Mediastinal Lymph-nodes Metastasis beyond the Lobe-specific: An Independent Risk Factor toward Worse Prognoses

Video-assisted mediastinoscopic lymphadenectomy (VAMLA): Mature results for staging non-small cell lung cancer with normal mediastinum

OBJECTIVES

The aim of this study is to analyze the accuracy of video-assisted mediastinoscopic lymphadenectomy (VAMLA) and the unsuspected (u) N2/3 rates in patients with non-small cell lung cancer (NSCLC) and normal mediastinum by integrated positron emission tomography-computed tomography.

METHODS

Prospective observational single-center study of 603 consecutive VAMLAs from 2010 to 2022.

EXCLUSION CRITERIA

other indications (n = 32), tumors different from NSCLC (n = 91), and clinical (c) N2/3 tumors by positron emission tomography-computed tomography (n = 46). Systematic nodal dissection was the gold standard to validate negative VAMLAs. Those patients with negative VAMLA and missing reference standard test were excluded. uN2/3 rates were analyzed in the global series and in the subgroups of tumors according to their clinical nodal and tumor categories. Pathologic findings were reviewed, and staging values were calculated.

RESULTS

Three hundred eighty-three patients with cN0/1 NSCLC underwent VAMLA. Staging values of VAMLA were: sensitivity, 0.98 (95% CI, 0.92-0.99); negative predictive value, 0.99 (95% CI, 0.98-1); and diagnostic accuracy, 0.99 (95% CI, 0.98-1). The uN2/3 rate for the whole series (N = 383) was 18.8%. The uN2/3 rates according to presurgical nodal and tumor categories determined by positron emission tomography computed tomography were: 3.6% (4 out of 111) in cT1N0; 16.3% (18 out of 110) in cT2N0; 10.25% (4 out of 39) in cT3N0; and 32% (7 out of 22) in cT4N0. Forty-two percent (39 out of 93) in cN1; complication rate was 7%.

CONCLUSIONS

This series of NSCLC with normal mediastinum staged by VAMLA demonstrates a high accuracy of this technique and a high rate of uN2/3 disease (specially in cN1 and cT4N0). VAMLA could be considered the reference staging procedure for staging cN0/1 NSCLC.

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Proposals for Revision of the TNM Stage Groups in the Forthcoming (Ninth) Edition of the TNM Classification for Lung Cancer

INTRODUCTION

The TNM classification of lung cancer is periodically revised. The International Association for the Study of Lung Cancer collected and analyzed a new database to inform the forthcoming ninth edition of the TNM classification. The results are herewith presented.

METHODS

After exclusions, 76,518 patients from a total of 124,581 registered patients were available for analyses: 58,193 with clinical stage, 39,192 with pathologic stage, and 62,611 with best stage NSCLC. The proposed new N2 subcategories (N2a, involvement of single ipsilateral mediastinal or subcarinal nodal station, and N2b, involvement of multiple ipsilateral mediastinal nodal stations with or without involvement of the subcarinal nodal station) and the new M1c subcategories (M1c1, multiple extrathoracic metastases in one organ system, and M1c2, multiple extrathoracic metastases in multiple organ systems) were considered in the survival analyses. Several potential stage groupings were evaluated, using multiple analyses, including recursive partitioning, assessment of homogeneity within and discrimination between potential groups, clinical and statistical significance of survival differences, multivariable regression, and broad assessment of generalizability.

RESULTS

T1N1, T1N2a, and T3N2a subgroups are assigned to IIA, IIB, and IIIA stage groups, respectively. T2aN2b and T2bN2b subgroups are assigned to IIIB. M1c1 and M1c2 remain in stage group IVB. Analyses reveal consistent ordering, discrimination of prognosis, and broad generalizability of the proposed ninth edition stage classification of lung cancer.

CONCLUSIONS

The proposed stages for the ninth edition TNM improve the granularity of nomenclature about anatomic extent that has benefits as treatment approaches become increasingly differentiated and complex.

Neoadjuvant Immuno-Chemotherapy: A New Perspective for Stage III NSCLC?

Background

Stage III Non-small cell lung cancer (NSCLC) is a heterogenous disease with novel treatment options. Recently, immunotherapy has attracted a lot of attention for advanced NSCLC.

Objective

The objective of our study was to assess the efficacy and safety of neoadjuvant immuno-chemotherapy for resectable stage III NSCLC.

Methods

We analyzed 11 stage III primary NSCLC surgical cases who had undergone standard lobectomy or bronchial sleeve resection and lymph node dissection between December 2020 and July 2021. The data analyzed included basic clinical features, serum levels of key biomarkers, clinical efficacy in the perioperative period, postoperative pathological results, postoperative complications and the incidence rates of Immune-Related Adverse Events.

Results

Eleven patients were enrolled in our study with a mean age of 67.7 ± 4.8 years, and 10 patients being men with former or current smoking history. Squamous carcinoma (10/11, 91.1%) was the most common cancer type. Six patients had stage IIIa, five had stage IIIb. All patients received two or three cycles of neoadjuvant immuno-chemotherapy, with the median duration between the last treatment and surgery being 39 days (range, 32–46 days). All patients underwent R0 resection with ten patients undergoing single-port video-assisted thoracoscopic surgery. The median operative time was 170 min (range, 120–240 min). Only three (3/11, 27.3%) patients experienced mild postoperative complications and the mean hospital stay time was 6.9 days (range, 4–15 days). Nine (9/11, 81.8%) patients experienced major pathological response of which seven (7/11, 63.6%) was complete pathological response in postoperative results. The pathological stage was downgraded in 10 (10/11, 91.1%) patients, and although the incidence of Immune-Related Adverse Events was slightly higher (8/11, 72.7%), most events were grade 1–2 and did not delay surgery.

Conclusion

Our study demonstrated that neoadjuvant immuno-chemotherapy is feasible and relatively safe for resectable stage III primary NSCLC patients. We hope this new neoadjuvant immuno-chemotherapy model can improve overall survival and open a new era for stage III primary NSCLC patients.

Lymph-node ratio predicts survival among the different stages of non-small-cell lung cancer: a multicentre analysis†

OBJECTIVES

The prognostic role of the number of resected and metastatic lymph nodes in non-small-cell lung cancer (NSCLC) is still being debated. The aim of this study was to evaluate the impact of lymphadenectomy in addition to the already validated variables in NSCLC survival.

METHODS

From January 2002 to December 2012, data on 4858 patients with NSCLC undergoing anatomical lung resection and hilomediastinal lymphadenectomy in 6 institutions were analysed retrospectively. Established prognostic factors in addition to the number of resected lymph nodes and the ratio between the number of metastatic lymph nodes and the number of resected lymph nodes (NR) were correlated to overall survival (OS) and disease-free survival (DFS) using the multivariable Cox regression model. Harrell's C-statistic with the 95% confidence interval (CI) was determined. Analysis by means of maximally selected log-rank statistics was performed to find optimal cut-off points in order to split patients into groups with different outcome probabilities.

RESULTS

The median numbers of resected lymph nodes and of metastatic lymph nodes were 17 (range 6-85) and 2 (1-36), respectively. Hilar (N1) and mediastinal (N2) metastases were identified in 21.3% and 20.0% of cases, respectively. Overall, the 5-year OS and DFS rates were 54.6% and 44.8%, respectively. At multivariable analysis, age, gender, pathological stage, R0 resection, type of surgery and NR correlated with longer OS rates; the same variables plus tumour grading were further related to DFS. C-statistics were 66.0 (95% CI 62.7-69.4) for DFS and 60.5 (95% CI 58.3-62.6) for OS. An NR <40% significantly correlated with a higher 5-year survival rate in the total sample (OS 57.6% vs 23.8%, P < 0.001; DFS 48.2% vs 11.4, P < 0.001) and in patients with N1 (OS 47.9% vs 36.1%, P = 0.03; DFS 39% vs 24.2%, P = 0.02) and N2 (OS 36.9% vs 21.8%, P < 0.001 DFS 23.9% vs 9.1%, P < 0.001).

CONCLUSIONS

Our study confirms that the number of resected lymph nodes is a strong prognostic indicator in NSCLC. In particular, an NR cut-off value of 40% may predict both OS and DFS.

Combining node location and node ratio as a prognostic factor for surgical resected non-small cell lung cancer: a population-based study

Background

In the TNM system only the anatomic location is used to define nodal status. In this study we aim to evaluate the effectiveness of combining the location and ratio of metastatic lymph node (pN-NR) for the prognosis of non-small cell lung cancer (NSCLC).

Methods

Patients with pN1/pN2 NSCLC were retrieved from the SEER database. The optimal cut point of NR was determined with the maximal selecting test. All patients were divided into 4 categories with combination of pN (pN1 or pN2) and NR (low or high). The pN-NR was investigated as a predictor of overall survival (OS) and cause-specific survival (CSS) using Cox regression models. Survival curves were plotted using the Kaplan-Meier method and the difference was compared with log-rank test.

Results

A total of 12,170 patients were enrolled. The optimal cut point of NR was 0.3. Patients were divided into 4 groups: pN1-NR <0.3, pN1-NR ≥0.3, pN2-NR <0.3 and pN2-NR ≥0.3. The pN-NR was an independent prognostic factor for survival. Compared with pN1-NR <0.3, the hazard ratio of OS was 1.405 (95% CI: 1.295-1.524), 1.183 (95% CI: 1.113-1257) and 1.717 (95% CI: 1.607-1.835) times higher for pN1-NR ≥0.3, pN2-NR <0.3 and pN2-NR ≥0.3 group, respectively. The survival curves of OS separated well between the 4 pN-NR groups, with 5-year OS 47.1% for pN1-NR <0.3, 43.0% for pN2-NR <0.3, 35.0% for pN1-NR ≥0.3 and 28.5% for pN2-NR ≥0.3, and the P value between neighboring curves was statistically significantly. The same trend was observed for CSS. Subgroup analysis revealed similar results except the pneumonectomy group.

Conclusions

pN-NR could be a good predictor for the prognosis of NSCLC.

Lung cancer staging: a concise update

Diagnosis and clinical staging of lung cancer are fundamental to planning therapy. The techniques for clinical staging, i.e anatomic and metabolic imaging, endoscopies and minimally invasive surgical procedures, should be performed sequentially and with an increasing degree of invasiveness. Intraoperative staging, assessing the magnitude of the primary tumour, the involved structures, and the loco-regional lymphatic spread by means of systematic nodal dissection, is essential in order to achieve a complete resection. In resected tumours, pathological staging, with the systematic study of the resected specimens, is the strongest prognostic indicator and is essential to make further decisions on therapy. In the present decade, the guidelines on lung cancer staging of the American College of Chest Physicians and the European Society of Thoracic Surgeons are based on the best available evidence and are widely followed. Recent advances in the classification of the adenocarcinoma of the lung, with the definition of adenocarcinoma in situ, minimally invasive adenocarcinoma and lepidic predominant adenocarcinoma, and the publication of the eighth edition of the tumour, node and metastasis classification of lung cancer, have to be integrated into the staging process. The present review complements the latest guidelines on lung cancer staging by providing an update of all these issues.

Incidence of occult pN2 disease following resection and mediastinal lymph node dissection in clinical stage I lung cancer patients

Objectives

Early clinical stage (T1 and T2) non-small cell lung cancer (NSCLC) is commonly treated with anatomic lung resection and lymph node sampling or dissection. The aims of this study were to evaluate the incidence and the distribution of occult N2 disease according to tumour location and the short- and long-term outcomes.

Methods

We performed a retrospective review of patients with clinical stage I NSCLC who underwent anatomic lung resection and lymphadenectomy. Mediastinal lymphadenectomy (ML) was defined as resection of at least 2 mediastinal stations, always including station 7 lymph nodes. Patients who had a lobe-specific lymphadenectomy were excluded.

Results

One thousand six hundred and sixty-seven consecutive patients met inclusion criteria and were included. Overall, 9% (146/1667) of the patients had occult pN2 disease. At multivariable analysis, adenocarcinoma histology and vascular invasion were independently associated with greater risk of occult pN2 disease. In left and right upper lobe tumours, station 7 nodes were involved in 5 and 13% of pN2 positive cases, respectively. Station 5 and station 2/4 nodes were involved in 29 and 18% of left and right lower lobe pN2 tumours, respectively. There was no postoperative mortality, and postoperative morbidity was 28%. The median overall survival was 77.4 months. N0 patients had a median overall survival of 83.7 months vs 48.0 months and 37.9 months in N1 and N2 populations, respectively ( P  < 0.001).

Conclusions

Sixteen percent of pN2 patients had mediastinal lymph node metastasis beyond the lobe-specific lymphatic drainage. We recommend a complete lymphadenectomy be performed, even in clinical stage I NSCLC.

Selective lymph node dissection in early-stage non-small cell lung cancer

Lymph node dissection is a vital part of surgical treatment in early-stage non-small cell lung cancer (NSCLC). Removal of metastatic lymph nodes while preservation of intact lymph nodes are equally important. For hospitalized early-stage patients with limited lymph node metastasis, the operation treatment should be made according to some rules such as lobe-specific lymph node drainage pattern. In order to prevent unnecessary surgical trauma in early-stage patients, a minimally invasive approach with selective lymph node excision is preferred for more clinical benefits. This review summarizes the existing findings on lobe-specific lymph node drainage pattern and we hope to provide guidance for selective lymph node dissection (SLND). Furthermore, we include information on histologic views, a tumor marker and protocols of SLND, with hope to inspire creative research and clinical trials in this field.

Prognostic Factors for Surgically Resected N2 Non-small Cell Lung Cancer

PURPOSE

Non-small cell lung cancers (NSCLCs) with pathologically documented ipsilateral mediastinal lymph node (LN) metastases (pN2) are a broad spectrum of diseases. We retrospectively analyzed prognostic factors for cases of pN2 NSCLC treated by surgical resection.

METHODS

Clinicopathological data were reviewed for consecutive 121 patients who underwent anatomical pulmonary resection with mediastinal LN sampling or dissection for pN2 NSCLC over a 15-year period.

RESULTS

The 5-year survival rate for all patients was 29.9%. Clinical N status, curability, surgical procedure and adjuvant chemotherapy were favorable prognostic factors in univariate analysis, with 5-year survival rates of 35.0% for cN0/1 vs. 17.7% for cN2/3 cases; 33.1% for R0 vs. 14.7% for R1/2 resection; 31.5% for lobectomy vs. 25.0% for bilobectomy and 15.6% for pneumonectomy; and 72.7% with adjuvant chemotherapy vs. 23.8% without adjuvant chemotherapy. Survival did not differ significantly based on gender, age, smoking status, clinical T status, tumor location, histology, skip metastasis, subcarinal LN metastasis, or number of involved N2 levels. In multivariate analysis, adjuvant chemotherapy, R0 resection, and lobectomy emerged as independent favorable prognostic factors.

CONCLUSION

Complete resection using lobectomy and adjuvant chemotherapy are favorable prognostic factors in cases of pN2 NSCLC.