Prognostic Impact of Extracapsular Lymph Node Invasion on Survival in Non-small-Cell Lung Cancer: A Systematic Review and Meta-analysis

Clinical practice guidelines for perioperative multimodality treatment of non-small cell lung cancer

BACKGROUND

Lung cancer is currently the most prevalent malignancy and the leading cause of cancer deaths worldwide. Although the early stage non-small cell lung cancer (NSCLC) presents a relatively good prognosis, a considerable number of lung cancer cases are still detected and diagnosed at locally advanced or late stages. Surgical treatment combined with perioperative multimodality treatment is the mainstay of treatment for locally advanced NSCLC and has been shown to improve patient survival. Following the standard methods of neoadjuvant therapy, perioperative management, postoperative adjuvant therapy, and other therapeutic strategies are important for improving patients' prognosis and quality of life. However, controversies remain over the perioperative management of NSCLC and presently consensus and standardized guidelines are lacking for addressing critical clinical issues in multimodality treatment.

METHODS

The working group consisted of 91 multidisciplinary experts from thoracic surgery, medical oncology, radiotherapy, epidemiology, and psychology. This guideline was developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The clinical questions were collected and selected based on preliminary open-ended questionnaires and subsequent discussions during the Guideline Working Group meetings. PubMed, Web of Science, Cochrane Library, Scopus, and China National Knowledge Infrastructure (CNKI) were searched for available evidence. The GRADE system was used to evaluate the quality of evidence and grade the strengths of recommendations. Finally, the recommendations were developed through a structured consensus-building process.

RESULTS

The Guideline Development Group initially collected a total of 62 important clinical questions. After a series of consensus-building conferences, 24 clinical questions were identified and corresponding recommendation were ultimately developed, focusing on neoadjuvant therapy, perioperative management, adjuvant therapy, postoperative psychological rehabilitation, prognosis assement, and follow-up protocols for NSCLC.

CONCLUSIONS

This guideline puts forward reasonable recommendations focusing on neoadjuvant therapy, perioperative management, adjuvant therapy, postoperative psychological rehabilitation, prognosis assessment, and follow-up protocol of NSCLC. It standardizes perioperative multimodality treatment and provides guidance for clinical practice among thoracic surgeons, medical oncologists, and radiotherapists, aiming to reduce postoperative recurrence, improve patient survival, accelerate recovery, and minimize postoperative complications such as atelectasis.

Validation of the Proposed International Association for the Study of Lung Cancer Residual Tumor Classification to Upgrade Extracapsular Extension of Tumor in Nodes From R0 to Incomplete Resection

INTRODUCTION

The International Association for the Study of Lung Cancer (IASLC) proposed a revised R classification to upstage extracapsular extension (ECE) of tumor in nodes from R0 to R1. Nevertheless, evidence to confirm this proposal is insufficient.

METHODS

The study included 4061 surgical patients with NSCLC. After reclassification by IASLC-R classification, overall survival (OS) was analyzed to compare patients with ECE with those with R0, R(un), and incomplete resection (R1 and R2). The recurrence pattern of ECE was evaluated to determine whether it correlated with incomplete resection.

RESULTS

Among 1136 patients with N disease, those without ECE (n = 754, 67%) had a significantly better OS than those with ECE (n = 382, 33%) (p < 0.001). This negative prognostic significance was consistent across multiple subgroups. Multivariate analysis revealed that ECE was an independent prognostic risk factor (p < 0.001). When patients with ECE were separated from the IASLC-R1 group, their OS was significantly worse than that of IASLC-R(un) patients, but comparable to that of the remaining patients in the IASLC-R1 patients when analyzing all patients and patients with N disease. Moreover, patients with ECE had an increased risk of local recurrence in the mediastinum (p < 0.001), ipsilateral lung (p = 0.031), and malignant pleural effusion or nodes (p = 0.004) but not distant recurrence including contralateral or both lungs (p = 0.268), liver (p = 0.728), brain (p = 0.252), or bone (p = 0.322).

CONCLUSIONS

The prognosis of ECE patients is comparable with that of R1 patients. Moreover, their higher risk of local recurrence strongly suggests the presence of occult residual tumor cells in the surgical hemithoracic cavity. Therefore, upgrading ECE into incomplete resection is reasonable.

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Overview of Challenges and Opportunities in Revising the Nodal Classification of Lung Cancer

The status of lymph node involvement is a major component of the TNM staging system. The N categories for lung cancer have remained unchanged since the fourth edition of the TNM staging system, partly because of differences in nodal mapping nomenclature, partly because of insufficient details to verify possible alternative approaches for staging. In preparation for the rigorous analysis of the International Association for the Study of Lung Cancer database necessary for the ninth edition TNM staging system, members of the N-Descriptors Subcommittee of the International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee reviewed the evidence for alternative approaches to categorizing the extent of lymph node involvement with lung cancer, which is currently based solely on the anatomical location of lymph node metastasis. We reviewed the literature focusing on NSCLC to stimulate dialogue and mutual understanding among subcommittee members engaged in developing the ninth edition TNM staging system for lung cancer, which has been proposed for adoption by the American Joint Committee on Cancer and Union for International Cancer Control in 2024. The discussion of the range of possible revision options for the N categories, including the pros and cons of counting lymph nodes, lymph node stations, or lymph node zones, also provides transparency to the process, explaining why certain options may be discarded, others deferred for future consideration. Finally, we provide a preliminary discussion of the future directions that the N-Descriptors Subcommittee might consider for the 10th edition and beyond.

Real world practice of postoperative radiotherapy for patients with completely resected pIIIA-N2 non-small cell lung cancer: a national survey of radiation oncologists in China

BACKGROUND

Results from Lung ART and PORT-C trials suggest that postoperative radiotherapy (PORT) cannot routinely be recommended as standard treatment in completely resected pIIIA-N2 NSCLC patients, but their effects on the real-world practice of PORT in China remain unclear.

METHODS

A national cross-section survey was conducted by using an online survey service. Participants were voluntarily recruited using a river sampling strategy. A link to the survey was posted on websites of radiation oncologist associations and tweets from public WeChat accounts. The survey collected the real names of participants to ensure that they were board-certified radiation oncologists.

RESULTS

A total of 484 radiation oncologists were included with a median age of 40 years (IQR, 35-47). A total of 377 (77.9%) participants were male, and 282 (58.1%) had more than 10 years of clinical experience practicing thoracic radiotherapy. Before Lung ART and PORT-C trials were published, 313 (64.7%) respondents recommended PORT, 11 (2.3%) did not recommend it, and 160 (33.1%) reported that they made decisions based on risk factors. After the presentation of two trials, only 42 (8.7%) did not recommend PORT, while 108 (22.3%) recommended it, and 334 (69.0%) made decisions based on risk factors. The five most commonly considered risk factors among these 334 respondents were as follows: nodal extracapsular extension, the highest lymph node (LN) station involved, the number of dissected mediastinal LN stations, the number of positive mediastinal LN stations, and surgical approaches. In addition, the majority of all 484 respondents recommended a total dose of 50 Gy, lung stump + ipsilateral hilus + regions containing positive LNs as the targeted region, lung V20 < 25%, and heart V30 < 40% as dose constraints for PORT.

CONCLUSION

Most Chinese radiation oncologists recommended PORT for completely resected IIIA-N2 NSCLC patients based on risk factors, especially status of LN station.

Endosonographic characteristics of mediastinal lymph nodes for predicting malignancy in high tuberculosis burden settings: a study of 774 subjects

BACKGROUND

Whether sonographic features of mediastinal lymph nodes can differentiate malignancy from tuberculosis remains unclear.

RESEARCH DESIGN AND METHODS

We retrospectively identified subjects with a confirmed diagnosis of tuberculosis or malignancy on endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Our primary objective was to compare the endosonographic characteristics of lymph nodes on EBUS between tuberculosis and malignancy. Our secondary objective was to assess the diagnostic performance of endosonographic characteristics in predicting malignancy.

RESULTS

We included 774 subjects (1,498 lymph nodes) with a confirmed diagnosis of tuberculosis (n = 497) or malignancy (n = 277). Distinct lymph node margins (84.1% vs. 93.8%, P < 0.001) and coagulation necrosis sign (11.2% vs. 29.8%, P < 0.001) were less common in malignancy than tuberculosis. The absence of central hilar structure had the highest sensitivity (92.1%) for malignancy. Endosonographic characteristics had poor specificity for malignancy(round shape and coagulation necrosis sign, 77.3% and 70.2%. In multivariate analysis, coagulation necrosis sign was associated with a lower odds of malignancy (odds ratio 0.45 [95% confidence intervals, 0.21-0.95]).

CONCLUSIONS

Endosonographic characteristics, such as round shape and the coagulation necrosis sign, are not specific for malignancy in high tuberculosis prevalence areas.

Prognostic Significance of the Extranodal Extension of Regional Lymph Nodes in Stage III-N2 Non-Small-Cell Lung Cancer after Curative Resection

The present study investigated the prognostic role of extranodal extension (ENE) in stage III-N2 non-small-cell lung cancer (NSCLC) following curative surgery. From January 2005 to December 2018, pathologic stage III-N2 disease was diagnosed in 371 patients, all of whom underwent anatomic pulmonary resection accompanied by mediastinal lymph node dissection. This study included 282 patients, after excluding 89 patients who received preoperative chemotherapy or incomplete surgical resection. Their lymph nodes were processed; after hematoxylin and eosin staining, histopathologic slides of the metastatic nodes were reviewed by a designated pathologist. Predictors of disease free survival (DFS), including age, sex, operation type, pathologic T stage, nodal status, visceral pleural invasion, perioperative treatment, and the presence of ENE, were investigated. Among the 282 patients, ENE was detected in 85 patients (30.1%). ENE presence was associated with advanced T stage (p = 0.034), N2 subgroups (p < 0.001), lymphatic invasion (p = 0.001), and pneumonectomy (p = 0.002). The multivariable analysis demonstrated that old age (p < 0.001), advanced T stage (p = 0.012), N2 subgroups (p = 0.005), and ENE presence (p = 0.005) were significant independent predictors of DFS. The DFS rate at five years was 21.4% in patients who had ENE and 43.4% in patients who did not have ENE (p < 0.001). The presence of ENE, coupled with tumor-node-metastasis staging, should be recognized as a meaningful prognostic factor in stage III-N2 NSCLC patients.

Is Adjuvant Radiochemotherapy Always Mandatory in Patients with Resected N2 Non-Small Cell Lung Cancer?

BACKGROUND

 In patients with non-small cell lung cancer (NSCLC), the pathologic union for international cancer control (UICC) stage IIIA is a heterogeneous entity, with different forms of N2-lymph node involvement representing different prognoses. Although a multimodality treatment approach, including surgery, systemic therapy, and/or radiotherapy, is almost always recommended, in this retrospective observational study, we sought to determine whether long-term survival might be possible in selected patients who are treated with complete surgical resection alone.

METHODS

 Between 2013 and 2018, we retrospectively identified 24 patients with NSCLC (16 men and 8 women), who were found to have pathologic N2-lymph node involvement, and were treated with complete surgical lung resection and systematic mediastinal and hilar lymph node dissection but no neoadjuvant or adjuvant treatment.

RESULTS

 The most frequent reason (n = 14) for forgoing adjuvant treatment was patient refusal. The mean overall survival (OS) was 34.5 months (interquartile range [IQR]: 15.5-53.5 months). The mean disease-free survival (DFS) was 18 months (IQR: 4.75-46.75 months). We identified five patients who survived at least 5 years without recurrence (21%). In each of these cases, the nodal metastases were restricted to a single level and no extracapsular lymph node involvement were detected. Additionally, worse DFS was associated with pT3/4 (vs. a lower T-stage), as well as microscopic lymphovascular invasion.

CONCLUSION

 Although the small sample size precludes any definitive conclusions, it was possible to demonstrate that long-term survival without neoadjuvant and adjuvant treatment is possible in some patients if complete tumor and nodal resection is performed.

Prognostic value of lymph node ratio in non-small-cell lung cancer: a meta-analysis

BACKGROUND

This meta-analysis aimed to investigate the prognostic value of lymph node ratio in non-small-cell lung cancer.

METHODS

We searched systematically for eligible studies in PubMed, Web of Science, Medline (via Ovid) and Cochrane library through 6 November 2018. The primary outcome was overall survival. Disease-free survival and cancer-specific survival were considered as secondary outcomes. Hazard ratio with corresponding 95% confidence interval were pooled. Quality assessment of included studies was conducted. Subgroup analyses were performed based on N descriptors, types of tumor resection, types of lymphadenectomy and study areas. Sensitivity analysis and evaluation of publication bias were also performed.

RESULTS

Altogether, 20 cohorts enrolling 76 929 patients were included. Mean Newcastle-Ottawa Scale was 7.65 ± 0.59, indicating the studies' quality was high. The overall result showed non-small-cell lung cancer patients with lower lymph node ratio was associated with better overall survival (HR: 1.946; 95% CI: 1.746-2.169; P < 0.001), disease-free survival (HR: 2.058; 95% CI: 1.717-2.467; P < 0.001) and cancer-specific survival (HR: 2.149; 95% CI: 1.864-2.477; P < 0.001). Subgroup analysis prompted types of lymphadenectomy and the station of positive lymph node have an important effect on the prognosis. No significant discovery was found in sensitivity analysis.

CONCLUSION

Patients with lower lymph node ratio was associated with better survival, indicating that lymph node ratio may be a promising prognostic predictor in non-small-cell lung cancer. The type of lymphadenectomy, an adequate examined number and the removed stations should be considered for more accurate prognosis assessment.