Effectiveness of radical systematic mediastinal lymphadenectomy in patients with resectable non-small cell lung cancer: results of a prospective randomized trial

So Now We Know-Reflections on the Extent of Resection for Stage I Lung Cancer

Lobectomy has been the standard treatment for stage I lung cancer in healthy patients, largely based on a randomized trial published in 1995. Nevertheless, research has continued regarding the role of sublobar resection. Three additional randomized trials addressing resection extent in healthy patients have recently been published. These 4 trials involve differences in design, eligibility, interventions, and intraoperative processes. Patients were ineligible if intraoperative assessment demonstrated stage > IA or inadequate resection margins. All trials consistently show no differences in perioperative morbidity, mortality, and postoperative changes in lung function between sublobar resection and lobectomy-consistent with other nonrandomized evidence. Long-term outcomes are generally encouraging of lesser resection, but some inconsistencies are apparent. The 2 larger recent trials demonstrated no overall survival difference while the others suggested better survival after lobectomy versus sublobar resection. Recurrence-free survival was found to be the same after lobectomy versus sublobar resection in 3 trials, despite higher locoregional recurrences after sublobar resection. The low 5-year recurrence-free survival (64%, regardless of resection extent) in 1 recent trial highlights the need for further optimization. Thus, there is high-level evidence that sublobar resection is a reasonable alternative to lobectomy in healthy patients. However, variability in long-term results suggests that aspects of patients, tumors and interventions need to be better understood. Therefore, we propose to apply sublobar resection cautiously; especially because there are no short-term benefits. Sublobar resection requires careful attention to intraoperative details (nodes, margins), and may be best suited for less aggressive (eg, ground glass, slow growing) tumors.

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.

The Role of Lymphadenectomy in Early-Stage NSCLC

Lung cancer remains the leading cause of cancer-related death worldwide. The involvement of lymph nodes by the tumor has a strong impact on survival of patients. For this reason, lymphadenectomy plays a crucial role in the staging and prognosis of NSCLC, to define the most appropriate therapeutic strategies concerning the stage of the disease. To date, the benefit, in terms of survival, of the different extents of lymphadenectomy remains controversial in the scientific community. It is recognized that metastatic involvement of mediastinal lymph nodes in lung cancer is one of the most significant prognostic factors, in terms of survival, and it is therefore mandatory to identify patients with lymph node metastases who may benefit from adjuvant therapies, to prevent distant disease and local recurrences. The purpose of this review is to evaluate the role of lymphadenectomy in early-stage NSCLC in terms of efficacy and accuracy, comparing systematic, sampling, and lobe-specific lymph node dissection and analyzing the existing critical issue, through a search of the most relevant articles published in the last decades.

A Comparison of Total Thoracoscopic and Robotic Surgery for Lung Cancer Lymphadenectomy

BACKGROUND

Robotic-assisted thoracic surgery (RATS) is used increasingly frequently in major lung resection for early stage non-small-cell lung cancer (NSCLC) but has not yet been fully evaluated. The aim of this study was to compare the surgical outcomes of lymph node dissection (LND) performed via RATS with those from totally thoracoscopic (TT) four-port videothoracoscopy.

METHODS

Clinical and pathological data were collected retrospectively from patients with clinical stage N0 NSCLC who underwent pulmonary resection in the form of lobectomy or segmental resection between June 2010 and November 2022. The assessment criteria were number of mediastinal lymph nodes and number of mediastinal stations dissected via the RATS approach compared with the four-port TT approach.

RESULTS

A total of 246 pulmonary resections with LND for clinical stages I-II NSCLC were performed: 85 via TT and 161 via RATS. The clinical characteristics of the patients were similar in both groups. The number of mediastinal nodes dissected and mediastinal stations dissected was significantly higher in the RATS group (TT: mean ± SD, 10.72 ± 3.7; RATS, 14.74 ± 6.3 [p < 0.001]), except in the inferior mediastinal stations. There was no difference in terms of postoperative complications.

CONCLUSIONS

In patients with early stage NSCLC undergoing major lung resection, the quality of hilomediastinal LND performed using RATS was superior to that performed using TT.

Comparison of the Outcomes between Systematic Lymph Node Dissection and Lobe-Specific Lymph Node Dissection for Stage I Non-small Cell Lung Cancer

BACKGROUND

This study compares the surgical and long-term outcomes, including disease-free survival (DFS), overall survival (OS), and cancer-specific survival (CSS), between lobe-specific lymph node dissection (L-SND) and systematic lymph node dissection (SND) among patients with stage I non-small cell lung cancer (NSCLC).

METHODS

In this retrospective study, 107 patients diagnosed with clinical stage I NSCLC undergoing video-assisted thoracic surgery lobectomy (exclusion of the right middle lobe) from January 2011 to December 2018 were enrolled. The patients were assigned to the L-SND (n = 28) and SND (n = 79) groups according to the procedure performed on them. Demographics, perioperative data, and surgical and long-term oncological outcomes were collected and compared between the L-SND and SND groups.

RESULTS

The mean follow-duration was 60.6 months. The demographic data and surgical outcomes and long-term oncological outcomes were not significantly different between the two groups. The 5-year OS of the L-SND and SND groups was 82% and 84%, respectively. The 5-year DFS of the L-SND and SND groups was 70% and 65%, respectively. The 5-year CSS of the L-SND and SND groups was 80% and 86%, respectively. All the surgical and long-term outcomes were not statistically different between the two groups.

CONCLUSION

L-SND showed comparable surgical and oncologic outcomes with SND for clinical stage I NSCLC. L-SND could be a treatment choice for stage I NSCLC.

Comparison of neoadjuvant chemohormonal therapy vs. extended pelvic lymph-node dissection in high-risk prostate cancer treated with robot-assisted radical prostatectomy

We compared the impact of treatment strategies on postoperative complications and prognosis between robot-assisted radical prostatectomy (RARP) plus extended pelvic lymph-node dissection (ePLND) and RARP plus neoadjuvant chemohormonal therapy (NCHT) without ePLND. We retrospectively evaluated 452 patients with high-risk prostate cancer (defined as any one of prostate-specific antigen ≥ 20 ng/mL, Gleason score 8-10, or cT2c-3) who were treated with RARP between January 2012 and February 2021. The patients were divided into two groups: RARP with ePLND (ePLND group) and NCHT plus RARP without ePLND (NCHT group). We compared the complication rate (Clavien-Dindo classification), biochemical recurrence-free survival, and castration-resistant prostate cancer (CRPC)-free survival between the groups. We performed multivariable Cox regression analysis using inverse probability weighting (IPTW) methods to assess the impact of the different treatments on prognosis. There were 150 and 302 patients in the ePLND and NCHT groups, respectively. The postoperative complication rate was significantly higher in the ePLND group than in the NCHT group (P < 0.001). IPTW-adjusted biochemical recurrence-free survival and CRPC-free survival were significantly higher in the NCHT group than in the ePLND group (hazard ratio [HR] 0.29, P < 0.001, and HR 0.29, P = 0.010, respectively). NCHT plus RARP without ePLND may reduce the risk of postoperative complications compared with ePLND during RARP. The impact of treatment strategies on oncological outcomes needs further studies.

[Prediction of Lymph Node Metastasis of Mixed Ground-glass Nodules Based on Clinical Imaging Information]

BACKGROUND

Previous studies have shown that lymph node metastasis only occurs in some mixed ground-glass nodules (mGGNs) which the pathological results were invasive adenocarcinoma (IAC). However, the presence of lymph node metastasis leads to the upgrading of tumor-node-metastasis (TNM) stage and worse prognosis of the patients, so it is important to perform the necessary evaluation before surgery to guide the operation method of lymph node. The aim of this study was to find suitable clinical and radiological indicators to distinguish whether mGGNs with pathology as IAC is accompanied by lymph node metastasis, and to construct a prediction model for lymph node metastasis.

METHODS

From January 2014 to October 2019, the patients with resected IAC appearing as mGGNs in computed tomography (CT) scan were reviewed. All the lesions were divided into two groups (with lymph node metastasis or not) according to their lymph node status. Lasso regression model analysis by applying R software was used to evaluate the relationship between clinical and radiological parameters and lymph node metastasis of mGGNs.

RESULTS

A total of 883 mGGNs patients were enroled in this study, among which, 12 (1.36%) showed lymph node metastasis. Lasso regression model analysis of clinical imaging information in mGGNs with lymph node metastasis showed that previous history of malignancy, mean density, mean density of solid components, burr sign and percentage of solid components were informative. Prediction model for lymph node metastasis in mGGNs was developed based on the results of Lasso regression model with area under curve=0.899.

CONCLUSIONS

Clinical information combined with CT imaging information can predict lymph node metastasis in mGGNs.

Long-term survival outcomes after lobe-specific nodal dissection in patients with early non-small-cell lung cancer

OBJECTIVES

We investigated the long-term outcomes of lobe-specific nodal dissection (LSD) and systematic nodal dissection (SND) in patients with non-small-cell lung cancer (NSCLC).

METHODS

Patients with c-stage I and II NSCLC who underwent lobectomy with mediastinal nodal dissection were retrospectively analysed. After propensity score matching, we assessed the overall survival (OS), recurrence-free survival (RFS) and cumulative incidence of death (CID) from primary lung cancer and other diseases.

RESULTS

The median follow-up period was 8.4 years. Among 438 propensity score-matched pairs, OS and RFS were similar between the LSD and SND groups [hazard ratio (HR), 0.979; 95% confidence interval (CI), 0.799-1.199; and HR, 0.912; 95% CI, 0.762-1.092, respectively], but the LSD group showed a better prognosis after 5 years postoperatively. CID from primary lung cancer was similar between the 2 groups (HR, 1.239; 95% CI, 0.940-1.633). However, the CID from other diseases was lower in the LSD group than in the SND group (HR, 0.702; 95% CI, 0.525-0.938). According to c-stage, the LSD group tended towards worse OS and RFS, with higher CID from primary lung cancer than the SND group, in patients with c-stage II.

CONCLUSIONS

LSD provides acceptable long-term survival for patients with early-stage NSCLC. However, LSD may not be suitable for patients with c-stage II NSCLC due to the higher mortality risk from primary lung cancer.

[Bronchial carcinoma: metastatic pathways with involvement of hilar and mediastinal lymph nodes]

SIGNIFICANCE OF LUNG CANCER

Lung cancer has enormous socioeconomical impact on our society due to its high prevalence and mortality. About 59,700 new cases of lung cancer were forecasted for 2022.

TNM SCHEME FOR STAGING

Correct staging is the basis for therapy planning, prognosis estimation, and future analyses. Staging is performed using the TNM scheme from the Union for International Cancer Control (UICC). Involvement of lymph nodes is used to differentiate between stage IIB and IIIC.

LYMPH NODE LEVELS FOR LUNG CANCER

Knowledge of the intrathoracic lymph node levels is crucial for the exact classification and its involvement has direct implications on therapy. The International Association for the Study of Lung Cancer (IASLC) proposed a unified lymph node map with exact anatomic definitions, which is recommended by the German national lung cancer guideline. The extent of lymph node involvement is stratified into N0-N3. Different metastatic paths are known depending on the location of the primary tumor, but the burden of disease has a greater influence on survival, than the location of metastases.

ASSESSING THE SPREAD OF LUNG CANCER

Computed tomography can assess operability of the primary tumor safely in most cases. Invasive procedures to confirm the diagnosis by sampling tissue should be performed after noninvasive diagnostics.

PRACTICAL RECOMMENDATION

Systematic lymph node dissection for all patients with non-small cell lung cancer intended for curative resection is recommended in the current German national guideline for lung cancer.

Type of lymphadenectomy does not influence survival in pIa NSCLC patients who underwent VATS lobectomy: Results from the national VATS group database

INTRODUCTION

Stage Ia presents an optimal survival rate after surgical resection, but the type of lymphadenectomy to use in these patients is still debated. The aim of this study is evaluate if one type of lymphadenectomy adopted influences survival in patients who underwent VATS lobectomy for stage Ia NSCLC.

METHODS

Clinical and pathological data from pIa patients in the prospective VATS Italian nationwide registry were reviewed and analysed. Patients and tumour characteristics,type of lymphadenectomy (sampling or radical nodal dissection,MRLD), were collected and correlated to Overall Survival(OS) and Disease free Survival(DFS). The Kaplan-Meier product-limit method was used to estimate OS and DFS and the log-rank test was adopted to evaluate the differences between groups. A propensity match was performed to reduce bias due to the retrospective study design.

RESULTS

The final analysis was conducted on 2039 patients, 179 died during follow-up,recurrence rate was 13%. MRLD was performed in 1287(63.1%)patients. The univariable analysis identified as favourable prognostic factors for OS the female sex(p = 0.023), low ECOG-score(0.008),low SUVmax(p < 0.001), GGO appearance(p < 0.001), pT < 2 cm(p = 0.002) and low tumour grading(p = 0.002). The multivariable analysis confirmed as independent prognostic factors low ECOG-score(p = 0.012), low SUVmax(p < 0.001) and low tumour grading(p < 0.001). Analysing survival in patients with solid/sub-solid nodules and after propensity score matching for pTdimension and number of N2 resected lymphnodes, no OS differences were present comparing sampling vs MRLD.

CONCLUSION

Survival in pIa patients seems to be determined by patient and tumour characteristics such as performance status,grading and SUVmax. Type of lymphadnectomy did not seem to be correlated with OS in these patients.

The IASLC Proposed Grading System Accurately Predicts Prognosis and Mediastinal Nodal Metastasis in Patients With Clinical Stage I Lung Adenocarcinoma

The International Association for the Study of Lung Cancer (IASLC) recently proposed a new grading system for lung adenocarcinoma (LUAD). We aimed to validate the prognostic performance of the grading system and explore its role in guiding the strategy of lymph node (LN) dissection. We retrospectively reviewed 1029 patients with clinical stage I LUAD who underwent surgery between 2011 and 2013. The association between mediastinal nodal metastasis and grading system was evaluated. To investigate the value of the grading system in guiding LN dissection strategies, 3 pathologists evaluated the feasibility of identifying the grading system using frozen section (FS). The differences in prognosis between all neighboring grades were highly significant based on the grading system ( P <0.001). Notably, almost no grade 1 LUAD (1.4%) had pN2 disease, whereas higher rates were found in grade 2 LUAD (9.6%) and grade 3 LUAD (18.3%) ( P <0.001). Multivariate logistic regression analysis revealed that higher tumor grade was an independent predictor of mediastinal nodal metastasis ( P =0.002). Moreover, limited mediastinal LN dissection had equivalent prognosis in grade 1 LUAD, but significantly worse prognosis in grade 2 and grade 3 LUAD than systematic mediastinal LN dissection. The overall accuracy of using intraoperative FS to identify the IASLC grading system was 85.4% (κ=0.765) with substantial agreement. The IASLC grading system could accurately stratify prognosis and predict mediastinal nodal metastasis in patients with clinical stage I LUAD. FS was feasible for identifying the IASLC grading system.

Clinical impact of number of lymph nodes dissected on postoperative survival in node-negative small cell lung cancer

OBJECTIVES

Small cell lung cancer (SCLC) is a lethal histologic subtype of lung cancer. Although the Commission on Cancer recommends pathological examination of at least 10 lymph nodes dissected (LNDs) for resected early-stage non-small cell lung cancer, its survival benefit of LNDs in patients with early-stage SCLC is unknown.

METHODS

The National Cancer Database was queried for SCLC patients with clinical stage I-II and clinical N0, NX disease per AJCC 7^th edition who had undergone lobectomy between 2004 and 2017. Overall survival of SCLC patients by the number of LNDs was compared using Log-rank tests. Univariate and multivariable Cox proportional hazards analyses were performed.

RESULTS

In total, 688 (42%), 311 (20%), 247 (16%), 196 (12%), 126 (8%), and 36 (2%) of 1,584 patients with early-stage SCLC had ≥10, 7-9, 5-6, 3-4, 1-2, and 0 LNDs, respectively. The sequential improvement in the HRs was no longer evident if the number of LNDs exceeds 4. Patients with ≥3 LNDs (n = 1,422) had a significantly longer overall survival than those with <3 LNDs (n = 162) (hazard ratio for death: 0.76, 95% confidence interval: 0.62-0.94, P = 0.0087). Multivariate analysis revealed that ≥3 LNDs was an independent factor for predicting overall survival (hazard ratio for death: 0.76, 95% confidence interval: 0.61-0.93, P = 0.0083).

CONCLUSIONS

Although we are reluctant to recommend a definitive "optimal number" of LNDs, our findings suggest the prognostic and therapeutic roles for performing ≥3 LNDs in patients with early-stage SCLC who undergo lobectomy.

Visualization of patterns of lymph node metastases in non-small cell lung cancer using network analysis

Objective

We aimed to visualize complicated patterns of lymph node metastases in surgically resected non-small cell lung cancer by applying a data mining technique.

Methods

In this retrospective study, 783 patients underwent lobectomy or pneumonectomy with systematic mediastinal lymph node dissection for non-small cell lung cancer between January 2010 and December 2018. Surgically resected lymph nodes were classified according to the International Association for the Study of Lung Cancer lymph node map. Network analysis generated patterns of lymph node metastases from stations 1 to 14, and the degree of connection between 2 lymph node stations was assessed.

Results

The median number of lymph nodes examined per patient was 20, and the pathological N category was pN0 in 428 cases, pN1 in 132, pN2 in 221, and pN3 in 2. N1 lymph node stations had strong associations with superior mediastinal lymph node stations for patients with primary tumors in the upper lobes and with station 7 for the lower lobes. There was also a connection from the N1 lymph node stations to superior mediastinal lymph node stations in the lower lobes. In the right middle lobe, an even distribution from station 12m toward stations 2R, 4R, and 7 was noted. We released an interactive web application to visualize these data: http://www.canexapp.com.

Conclusions

Lymph node metastasis patterns differed according to the lobe bearing the tumor. Our results support the need for clinical trials to further investigate selective mediastinal lymph node dissection.

Lymph node metastases outside tumor-bearing lobes and/or segments in non–small cell lung cancer

Objective

Hilar and lung lymph node metastases (N1) are defined as ipsilateral bronchial and intrapulmonary lymph nodes. However, the cleaning standards for ipsilateral bronchial lymph nodes in different lobes and segments within the same lobe in segmentectomy are not clearly defined.

Materials and methods

Sixty-six patients undergoing pulmonary resection for the treatment of lung cancer were evaluated. Intraoperatively visible non-tumor-bearing lobe (NTBL) and post-operatively non-tumor-bearing segment (NTBS) lymph nodes were removed and analyzed. The associations between the NTBL LNs and clinicopathological characteristics were analyzed.

Results

Non-tumor-bearing lobe LNs metastases were found in 8 (12.1%) of the 66 patients, NTBS LNs metastasis were not found (0/13). The presence of NTBL metastases was significantly associated with age (&lt;60 years vs. ≥60 years, P = 0.037), differentiation (Grade 1 well differentiated vs. Grade 2 moderately differentiated vs. Grade 3 poorly differentiated, P = 0.012), CAT-scan-findings of Mediastinal and hilar lymph nodes metastasis (node-positive vs. node-negative, P = 0.022), pN stage (N0 vs. N1 vs. N2, P = 0.003) and p stage (I vs. II vs. III, P = 0.009). Multivariate logistic analysis showed that tumor differentiation (P = 0.048, HR 6.229; 95% CI 1.016–38.181) and pN (P = 0.024, HR 5.099; 95% CI 1.245–20.878) were statistically significant predictors.

Conclusions

Lobar lymph node metastasis of NTBL occurs frequently in patients with NSCLC, but lymph node metastases in NTBS LNs are rare. Advanced age, poorly differentiated and N1 and N2 status of CAT-scan-findings were independent risk factors for the involvement of the NTBL lobar lymph nodes. Although lymph node metastases in NTBS are rare, further investigation of the need to dissect is required.

Development and validation of nomograms based on clinical characteristics and CT reports for the preoperative prediction of precise lymph node dissection in lung cancer

OBJECTIVE

To develop and validate nomograms for preoperative prediction of precision lymph node (LN) dissection in lung cancer.

PATIENTS AND METHODS

The prediction models of each group LNs (LNx) were developed in a primary cohort that consisted of 1380 patients with clinicopathologically confirmed lung cancer. Clinical characteristics and CT reports were extracted. Patients with LNx dissection were divided into training cohort and testing cohort. Nomograms were built through univariate and multivariate regression analysis in the training cohort and internally verified in the testing cohort. The accuracy of the models was verified by constructing survival analysis in patients without LNx dissection.

RESULTS

Due to the lack of sufficient patients for LN1, 8, 13, a total of 10 nomograms were constructed in this study, including LN-2 ∼ 7, 9 ∼ 12. According to the nomogram of each group LN, the most common independent risk factors predicting LN status were CT-reported lymphadenectasis, tumor diameter and location, and the others include age, gender, and whether there were multiple nodules, etc. All models showed good discrimination, with the average C-index of 0.738 in the training cohort and 0.707 in the testing cohort. Survival analysis in patients without LNx dissection all showed the high accuracy of each nomogram to predict LN metastasis status and TNM staging.

CONCLUSION

We constructed nomograms to predict the metastasis status of each group of lymph nodes based on clinical characteristics and CT reports. Surgeons can accurately determine the extent of lymph node dissection in patients with lung cancer based on our nomogram models before surgery.

Reclassifying the International Association for the Study of Lung Cancer Residual Tumor Classification According to the Extent of Nodal Dissection for NSCLC: One Size Does Not Fit All

INTRODUCTION

The extent of nodal assessment may require risk-based adjustments in NSCLC. We reclassified the International Association for the Study of Lung Cancer Residual tumor classification according to the extent of nodal dissection and evaluated its long-term prognosis by tumor stage and histologic subtype.

METHODS

We reclassified 5117 patients who underwent resection for clinical stages I to III NSCLC and had complete or uncertain resection by International Association for the Study of Lung Cancer classification into the following 3 groups according to compliance with three components (N1, N2, and subcarinal node) of systematic nodal dissection criteria: fully compliant group (FCG), partially compliant group (PCG), and noncompliant group (NCG). Recurrence-free survival (RFS) and overall survival (OS) were compared.

RESULTS

Of the 5117 patients, 2806 (55%), 1959 (38%), and 359 (7%) were FCG, PCG, and NCG, respectively. PCG and NCG were more likely to be of lower clinical stage and adenocarcinoma with lepidic component than FCG. The 5-year RFS and OS were significantly better in NCG than in FCG or PCG (RFS, 86% versus 70% or 74%, p < 0.001; OS, 90% versus 80% or 83%, p < 0.001). In particular, NCG had better RFS and OS than FCG or PCG in clinical stage I and in lepidic-type adenocarcinoma.

CONCLUSIONS

In early stage NSCLC with low-risk histologic subtype, a less rigorous nodal assessment was not associated with a worse prognosis. Although surgeons should continue to aim for complete resection and thorough nodal assessment, a uniform approach to the extent and invasiveness of nodal assessment may need to be reconsidered.

Station 3A lymph node dissection does not improve long-term survival in right-side operable non-small-cell lung cancer patients: A propensity score matching study

Background

To investigate the impact of station 3A lymph node dissection (LND) on overall survival (OS) and disease‐free survival (DFS) in completely resected right‐side non‐small‐cell lung cancer (NSCLC) patients.

Methods

A total of 1661 cases with completely resected right‐side NSCLC were included. Propensity score matching (PSM) was performed to minimize selection bias, and a logistic regression model was conducted to investigate the risk factors associated with station 3A lymph node metastasis (LNM). The Kaplan–Meier method and Cox proportional hazards model were used to evaluate the impact of station 3A LND on survival.

Results

For the entire cohort, 503 patients (30.3%) underwent station 3A LND. Of those, 11.3% (57/503) presented station 3A LNM. Univariate and multivariate logistic analyses showed that station 10 LNM, tumor location, and the number of resected lymph nodes were independent risk factors associated with station 3A LNM. Before PSM, patients with station 3A LND had worse 5‐year OS (p = 0.002) and DFS (p = 0.011), and more drainage on postoperative day 1 (p = 0.041) than those without. After PSM, however, station 3A LND was not associated with the 5‐year OS (65.7% vs. 63.6%, p = 0.432) or DFS (57.4% vs. 56.0%, p = 0.437). The multivariate analysis further confirmed that station 3A LND was not a prognostic factor (OS, p = 0.361; DFS, p = 0.447).

Conclusions

Station 3A LND could not improve long‐term outcomes and it was unnecessary to dissect station 3A lymph nodes during surgery of right‐side NSCLC.

Significance of pelvic lymph node dissection during radical prostatectomy in high-risk prostate cancer patients receiving neoadjuvant chemohormonal therapy

We aimed to determine the survival and staging benefit of limited pelvic lymph node dissection (PLND) during radical prostatectomy (RP) in high-risk prostate cancer (PC) patients treated with neoadjuvant chemohormonal therapy. We retrospectively analyzed 516 patients with high-risk localized PC (< cT4N0M0) who received neoadjuvant androgen-deprivation therapy plus estramustine phosphate followed by RP between January 2010 and March 2020. Since we stopped limited PLND for such patients in October 2015, we compared the surgical outcomes and biochemical recurrence-free survival (BCR-FS) between the limited-PLND group (before October 2015, n = 283) and the non-PLND group (after November 2015, n = 233). The rate of node metastases in the limited-PLND group were 0.8% (2/283). Operation time was significantly longer (176 vs. 162 min) and the rate of surgical complications were much higher (all grades; 19 vs. 6%, grade ≥ 3; 3 vs. 0%) in the limited-PLND group. The inverse probability of treatment weighting-Cox analysis revealed limited PLND had no significant impact on BCR-FS (hazard ratio, 1.44; P = 0.469). Limited PLND during RP after neoadjuvant chemohormonal therapy showed quite low rate of positive nodes, higher rate of complications, and no significant impact on BCR-FS.

The Independent Prognostic Effect of Lymph Node Dissection on Patients With Stage IA NSCLC With Different T Stages

Background: Currently, the extent of lymph node evaluation necessary for patients with early-stage non-small-cell lung cancer (NSCLC) remains controversial according to the latest ESMO and NCCN guidelines. In this study, we aimed to evaluate the survival effect of different numbers of lymph nodes examined (LNE) and regions of lymph nodes removed (LNR) in patients with stage IA NSCLC.

Method: All patients with stage IA NSCLC undergoing lobectomy or bilobectomy were selected from the surveillance, epidemiology, and end results (SEER) database. The number of LNE and LNR were stratified into 4 groups (0, 1–2, 3–8, and ≥9 lymph nodes) and 3 groups (0, 1–3, and ≥4 regions) respectively. Additionally, the survival curves of overall survival (OS) and cancer-specific survival (CSS) were plotted and compared with the Kaplan-Meier method and log-rank test. Independent prognostic clinicopathological factors were evaluated via Cox proportional hazard regression and subgroup analysis.

Results: Totally, 12,490 patients with stage IA NSCLC were enrolled in our study. Patients with ≥9 LNE and ≥4 LNR in both the T1b and T1c stages consistently demonstrated the significantly best OS and CSS outcomes. In the multivariate analysis, patients with ≥9 LNE consistently had a significantly better CSS [hazards ration (HR) (95% CI):0.539 (0.438–0.663)], and those with ≥4 LNR consistently had a significantly better OS [HR (95% CI):0.678 (0.476–0.966)]. Furthermore, ≥9 LNE and ≥4 LNR were associated with better survival in most subgroups.

Conclusion: This study demonstrated that ≥9 LNE and ≥4 LNR are highly recommended for stage IA2 and stage IA3 patients but optional for stage IA1 patients.

Positive nodal status is still a risk factor for long-term survivors of non-small cell lung cancer 5 years after complete resection

Background

Lung cancer has a poor prognosis; the number of long-term survivors (LTSs) is small compared with that of other cancers. Few studies have focused on late recurrence in LTSs with lung cancer. The purpose of this study was to analyze the risk factors for survival and late recurrence in LTSs after disease-free period of 5 years.

Methods

A retrospective analysis of patients with a disease-free survival of at least 5 years after surgical resection for non-small cell lung cancer (NSCLC) between January 1998 and December 2012 was conducted. Patients who underwent neo-adjuvant therapy, had an incomplete resection, or had advanced stage (stages IIIb and IV) cancer were excluded.

Results

A total of 1,254 (53.2%) of 2,357 patients were enrolled. Of these, 759 (60.5%) were men, and the mean patient age was 61.9±10.1 (range, 10-87 years) years. Pathologic N0 (997 patients, 79.5%) and stage I (860 patients, 68.6%) were the dominant stages. Late recurrence occurred in 22 patients (1.8%) 5 years postoperatively. On multivariate analysis, male sex, older age, node-positive status, and late recurrence were found to be independent risk factors for overall survival (OS), while a node-positive status was the only independent risk factor for disease-free survival [hazard ratio (HR) =3.824; P=0.002; 95% confidence interval (CI): 1.658-8.821].

Conclusions

The nodal stage at the time of surgical resection was found to be an independent risk factor for both OS and disease-free survival 5 years after initial treatment in patients with completely resected NSCLC.

Adequacy of Mediastinal Lymph Node Sampling in Patients With Lung Cancer Undergoing Lung Resection

BACKGROUND

Intraoperative mediastinal lymph node sampling (MLNS) is a crucial component of lung cancer surgery. Whilst several sampling strategies have been clearly defined in guidelines from international organizations, reports of adherence to these guidelines are lacking. We aimed to assess our center's adherence to guidelines and determine whether adequacy of sampling is associated with survival.

MATERIALS AND METHODS

A single-center retrospective review of consecutive patients undergoing lung resection for primary lung cancer between January 2013 and December 2018 was undertaken. Sampling adequacy was assessed against standards outlined in the International Association for the Study of Lung Cancer 2009 guidelines. Multivariable logistic and Cox proportional hazards regression analyses were used to assess the impact of specific variables on adequacy and of specific variables on overall survival, respectively.

RESULTS

A total of 2380 patients were included in the study. Overall adequacy was 72.1% (n= 1717). Adherence improved from 44.8% in 2013 to 85.0% in 2018 (P< 0.001). Undergoing a right-sided resection increased the odds of adequate MLNS on multivariable logistic regression (odds ratio 1.666, 95% confidence interval [CI]: 1.385-2.003, P< 0.001). Inadequate MLNS was not significantly associated with reduced overall survival on log rank analysis (P= 0.340) or after adjustment with multivariable Cox proportional hazards (hazard ratio 0.839, 95% CI 0.643-1.093).

CONCLUSIONS

Adherence to standards improved significantly over time and was significantly higher for right-sided resections. We found no evidence of an association between adequate MLNS and overall survival in this cohort. A pressing need remains for the introduction of national guidelines defining acceptable performance.

Prognostic Impact of Mediastinal Lymph Node Dissection in Octogenarians With Lung Cancer: JACS1303

INTRODUCTION

The prognostic significance of mediastinal lymph node dissection (MLND) in elderly patients with non-small cell lung cancer (NSCLC) remains unclear. This post hoc analysis of a nationwide multicenter cohort study (JACS1303) evaluated the prognostic significance of MLND in octogenarians with NSCLC.

MATERIALS AND METHODS

We included 622 octogenarians with NSCLC who underwent lobectomy. The median follow-up duration was 41.1 months. We compared survival and perioperative outcomes between patients who did and did not undergo MLND.

RESULTS

In total, 414 (67%) patients underwent MLND (ND2 group), whereas 208 (33%) did not undergo MLND (ND0-1 group). The disease stage was more advanced in the ND2 group than in the ND0-1 group. Disease-free survival was slightly greater in the ND0-1 group with marginal significance (P= .079). In the matched cohort (N = 228), which mainly consisted of patients with clinical stage I disease (96%), there was no significant difference between the 2 groups regarding overall and disease-free survival (P= .908 and P = .916, respectively). Operative time and blood loss were significantly lower in the ND0-1 group than in the ND2 group in the entire cohort (P< .001 and P = .050, respectively) and in the matched cohort (P = .003 and P= .046, respectively).

CONCLUSION

Based on a nationwide prospective database, we found limited prognostic impact of MLND, suggesting that MLND can be omitted for octogenarians with early-stage NSCLC.

Comparison between robot-assisted thoracoscopic surgery and video-assisted thoracoscopic surgery for mediastinal and hilar lymph node dissection in lung cancer surgery

OBJECTIVES

Lymph node dissection (LND) with robot-assisted thoracoscopic surgery (RATS) in lung cancer surgery has not been fully evaluated. The aim of this study was to compare LND surgical results between video-assisted thoracoscopic surgery (VATS) and RATS.

METHODS

We retrospectively compared perioperative parameters, including the incidence of LND-associated complications (chylothorax, recurrent and/or phrenic nerve paralysis and bronchopleural fistula), lymph node (LN) counts and postoperative locoregional recurrence, among 390 patients with primary lung cancer who underwent lobectomy and mediastinal LND by RATS (n = 104) or VATS (n = 286) at our institution.

RESULTS

The median total dissected LN numbers significantly differed between the RATS and the VATS groups (RATS: 18, VATS: 15; P < 0.001). They also significantly differed in right upper zone and hilar (#2R + #4R + #10L) (RATS: 12, VATS: 10; P = 0.002), left lower paratracheal and hilar (#4L + #10L) (RATS: 4, VATS: 3; P = 0.019), aortopulmonary zone (#5 + #6) (RATS: 3, VATS: 2; P = 0.001) and interlobar and lobar (#11 + #12) LNs (RATS: 7, VATS: 6; P = 0.041). The groups did not significantly differ in overall nodal upstaging (P = 0.64), total blood loss (P = 0.69) or incidence of LND-associated complications (P = 0.77).

CONCLUSIONS

In this comparison, it was suggested that more LNs could be dissected using RATS than VATS, especially in bilateral superior mediastinum and hilar regions. Accumulation of more cases and longer observation periods are needed to verify whether RATS can provide the acceptable quality of LND and local control of lung cancer.

Lobe-specific lymph node dissection in stage IA non-small-cell lung cancer: a retrospective cohort study

OBJECTIVES

To investigate lymph node (LN) metastasis according to tumour location and assess the impact of lobe-specific LN dissection on survival in stage IA non-small-cell lung cancer (NSCLC).

METHODS

We retrospectively analysed the data of patients with clinical stage IA NSCLC treated with lobectomy and systematic LN dissection at Asan Medical Center (Seoul, Korea) between June 2005 and April 2017. Patients who received neoadjuvant therapy had multiple primary tumours or missed the follow-up during the first postoperative year were excluded. The patients were divided into five groups according to involved lung lobes: right upper lobe (RUL), right middle lobe (RML), right lower lobe (RLL), left upper lobe (LUL) and left lower lobe (LLL), which were further divided into subgroups according to LN station metastasis. Overall survival (OS) and the incidence of metastasis were calculated for each subgroup. Efficacy indices (EIs) were calculated to determine the correlation between each lung lobe and LN station, and the impact of the dissection of these stations on survival.

RESULTS

A total of 1202 patients were analysed. The 5-year OS in the RUL, RML, RLL, LUL and LLL groups was 74%, 88%, 78%, 80% and 75%, respectively. The incidence of single LN station metastasis was 11%, 10%, 10%, 16% and 14%, respectively. The lobe-specific LNs for RUL, RML, RLL, LUL and LLL were stations 2/3/4, 4/7, 2/4/7, 4/5/6 and 6/7/9, respectively. Moreover, the LN stations with high EIs for RUL, RML, RLL, LUL and LLL were 4, 7, 7, 5 and 7, respectively. In the RUL group, the incidence of metastasis to stations 2, 3 and 4 was 2.3%, 0.5% and 7.6%, and the EI was 0.8, 0.3 and 4.3, respectively. In RML, the incidence of metastasis to stations 4 and 7 was 4% and 6%, and the EI was 1.3 and 2.4, respectively. In RLL, the incidence of metastasis to stations 2, 4 and 7 was 4.4%, 5.6% and 8.3%, and the EI was 1.3, 1.4 and 3.3, respectively. In LUL, the incidence of metastasis to stations 4, 5 and 6 was 1.4%, 11.8% and 2.5%, and the EI was 0.4, 7.1 and 0.5, respectively. In LLL, the incidence of metastasis to stations 6, 7 and 9 was 1.1%, 5.7% and 1.7%, and the EI was 0.6, 2.3 and 0.5, respectively. Furthermore, the OS of patients with lobe-specific LN metastasis was statistically significantly different from that of the non-lobe-specific LN metastasis group with P-values of <0.001 for RUL, 0.002 for RML, 0.002 for RLL, 0.001 for LUL and 0.003 for LLL.

CONCLUSIONS

Our findings support the use of lobe-specific LN dissection in stage IA NSCLC. When LN stations with high EI were negative, LN metastasis in other stations was unlikely. The incidence of LN metastasis beyond lobe-specific LN stations was ∼1% in all subgroups. Dissection of non-lobe-specific LNs may not improve the OS; however, prospective randomized controlled trials are needed to modify the standard approach.

Limited versus Extended Pelvic Lymph Node Dissection for Prostate Cancer: A Randomized Clinical Trial

BACKGROUND

Pelvic lymph node dissection (PLND) is the most reliable procedure for lymph node staging. However, the therapeutic benefit remains unproven; although most radical prostatectomies at academic centers are accompanied by PLND, there is no consensus regarding the optimal anatomical extent of PLND.

OBJECTIVE

To evaluate whether extended PLND results in a lower biochemical recurrence rate.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a single-center randomized trial. Patients, enrolled between October 2011 and March 2017, were scheduled to undergo radical prostatectomy and PLND. Patients were assigned to limited or extended PLND by cluster randomization. Specifically, surgeons were randomized to perform limited or extended PLND for 3-mo periods.

INTERVENTION

Randomization to limited (external iliac nodes) or extended (external iliac, obturator fossa and hypogastric nodes) PLND.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was the rate of biochemical recurrence.

RESULTS AND LIMITATIONS

Of 1440 patients included in the final analysis, 700 were randomized to limited PLND and 740 to extended PLND. The median number of nodes retrieved was 12 (interquartile range [IQR] 8-17) for limited PLND and 14 (IQR 10-20) extended PLND; the corresponding rate of positive nodes was 12% and 14% (difference -1.9%, 95% confidence interval [CI] -5.4% to 1.5%; p = 0.3). With median follow-up of 3.1 yr, there was no significant difference in the rate of biochemical recurrence between the groups (hazard ratio 1.04, 95% CI 0.93-1.15; p = 0.5). Rates for grade 2 and 3 complications were similar at 7.3% for limited versus 6.4% for extended PLND; there were no grade 4 or 5 complications.

CONCLUSIONS

Extended PLND did not improve freedom from biochemical recurrence over limited PLND for men with clinically localized prostate cancer. However, there were smaller than expected differences in nodal count and the rate of positive nodes between the two templates. A randomized trial comparing PLND to no node dissection is warranted.

PATIENT SUMMARY

In this clinical trial we did not find a difference in the rate of biochemical recurrence of prostate cancer between limited and extended dissection of lymph nodes in the pelvis. This study is registered on ClinicalTrials.gov as NCT01407263.

Extent of mediastinal nodal dissection in stage I non-small cell lung cancer with a radiological pure-solid appearance

BACKGROUND

Radiological pure-solid lung cancer denotes a high invasive nature compared to one that is part-solid. Mediastinal lymph nodal dissection (mLND) is a standard surgical procedure for nodal management in lung cancer surgery, however, the prognostic impact of the extent of mLND in pure-solid lung cancer is still unknown.

METHODS

We reviewed 459 patients with c-stage I radiological pure-solid lung cancer that underwent pulmonary lobectomy with mLND. Pure-solid was defined as a tumor showing only a consolidation without any ground glass opacity. The extent of mLND was classified into lobe-specific (L-mLND) and systematic (S-mLND). Prognostic significance of mLND was assessed by a multivariable analysis using propensity-score matching. Survivals were calculated by Kaplan-Meier methods using log-rank test.

RESULTS

Pathological nodal metastasis was found in 127 (27.6%) patients (hilar: 52 (11.3%), mediastinal: 75 (16.3%)). L-mLND was performed in 278 (61%) patients. A multivariable analysis did not show the survival difference for the extent of mLND (p = 0.266). The 5-year overall survival (OS) was not significantly different between S-mLND and L-mLND (74.3% vs. 72.7%, p = 0.712), which was similar even in 114 propensity-score matched pairs (78.8% vs. 79.9%, p = 0.665). While S-mLND showed a trend for survival benefit compared to L-mLND provided that the tumor showed higher standardized uptake value (SUVmax) (5y-OS: 70.0% vs. 59.2%, p = 0.093).

CONCLUSIONS

Prognostic impact of L-mLND was similar to S-mLND in c-stage I radiological pure-solid lung cancers in the propensity-score matched comparison. Among them, higher SUVmax value might be a promising indicator to decide the extent of mediastinal lymphadenectomy.

Selection of Pathological N0 (pN0) in Clinical IA (cIA) Lung Adenocarcinoma by Imaging Findings of the Main Tumor

OBJECTIVES

We would like to clarify the imaging findings of the main tumor that may omit the requirement for lymph node dissection in clinical IA (cIA) lung adenocarcinoma.

METHODS

A total of 336 patients with cIA lung adenocarcinomas with normal preoperative carcinoembryonic antigen (CEA) who underwent surgical resection were analyzed. We investigated the association between various computed tomography (CT) imaging findings or the maximum standardized uptake value (SUVmax) of fluorodeoxyglucose-position emission tomography (FDG-PET) and lymph node metastasis. The maximum tumor diameter was calculated from the CT images using both the lung window setting (LD) and mediastinal window setting (MD). The diameter of the solid component (CD) was defined as consolidation diameter in lung window setting. The solid component ratio (C/T) was defined as CD/LD.

RESULTS

SUVmax, MD, and C/T were independent factors related to lymph node metastasis, but CD was not (p = 0.38). The conditions required for the positive predictive value (PPV) to reach 100% were 10.6 mm for MD, 12.5 mm for CD, and 0.55 for C/T. SUVmax did not reach 100%.

CONCLUSIONS

In cIA lung adenocarcinoma with CEA in the normal range, we found that it may be possible for lymph node dissection to be omitted by MD, CD, and C/T.

Thermal Ablation Versus Wedge Resection for Stage I Non-small Cell Lung Cancer Based on the Eighth Edition of the TNM Classification: A Population Study of the US SEER Database

Background

The incidence rates of early-stage non-small cell lung cancer (NSCLC) are now increasing, and therapies such as thermal ablation have shown potential therapeutic promise. This study aimed to determine the influence of different surgical methods on overall survival (OS) and cancer-specific survival (CSS) in patients with stage I NSCLC.

Methods

Patients diagnosed with stage I NSCLC who had received thermal ablation or wedge resection between 2004 and 2014 were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was performed according to the surgical method. Kaplan–Meier curves and a Cox proportional hazard model were used to evaluate OS and CSS.

Results

In all, 4,372 patients with stage I NSCLC were included. Before PSM, the respective 3- and 5-year OS rates were 68.9 and 52.7% in the wedge resection group and 68.5 and 47.8% in the thermal ablation group (p < 0.0001); the corresponding CSS rates were 79.1 and 69.4% and 62.6 and 46.0% (p < 0.0001). After PSM, survival analysis showed that wedge resection had better OS (44.5% vs. 30.1%, p = 0.033) and CSS (63.5% vs. 46%, p = 0.038) than thermal ablation. After PSM, Cox regression showed that treatment was not associated with OS or CSS. For patients aged >75 years, thermal ablation showed similar OS and CSS as wedge resection (OS: 30.6% vs. 41.7%, p = 0.470; CSS: 46.4% vs. 64.1%, p = 0.100). After PSM, thermal ablation still had OS (30.6% vs. 41.0%, p = 0.470) and CSS (46.4% vs. 59.8%, p = 0.100) comparable to wedge resection.

Conclusion

For patients with stage I NSCLC who are unfit for lobectomy, thermal ablation could be a potential therapeutic option, especially for those >75 years old.

Lymph node assessment in early stage non-small cell lung cancer lymph node dissection or sampling?

Lymph node assessment is an essential component of the treatment of lung cancer. Identification of the correct "N" stage is important for staging which in turn determines treatment. Assessment of lymph nodes may be accomplished using imaging with CT scan and PET-CT, invasive techniques such as mediastinoscopy, endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) or endoscopic ultrasound fine needle aspiration (EUS-FNA). Ultimately, regardless of any pre-resection assessment, lymph nodes must be assessed at the time of resection. The question to be addressed in this report is the role of mediastinal lymph node dissection versus lymph node sampling. However, the issues surrounding lymph node assessment in NSCLC are complex, depending on clinical stage, imaging and histology.

[Advances in Lymph Node Metastasis and Lymph Node Dissection in Early Non-small Cell Lung Cancer]

肺癌是目前我国发病率和死亡率均居首位的恶性肿瘤，其中以非小细胞肺癌为主要病理类型。淋巴结转移是非小细胞肺癌最常见和最主要的转移途径，也是影响肺癌分期和预后最重要的因素。由于目前通过现有手段术前很难准确判断早期非小细胞肺癌患者的淋巴结受累情况。因此，在早期非小细胞肺癌中，尤其是在临床Ⅰ期非小细胞肺癌患者中，淋巴结清扫方式一直存在很大争议。本文就非小细胞肺癌淋巴结转移的规律及清扫方式进行综述。

Pathological lymph node involvement is not a predictor of adverse outcomes in patients undergoing thoracoscopic lobectomy for lung cancer†

OBJECTIVES

As the practice of video-assisted thoracoscopic surgery (VATS) lobectomy gains widespread acceptance, the complexity of procedures attempted increases and the stage of tumour that may be safely approached remains controversial. We examined the impact of nodal involvement with respect to perioperative outcomes after VATS lobectomy.

METHODS

All patients listed for VATS lobectomy for non-small-cell lung cancer at our institution from 2012 to 2016 were analysed. Bronchoplastic or chest wall resections and tumours over 7 cm were considered a contraindication to a thoracoscopic approach.

RESULTS

Of the 489 patients identified, 97 (19.8%) patients had pathological nodal involvement. The overall conversion rate was 6.1%, reoperation rate was 5.3% and readmission rate was 5.9%. Median hospital stay was 5 days, 30-day mortality was 0.6% and 90-day mortality was 1.6%. No significant difference was identified between the nodal-negative or -positive groups in terms of preoperative demographics, hospital stay, postoperative complications, conversion rate, reoperation rate or readmission rate. Univariate logistic regression identified gender, Thoracoscore, dyspnoea score, performance status, chronic obstructive pulmonary disease, previous stroke, preoperative lung function and non-adenocarcinoma as predictors of postoperative complications. A multivariate model including nodal status identified Thoracoscore (odds ratio 1.57, 95% confidence interval 1.16-2.18; P < 0.001) and preoperative transfer factor (odds ratio 0.97, 95% confidence interval 0.96-0.98; P < 0.001) as the only predictors of complications.

CONCLUSIONS

In non-small-cell lung cancer patients with pathological hilar or mediastinal lymph node involvement, VATS lobectomy can be safely performed, as there does not appear to be an adverse effect on the incidence of perioperative complications, length of stay or readmissions.

[The technique of thoracic lymph node dissection]

Systematic mediastinal, hilar and interlobar lymph node dissection is required in the S3 guidelines for the treatment of operable lung cancer. The lymph node involvement is considered one of the key prognostic factors. The type of lymph node resection is repeatedly the subject of controversially discussion. Lymph node dissection is essential for staging, prognosis, survival and recurrence rate. It should be standardized as a compartmental dissection with en bloc resection of lymph nodes including surrounding fat and connective tissue. Thus, exact knowledge of the anatomy of the thoracic organs with their peculiarities and high anatomical variability is necessary.

Factors associated with nodal metastasis in 2-centimeter or less non-small cell lung cancer

OBJECTIVE

Lymph node involvement is an important determinant of treatment and prognosis in non-small cell lung cancer (NSCLC) and must be determined via surgical lymph node (LN) evaluation. However, lymphadenectomy is associated with multiple significant morbidities. Recent studies have suggested LN evaluation can be foregone in some or all patients with NSCLC ≤2.0 cm. Our objective was to identify whether these patients may be safely spared the morbidity of lymphadenectomy.

METHODS

We undertook a retrospective study of patients treated for NSCLC ≤2.0 cm at a single institution from 2005 to 2017. We examined patient, demographic, and tumor variables for associations with LN metastases via univariable and multivariable analyses.

RESULTS

In total, 555 patients met our inclusion criteria. Our primary independent variables included tumor size, histology, and histologic subtype. Although tumors ≤1 cm were less likely to have LN metastases than 1.1- to 2-cm tumors (6.8% vs 13.3%), there was no statistically significant difference. Histologic type was not associated with LN status. In an adenocarcinoma subgroup analysis, micropapillary predominant tumors were more likely to have LN metastases. All invasive mucinous adenocarcinomas and minimally invasive adenocarcinomas were N0.

CONCLUSIONS

LN evaluation may be unnecessary in patients with minimally invasive adenocarcinoma or invasive mucinous adenocarcinomas ≤2.0 cm. However, this information is rarely available pre- or intraoperatively. Thus, we recommend LN evaluation always be performed when possible, even for subcentimeter NSCLC, unless the histology is absolutely certain. To our knowledge, this is the largest dataset published to study patients with NSCLC ≤2.0 cm.

Clinicopathologic predictors of metastasis of different regional lymph nodes in patients intraoperatively diagnosed with stage-I non-small cell lung cancer

Background

Selection of the best lymph node for dissection is a controversial topic in clinical stage-I non-small cell lung cancer (NSCLC). Here, we sought to identify the clinicopathologic predictors of regional lymph node metastasis in patients intraoperatively diagnosed with stage-I NSCLC.

Methods

A retrospective review of 595 patients intraoperatively diagnosed as stage I non-small-cell lung cancer who underwent lobectomy with complete lymph node dissection was performed. Univariate and multivariable logistic regression analysis was performed to determine the independent predictors of regional lymph node metastasis.

Results

Univariate logistic regression and multivariable analysis revealed three independent predictors of the presence of metastatic hilar lymph nodes, five independent predictors for lobe specific mediastinal lymph nodes, two independent predictors for lobe nonspecific mediastinal lymph nodes and two independent predictors for skipping mediastinal lymph nodes.

Conclusions

A complete mediastinal lymph node dissection may be considered for patients suspected of nerve invasion and albumin (> 43.1 g/L) or nerve and vascular invasions. Lobe-specific lymph node dissection should probably be performed for patients suspected of pulmonary membrane invasion, vascular invasion, CEA (> 2.21 ng/mL), and tumor (> 1.6 cm) in the right lower lobe or mixed lobes. Hilar lymph node dissection should probably be performed for patients suspected of having bronchial mucosa and cartilage invasion, vascular invasion, and CEA (> 2.21 ng/mL).

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5632-2) contains supplementary material, which is available to authorized users.

Comparison of lymph node dissection and lymph node sampling for non-small cell lung cancers by video-assisted thoracoscopic surgery

Background

Video-assisted thoracoscopic surgery (VATS) has been increasingly used in the treatment of lung cancers. But it is still unclear whether mediastinal lymph node dissection (LND) under VATS is safe and feasible. The aim of this study is to figure out whether LND by VATS is safe and feasible.

Methods

Consecutive patients with primary resectable lung cancers referred for lobectomy and LND or sampling by VATS between January 2012 and December 2016 were retrospectively reviewed. Clinicopathological characteristics and perioperative results were collected for statistical analysis.

Results

Seven-hundred and seventy-three VATS lobectomy patients were included in this study, 494 received LND and 279 received lymph node sampling (LNS). There were more male patients, higher pathological T and N stage in the LND group than in the LNS group. Multivariate analysis suggested that clinical N stage higher than cN0 category and LND were independent risk factors for finding pN2 diseases in all lung cancers, while higher than cN0 category, solid or micropapillary component, and LND were independently related to finding pN2 stage in adenocarcinomas. Propensity-score matching rendered 279 pairs of patients with no significant difference in age, gender, co-morbidity, tumor location, or T stage. Although the LND group had longer operation time (128 vs. 114 minutes, P<0.001), higher amount of postoperative drainage (920 vs. 720 mL, P<0.001), longer postoperative hospital stay (6 vs. 4 days, P<0.001) than the LNS group, no difference was observed in overall morbidity or mortality between the two groups.

Conclusions

LND by VATS has acceptable perioperative results but can provide more accurate nodal staging compared with LNS. LND by VATS is safe, feasible, and should be recommended in patients with tumors in clinical N stages higher cN0 category or with more invasive histology.

Predictive risk factors for lymph node metastasis in patients with resected non-small cell lung cancer: a case control study

Background

Estimation of lymph node status is essential in order to determine precise therapy for patients with non-small cell lung cancer (NSCLC). Furthermore, lymph node involvement is a very powerful prognostic factor in these patients. In this analysis, we aim to evaluate the predictive factors for lymph node metastasis in NSCLC-patients.

Methods

In a prospectively-established database, we analyzed all data of patients with NSCLC, who underwent oncological surgical resections from 01/2007 to 12/2016, retrospectively. The correlation between clinicopathological parameters and lymph node metastasis was investigated by using univariate and binary logistic regression analysis.

Results

In this study, we operated on 204 consecutive patients, 142 men (71.7%) and 56 women (28.3%). Lymph node metastases were detected in 38.2% (78/204). Preoperatively, central tumor localization (OR = 2.6, 95% CI = 1.3–5.1, P = 0.005) and tumor size > 3 cm (OR = 2.5, 95% CI = 1.3–4.4, P = 0.005) were found to be significant predictive factors for lymph node metastasis. Postoperatively, multivariate analysis showed that intratumoral lymph vessel invasion (L1-status) (OR = 17.3, 95% CI = 5.1–58.4, P <  0.001) along with the central tumor localization (OR = 2.8, 95% CI = 1.4–5.8, P = 0.004) were significantly associated with lymph node metastasis. In small size tumors (≤3 cm), two predictive factors for lymph node metastasis were found: central tumor localization (OR = 19.4, 95% = 2.1–186.4, P = 0.01) and L1-status (OR = 43.9, 95% CI = 3.6–529.4, P = 0.003).

Conclusions

A precise pre- and intraoperative assessment of the lymph node status is essential in patients with larger sized tumors and central localization. Furthermore, L1-status is a highly significant risk factor for lymph node metastasis in NSCLC-Patients. Therefore, an adjuvant therapy in patients with L1-status and pNX category should be considered.

Impact of examined lymph node counts on survival of patients with stage IA non-small cell lung cancer undergoing sublobar resection

Background

The correlation between the number of examined lymph nodes (ELNs) and lung cancer-specific survival (LCSS) of stage IA non-small cell lung cancer (NSCLC) patients, who underwent sublobar resection in which lymph node (LN) sampling was relatively restricted as compared with standard lobectomy remains unclear.

Methods

Patients from the Surveillance, Epidemiology, and End Results database with stage IA NSCLC who underwent sublobar resection were categorized based on ELN count (1-6 vs. ≥7; the cut point 7 was identified by Cox model).

Results

Collectively, 3,219 patients with a median follow-up time of 37 months were included in this study (G1: 1-6 ELN, n=2,410; G2: ≥7 ELN, n=809). The 5-year LCSS rate of the G1 and G2 cohorts were 75% and 83%, respectively. Cox analysis suggested that the LCSS of G1 cohort patients was lower as compared with the G2 cohort [hazard ratio (HR) =1.530; 95% confidence interval (CI): 1.240-1.988, P<0.001). Propensity score analysis also showed decreased survival of the matched G1 cohort (HR =1.499; 95% CI: 1.176-1.911; P=0.001).

Conclusions

The data suggested the ELNs ≤6 were associated with poor prognoses. Adequate LN sampling is essential even for stage IA NSCLC patients undergoing sublobar resection.

The impact on mediastinal recurrence based on the number of harvested mediastinal lymph nodes and assessed N2 Stations in patients with stage I invasive lung adenocarcinoma

Background

To determine the impact of the number of harvested mediastinal lymph nodes (MLNs) and assessed N2 stations on the mediastinal recurrence for pathologic stage I invasive lung adenocarcinoma (IADC).

Methods

A total of 2,048 patients with stage I IADC undergoing surgical resection were enrolled at Shanghai Chest Hospital from 2009 to 2013. Survival analysis was performed by Kaplan-Meier method along with univariable and multivariable cox regression analysis.

Results

For patients with ≥5 MLNs, mediastinum-specific relapse-free survival (MS-RFS) rates were 98.3% and 96.6% for 3- and 5-year, respectively, which significantly demonstrated better survival outcomes against those with <5 MLNs (96.3% and 92.8%, respectively, log-rank P=0.018). Additionally, the 3- and 5-year RFS of patients with assessed N2 stations ≥3 (98.2% and 95.8%) were exceptionally better when compared with those with N2 stations <3 (95.5%, 90.3%, log-rank P<0.001). In the univariable and multivariable cox analyses, we found that the number of assessed N2 stations was an independent predictor to MS-RFS (HR =0.468; 95% CI, 0.312-0.867; P=0.020) as opposed to the number of harvested MLNs (HR =0.856; 95% CI, 0.423-1.489; P=0.543) which was not a predictor.

Conclusions

Based on our results, we recommend, for a better MS-RFS among patients with pathological stage I IADC, that the cutoff values for harvested MLNs and assessed N2 stations be 5 and 3, respectively. In addition, the number of assessed N2 stations was still an independent predictor to MS-RFS.

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.

Selective versus systematic lymph node dissection (other than sampling) for clinical N2-negative non-small cell lung cancer: a meta-analysis of observational studies

Background

The proper extent of lymph node dissection is still controversial. Hence, we compared the clinical efficacy between two strategies of lymph node dissection [selective lymph node dissection (SLND) and systematic lymph node dissection (LND)] for clinical N2-negative non-small cell lung cancer (NSCLC) patients.

Methods

After searching five databases, six cohort studies were eligible for this meta-analysis and the primary endpoint was overall survival (OS). In order to provide a comprehensive perspective, we estimated some perioperative outcomes as well. Either fixed effect or random effects model were properly selected to evaluate the data according to the heterogeneity of included studies.

Results

A total of 7,333 patients with clinical N2-negative NSCLC patients were analyzed for OS. The pooled results demonstrated that LND did not improve survival in OS [hazard ratio (HR) =1.05, 95% confidence interval (CI): 0.82-1.34, P=0.69] compared with SLND. In accordance with OS, there is no significant difference in DFS between LND and SLND (HR =0.98, 95% CI: 0.78-1.23, P=0.87). Moreover, SLND could significantly reduce the operative time [mean difference (MD) =-21.45, 95% CI: -29.53 to -13.36, P<0.001] and blood loss (MD =-28.88, 95% CI: -44.38 to -13.39, P<0.001). Both postoperative morbidity and recurrence showed no significant between two groups.

Conclusions

SLND is an alternative to LND for clinical N2-negative NSCLC patients, which may even provide clinical benefits. However, more randomized controlled trials (RCTs) are expected to determine whether SLND is valid and practical to become a standard procedure of surgical treatment for early-stage NSCLC patients.

Lymph node metastasis in melanoma: a debate on the significance of nodal metastases, conditional survival analysis and clinical trials

While there is no doubt that regional lymph node metastases are an enormously important factor in melanoma staging and treatment, the biology behind this significance and its precise implications for treatment planning have been a leading controversy in melanoma and other solid tumors for over a century. Recent clinical data, including data from prospective randomized clinical trials have refined our understanding of the process of nodal metastases and the advantages and disadvantages of different clinical management strategies. This review presents two points of view in this debate and discusses the results of new data analyses as well as pivotal clinical trials informing the discussion.

Systematic lymphadenectomy versus sampling of ipsilateral mediastinal lymph-nodes during lobectomy for non-small-cell lung cancer: a systematic review of randomized trials and a meta-analysis

OBJECTIVES

To re-examine the evidence for recommendations for complete dissection versus sampling of ipsilateral mediastinal lymph nodes during lobectomy for cancer.

METHODS

We searched for randomized trials of systematic mediastinal lymphadenectomy versus mediastinal sampling. We performed a textual analysis of the authors' own starting assumptions and conclusion. We analysed the trial designs and risk of bias. We extracted data on early mortality, perioperative complications, overall survival, local recurrence and distant recurrence for meta-analysis.

RESULTS

We found five randomized controlled trials recruiting 1980 patients spanning 1989-2007. The expressed starting position in 3/5 studies was a conviction that systematic dissection was effective. Long-term survival was better with lymphadenectomy compared with sampling (Hazard Ratio 0.78; 95% CI 0.69-0.89) as was perioperative survival (Odds Ratio 0.59; 95% CI 0.25-1.36, non-significant). But there was an overall high risk of bias and a lack of intention to treat analysis. There were higher rates (non-significant) of perioperative complications including bleeding, chylothorax and recurrent nerve palsy with lymphadenectomy.

CONCLUSIONS

The high risk of bias in these trials makes the overall conclusion insecure. The finding of clinically important surgically related morbidities but lower perioperative mortality with lymphadenectomy seems inconsistent. The multiple variables in patients, cancers and available treatments suggest that large pragmatic multicentre trials, testing currently available strategies, are the best way to find out which are more effective. The number of patients affected with lung cancer makes trials feasible.