasis based on location, either by distance from the carina (OR, 0.99; P = .156) or tumor coordinates (X: P = .180; Y: P = .311; Z: P = .292). When adjusted for age, sex, histology, and smoking history, there was no change in the magnitude of the risk, and tests of significance were not altered.

INTERPRETATION

Our data indicate a high rate of N2 metastasis among T1 tumors and no significant relationship between tumor diameter or location. This suggests that patients with small, peripheral lung cancers may benefit from invasive mediastinal staging.

Age-different extent of resection for clinical IA non-small cell lung cancer: analysis of nodal metastasis

Whether age has any impact on the risk of lymph node (LN) metastasis in patients with early-stage non-small cell lung cancer (NSCLC) remains controversial. Therefore, we aimed to objectively compare the risk of LN metastasis between elderly and young patients so as to justify for age-different extent of surgical resection for treating these patients. We retrospectively collected clinical data of patients undergoing lobectomy or segmentectomy with systematic hilar and mediastinal LN dissection for clinical stage IA peripheral NSCLC from January 2015 to December 2018. Both multivariate logistic regression analysis and propensity score-matched (PSM) analysis were applied to compare the risk of LN metastasis between elderly (>65 years old) and young (≤65 years old) patients. We finally included a total of 590 patients for analysis (142 elderly patients and 448 young patients). In the analysis of unmatched cohorts, young patients tended to have higher rates of hilar/intrapulmonary LN (13.4% VS 9.2%) and mediastinal LN metastasis (10.5% VS 6.3%) than elderly patients. In the multivariate analysis, age was found to be an independent predictor of both hilar/intrapulmonary (Odds ratio(OR) = 2.065, 95%confidence interval(CI): 1.049–4.064, P = 0.036) and mediastinal (OR = 2.400, 95%CI: 1.083–5.316, P = 0.031) LN metastasis. Moreover, in the analysis of well-matched cohorts generated by PSM analysis, young patients had significantly higher rates of hilar/intrapulmonary (18.8% VS 9.4%, P = 0.039) and mediastinal LN metastasis (17.1% VS 6.0%, P = 0.008) than elderly patients. Therefore, age remains to be an independent predictor of LN metastasis in early-stage NSCLC and age-different extent of surgical resection may be justified for these patients.

A Prediction Model to Help with Oncologic Mediastinal Evaluation for Radiation: HOMER

Rationale: When stereotactic ablative radiotherapy is an option for patients with non-small cell lung cancer (NSCLC), distinguishing between N0, N1, and N2 or N3 (N2|3) disease is important.Objectives: To develop a prediction model for estimating the probability of N0, N1, and N2|3 disease.Methods: Consecutive patients with clinical-radiographic stage T1 to T3, N0 to N3, and M0 NSCLC who underwent endobronchial ultrasound-guided staging from a single center were included. Multivariate ordinal logistic regression analysis was used to predict the presence of N0, N1, or N2|3 disease. Temporal validation used consecutive patients from 3 years later at the same center. External validation used three other hospitals.Measurements and Main Results: In the model development cohort (n = 633), younger age, central location, adenocarcinoma, and higher positron emission tomography-computed tomography nodal stage were associated with a higher probability of having advanced nodal disease. Areas under the receiver operating characteristic curve (AUCs) were 0.84 and 0.86 for predicting N1 or higher (vs. N0) disease and N2|3 (vs. N0 or N1) disease, respectively. Model fit was acceptable (Hosmer-Lemeshow, P = 0.960; Brier score, 0.36). In the temporal validation cohort (n = 473), AUCs were 0.86 and 0.88. Model fit was acceptable (Hosmer-Lemeshow, P = 0.172; Brier score, 0.30). In the external validation cohort (n = 722), AUCs were 0.86 and 0.88 but required calibration (Hosmer-Lemeshow, P < 0.001; Brier score, 0.38). Calibration using the general calibration method resulted in acceptable model fit (Hosmer-Lemeshow, P = 0.094; Brier score, 0.34).Conclusions: This prediction model can estimate the probability of N0, N1, and N2|3 disease in patients with NSCLC. The model has the potential to facilitate decision-making in patients with NSCLC when stereotactic ablative radiotherapy is an option.

Surgical Choice for Clinical Stage IA Non-Small Cell Lung Cancer: View From Regional Lymph Node Metastasis

BACKGROUND

We aimed to investigate the pattern of regional lymph node (LN) metastasis of early-stage non-small cell lung cancer (NSCLC) to provide novel rationale for surgical choice (lobectomy, segmentectomy, or wedge resection) for these patients.

METHODS

We retrospectively collected clinical data of patients undergoing lobectomy with systematic mediastinal LN dissection or sampling for cT1N0M0 peripheral NSCLC from January 2015 to December 2018. The regional LN metastasis pattern was analyzed based on tumor size.

RESULTS

We included a total of 354 patients for analysis. The rate of hilar or intrapulmonary LN metastasis was 13.6%. When stratified by tumor size, NSCLC less than or equal to 1 cm had no hilar or intrapulmonary LN metastasis (0%) while NSCLC greater than 2 cm but less than or equal to 3 cm had a significantly high rate of hilar or intrapulmonary LN metastasis (18.4%) and the rates of hilar, interlobar, and peripheral LN metastasis were also relatively high (5.4%, 5.4%, and 12.2%, respectively). NSCLC greater than 1.5 cm but less than or equal to 2 cm also had relatively high rates of hilar (6.5%) and peripheral (18.3%) LN metastasis, while NSCLC greater than 1 cm but less than or equal to 1.5 cm had significantly low rates of hilar or intrapulmonary (2.5%) and peripheral (2.5%) LN metastasis. Radiographic feature and histology were found to be independent predictors of regional LN metastasis.

CONCLUSIONS

The pattern of regional LN metastasis in clinical stage IA peripheral NSCLC was significantly influenced by tumor size, which may provide evidence on surgical choice (lobectomy, segmentectomy, or wedge resection) for these early-stage NSCLC patients based on tumor size.

Lung Adenocarcinoma has a Higher Risk of Lymph Node Metastasis than Squamous Cell Carcinoma: A Propensity Score-Matched Analysis

BACKGROUND

Controversy still exists in which subtype of non-small-cell lung cancer [squamous cell carcinoma (SCC) or adenocarcinoma] is more likely to have lymph node (LN) metastasis. The aim of this study is to compare the pattern of LN metastasis in two cohorts of matched patients surgically treated for SCC or adenocarcinoma.

METHODS

A retrospective analysis of patients undergoing lobectomy or segmentectomy with systematic lymphadenectomy without preoperative treatment for lung SCC or adenocarcinoma was conducted in this study. Data for analysis consisted of age, gender, tumor size, lobe-specific tumor location, tumor location (peripheral or central), and pathologic findings. We conducted the propensity score-matched (PSM) analysis to eliminate potential bias effects of possible confounding factors.

RESULTS

From January 2015 to December 2016 in our department, we finally included a total of 387 patients (including 63 patients with SCC and 324 patients with adenocarcinoma) for analysis. For the unmatched cohort, there was no sufficient evidence of significantly different number of positive LNs (P = 0.90) and rate of LN metastasis (P = 0.23) between SCC patients and adenocarcinoma patients. However, potential confounding factors, for example gender, tumor size, tumor location, tumor differentiation, and total number of dissected LNs, were significantly different between patients with SCC and those with adenocarcinoma. In the analysis of matched cohort after PSM analysis, those above confounding factors were comparable between the two groups. However, patients with adenocarcinoma had significantly more mean positive LNs (2.2 and 0.7; P = 0.008) and a higher rate of LN metastasis (53% and 29%; P = 0.016) than those with SCC.

CONCLUSIONS

Lung adenocarcinoma had a higher risk of LN metastasis than SCC, suggesting that different therapeutic modalities may be indicated for the two different subtypes of lung cancer.

Which definition of a central tumour is more predictive of occult mediastinal metastasis in nonsmall cell lung cancer patients with radiological N0 disease?

Background

Guidelines recommend invasive mediastinal staging for centrally located tumours, even in radiological N0 nonsmall cell lung cancer (NSCLC). However, there is no uniform definition of a central tumour that is more predictive of occult mediastinal metastasis.

Methods

A total of 1337 consecutive patients with radiological N0 disease underwent invasive mediastinal staging. Tumours were categorised into central and peripheral by seven different definitions.

Results

About 7% (93 out of 1337) of patients had occult N2 disease, and they had significantly larger tumour size and more solid tumours on computed tomography. After adjustment for patient- and tumour-related characteristics, only the central tumour definition of the inner one-third of the hemithorax adopted by drawing concentric lines arising from the midline significantly predicted occult N2 disease (adjusted OR 2.13, 95% CI 1.17–3.87; p=0.013). This association was maintained after excluding patients with pure ground-glass nodules (adjusted OR 2.54, 95% CI 1.37–4.71; p=0.003) or only including those with solid tumours (adjusted OR 2.30, 95% CI 1.08–4.88; p=0.030).

Conclusions

We suggest that a central tumour should be defined using the inner one-third of the hemithorax adopted by drawing concentric lines from the midline. This is particularly useful for predicting occult N2 disease in patients with NSCLC.

Central tumours defined as located in the inner one-third of the hemithorax adopted by drawing concentric lines from the midline are associated with occult mediastinal metastasis in patients with NSCLC and radiological N0 diseasehttp://ow.ly/scg630nbRmY

Centrally located lung cancer and risk of occult nodal disease: an objective evaluation of multiple definitions of tumour centrality with dedicated imaging software

Introduction

Current guidelines recommend invasive mediastinal staging in patients with centrally located radiographic stage T1N0M0 nonsmall cell lung cancer (NSCLC). The lack of a specific definition of a central tumour has resulted in discrepancies among guidelines and heterogeneity in practice patterns.

Methods

Our objective was to study specific definitions of tumour centrality and their association with occult nodal disease. Pre-operative chest computed tomography scans from patients with clinical (c) T1N0M0 NSCLC were processed with a dedicated software system that divides the lungs in thirds following vertical and concentric lines. This software accurately assigns tumours to a specific third based both on the location of the centre of the tumour and its most medial aspect, creating eight possible definitions of central tumours.

Results

607 patients were included in our study. Surgery was performed for 596 tumours (98%). The overall pathological (p) N disease was: 504 (83%) N0, 56 (9%) N1, 47 (8%) N2 and no N3. The prevalence of N2 disease remained relatively low regardless of tumour location. Central tumours were associated with upstaging from cN0 to any N (pN1/pN2). Two definitions were associated with upstaging to any N: concentric lines, inner one-third, centre of the tumour (OR 3.91, 95% CI 1.85–8.26; p<0.001) and concentric lines, inner two-thirds, most medial aspect of the tumour (OR 1.91, 95% CI 1.23–2.97; p=0.004).

Conclusions

We objectively identified two specific definitions of central tumours. While the rate of occult mediastinal disease was relatively low regardless of tumour location, central tumours were associated with upstaging from cN0 to any N.