Multiparametric evaluation of mediastinal lymph node metastases in clinical T0-T1c stage non-small-cell lung cancers

OBJECTIVES

This study aimed to determine the predictive factors of lymph node metastases in clinical T0-T1c stage non-small-cell lung cancers, so as to help making surgical strategy.

METHODS

From January 2016 to December 2017, patients with clinical T0-T1c stage non-small-cell lung cancers were retrospectively reviewed. We elucidated the lymph node metastatic incidence and distribution according to the primary tumour radiographic findings and maximal standard uptake values, and extracted the associated clinicopathological factors. Univariable and multivariable logistic regressions were used to identify independent predictive parameters for lymph node metastases. The performance of predictive model was evaluated using receiver operating characteristic analysis.

RESULTS

A total of 517 patients were included. Seventy-two patients had lymph node metastases. Among patients with pure ground-glass nodule and solid component size ≤10 mm, none had any lymph node metastasis. Multivariable logistic regression analysis demonstrated that age, carcinoembryonic antigen level, solid component size, consolidation-tumour ratio and tumour maximal standard uptake values were independent predictors of lymph nodal metastases. Receiver operating characteristic analyses indicated that the area under the curve of predictive model in evaluating lymph node metastases was 0.838 (95% CI 0.791-0.886).

CONCLUSIONS

Younger age, elevated carcinoembryonic antigen level, larger solid component size, higher consolidation-tumour ratio and tumour maximal standard uptake values were associated with lymph node involvement. Employing such a predictive model in the future may affect the surgical option of lymph node excision for patients in cT1 stage non-small-cell lung cancer.

Programmed death ligand-1 expression and occult lymph node metastasis in non-small cell lung cancer

BACKGROUND

Identifying the preoperative risk factors for lymph node upstaging could contribute to the development of individualized perioperative treatment for patients with non-small cell lung cancer (NSCLC). The current study aimed to evaluate the risk factors for lymph node upstaging, including gene mutation and programmed death ligand-1 expression in patients with resectable NSCLC.

METHODS

Data on the clinicopathological characteristics of patients who underwent lobectomy for clinical N0 NSCLC at our institution were collected. The clinicopathological findings of the pathological N0 and lymph node upstaging groups were then analyzed. Univariate and multivariate analyses were performed to examine the predictive factors for nodal upstaging.

RESULTS

Of 291 patients, 40 had postoperative nodal upstaging (n = 25, N1; n = 15, N2). Large tumor size and high maximum standardized uptake value were significantly associated with nodal upstaging. The nodal upstaging group had a higher proportion of patients with solid adenocarcinoma and lymphatic, vascular, and pleural invasion than the pathological N0 group. Further, the nodal upstaging group had a higher proportion of patients with positive programmed death ligand-1 expression than the pathological N0 group. Univariate and multivariate analyses showed that tumor size and positive programmed death ligand-1 expression were associated with nodal upstaging.

CONCLUSION

The appropriate therapeutic strategy including preoperative treatment and resection should be cautiously considered preoperatively in patients with clinical N0 NSCLC who have large tumors and positive programmed death ligand-1 expression.

Role of skip N2 lymph node metastasis for patients with the stage III-N2 lung adenocarcinoma: a propensity score matching analysis

PURPOSE

Recent studies have indicated some differences in the prognosis of patients with stage III-N2 lung adenocarcinoma, and the prognosis of patients with skip N2 lymph node metastasis (SKN2) is good. This study grouped patients with stage III-N2 lung adenocarcinoma by propensity score matching (PSM) to evaluate the impact of SKN2 on the prognosis of these patients.

METHODS

The clinical data for patients who underwent radical lobectomy and had a postoperative pathological diagnosis of stage III-N2 lung adenocarcinoma at our centre from 2016 to 2018 were collected, and PSM was performed at a ratio of 1:1.

RESULTS

A total of 456 patients were enrolled in this study. After PSM, 112 patients were included in the SKN2 group, and 112 patients were included in the non-SKN2 group. When comparing the SKN2 group with the non-SKN2 group, the 3-year OS rate was (71.4% vs. 12.5%, p < 0.001), and the 3-year DFS rate was (35.7% vs. 5.4%, p < 0.001). It is further divided into four groups:single-station SKN2 (N2a1),Multi-station SKN2 (N2a2),single-station non-SKN2 (N2b1) and Multi-station non-SKN2 (N2b2).The 3-year OS and DFS rates of skip lymph node metastasis were better than those of non-skip lymph node metastasis(OS:N2a1 vs. N2b1 68.4% vs. 23.5%,p < 0.001;N2a2 vs. N2b2 73.0% vs. 7.7%,p < 0.001)(DFS:N2a1 vs. N2b1 68.4% vs. 5.9%,p < 0.001;N2a2 vs. N2b2 62.2% vs. 5.1%,p < 0.001), regardless of the number of N2 station(OS:N2a1 vs. N2a2 68.4% vs. 73.0%,p = 0.584;N2b1 vs. N2b2 23.5% vs. 7.7%,p = 0.051). On multivariate analysis, sex (p = 0.008) ,Vascular tumour thrombus(p = 0.047),size(p = 0.002)and SKN2 (p < 0.001) were independent predictors of OS.

CONCLUSION

For patients with stage III-N2 lung adenocarcinoma, the prognosis of SKN2 patients is better than non-SKN2 patients', and SKN2 may be used as an important factor in the N2 subgroup classification in future TNM staging.

Somatic mutations combined with clinical features can predict the postoperative prognosis of stage IIIA lung adenocarcinoma

Background

Prognostic factors for stage IIIA lung adenocarcinoma (LUAD) are unclear. The current main treatment for stage IIIA LUAD is still controversial. Some Clinicians advocate synchronous chemoradiotherapy as the main treatment for stage IIIA LUAD. In contrast, some clinicians argue that there are still certain patients with stage IIIA LUAD who have a better postoperative prognosis. This study aimed to analyze preoperative factors as well as the association between somatic mutations and prognosis in stage IIIA LUAD [including overall survival (OS) time and the risk of postoperative recurrence].

Methods

This study retrospectively reviewed the data of patients with stage IIIA LUAD who underwent radical resection of lung cancer in the thoracic surgery department of Tianjin Chest Hospital from January 01, 2011 to September 30, 2016. All patients involved in the study provided written informed consent. The associations between OS and DFS and the clinical characteristics as well as somatic mutations of patients were analyzed separately. The Kaplan-Meier method was used for univariate analysis, and survival curves were drawn. Multivariate analysis was performed by the Cox regression model.

Results

For univariate analysis, the prognostic factors of OS were the level of preoperative CYFRA21-1, the number of metastatic lymph node stations (NMLS), maximum tumor diameter, EGFR (epidermal growth factor receptor) classical base mutations, and the number of copies of POLE (polymerase epsilon) mutation (NCPM). Preoperative total protein level, preoperative CYFRA21-1 level, the number of metastatic lymph nodes (NMLN), maximum tumor diameter, the number of mutated genes (NMG) in tumor samples, TP53 mutations, and the number of copies of POLE mutation (NCPM) were associated with disease-free survival (DFS). The multivariate analysis showed that the preoperative CYFRA21-1 level, the number of metastatic lymph node stations (NMLS), and EGFR typical base mutations were independent prognostic factors of OS. The number of mutated genes (NMG), EGFR classical base mutations, preoperative NSE level, maximum tumor diameter, and the number of metastatic lymph node stations (NMLS) were independent prognostic factors for DFS.

Conclusions

The preoperative level of tumor markers, the number of metastatic lymph node stations, and EGFR typical base mutations are important factors for the prognosis of patients with resectable stage IIIA LUAD.

Slug and Vimentin downregulation at the metastatic site is associated with Skip-N2 metastasis of lung adenocarcinoma

OBJECTIVE

Lung cancer displays heterogeneity both in the tumor itself and in its metastatic regions. One interesting behavior of the tumor is known as Skip N2 metastasis, which N2 lymph nodes contain tumor cells while N1 are clean. In this study, mRNA levels of epithelial mesenchymal transition (EMT) related genes in skip N2 and normal N2 involvements of non-small cell lung cancer tissues were investigated to evaluate the possible molecular background that may contribute to the pathogenesis of Skip N2 metastasis.

MATERIALS AND METHODS

Eighty-three surgically resected and paraffin embedded lymph node samples of lung cancer patients were analyzed in this study, which 40 of them were Skip N2. N2 tissues were sampled from 50% tumor containing areas and total RNA was extracted. mRNA levels for 18S, E-cadherin, Vimentin, ZEB1 and SLUG were analyzed via qPCR and E-cadherin and vimentin protein levels via immunohistochemistry (IHC). Bioinformatic analysis were adopted using online datasets to evaluate significantly co-expressed genes with SLUG in lung cancer tissue samples.

RESULTS

Skip-N2 patients who had adenocarcinoma subtype had better survival rates. Comparative analysis of PCR results indicated that Skip N2 tumor tissues had increased E-Cadherin/Vimentin ratio and ZEB1 mRNA expression, and significantly decreased levels of SLUG. E-cadherin IHC staining were higher in Skip N2 and Vimentin were in Non-Skip N2. TP63 had a strong correlation with SLUG expression in the bioinformatics analyses.

CONCLUSION

The results indicate that, at molecular level, Skip N2 pathogenesis has different molecular background and regulation of SLUG expression may orchestrate the process.

The Impact of Skip vs. Non-Skip N2 Lymph Node Metastasis on the Prognosis of Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Objective: The skip N2 metastases were frequent in non-small-cell lung cancer (NSCLC) and the better prognosis of NSCLC with a skip over non-skip N2 lymph node metastases is controversial. The primary aim of this study is to investigate the prognosis effect of skip N2 lymph node metastases on the survival of NSCLC.

Setting: A literature search was conducted in PubMed, EMBASE, and Cochrane Library with the term of “N2” or “mediastinal lymph node” or “mediastinal nodal metastases”, and “lung cancer” and “skip” or “skipping” in the title/abstract field. The primary outcomes of interests are 3- and 5-year survival in NSCLC.

Participants: Patients who underwent complete resection by lobectomy, bilobectomy, or pneumonectomy with systemic ipsilateral lymphadenectomy and were staged as pathologically N2 were included.

Primary and Secondary Outcome Measures: The 3- and 5-year survival of NSCLC was analyzed. The impact of publication year, number of patients, baseline mean age, gender, histology, adjuvant therapy, number of skip N2 stations, and survival analysis methods on the primary outcome were also analyzed.

Results: A total of 21 of 409 studies with 6,806 patients met the inclusion criteria and were finally included for the analysis. The skip N2 lymph node metastases NSCLC had a significantly better overall survival (OS) than the non-skip N2 NSCLC [hazard ratio (HR), 0.71; 95% CI, 0.62–0.82; P < 0.001; I² = 40.4%]. The skip N2 lymph node metastases NSCLC had significantly higher 3- and 5-year survival rates than the non-skip N2 lymph node metastases NSCLC (OR, 0.75; 95% CI, 0.66–0.84; P < 0.001; I² = 60%; and OR, 0.78; 95% CI, 0.71–0.86; P < 0.001; I² = 67.1%, respectively).

Conclusion: This meta-analysis suggests that the prognosis of skip N2 lymph node metastases NSCLC is better than that of a non-skip N2 lymph node.

The Significance of Skip Mediastinal Lymph Node Metastasis in the Prognosis of Patients with Resected Non-Small-Cell Lung Carcinoma: Is It Really a Better N2 Disease Subtype?

Objective: In this study, we aimed to reveal the prognostic differences between skip and non-skip metastasis mediastinal lymph node (MLN) metastasis.

Methods: A total of 202 patients (179 males and 23 females; mean age, 59.66 ± 9.89 years; range: 29–84 years) who had ipsilateral single-station MLN metastasis were analyzed in two groups retrospectively between January 2009 and December 2017: “skip ipsilateral MLN metastasis” group (sN2) (n = 55,27.3%) [N1(–), N2(+)], “non-skip ipsilateral MLN metastasis” group (nsN2) (n = 147,72.7%) [N1(+), N2(+)].

Results: The mean follow-up was 42.63 ± 34.91 months (range: 2–117 months). Among all patients, and in the sN2 and nsN2 groups, the median overall survival times were 63.5 ± 4.56, 68.8 ± 7, and 59.3 ± 5.35 months, respectively, and the 5-year overall survival rates were 38.2%, 46.3%, and 36.4%.

Conclusion: Skip metastasis did not take its rightful place in TNM classification; thus, further studies will be performed. To detect micrometastasis, future studies on skip metastasis should examine non-metastatic hilar lymph nodes (LNs) through staining methods so that heterogeneity in patient groups can be avoided, that is, to ensure that only true skip metastasis cases are included. Afterwards, more accurate and elucidative studies on skip metastasis can be achieved to propound its prognostic importance in the group of N2 disease.

Skip metastasis in mediastinal lymph node is a favorable prognostic factor in N2 lung cancer patients: a meta-analysis

Background

Skip metastasis is a common lymph node metastatic pattern in non-small cell lung cancer (NSCLC). The relationship between skip metastasis and specific clinicopathologic factors and the prognostic value of skip metastasis are controversial.

Methods

A systematic search and analysis of skip metastasis in NSCLC was conducted in the databases of PubMed, EMBASE, and Web of Science up to Dec 2019. Summarized hazard ratio (HR), mean difference (MD), and odds ratio (OR) with associated 95% confidence intervals (CI) were evaluated to investigating the relationship between skip metastasis and overall survival (OS), disease-free survival (DFS), recurrence-free survival (RFS) and clinicopathological features in NSCLC.

Results

29 studies with a total of 1,806 skip and 4,670 non-skip N2 patients were included. The upper lobe tumor showed a higher rate of skip metastasis compared with lower lobe one (RR =1.16, 95% CI: 1.00–1.34, P=0.044, I²=39.8%). The presence of skip metastasis correlated with superior overall survival (HR =0.74, 95% CI: 0.66–0.83, P<0.001, I²=48.2%) and DFS or RFS (HR =0.71, 95% CI: 0.61–0.84, P<0.001, I²=18.2%). Further subgroup analyses indicated similar results in articles that reported intrapulmonary lymph node dissection (HR =0.67, 95% CI: 0.57–0.77, P<0.001, I²=0).

Conclusions

The results indicate that the presence of skip metastasis is associated with a marked increase in survival of NSCLC patients compared to patients with non-skip N2 metastasis. These results suggest that skip metastasis might be a distinct subgroup for purposes of N staging of NSCLC patients, and intrapulmonary lymph node assessment is needed.

Metastatic Patterns of Mediastinal Lymph Nodes in Small-Size Non-small Cell Lung Cancer (T1b)

Background: Lymph node metastasis (LNM) status is critical to the treatment. Fewer studies has focused on LNM in patients with small-size non-small cell lung cancer (NSCLC). This study aims to investigate clinicopathological characteristics associated with skip N2 (SN2) and non-skip N2 (NSN2) metastasis, and their metastatic patterns in NSCLC with tumor size of 1–2 cm.

Methods: We reviewed the records of NSCLC patients with tumor size of 1–2 cm who underwent lobectomy with systematic lymph node dissection (LND) between January 2013 and June 2019. Clinical, radiographical, and pathological characteristics were compared among N1, SN2, and NSN2 groups. Metastatic patterns of mediastinal lymph node were analyzed based on final pathology.

Results: A total of 63 NSCLC patients with tumor size of 1–2 cm were staged as pN2, including 25 (39.7%) SN2 and 38 (60.3%) NSN2. The incidence rates of SN2 and NSN2 were 2.8% (25/884) and 4.3% (38/884), respectively. For all clinicopathological characteristics, no significant difference was observed among the groups of N1, SN2, and NSN2. For the tumor located in each lobe, specific nodal drainage stations were identified: 2R/4R for right upper lobe; 2R/4R and subcarinal node (#7) for right middle lobe and right lower lobe; 4L and subaortic node (#5) for left upper lobe; #7 for left lower lobe. However, there were still a few patients (10.9%, 5/46) had the involvement of lower zone for tumors of upper lobe and the involvement of upper zone for lower lobe.

Conclusions: SN2 occurs frequently in patients with small-size NSCLC. Whether lobe-specific selective LND is suitable for all small-size patients deserves more studies to confirm. Surgeons should be more careful when performing selective LND for tumors located in the lower and upper lobes.

[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。

Risk of recurrence in stage I adenocarcinoma of the lung: a multi-institutional study on synergism between type of surgery and type of nodal staging

Background

In last years, an increasing interest emerges on the role of sub-lobar resection and lobe-specific lymph nodal dissection in the treatment of early-stage lung cancer. The aim of our study was to define the impact on cumulative incidence of recurrence (CIR) of type of surgical resection and type of nodal staging in this subset of patients. Furthermore, we evaluated the possible synergism between the different kinds of procedure.

Methods

An analysis of 969 consecutive stage I pulmonary adenocarcinoma patients, operated in six Thoracic Surgery Institutions between 2001 and 2013, was conducted. Type of surgical resection included lobectomy and sub-lobar resection; while pneumonectomy and bilobectomy were excluded from the analysis. Nodal staging procedures were classified in nodal sampling (NS), lobe-specific lymph node dissection (LS-ND) and systematic lymph node dissection (SND). Multivariable-adjusted comparisons for CIR was performed using Fine and Grey model, taking into account of death by any cause as competing event. In order to evaluate synergism between the different procedures, the test of interaction between type of surgical resection and type of nodal staging was carried out and results presented in a stratified way.

Results

Eight-hundred forty-six (87%) patients were submitted to lobectomy, while 123 (13%) to sub-lobar resection. Four-hundred fifty-five (47%) patients received SND, 98 (10%) LS-ND and 416 (43%) NS. Two-hundred forty-seven (26%) patients developed a local/distant recurrence with a 5-year CIR of 24.2%. Multivariable-adjusted comparisons showed an independent negative effect of sub-lobar resection (HR =1.52; 95% CI: 1.07-2.17), LS-ND (HR =1.74; 95% CI: 1.16-2.6) and NS (HR =1.49; 95% CI: 1.12-1.98) on CIR. Test of interaction showed a homogeneity of results among subgroups.

Conclusions

Patients affected by stage I pulmonary adenocarcinoma and submitted to lobectomy presented a significant lower recurrence rate than those submitted to sub-lobar resection. Moreover, SND presented an independent positive effect on recurrence development than other lymph node assessment strategy. Finally, lobectomy in combination with systematic lymph nodal resection showed the best results in term of CIR.

Role of Skip Mediastinal Lymph Node Metastasis for Patients With Resectable Non-small-cell Lung Cancer: A Propensity Score Matching Analysis

BACKGROUND

N2 disease represents a heterogeneous group of non-small-cell lung cancer (NSCLC) with varying 5-year overall survival (OS) rates. The skip N2 phenomenon is quite frequent, and its prognostic impact remains a matter of debate. The aim of this study is to further assess the clinical significance and prognostic value of skip N2 disease using propensity score matching.

PATIENTS AND METHODS

The study cohort included 437 patients with stage pN2 NSCLC who underwent resection from 2005 to 2011. Differences in clinicopathologic characteristics were identified in the overall cohort. The effect of skip N2 on OS was assessed, stratified by histology, tumor size, N2 involved stations, and T stage after propensity score matching.

RESULTS

A total of 130 patients had skip N2 diseases in our study. Skip N2 metastasis was associated with age, tumor size, histology, and number of involved N2 stations. Matching of 130 pairs of patients showed that skip N2 was associated with a significantly better 5-year OS rate when compared with non-skip N2 disease (42.7% vs. 25.3%; P = .004), and OS is significantly better in the patients with tumor size of ≤ 3 cm (P = .014) or patients with single N2 station involvement (P = .002). Skip N2 conferred a significantly better OS in stage IIIA (P = .026) and IIIB (P = .029) disease.

CONCLUSION

The presence of skip N2 metastasis was a good prognostic factor of resectable N2 disease. N2 disease may be classified into more subgroups in the revision of the current tumor-lymph node-metastasis (TNM) system.