Lymph Node Dissection for Lung Cancer: Significance, Strategy, and Technique

Lung adenocarcinoma manifested as ground-glass nodules in teenagers: characteristics, surgical outcomes and management strategies

OBJECTIVES

Ground-glass nodules-featured lung cancer have been identified in some teenagers in recent years. This study aims to investigate the characteristics and surgical outcomes of these patients and explore proper management strategy.

METHODS

Patients aged ≤20 with incidentally diagnosed lung cancer were retrospectively reviewed from February 2016 to March 2023. Based on lymph node evaluation status, these patients were divided into non-lymph node evaluation and lymph node evaluation groups. The clinical and pathological characteristics were analysed.

RESULTS

A total of 139 teenage patients were included, with an obviously increased cases observed from 2019, corresponding to the COVID-19 pandemic. The median age of the 139 patients was 18 years (range 12-20). Eighty-five patients had pure ground-glass nodules, while others had mixed ground-glass nodules. The mean diameter of nodules was 8.87 ± 2.20 mm. Most of the patients underwent wedge resection (64%) or segmentectomy (31.7%). Fifty-two patients underwent lymph node sampling or dissection. None of these patients had lymph node metastasis. The majority of lesions were adenocarcinoma in situ (63 cases) and minimally invasive adenocarcinoma (72 cases), while four lesions were invasive adenocarcinoma. The median follow-up time was 2.46 years, and none of these patients experienced recurrence or death during follow-up. The lymph node evaluation group had longer hospital stays (P < 0.001), longer surgery time (P < 0.001), and greater blood loss (P = 0.047) than the non-lymph node evaluation group.

CONCLUSIONS

The COVID-19 pandemic significantly increased the number of teenage patients incidentally diagnosed with lung cancer, presenting as ground-glass nodules on CT scans. These patients have favourable surgical outcomes. We propose a management strategy for teenage patients, and suggest that sub-lobar resection without lymph node dissection may be an acceptable surgical procedure for these patients.

Revolutionizing lymph node metastasis imaging: the role of drug delivery systems and future perspectives

The deployment of imaging examinations has evolved into a robust approach for the diagnosis of lymph node metastasis (LNM). The advancement of technology, coupled with the introduction of innovative imaging drugs, has led to the incorporation of an increasingly diverse array of imaging techniques into clinical practice. Nonetheless, conventional methods of administering imaging agents persist in presenting certain drawbacks and side effects. The employment of controlled drug delivery systems (DDSs) as a conduit for transporting imaging agents offers a promising solution to ameliorate these limitations intrinsic to metastatic lymph node (LN) imaging, thereby augmenting diagnostic precision. Within the scope of this review, we elucidate the historical context of LN imaging and encapsulate the frequently employed DDSs in conjunction with a variety of imaging techniques, specifically for metastatic LN imaging. Moreover, we engage in a discourse on the conceptualization and practical application of fusing diagnosis and treatment by employing DDSs. Finally, we venture into prospective applications of DDSs in the realm of LNM imaging and share our perspective on the potential trajectory of DDS development.

Prognostic significance of ground-glass areas within tumours in non-small-cell lung cancer

OBJECTIVES

To validate or refute the hypothesis that non-small-cell lung cancers (NSCLC) with ground-glass areas (GGA+) within the tumour on high-resolution computed tomography are associated with a more favourable prognosis than those without GGA (GGA-).

METHODS

We analysed data from a multicentre observational cohort study in Japan including 5005 patients with completely resected pathological stage I NSCLC, who were excluded from the Japan Clinical Oncology Group (JCOG) 0707 trial on oral adjuvant treatment during the enrolment period. The patients' medical and pathological records were assessed retrospectively by physicians and re-staged according to the 8th tumour, node, metastasis edition.

RESULTS

Of the 5005 patients, 2388 (48%) were ineligible for the JCOG0707 trial and 2617 (52%) were eligible but were not enrolled. A total of 958 patients (19.1%) died. Patients with GGA+ NSCLC and pathological invasion ≤3 cm showed significantly better overall survival than others. In patients with tumours with an invasive portion ≤4 cm, GGA+ was associated with better survival. The prognoses of patients with GGA+ T2a and GGA- T1c tumours were similar (5-year overall survival: 84.6% vs 83.1%, respectively). The survival with T2b or more tumours appeared unaffected by GGA, and GGA was not prognostic in these larger tumours.

CONCLUSIONS

Patients with GGA+ NSCLC on high-resolution computed tomography and ≤4 cm invasion size may have a better prognosis than patients with solid GGA- tumours of the same T-stage. However, the presence or absence of radiological GGA has little impact on the prognosis of patients with NSCLC with greater (>4 cm) pathological invasion.

A Shift in Paradigm: Selective Lymph Node Dissection for Minimizing Oversurgery in Early Stage Lung Cancer

Systematic lymph node dissection has been widely accepted and turned into a standard procedure for lung cancer surgery. In recent years, the concept of "minimal invasive surgery (MIS)" has greatly changed the surgical paradigm of lung cancer. Previous studies revealed that excessive dissection of lymph nodes without metastases had uncertain clinical benefit. Meanwhile, it leads to the elevated risk of postoperative complications including chylothorax and laryngeal nerve injury. In addition, dissection of nonmetastatic lymph nodes may disturb systematic immunity, resulting in the secondary effect on primary tumor or latent metastases. The past decades have witnessed the innovative strategies such as lobe-specific lymph node dissection and selective lymph node dissection. On the basis of evolution of lymph node dissection strategy, we discuss the negative effects of excessive nonmetastatic lymph node dissection and summarize the recent advances in the optimized dissection strategies, hoping to provide unique perspectives on the future directions.

Clinico-biological-radiomics (CBR) based machine learning for improving the diagnostic accuracy of FDG-PET false-positive lymph nodes in lung cancer

BACKGROUND

The main problem of positron emission tomography/computed tomography (PET/CT) for lymph node (LN) staging is the high false positive rate (FPR). Thus, we aimed to explore a clinico-biological-radiomics (CBR) model via machine learning (ML) to reduce FPR and improve the accuracy for predicting the hypermetabolic mediastinal-hilar LNs status in lung cancer than conventional PET/CT.

METHODS

A total of 260 lung cancer patients with hypermetabolic mediastinal-hilar LNs (SUVmax ≥ 2.5) were retrospectively reviewed. Patients were treated with surgery with systematic LN resection and pathologically divided into the LN negative (LN-) and positive (LN +) groups, and randomly assigned into the training (n = 182) and test (n = 78) sets. Preoperative CBR dataset containing 1738 multi-scale features was constructed for all patients. Prediction models for hypermetabolic LNs status were developed using the features selected by the supervised ML algorithms, and evaluated using the classical diagnostic indicators. Then, a nomogram was developed based on the model with the highest area under the curve (AUC) and the lowest FPR, and validated by the calibration plots.

RESULTS

In total, 109 LN- and 151 LN + patients were enrolled in this study. 6 independent prediction models were developed to differentiate LN- from LN + patients using the selected features from clinico-biological-image dataset, radiomics dataset, and their combined CBR dataset, respectively. The DeLong test showed that the CBR Model containing all-scale features held the highest predictive efficiency and the lowest FPR among all of established models (p < 0.05) in both the training and test sets (AUCs of 0.90 and 0.89, FPRs of 12.82% and 6.45%, respectively) (p < 0.05). The quantitative nomogram based on CBR Model was validated to have a good consistency with actual observations.

CONCLUSION

This study presents an integrated CBR nomogram that can further reduce the FPR and improve the accuracy of hypermetabolic mediastinal-hilar LNs evaluation than conventional PET/CT in lung cancer, thereby greatly reducing the risk of overestimation and assisting for precision treatment.

Clinical efficacy and safety of adjuvant EGFR-TKIs for resected stage IB lung adenocarcinoma: A real-world study based on propensity score matching

BACKGROUND

Adjuvant therapy for stage IB non-small cell lung cancer remains debatable. In this real-world study, we evaluate the efficacy and safety of adjuvant epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) for resected stage IB lung adenocarcinoma.

METHODS

This real-world study recruited 249 patients diagnosed with stage IB disease after surgical resection between January 2013 and September 2021. Sixty-six (26.5%) patients received adjuvant targeted therapy (TKIs group), and 183 (73.5%) were enrolled in the clinical observation (CO) group. Propensity scores were matched to minimize the observed confounder effects between the two groups, and 59 patient pairs were matched. The primary endpoint was disease-free survival (DFS).

RESULTS

In the TKI group, 38 (64.4%) patients chose to receive icotinib, 27.1% (16/59) received gefitinib, and 5 patients (8.5%) chose osimertinib. The median follow-up time was 30.8 months (range: 7-107 months). Two (3.4%) patients in the TKI group and 10 (16.9%) in the CO group experienced disease relapse. The 3-year DFS rates were 98.3% in the TKI group and 83.0% in the CO group (HR: 0.10; 95% CI: 0.01-0.78; p = 0.008). DFS differences were found in the entire cohort (p = 0.005) and the matched cohort (p = 0.024) between the two groups. Multivariate analysis showed that adjuvant EGFR-TKIs was an independent factor for DFS (HR: 0.211; 95% CI: 0.045-0.979; p = 0.047), along with poor cell differentiation (HR: 5.256; 95% CI: 1.648-16.769; p = 0.005), and spread through air spaces (HR: 5.612; 95% CI: 1.137-27.700; p = 0.034). None of the patients discontinued EGFR-TKIs owing to the low occurrence rate of treatment-related serious adverse events.

CONCLUSION

Adjuvant EGFR-TKIs could significantly improve DFS among patients with stage IB lung adenocarcinoma compared with CO, with a safe and tolerable profile.

Impact of the Number of Harvested Lymph Nodes on Long-Term Survival in Node-Negative Non-Small-Cell Lung Cancer: Based on Clinical Stage But Not Pathological Stage

BACKGROUND

We aimed to investigate the impact of the number of harvested lymph nodes (LNs) on the overall survival (OS) and disease-free survival (DFS) of patients with clinical node-negative (cN0) non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

A total of 2247 patients with cN0 NSCLC between 2001 and 2014 were included. Scatter plots of hazard ratios from Cox proportional hazards models against the number of harvested LNs were created, and curves were fitted using a LOWESS smoother. Chow test was used to determine the cut-off points for the optimal number of harvested LNs. Long-term survival was compared between groups divided by the cut-off points.

RESULTS

The increasing numbers of harvested LNs and N2 level LNs were independent factors favoring OS and DFS. Seventeen LNs and 10 N2 level LNs were determined as the optimal cut-off points. The patients with ≥17 harvested LNs had a better OS (P = .001) and DFS (P = .002), while the patients with ≥10 harvested N2 level LNs also had a better OS (P < .001) and DFS (P = .001). The increasing numbers of harvested LNs and N2 level LNs were independent prognostic factors associated with prolonged OS and DFS only in patients with clinical T2 (cT2) NSCLC.

CONCLUSIONS

The increasing numbers of harvested LNs and N2 level LNs were associated with better OS and DFS in cN0 NSCLC patients that were suitable for lobectomies. At least 17 LNs and 10 N2 level LNs were required to be harvested, especially in cT2 patients.

Selective Mediastinal Lymph Node Dissection Strategy for Clinical T1N0 Invasive Lung Cancer: A Prospective, Multicenter, Clinical Trial

INTRODUCTION

We aimed to prospectively evaluate our previously proposed selective mediastinal lymph node (LN) dissection strategy for peripheral clinical T1N0 invasive NSCLC.

METHODS

This is a multicenter, prospective clinical trial in China. We set six criteria for predicting negative LN stations and finally guiding selective LN dissection. Consolidation tumor ratio less than or equal to 0.5, segment location, lepidic-predominant adenocarcinoma (LPA), negative hilar nodes (stations 10-12), and negative visceral pleural invasion (VPI) were used separately or in combination as predictors of negative LN status in the whole, superior, or inferior mediastinal zone. LPA, hilar node involvement, and VPI were diagnosed intraoperatively. All patients actually underwent systematic mediastinal LN dissection. The primary end point was the accuracy of the strategy in predicting LN involvement. If LN metastasis occurred in certain mediastinal zone that was predicted to be negative, it was considered as an "inaccurate" case.

RESULTS

A total of 720 patients were enrolled. The median number of LN dissected was 15 (interquartile range: 11-20). All negative node status in certain mediastinal zone was correctly predicted by the strategy. Compared with final pathologic findings, the accuracy of frozen section to diagnose LPA, VPI, and hilar node metastasis was 94.0%, 98.9%, and 99.6%, respectively. Inaccurate intraoperative diagnosis of LPA, VPI, or hilar node metastasis did not lead to inaccurate prediction of node-negative status.

CONCLUSIONS

This is the first prospective trial validating the specific mediastinal LN metastasis pattern in cT1N0 invasive NSCLC, which provides important evidence for clinical applications of selective LN dissection strategy.

The comparison of Lobe-Specific or Systematic Mediastinal Lymph Node Dissection for Early-Stage Lung Adenocarcinoma With Consolidation Tumor Ratio Over 0.5

INTRODUCTION

Surgery is the most effective treatment for early-stage lung cancer. This study will propose a personalized plan for mediastinal lymph node dissection in early-stage lung adenocarcinoma to reduce the risk of surgery and improve the quality of life.

METHODS

This study retrospectively analyzed the patients underwent lobectomy and lymph node dissection in the Department of Thoracic Surgery, Zhongshan Hospital, Fudan University. Clinical stage I lung adenocarcinoma patients with solid component ratio (CTR) between 0.5 and 1 were included. Patients were divided into systematic (S-MLND) and lobe-specific (L-MLND) mediastinal lymph node dissection groups. The days of hospitalization, the presence or absence of complications, the recurrence-free survival rate, and the overall survival rate were calculated to evaluate the postoperative quality and operation risk of the patients.

RESULTS

210 patients (138 L-MLND and 72 S-MLND) were included. 2 lymph node metastases appeared in the S-MLND group while none in the L-MLND group (P = .049). No differences were shown in age, tumor site, size, solid component, degree of tumor invasion, and stage. The proportion of patients with severe postoperative cough and the length of hospital stay in the L-MLND group decreased. The 5-year OS of the entire cohort was 98.1%, 98.6% in L-MLND, compared with 97.2% in S-MLND; RFS was 94.8%, 95.7% in L-MLND, compared with 93.0% in S-MLND.

CONCLUSION

For cIA lung adenocarcinoma, according to the Thin-slice CT within 1 month before the operation, if the main lesion was less than 3 cm and CTR over 0.5, L-MLND is as effective as S-MLND.

Future in precise surgery: Fluorescence-guided surgery using EVs derived fluorescence contrast agent

Surgery is the only cure for many solid tumors, but positive resection margins, damage to vital nerves, vessels and organs during surgery, and the range and extent of lymph node dissection are significant concerns which hinder the development of surgery. The emergence of fluorescence-guided surgery (FGS) means a farewell to the era when surgeons relied only on visual and tactile feedback, and it gives surgeons another eye to distinguish tumors from normal tissues for precise resection and helps to find a balance between complete tumor lesions removal and maximal organ function conservation. However, the existing synthetic fluorescence contrast agent has flaws in safety, specificity and biocompatibility to various extents. Extracellular vesicles (EVs) are a group of heterogeneous types of cell-derived membranous structures present in all biological fluids. EVs, especially engineered targeting EVs, play an increasingly important role in drug delivery because of their good biocompatibility, validated safety and targeting ability. Nevertheless, few studies have employed EVs loaded with fluorophores to construct fluorescence contrast agents and used them in FGS. Here, we systematically reviewed the current state of knowledge regarding FGS, fundamental characteristics of EVs, and the development of engineered targeting EVs, and put forward a novel strategy and procedures to produce EVs-based fluorescence contrast agent used in fluorescence-guided surgery.

Clinicopathological and survival outcomes of 4L lymph node dissection in left lung adenocarcinoma and squamous cell carcinoma

Background

Whether 4L lymph node dissection (LND) should be performed remains unclear and controversial. Prior studies have found that station 4L metastasis was not rare and that 4L LND may provide survival benefits. The objective of this study was to analyze the clinicopathological and survival outcomes of 4L LND from the perspective of histology.

Methods

This retrospective study included 74 patients with squamous cell carcinoma (SCC) and 84 patients diagnosed with lung adenocarcinoma (ADC) between January 2008 and October 2020. All patients underwent pulmonary resection with station 4L LND and were staged as T1-4N0-2M0. Clinicopathological features and survival outcomes were investigated based on histology. The study endpoints were disease-free survival (DFS) and overall survival (OS).

Results

The incidence rate of station 4L metastasis was 17.1% (27/158) in the entire cohort, with 8.1% in the SCC group, and 25.0% in the ADC group. No statistical differences in the 5-year DFS rates (67.1% vs. 61.7%, P=0.812) and 5-year OS rates (68.6% vs. 59.3%, P=0.100) were observed between the ADC group and the SCC group. Multivariate logistic analysis revealed that histology (SCC vs. ADC: OR, 0.185; 95% CI, 0.049-0.706; P=0.013) was independently associated with 4L metastasis. Multivariate survival analysis showed that the status of 4L metastasis was an independent factor for DFS (HR, 2.563; 95% CI, 1.282-5.123; P=0.008) but not for OS (HR, 1.597; 95% CI, 0.749-3.402; P=0.225).

Conclusion

Station 4L metastasis is not rare in left lung cancer. Patients with ADC have a greater predilection for station 4L metastasis and may benefit more from performing 4L LND.

Identification of the Characteristic Genes and their Roles in Lung Adenocarcinoma Lymph Node Metastasis through Machine Learning Algorithm

Background. Lymph node metastasis is an important route of lung cancer metastasis and can significantly affect the survival of lung cancer. Methods. All the analysis was conducted out in the R software. Expression profile and clinical information of lung adenocarcinoma (LUAD) patients were downloaded from The Cancer Genome Atlas database. Results. In our study, we firstly identified the characteristic genes of lymph node metastasis in LUAD through two machine learning algorithms, least absolute shrinkage and selection operator (LASSO) logistic regression, and SVM-RFE algorithms. Ten characteristic genes were finally identified, including CRHR2, ITIH1, PRSS48, MAS1L, CYP4Z1, LMO1, TCP10L2, KRT78, IGFBP1, and PITX3. Next, we performed univariate Cox regression, LASSO regression, and multivariate Cox regression sequentially to construct a prognosis model based on MAS1L, TCP10L2, and CRHR2, which had a good prognosis prediction efficiency in both training and validation cohorts. Univariate and multivariate analysis indicated that our model is a risk factor independent of other clinical features. Pathway enrichment analysis showed that in the high-risk patients, the pathway of MYC target, unfolded protein response, interferon alpha response, DNA repair, reactive oxygen species pathway, and glycolysis were significantly enriched. Among three model genes, MAS1L aroused our interest and therefore was selected for further analysis. KM survival curves showed that the patients with higher MAS1L might have better disease-free survival and progression-free survival. Further, pathway enrichment, genomic instability, immune infiltration, and drug sensitivity analysis were performed to in-deep explore the role of MAS1L in LUAD. Conclusions. Results showed that the signature based on MAS1L, TCP10L2, and CRHR2 is a useful tool to predict prognosis and lung cancer lymph node metastasis.

Non-small cell lung cancer in China

In China, lung cancer is a primary cancer type with high incidence and mortality. Risk factors for lung cancer include tobacco use, family history, radiation exposure, and the presence of chronic lung diseases. Most early-stage non-small cell lung cancer (NSCLC) patients miss the optimal timing for treatment due to the lack of clinical presentations. Population-based nationwide screening programs are of significant help in increasing the early detection and survival rates of NSCLC in China. The understanding of molecular carcinogenesis and the identification of oncogenic drivers dramatically facilitate the development of targeted therapy for NSCLC, thus prolonging survival in patients with positive drivers. In the exploration of immune escape mechanisms, programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitor monotherapy and PD-1/PD-L1 inhibitor plus chemotherapy have become a standard of care for advanced NSCLC in China. In the Chinese Society of Clinical Oncology's guidelines for NSCLC, maintenance immunotherapy is recommended for locally advanced NSCLC after chemoradiotherapy. Adjuvant immunotherapy and neoadjuvant chemoimmunotherapy will be approved for resectable NSCLC. In this review, we summarized recent advances in NSCLC in China in terms of epidemiology, biology, molecular pathology, pathogenesis, screening, diagnosis, targeted therapy, and immunotherapy.

Surgery for early-stage lung cancer with video-assisted thoracoscopic surgery versus open thoracotomy: A narrative review

Recommending video-assisted thoracic surgery (VATS) over open thoracotomy to patients with early-stage non-small-cell lung cancer (NSCLC) is controversial. Accordingly, we reviewed randomized comparative studies to determine the risks and benefits of VATS lobectomy. Electronic searches on PubMed with standard search terms revealed 97 comparative studies published between 1990 and 2022. Of those, only 5 were randomized controlled clinical trials (RCT) and 1 is still ongoing although initial data has been published as an abstract form. A total of 918 patients were evaluated in 5 RCT's. All studies included patients with known or suspected primary lung cancer randomized in a 1:1 ratio to VATS or thoracotomy. Between 2 studies, reports of 1-year, 3-year and 5-year overall survival were found to be similar across surgical modalities. Additionally, no differences were found in the rates of locoregional and distant recurrence. Three studies reported no statistical differences in the number of hilar and mediastinal lymph nodes sampled. Two studies found decreased length of stay following VATS (4 days v 5 days, P = 0.027 and P = 0.008), while 2 found no difference. Increased in-hospital complications were seen in 2 studies (P = 0.008 and P = 0.039). VATS was associated with decreased pain scores, better self-reported QOL at 52 weeks (P = 0.014). Few randomized clinical trials comparing VATS lobectomy to open thoracotomy and lobectomy in early stage NSCLC have been reported. These studies suggest that VATS lobectomy offers similar outcomes with decreased in-hospital complications, pain, length of stay, and improved physical functioning when compared to thoracotomy.

The Prognostic Impact of Lymph Node Dissection on Primary Tumor Resection for Stage IV Non-Small Cell Lung Cancer: A Population-Based Study

Objective

Selected patients with stage IV non–small cell lung cancer (NSCLC) who underwent primary tumor resection have witnessed a survival benefit. Whether additional lymph node dissection (LND) would result in a better effect remain unknown. We investigated the prognostic impact of LND on patients with stage IV NSCLC who received primary tumor resection (PTR).

Methods

Patients with stage IV NSCLC who underwent PTR were identified from the Surveillance, Epidemiology, and End Results database from 2004 to 2016. Propensity-score matching was performed to minimize the confounding effect, and lung cancer-specific survival (CSS) and overall survival (OS) were compared after matching. Multivariable Cox regression was used to identify prognostic factors and to adjust for covariates in subgroup analysis. The effect of the number of lymph nodes examined on the CSS was evaluated by repeating the Cox analysis in a binary method.

Results

A total of 4,114 patients with stage IV NSCLC who receive surgery met our criteria, of which 2,622 (63.73%) underwent LND and 628 patients were identified 1:1 in LND and non-LND groups after matching. Compared with the non-LND group, the LND group had a longer CSS (median: 23 vs. 16 months, p < 0.001) and OS (median: 21 vs. 15 months, p < 0.001). Multivariable regression showed that LND was independently associated with favorable CCS [hazard ratio (HR) = 0.78, 95% confidence interval (CI) 0.69–0.89, P < 0.001] and OS (HR = 0.79, 95% CI 0.70–0.89, P < 0.001). Subgroup analysis suggested that LND is an independent favorable predictor to survival in the surgical patients who were older age (>60 years old), female, T3-4, N0, and M1a stage and those who underwent sublobar resection. In addition, a statistically significant CCS benefit was associated with an increasing number of lymph nodes examined through 25 lymph nodes.

Conclusions

LND with a certain range of lymph nodes number examined was associated with improved survival for patients with stage IV NSCLC who received primary tumor resection. The results may have implications for guidelines on lymph nodes management in selective advanced NSCLC for surgery.

Lymphatic Node Metastasis Risk Scoring System: A Novel Instrument for Predicting Lymph Node Metastasis After Thymic Epithelial Tumor Resection

BACKGROUND

The authors aimed to create a novel model to predict lymphatic metastasis in thymic epithelial tumors.

METHODS

Data of 1018 patients were collected from the Surveillance, Epidemiology, and End Results database from 2004 to 2015. To construct a nomogram, the least absolute shrinkage and selection operator (LASSO) regression model was used to select candidate features of the training cohort from 2004 to 2013. A simple model called the Lymphatic Node Metastasis Risk Scoring System (LNMRS) was constructed to predict lymphatic metastasis. Using patients from 2014 to 2015 as the validation cohort, the predictive performance of the model was determined by receiver operating characteristic (ROC) curves.

RESULTS

The LASSO regression model showed that age, extension, and histology type were significantly associated with lymph node metastasis, which were used to construct the nomogram. Through analysis of the area under the curve (AUC), the nomogram achieved a AUC value of 0.80 (95 % confidence interval [Cl] 0.75-0.85) in the training cohort and 0.82 (95 % Cl 0.70-0.93) in the validation cohort, and had closed calibration curves. Based on the nomogram, the authors constructed the LNMRS model, which had an AUC of 0.80 (95 % Cl 0.75-0.85) in the training cohort and 0.82 (95% Cl 0.70-0.93) in the validation cohort. The ROC curves indicated that the LNMRS had excellent predictive performance for lymph node metastasis.

CONCLUSION

This study established a nomogram for predicting lymph node metastasis. The LNMRS model, constructed to predict lymphatic involvement of patients, was more convenient than the nomogram.

Oncological outcomes after lobe-specific mediastinal lymph node dissection via multiport video-assisted thoracoscopic surgery

OBJECTIVES

We retrospectively investigated oncological outcomes after video-assisted thoracoscopic surgery (VATS) lobectomy with lobe-specific mediastinal lymph node dissection (MLND).

METHODS

Between April 2008 and December 2016, a total of 660 patients underwent VATS lobectomy with lobe-specific MLND for clinical T1-3N0M0 non-small-cell lung cancer, of which 54 (8.2%) patients had pathological node-positive disease (18 N1 and 36 N2). We evaluated their oncological outcomes.

RESULTS

The predominant histological type was adenocarcinoma (87%). Six (33%) patients in the pN1 and 11 (31%) patients in the pN2 received adjuvant chemotherapy. The median follow-up period was 51.6 months. Postoperative recurrence was observed in 5 (28%) pN1 and 22 (61%) pN2 patients. One (6%) pN1 and 12 (33%) pN2 patients experienced locoregional recurrence. None of the pN1 patient experienced local recurrence at the dissected zone, whereas 11 (31%) pN2 patients had lymph node recurrence, including four at the dissected area and three in the area omitted from dissection in the lobe-specific MLND. The 5-year overall survival rates were 88.1% in the pN1 patients and 80.0% in the pN2 patients; the 5-year recurrence-free survival rates were 63.9% in the pN1 patients and 34.8% in the pN2 patients. In pN2 patients, pathological T classification was a prognostic factor for overall survival (P < 0.001) and recurrence-free survival (P = 0.034), and single-station N2 disease was also prognostic factor for overall survival (P = 0.023).

CONCLUSIONS

Recurrence at the omitted zone is an issue for this type of MLND. For pN1 patients, adequate MLND is an important factor for curative treatment. However, for pN2 patients, systemic treatment after recurrence may also contribute to survival.

Risk Factors for Occult Lymph Node Metastasis in Peripheral Non-Small Cell Lung Cancer with Invasive Component Size 3 cm or Less

BACKGROUND

In the seventh edition TNM staging system for lung cancer, a high maximum standardized uptake value (SUVmax) on positron emission tomography was regarded as a risk factor for occult lymph node metastasis in clinical T1N0 non-small cell lung cancer (NSCLC). However, in the eighth edition TNM classification, tumors are classified according to the size of the invasive component only, and those with invasive component size ≤3 cm are diagnosed as stage T1. The aim of this study was to reassess the risk factors for occult lymph node metastasis under the eighth edition TNM classification for lung cancer.

METHODS

From 2010 to 2017, 553 patients with clinical N0 peripheral NSCLC with invasive component size ≤3 cm underwent anatomical lobectomy with systematic lymph node dissection. We analyzed these cases retrospectively to identify risk factors for postoperative nodal upstaging.

RESULTS

Among 553 study patients, 54 (9.8%) had nodal upstaging after surgery. In multivariate analysis adopting the eighth edition TNM classification for lung cancer, serum carcinoembryonic antigen (CEA) level (hazard ratio [HR] = 1.113, p = 0.002), invasive component size (HR = 2.398, p = 0.004), visceral pleural invasion (HR = 2.901, p = 0.005), and lymphatic invasion (HR = 9.336, p < 0.001) were significant risk factors for nodal upstaging, but SUVmax was not.

CONCLUSION

SUVmax is not a predictor of nodal upstaging in clinical N0 peripheral NSCLC with invasive component size ≤3 cm under the eighth edition TNM classification for lung cancer. Significant risk factors of occult lymph node metastasis are serum CEA level, tumor invasive component size, visceral pleural invasion, and lymphatic invasion.

Association of Race, Socioeconomic Factors, and Treatment Characteristics With Overall Survival in Patients With Limited-Stage Small Cell Lung Cancer

IMPORTANCE

It has been established that disparities in race and socioeconomic status are associated with outcomes of non-small cell lung cancer. However, it remains unknown whether this extends to stage I, II, or III small cell lung cancer (SCLC), or limited-stage SCLC (L-SCLC).

OBJECTIVE

To investigate the associations of race, socioeconomic factors, and treatment characteristics with survival among patients with L-SCLC.

DESIGN, SETTING, AND PARTICIPANTS

Demographic information for patients with L-SCLC diagnosed between 2004 and 2014 was obtained from the National Cancer Database. The follow-up end point is death or last follow-up (date of last contact). Patients were divided into 5 mutually exclusive cohorts by race. Data analysis was performed in October 2019.

MAIN OUTCOMES AND MEASURES

Cox proportional hazards models were used to calculate univariable and multivariable models. Multivariable analyses were conducted to assess the associations of race and socioeconomic factors with risk-adjusted outcomes. Overall survival between groups was depicted by Kaplan-Meier curves.

RESULTS

Of 72 409 patients analyzed (median [range] age, 67.0 [23.0-90.0] years), 40 289 (55.6%) were women. The distribution of disease stage was 10 619 patients (14.7%) with stage I disease, 7689 patients (10.6%) with stage II disease, and 54 101 patients (74.7%) with stage III disease. The median (range) duration of follow-up was 8.2 (2.4-15.8) months. Compared with White patients, the hazard of death decreased to 0.92 (95% CI, 0.89-0.95; P < .001) for African American patients and 0.83 (95% CI, 0.77-0.91; P < .001) for Asian patients. The difference in median survival among different racial groups was significant only among those with stage III SCLC. Other factors associated with better survival were female sex, high income, high education, private insurance, diagnostic confirmation by positive cytological analysis, increase in number of sampled regional lymph nodes, and earlier stage at diagnosis.

CONCLUSIONS AND RELEVANCE

This analysis highlights disparities in race and socioeconomic factors associated with outcomes of L-SCLC. Racial minorities, including African American and Asian patients, have better survival than White patients for L-SCLC after adjustment for sociodemographic factors.

[Clinicopathological characteristics and risk factors of station 4L lymph node metastasis of left non-small cell lung cancer]

OBJECTIVE

To analyze the clinicopathological characteristics and risk factors of 4L lymph node metastasis in left non-small cell lung cancer.

METHODS

We retrospectively analyzed the data of 134 patients undergoing surgical resection of left non-small cell lung cancer and 4L lymph node dissection, including 60 patients with squamous cell carcinoma (SCC) and 74 with lung adenocarcinoma (ADC). The clinicopathological characteristics of the patients were analyzed, and logistic regression analysis was used to identify the predictors of station 4L metastasis.

RESULTS

Of these patients, 16.4% (22/134) presented with station 4L metastasis. The patients with SCC and ADC showed significant differences in age, gender, smoking history, neoadjuvant chemotherapy, tumor size, tumor location and type, visceral pleural invasion, Ki-67 index, 4L metastasis and pathological TNM stage (stage Ⅱ). The rate of station 4L metastasis was significantly lower in SCC group than in ADC group. Univariate analysis revealed that pathological types (SCC or ADC), visceral pleural invasion, lymphovascular invasion, tumor markerabnormality, and station 5 to 10 metastasis were all high-risk factors for station 4L metastasis. Multivariate analysis suggested that the pathological type (OR=0.120, P=0.025), station 5 metastasis (OR=18.784, P=0.007) and station 10 metastasis (OR=5.233, P=0.044) were independent risk factors for 4L metastasis in patients with left non-small cell lung cancer.

CONCLUSIONS

In patients with left non-small cell lung cancer, station 4L metastasis is not rare and is more likely to occur in patients with lung adenocarcinoma. Dissection of the 4L lymph nodes should be performed in cases with low risk of damages of the adjacent tissues and high risk of station 4L metastasis.

Impact of histological components on selecting limited lymphadenectomy for lung adenocarcinoma ≤ 2 cm

OBJECTIVES

There is still some dispute regarding the performance of limited mediastinal lymphadenectomy (LML) even for lung adenocarcinoma ≤ 2 cm. We aimed to recognize the potential candidates who can benefit from LML based on the percentage of histological components (PHC).

METHODS

We analyzed 1160 surgical patients with invasive lung adenocarcinoma ≤ 2 cm from seven institutions between January 2012 and December 2015. All histological subtypes were listed in 5% increments by pathological slices. To test the accuracy of frozen section in judging PHC, frozen section slides from 140 cases were reviewed by three pathologists.

RESULTS

There were 882 patients with systematic mediastinal lymphadenectomy (SML) and 278 with LML. Multivariable analysis indicated that, the total percentage of micropapillary and solid components (PHC_MIP+S) > 5 % was the independent predictor of N2 metastasis (P < 0.001). Overall, recurrence-free survival (RFS) and overall survival (OS) favored SML compared with LML, but the subgroup analysis revealed LML and SML had similar prognosis in the group of PHC_MIP+S ≤ 5 %. Moreover, multivariable Cox analysis showed LML (vs. SML) was independently associated with worse prognosis for patients with PHC_MIP+S > 5 % (RFS, HR = 2.143, P < 0.001; OS, HR=1.963, P < 0.001), but not for those with PHC_MIP+S ≤ 5 % (RFS, P = 0.398; OS, P = 0.298). The sensitivity and specificity of frozen section to intraoperatively identify PHC_MIP+S ≤ 5 % were 97.6 % and 84.2 %, respectively.

CONCLUSIONS

PHC_MIP+S showed the predictive value for N2 metastasis and procedure-specific outcome (LML vs. SML). It may serve as a feasible indicator for identifying proper candidates of LML by using intraoperative frozen section.

Clinical Significance of Station 3A Lymph Node Dissection in Patients with Right-Side Non-Small-Cell Lung Cancer: A Retrospective Propensity-Matched Analysis

PURPOSE

To investigate the prognostic impact of station 3A lymph node (LN) dissection in patients with right-side non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

We retrospectively reviewed data of 1906 patients with primary right-side NSCLC who underwent lobectomy between January 2005 and December 2017 (570 patients underwent station 3A LN dissection and 1336 patients did not). Propensity score matching was conducted to minimize the effects of potential confounding factors. Disease-free survival (DFS) and overall survival (OS) were analyzed.

RESULTS

The metastasis rate of station 3A LN was 15.3% (87/570), which was second only to station 4 (17.3%). Only stations 10 and 11 LN metastases were found to be independent risk factors for station 3A LN metastasis (odds ratio = 19.43, 95% CI 1.21-311.12; P = 0.036 and odds ratio = 53.28, 95% CI 2.02-1404.90; P = 0.016, respectively). After propensity score matching, patients with dissection of station 3A LNs showed higher DFS (5-year DFS, 52.4% vs. 37.1%; P = 0.001) and OS (5-year OS, 58.8% vs. 48.7%; P = 0.007) than those without dissection. Subgroup analysis indicated that station 3A LN dissection was associated with significantly higher DFS and OS in patients with stage II and III disease. In multivariate survival analysis, dissection of 3A LNs retained its independent favorable effect on both DFS (hazard ratio = 0.76, 95% CI 0.64-0.90; P = 0.001) and OS (hazard ratio = 0.73, 95% CI 0.60-0.88; P = 0.001).

CONCLUSION

Station 3A LN involvement was not rare and station 3A LN dissection was associated with a more favorable prognosis in patients with right-side NSCLC.

Prognostic factors in stage IB non-small cell lung cancer according to the 8th edition of the TNM staging system after curative resection

Background

Patients with stage IB non-small cell lung cancer (NSCLC) with poor prognostic factors can be treated selectively with postoperative adjuvant chemotherapy. The aim of this study was to identify the prognostic factors of stage IB NSCLC according to the new 8^th edition of the tumor, node, and metastasis (TNM) staging system.

Methods

From 2005 to 2016, 211 patients who were diagnosed with stage IB NSCLC according to the 8^th edition of the TNM staging system underwent anatomical pulmonary resection (lobectomy or bilobectomy). We analyzed the outcomes of patients receiving adjuvant chemotherapy. The risk factors for prognosis after surgery were also analyzed for NSCLC stage IB.

Results

Differences between the 5-year recurrence-free-survival (RFS) rates (71.4% vs. 60.2%, P=0.173) and the 5-year disease-specific-survival (DSS) rates (88.0% vs. 81.4%, P=0.437) obtained by patients receiving surgical treatment only versus patients receiving both surgery and adjuvant chemotherapy, retrospectively, were not significant. Multivariate analysis was conducted to identify the risk factors for recurrence and cancer-related death. Lymphovascular invasion was an independent risk factor for both recurrence and cancer-related death [hazard ratio (HR) =2.045, P=0.020; HR =3.150, P=0.048, respectively).

Conclusions

Lymphovascular invasion was the only prognostic factor identified in patients with 8^th edition stage IB NSCLC. Adjuvant chemotherapy was not an effective treatment for patients with stage IB NSCLC. The efficacy of adjuvant chemotherapy for stage IB patients with lymphovascular invasion should be evaluated in a future study.

Comparison of Long-term Survival of Patients With Early-Stage Non-Small Cell Lung Cancer After Surgery vs Stereotactic Body Radiotherapy

IMPORTANCE

Previous comparisons of surgery and stereotactic body radiotherapy (SBRT) for early-stage (ES) non-small cell lung cancer (NSCLC) did not account for the extent of regional lymph node examination (LNE) during surgery.

OBJECTIVE

To compare long-term overall survival (OS) of patients with ES NSCLC after surgery vs SBRT when the extent of regional LNE in patients undergoing surgery is thoroughly considered.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study with survival comparisons using the multivariable Cox proportional hazards model and after propensity score matching. Data from the National Cancer Database were analyzed from October 28, 2018, through April 18, 2019. Patients with ES NSCLC diagnosed between January 1, 2004, and December 31, 2015, who underwent any curative-intent surgery or SBRT were included.

MAIN OUTCOMES AND MEASURES

Long-term OS.

RESULTS

Of 104 709 total patients, 91 330 underwent surgery (42 508 [46.5%] male; median [interquartile range] age, 68 [61-75] years) and 13 379 received SBRT (6065 [45.3%] male; median [interquartile range] age, 75 [68-81] years). Surgery, especially lobectomy (hazard ratio [HR], 0.53; 95% CI, 0.50-0.56), and regional LNE, especially when more than 10 lymph nodes were examined (HR, 0.73; 95% CI, 0.69-0.77), were associated with better long-term OS (P < .001). Pneumonectomy was not associated with reduced mortality risk when 0 nodes were examined (HR for stage T1, 1.43; 95% CI, 0.67-3.06; P = .35; HR for stage T2-T3, 0.62; 95% CI, 0.34-1.13; P = .12) or when more than 15 nodes were examined for stage T1 disease in patients younger than 80 years (HR, 0.77; 95% CI, 0.54-1.09; P = .14) or when patients aged 80 years or older received regional LNE of any extent (>15 nodes examined: HR for stage T1, 0.65; 95% CI, 0.16-2.64; P = .54; HR for stage T2-T3, 0.90; 95% CI, 0.50-1.60; P = .71). Less extensive surgery was not associated with improved OS when 0 nodes were examined in patients aged 80 years or older with stage T2 to T3 tumors (HR for lobectomy, 0.90; 95% CI, 0.65-1.25; P = .53) and in selected operable patients older than 75 years with stage T1 tumors (HR for lobectomy, 1.07; 95% CI, 0.57-2.00; P = .84).

CONCLUSIONS AND RELEVANCE

This study found that, overall, surgery coupled with regional LNE of appropriate extent was associated with the best long-term OS in patients with ES NSCLC.

Predictors and survival impact of station 4L metastasis in left non-small cell lung cancer

BACKGROUND

It remains unclear about the predictors and survival impact of station 4L metastasis in left-sided non-small cell lung cancer (NSCLC). This study aims to investigate these issues to explore the significance of station 4L lymph-node dissection (LND).

METHODS

We retrospectively enrolled 405 patients with station 4L LND, and divided them into the positive station 4L metastasis group and the negative station 4L metastasis group. The logistic regression was performed to identify the predictors of station 4L metastasis. The survival outcomes including disease-free survival (DFS) and overall survival (OS) were analyzed in pN2 patients to explore the prognostic effect of station 4L metastasis.

RESULTS

There were 48 (11.9%) patients in the positive station 4L metastasis group and 357 (88.1%) patients in the negative station 4L metastasis group. Station 5 metastasis (P = 0.008, OR 7.578, 95% CI 1.710-33.589), station 10 metastasis (P = 0.004, OR 7.133, 95% CI 1.904-26.717), and cN2 (P = 0.010, OR 5.062, 95% CI 1.473-17.392) were independent risk factors of station 4L metastasis. In pN2 patients, the positive station 4L metastasis group had inferior DFS (P = 0.019) and OS (P = 0.006) compared with the negative station 4L metastasis group, and station 4L metastasis was the independent risk factor for poor prognosis.

CONCLUSION

It is of great necessity to perform station 4L LND in left NSCLC, because station 4L metastasis is not rare and has an unfavorable prognosis.

The clinical value of a new method of functional lymph node dissection in video-assisted thoracic surgery right non-small cell lung cancer radical resection

Background

To evaluate the safety, thoroughness and feasibility of "tunnel-type en bloc mediastinal lymph node dissection" in video-assisted thoracic surgery (VATS) for right non-small cell lung cancer (NSCLC) radical resection, which functionally dissected the lymph nodes of station 2R/4R/7.

Methods

A retrospective study was performed in the clinical data of 196 patients with VATS right NSCLC radical resection. According to the different methods of lymph node dissection of station 2R, 4R and 7, they were divided into the tunnel-type group (n=102) and the routine group (n=94). The clinical data of two group were compared.

Results

The analyses of the baselines of the two groups are comparable. For lymph nodes dissection of station 2R/4R/7, operation time, the total number, positive number and metastasis incidence shown no significant difference between two groups (P>0.05). However, the amount of bleeding, postoperative thoracic drainage volume, extubation time, hospitalization days, the incidence of postoperative pulmonary infection and chronic cough were significantly lower in the tunnel-type group (P<0.05). There was no significant difference in 3-year recurrence and metastasis and in 3-year survival between tunnel-type group and routine group.

Conclusions

The tunnel-type group has more advantages, such as less surgical trauma, shorter hospitalization time, faster postoperative rehabilitation, even less postoperative chronic cough compared with the routine group. Therefore, we believe that the tunnel-type en bloc mediastinal lymph node dissection is a safe, thorough and feasible surgical method, which is worthy of being popularized and applied in the VATS right NSCLC radical resection.

Hyperbaric oxygen therapy for postoperative ischemic bronchitis after resection of lung cancer

Background

Hyperbaric oxygen therapy (HBOT) has been used successfully in the treatment of specific ischemic injuries, but has been a little evaluated specifically in postoperative ischemic bronchitis (POIB). The purpose of this study was to evaluate the effect of HBOT when used for POIB after resection of lung cancer.

Methods

From January 1999 to December 2016, 1,100 patients underwent lymph node dissection (LND) and either anatomic pulmonary resection or lung resection with bronchoplasty for lung cancer. POIB was diagnosed by bronchoscopy. HBOT was administered after POIB was diagnosed. HBOT comprised one 60-minute session daily in the hyperbaric chamber at 2.0 absolute atmospheres with 100% oxygen. We retrospectively analyzed the clinical course, timing of onset of POIB, outcomes, and any adverse events.

Results

Seven patients were identified to have had POIB treated with HBOT, all of whom were men with a smoking history and a median age of 65 years (range, 57-72 years). The operative procedures included three lung resections with bronchoplasty, three right lower lobectomies, and one right middle lobectomy performed owing to torsion of the middle lobe after right upper sleeve lobectomy. All 7 patients underwent subcarinal LND. POIB was diagnosed at a median of 11 days (range, 4-41 days) postoperatively. The median duration of an HBOT session was 7 days (range, 3-11 days). POIB resolved in 5 patients but worsened in 2, both of whom required further surgery.

Conclusions

Prospective clinical trials are now needed to confirm the potential benefits of HBOT in POIB.

Clinical Significance of 4L Lymph Node Dissection in Left Lung Cancer

Purpose

To investigate the prognostic impact of 4L lymph node (LN) dissection in left lung cancer and to analyze the relative risk factors for 4L LN metastasis.

Patients and Methods

We retrospectively collected data from 657 patients with primary left lung cancer who underwent surgical pulmonary resection from January 2005 to December 2009. One hundred thirty-nine patients underwent 4L LN dissection (4LD+ group); the other 518 patients did not receive 4L LN dissection (4LD− group). Propensity score weighting was applied to reduce the effects of observed confounding between the two groups. Study end points were disease-free survival (DFS) and overall survival (OS).

Results

The metastasis rate of station 4L was 20.9%, which was significantly higher than those of station 7 (14.0%; P = .048) and station 9 (9.8%; P < .001). Station 4L metastasis was associated with most other LN station metastases in univariate analysis, but only station 10 LN metastasis was an independent risk factor for 4L LN metastasis (odds ratio, 0.253; 95% CI, 0.109 to 0.588; P = .001) in multivariate logistic analysis. The 4LD+ group had a significantly better survival than the 4LD− group (5-year DFS, 54.8% v 42.7%; P = .0376; 5-year OS, 58.9% v 47.2%; P = .0200). After allowing potential confounders in multivariate survival analysis, dissection of 4L LN retained its independent favorable effect on DFS (hazard ratio, 1.502; 95% CI, 1.159 to 1.947; P = .002) and OS (hazard ratio, 1.585; 95% CI, 1.222 to 2.057; P = .001). Propensity score weighting further confirmed that the 4LD+ group had a more favorable DFS ( P = .0014) and OS ( P < .001) than the 4LD− group.

Conclusion

Station 4L LN involvement is not rare in left lung cancer, and dissection of the 4L LN station seems to be associated with a more favorable prognosis as compared with those who did not undergo this dissection.

Predictors of lymph node metastasis and possible selective lymph node dissection in clinical stage IA non-small cell lung cancer

Background

The pathologic stages of lymph nodes usually differ from preoperatively predicted in lung cancers and it is difficult to predict the metastasis of lymph nodes for the patients diagnosed as clinical stage IA non-small cell lung cancers (NSCLC). This study aimed to investigate the patterns of lymph node metastasis and the risk factors predicting lymph node metastasis in the patients with clinical stage IA NSCLCs.

Methods

All patients diagnosed as clinical stage IA NSCLC from July 2013 to June 2017 in our center were retrospectively reviewed, and a total number of 1,543 patients who underwent anatomical lobectomy with systematic lymph node dissection were enrolled in this study. Multivariate logistic regression analysis was performed to identify the risk factors predicting lymph node metastasis, and Fisher's exact test was used to confirm the lymph node spread mode according to the locations of primary tumors.

Results

Totally, lymph node metastases presented in 131 patients (8.5%) in this series. Sixty-three patients presented N1 diseases, 17 patients showed only skipped N2 diseases, and 51 patients had simultaneous N1 and N2 positive lymph nodes. No lymph node metastasis was found in the patients with pure ground grass opacity (GGO). When patients were arbitrarily divided into six groups by the longest tumor diameter of ≤0.5, 0.6-1, 1.1-1.5, 1.6-2.0, 2.1-2.5, 2.6-3 cm, the lymph node metastasis rates of each group were 0% (0/20), 1.5% (4/264), 4.7% (20/429), 8.6% (29/336), 13.1% (38/290), 19.6% (40/204), respectively. When the patients with pure GGO were excluded, the lymph node metastasis rates in the patients with partial or total solid tumors were 0% (0/10), 2.4% (4/164), 6.6% (20/303), 11.7% (29/249), 16.0% (38/238) and 23.1% (40/173). The cut off value showed by receiver operating characteristic (ROC) curve for tumor size was 1.95 cm, and the area under the curve (AUC) was measured as 0.681 (P<0.001, 95% CI: 0.630-0.726). Multivariate logistic regression analysis indicated that male patients [odds ratio (OR) =3.34, P=0.012], smoking history (OR =14.12, P<0.001), solid components (OR =3.34, P=0.01), large tumor size (OR =1.9, P<0.001), poor differentiation (OR =2.25, P=0.013), lymphovascular invasion (OR =58.45, P<0.001), visceral pleural invasion (OR =48.37, P<0.001) were significantly associated with lymph node metastasis in clinical stage IA NSCLC. The rate of non-lobe specific lymph node metastasis was 15.8-40.0% when any of the lobe specific lymph nodes was positive, while it was only 0-2.2% when all lobe specific lymph nodes were negative.

Conclusions

Tumor size, solid components, poor differentiation, lymphovascular invasion, visceral pleural invasion and smoking history were significant factors predicting lymph node metastasis of clinical stage IA NSCLC. Patients with negative lobe-specific lymph node have very low risk of metastasis to the non-lobe specific lymph nodes. Lobe-specific lymph node dissection may become an alternative lymph node dissection mode for clinical stage IA NSCLC, especially for tumors ≤2 cm.

Tumor histology predicts mediastinal nodal status and may be used to guide limited lymphadenectomy in patients with clinical stage I non-small cell lung cancer

OBJECTIVE

Methods to minimize surgical trauma from mediastinal lymphadenectomy in patients with early-stage lung cancer are still immature. This study aimed to identify predictors of negative pathologic N2, which may be used to select patients for limited mediastinal lymphadenectomy.

METHODS

Clinicopathologic features of 1430 patients with resected clinical stage I non-small cell lung cancer and complete mediastinal lymphadenectomy were retrospectively analyzed for variables associated with negative N2 nodal metastasis (2008-2015). Overall and recurrence-free survival in patients after complete or limited mediastinal lymphadenectomy were assessed via Kaplan-Meier survival analysis and log-rank testing. The accuracy of frozen section diagnosis for predicting final pathology was retrospectively assessed in 126 randomly selected patients after the surgery.

RESULTS

Multivariable analysis revealed that tumor size ≤2 cm, negative pN1, lymphovascular invasion, and lepidic adenocarcinoma were associated with negative mediastinal nodal metastasis. Notably, none of the patients with histology of adenocarcinoma in situ, minimally invasive adenocarcinoma, or lepidic pattern-predominant adenocarcinoma on final pathology had pN2 disease, and the 5-year overall and recurrence free-survival of these patients (99.3% and 99.3%, respectively) was not different from those after limited mediastinal lymphadenectomy (98.7% and 100%, P = .582 and .511, respectively). If these subtypes were classified together as the low-risk group, the concordance rate between frozen section and final pathology diagnosis was 88.9% in the retrospective test cohort.

CONCLUSIONS

Tumor histology may predict negative mediastinal metastasis in patients with early-stage lung cancer. Future prospective studies are merited to validate the feasibility of using frozen section to select patients for limited mediastinal lymphadenectomy.

Lymph Node Dissection in Thymic Malignancies: Implication of the ITMIG Lymph Node Map, TNM Stage Classification, and Recommendations

OBJECTIVES

The aim of this study is to investigate the pattern of lymphatic metastasis and suggest a lymph node dissection (LND) strategy for thymic malignancies.

METHODS

We retrospectively reviewed 131 thymic malignancy patients who had undergone LND. The recently introduced nodal map of the International Thymic Malignancy Interest Group/International Association for the Study of Lung Cancer and the TNM (tumor, node, metastasis) stage classification were used for grouping and staging the lymph nodes. The pattern of lymphatic metastasis and factors in lymphatic metastasis were investigated.

RESULTS

Node metastasis was detected in 13 patients (N1 in six and N2 in seven). Six N2 patients (86%) had right paratracheal node (RPN) metastases. The rates of node metastasis were 1% at T1 and 37.5% at T2/3 (p < 0.001). The rates of node metastasis were 8% in the M0 and 43% in the M1 (p = 0.03). The rate was higher for thymic carcinoma (25%) than for thymoma (5.1%, p = 0.01), and the rates also differed between the subtypes of thymoma. There was no node metastasis of the A, AB, or B1 types. Tumor size was also a significant factor in node metastasis. The optimal cutoff value for the node metastasis was 6 cm and the specificity was 62%. Only 16% of the patients had received a preoperative histologic diagnosis. All patients with node metastasis had TNM stage II or higher thymic malignancy. The freedom from recurrence rate of the pN1/2 was significantly worse than that of the pN0 (5-year rate 38.5% versus 87.9%, p < 0.001).

CONCLUSION

A status of stage II or higher was the most specific predictor of node metastasis, and the RPN was a crucial station for lymphatic metastasis in thymic malignancies. Thus, LND including RPN is recommended in stage II or higher thymic malignancies.

The influence of the ipsilateral bronchopulmonary lymph node dissection on survival rate in non-small-cell lung cancer

Aim. The analysis of the survival rates depending on the extent of surgery and the influence of ipsilateral bronchopulmonary lymph node dissection on this indicator. Methods. Medical charts of 1324 in- and outpatients who underwent surgeries in the department of thoracic surgery №1 in 2000-2009 were analyzed. Patients were allocated to the groups (944 patients in total) according to clinical form and stage (peripheral cancer - 555 patients, central cancer - 389 patients), histological type (peripheral cancer - 254 patients with adenocarcinoma and 204 patients with squamous cell carcinoma, central cancer - 44 patients with adenocarcinoma and 304 patients with squamous cell carcinoma). 5-year survival rate was calculated in each group depending on the extent of surgery (lobectomy, pneumonectomy), and the impact of ipsilateral bronchopulmonary lymph node dissection that was performed in all cases of pulmonectomy on this indicator was analyzed. Results. After lobectomy, 5-year survival rates were similar in both groups - 57.08 and 55.14% (p=0.8). However, 5-year survival rate in patients after pneumonectomy due to central lung cancer (41.13%) was significantly higher compared to peripheral cancer (26.83%, p=0.02). Survival rates for the certain stages of the disease after pneumonectomy due to central cancer were significantly higher when compared to peripheral cancer. No significant differences in survival rates in different histological types of peripheral cancer and in the central form of lung adenocarcinoma were revealed, in contrast to squamous cell cancer. The survival rates after pulmonectomy in cases of central squamous cancer were only slightly different from those after lobectomy. Gained preliminary data of retrospective analysis reflect the influence of lymph node dissection on survival. Conclusion. The best results after pneumonectomy were obtained in patients with central form of squamous cell carcinoma. However, in the cases of peripheral cancer early stages of the disease prevailed after lobectomy, which obviously increased survival rates. If proven, the proposed method will enhance the survival rates in patients with non-small cell lung cancer.

The seventh tumour-node-metastasis staging system for lung cancer: Sequel or prequel?

Anatomical cancer extent is an important predictor of prognosis and determines treatment choices. In non-small-cell lung cancer (NSCLC) the tumour–node–metastasis (TNM) classification developed by Pierre Denoix replaced in 1968 the Veterans Administration Lung cancer Group (VALG) classification, which was still in use for small-cell lung cancer (SCLC). Clifton Mountain suggested several improvements based on a database of mostly surgically treated United States (US) patients from a limited number of centres. This database was pivotal for a uniform reporting of lung cancer extent by the American Joint Committee of Cancer (AJCC) and the International Union against Cancer (IUCC), but it suffered increasingly from obsolete diagnostic and staging procedures and did not reflect new treatment modalities. Moreover, its findings were not externally validated in large Japanese and European databases, resulting in persisting controversies which could not be solved with the available database. The use of different mediastinal lymph-node maps in Japan, the (US) and Europe facilitated neither the exchange nor the comparison of treatment results.

Peter Goldstraw, a United Kingdom (UK) thoracic surgeon, started the process of updating the sixth version in 1996 and brought it to a good end 10 years later. His goals were to improve the TNM system in lung cancer by addressing the ongoing controversies, to validate the modifications and additional descriptors, to validate the TNM for use in staging SCLC and carcinoid tumours, to propose a new uniform lymph-node map and to investigate the prognostic value of non-anatomical factors. A staging committee was formed within the International Association for the Study of Lung Cancer (IASLC) – which supervised the collection of the retrospective data from >100,000 patients with lung cancer – treated throughout the world between 1990 and 2000, analyse them with the help of solid statistics and validate externally with the Surveillance, Epidemiology and End Results (SEER) database.

The ten modifications and the mediastinal lymph-node map – which were proposed in 2007 and adopted by the AJCC and IUCC in their respective seventh revision of the TNM system – were implemented as of 2010 and were rapidly adopted by the thoracic oncology community and cancer registries. As expected, not all controversies could be fully addressed, and the need for a prospective data set containing more granular information was felt early on. This data set of 25,000 consecutive incident cases will form the base for the eighth revision in 2017 and is currently being collected. Other threats are the role of stage migration and the increasing number of biological factors interfering with disease extent for prognostication. The latter issue will be addressed by the creation of a prognostic index, including several prognostic factors, of which stage will be one.

For the time being, the seventh TNM classification is considered the gold standard for the description of disease extent, initial treatment allocation and the reporting of treatment results. The uniform use of the TNM descriptors and the lymph-node map by all involved in lung cancer care is to be considered a process indicator of quality.

The role of segmental nodes in the pathological staging of non-small cell lung cancer

Background

Segmental nodes are not examined routinely in current clinical practice for lung cancer, the role of segmental nodes in pathological staging of non-small cell lung cancer after radical resection was investigated.

Methods

A total of 113 consecutive non-small cell lung cancer patients who underwent radical resection between June 2009 and December 2011 were retrospectively reviewed. All the operations were performed by the same group of surgeons. N2 nodes, hilar nodes, interlobar nodes and some lobar nodes were collected during surgery. The removed lung lobes were dissected routinely along lobar and segmental bronchi to collect lobar nodes and segmental nodes. The collected lymph nodes were separately labeled for histological examination.

Results

The detection rates of hilar nodes, interlobar nodes, lobar nodes and segmental nodes were 61.1%, 85.0%, 75.2% and 80.5%, respectively. The metastasis rates of hilar nodes, interlobar nodes, lobar nodes and segmental nodes were 5.3%, 10.5%, 16.8% and 14.2%, respectively. There were 68 cases of N0 disease, 16 cases of N1 disease and 29 cases of N2 disease. If an analysis of segmental lymph nodes had been omitted, six patients (37.5% of N1 disease) would have been down-staged to N0, and two cases of multiple-zone N1 disease would have been misdiagnosed as single-zone N1 disease, one patient would have been misdiagnosed as N2 disease with skip metastases.

Conclusion

Segmental nodes play an important role in the accurate staging of non-small cell lung cancer, and routinely dissecting the segmental bronchi to collect the lymph nodes is feasible and may be necessary.

Design and characterization of an optimized simultaneous color and near-infrared fluorescence rigid endoscopic imaging system

We report the design, characterization, and validation of an optimized simultaneous color and near-infrared (NIR) fluorescence rigid endoscopic imaging system for minimally invasive surgery. This system is optimized for illumination and collection of NIR wavelengths allowing the simultaneous acquisition of both color and NIR fluorescence at frame rates higher than 6.8 fps with high sensitivity. The system employs a custom 10-mm diameter rigid endoscope optimized for NIR transmission. A dual-channel light source compatible with the constraints of an endoscope was built and includes a plasma source for white light illumination and NIR laser diodes for fluorescence excitation. A prism-based 2-CCD camera was customized for simultaneous color and NIR detection with a highly efficient filtration scheme for fluorescence imaging of both 700- and 800-nm emission dyes. The performance characterization studies indicate that the endoscope can efficiently detect fluorescence signal from both indocyanine green and methylene blue in dimethyl sulfoxide at the concentrations of 100 to 185 nM depending on the background optical properties. Finally, we performed the validation of this imaging system in vivo during a minimally invasive procedure for thoracic sentinel lymph node mapping in a porcine model.

Selective mediastinal lymphadenectomy without intraoperative frozen section examinations for clinical stage I non-small-cell lung cancer: retrospective study of 403 cases

OBJECTIVE

The extent of mediastinal lymphadenectomy for clinical stage I non-small-cell lung cancer (NSCLC) remains controversial. This study explored the value of selective mediastinal lymphadenectomy from the clinical viewpoint.

METHODS

From 2005 to 2008, a total of 403 patients diagnosed clinically as having stage I NSCLC underwent lobectomy and mediastinal lymph node dissection. Among them, 309 underwent complete mediastinal lymphadenectomy, and the other 94 underwent selective mediastinal lymphadenectomy. We compared the perioperative parameters and overall survival statistics for the two groups retrospectively.

RESULTS

The two groups had no significant differences in sex, pathology, tumor location, or preoperative staging. The selective mediastinal lymphadenectomy group had an older average age, with a much higher rate of patients >70 years of age (p = 0.016). Also, the patients were apt to undergo thoracoscopic lobectomy (p = 0.044). This group had shorter operating times and less intraoperative bleeding. No significant differences in total drainage volume, length of hospital stay, or complication rates were found between the two groups. The mean follow-up periods were 35.8 ± 13.7 vs. 34.6 ± 17.2 months. Local and distant recurrence rates were 25.6 % vs. 30.9 %, respectively (p = 0.560). The 3-year and 5-year overall survival rates were 83.0 % and 74.6 % vs. 75.1 % and 68.5 %, respectively (p = 0.216).

CONCLUSIONS

For patients with clinical stage I NSCLC, selective mediastinal lymphadenectomy can reduce the trauma caused by the procedure, especially for elderly patients and those with co-morbidities. Survival was acceptable and was no worse than that after complete mediastinal lymphadenectomy. Our results need to be confirmed by prospective randomized controlled studies.

Recurrence of mediastinal node cancer after lobe-specific systematic nodal dissection for non-small-cell lung cancer

OBJECTIVES

The standard surgical treatment for patients with non-small-cell lung cancer (NSCLC) is lobectomy with systematic nodal dissection (SND). Lobe-specific patterns of nodal metastases have been recognized, and lobe-specific SND (L-SND) has been reported. We performed L-SND depending on patient-related factors, such as age or the presence of diabetes or respiratory dysfunction, or in the context of specific tumour-related factors, such as the presence of a tumour with a wide area of ground-glass opacity.

METHODS

Between September 2002 and December 2008, 335 consecutive patients with clinical and intraoperative N0 NSCLC underwent curative lobectomies at Shizuoka Cancer Center Hospital. Among these 335 patients, 206 underwent SND (Group A) and 129 underwent L-SND. Of the 129 patients undergoing L-SND, 98 underwent L-SND due to patient-related factors (Group B) and 31 underwent L-SND due to tumour-related factors (Group C).

RESULTS

There were no significant differences in morbidity or blood loss between patients undergoing SND or L-SND, but there was a significant difference in the mean operative times. The 5-year disease-free survival (5-DFS) and 5-year overall survival (5-OS) of patients in Group C were 100%. Although the patients in Group B showed no significant difference in 5-DFS and 5-OS compared with Group A, patients in Group B had significantly more initial recurrence of mediastinal node cancer than did the Group A patients (P = 0.0050).

CONCLUSIONS

The recurrence of mediastinal node cancer in patients undergoing L-SND was significantly greater than that in those undergoing SND.

New staging system: how does it affect our practice?

The anatomic extent of disease, as described by the TNM classification, remains the most powerful prognostic indicator for lung cancer. It is used daily by specialists in all branches of lung cancer care and research. Any new edition of the TNM classification is therefore an important event in the thoracic oncology community and one greeted with mixed feelings. The changes introduced in the seventh edition were the first for 13 years and arguably the most profound since the first data-driven revision more than 40 years earlier. Inevitably there will be concerns that any change in the T, N, or M descriptors and resultant stage groupings will have implications for previous treatment pathways. In this article, the changes to the classification are described, and their possible impacts on clinical care and research are discussed.

Video-assisted vs open mediastinal lymphadenectomy for Stage I non-small-cell lung cancer: results of a prospective randomized trial

OBJECTIVES

Since the introduction of video-assisted lobectomy for non-small-cell lung cancer (NSCLC) into clinical practice, it has been discussed controversially whether mediastinal lymphadenectomy can be performed as effectively as an open procedure via thoracotomy. Therefore, we address this issue in a prospective randomized trial conducted in our institution.

METHODS

In total, 66 patients with completely staged clinical Stage I NSCLC were included and randomized either into a video-assisted group (n = 34) or into the conventional lobectomy group (n = 32). The video-assisted thoracoscopic (VATS) lobectomy was performed by using a 4- to 5-cm utility incision in the fourth or fifth intercostal space and two additional 10-mm ports without rib spreading. The conventional lobectomy was done via an anterolateral thoracotomy. Lymph nodes were classified according to the International Association for the Study of Lung Cancer classification; for right-sided tumours, lymph nodes number 2R, 4R, 7, 8, 9, 10, 11 and 12 were dissected, and for left-sided tumours, lymph nodes number 5, 6, 7, 8, 9, 10, 11 and 12. For the subsequent analyses, lymph nodes were grouped into different zones consisting of Zone 1 (2R and 4R), Zone 2 (7), Zone 3 (8R and 9R), Zone 4 (10R, 11 R and 12R), Zone 5 (4 L), Zone 6 (5 and 6), Zone 7 (8L and 9L) and Zone 8 (10 L, 11 L and 12L).

RESULTS

Both groups were comparable with respect to different clinical pathological parameters (age, tumour size and comorbidity). In the video-assisted group, 2 patients were excluded due to conversion to an open thoracotomy. The number of mediastinal lymph nodes removed was as follows: VATS (right side) 24.0 lymph nodes/patient, open right-sided 25.2 lymph nodes/patient, VATS (left side) 25.1 lymph nodes/patient and open left-sided 21.1 lymph nodes/patient. With respect to the zones mentioned above, we found the following results: VATS vs open (mean number of lymph nodes/patient): Zone 1: 9 vs 8.5; Zone 2: 6.3 vs 5.6; Zone 3: 2.4 vs 3.2; Zone 4: 6.5 vs 6.9; Zone 5: 0 vs 0.5; Zone 6: 3.2 vs 3.7; Zone 7: 4.6 vs 3.2 and Zone 8: 10.5 vs 8.9. There were no statistically significant differences between the procedures, either with respect to the overall number of lymph nodes or with respect to the number of lymph nodes in each zone.

CONCLUSIONS

Mediastinal lymph node dissection can be performed as effectively by the video-assisted approach as by the open thoracotomy approach. Furthermore, the video-assisted approach allows a better visualization of different lymph node zones.

Nodal involvement pattern in resectable lung cancer according to tumor location

The aim in this study was to define the pattern of lymph node metastasis according to the primary tumor location. In this retrospective cohort study, each of the operable patients diagnosed with lung cancer was grouped by tumor mass location. The International Association for the Study of Lung Cancer nodal chart with stations and zones, established in 2009, was used to define lymph node levels. From 2006 to 2010, 197 patients underwent a lobectomy with systematic nodal resection for primary lung cancer at Chiang Mai University Hospital. There were 123 male and 74 female patients, with ages ranging from 16– 85 years old and an average age of 61.31. Analyses of tumor location, histology type, and nodal metastasis were performed. The locations were the right upper lobe in 63 patients (31.98%), the right middle lobe in 18 patients (9.14%), the right lower lobe in 30 patients (15.23%), the left upper lobe in 55 patients (27.92%), the left lower lobe in 16 patients (8.12%), and mixed lobes (more than one lobe) in 15 patients (7.61%). The mean tumor size was 4.45 cm in diameter (range 1.2–16.5 cm). Adenocarcinoma was the most common histological type, which occurred in 132 cases (67.01%), followed by squamous cell carcinoma in 41 cases (20.81%), bronchiolo alveolar cell carcinoma in nine cases (4.57%), and large cell carcinoma in seven cases (3.55%). Eighteen cases (9.6%) had skip metastasis (mediastinal lymph node metastasis without hilar node metastasis). Adenocarcinoma and intratumoral lymphatic invasion were the predictors of mediastinal lymph node metastases. There were statistically significant differences between a tumor in the right upper lobe and the right lower lobe. However, there were no statistically significant differences between tumors in the other lobes. In conclusion, tumor location is not a precise predictor of the pattern of nodal metastasis. Systematic lymph node dissection is the only way to accurately determine lymph node status. Further studies are required for evaluation and conclusions.

Lymphatic microvessel density combined with CT used in the diagnosis of mediastinal and hilar lymph node metastasis of non-small cell lung cancer

BACKGROUND AND AIMS

Lymphatic microvessel density (LMVD) has been demonstrated to correlate with tumor metastasis. The purpose of this study is to determine whether the criteria combining LMVD with computed tomography (CT) could improve the diagnostic accuracy of lymph node (LN) metastasis in non-small cell lung cancer (NSCLC).

METHODS

Ninety four patients with NSCLC who had chest CT scans preoperatively and LMVD tested by immunohistochemistry postoperatively were randomized into two groups: the training set (n = 66) and the test set (n = 28). Cut-off point of LMVD was selected to separate the LN metastasis-predictive positive and negative groups. On the basis of LMVD levels, chest CTs of the training set were re-analyzed and hypothetical criteria for LN metastasis diagnosis were established. Diagnostic characteristics for LN metastasis were tested by using the combined criteria in the test set as compared to those of CT alone.

RESULTS

There was a significantly positive correlation between LMVD and LN metastasis (p <0.01). For sensitivity, specificity, positive predictive value (PPV) and negative predictive values (NPV), accuracy was 67, 81, 75, 81 and 79% for the combined criteria, respectively. Diagnostic efficacy of the combined criteria was significantly higher than that of CT only (p <0.05).

CONCLUSIONS

Diagnosis of LN metastasis using a combination of LMVD and CT is superior to the CT-only diagnosis. In future clinical trials, it is necessary to evaluate the efficacy of adjuvant therapy for the selection of patients according to the combined criteria.