Survival benefit of skip metastases in surgically resected N2 non-small cell lung cancer: A multicenter observational study of a large cohort of the Chinese patients

Extent of Lymph Node Dissection in Patients with Small-Sized Peripheral Non-Small Cell Lung Cancer during Intentional Segmentectomy

PURPOSE

Segmentectomy and mediastinal lymph node dissection (MLND) are becoming standard procedures for small-sized (<2 cm) peripheral non-small cell lung cancer (NSCLC). Although the benefits of the less resected lung are proven, the extent of lymph node dissection remains unchanged.

METHODS

We studied 422 patients who underwent lobectomy with MLND (lobe specific or systemic) for small peripheral NSCLC with clinical N0 disease. Patients with middle lobectomy (n = 39) and a consolidation-to-tumor (C/T) ratio ≤0.50 (n = 33) were excluded. We investigated the clinical factors, lymph node metastasis distributions, and lymph node recurrence patterns of 350 patients.

RESULTS

Thirty-five (10.0%) patients had lymph node metastasis; none with C/T ratio <0.75 had lymph node metastasis and lymph node recurrence. None had solitary lymph node metastasis in the outside lobe-specific MLND. Six patients had mediastinal lymph node metastasis at the initial site of recurrence; none had mediastinal lymph node recurrence outside the lobe-specific MLND, except for two patients with S6 primary disease.

CONCLUSION

NSCLC patients with small peripheral tumors and a C/T ratio <0.75 during segmentectomy may not require MLND. The optimal MLND for patients with a C/T ratio ≥0.75, except for those with S6 primary, may be lobe-specific MLND.

Non-Small Cell Lung Cancer With N1 Involvement or Skip Metastases Presents the Same Survival Outcome: Results From a Multicentric Study

BACKGROUND

The prognostic difference among patients affected by NSCLC with hilar metastases only or mediastinal nodes metastases without hilar involvement (skip metastases) is still unclear. Aim of this study is to analyse if prognostic difference are present or if the two groups present the same survival outcome.

MATERIALS AND METHODS

Data on NSCLC patients from 7 high volume centres (2004-2014) were collected and retrospectively reviewed. Histology different from adenocarcinoma(ADC) or squamous cell carcinoma(SCC), patients without data on lymphadenectomy, who underwent neoadjuvant treatment, with distant metastases or incomplete resection were excluded, selecting patients with hilar involvement or with skip metastases. Different prognostic factors such as Tstage, histology, pathological stage, nodal characteristics and adjuvant therapy administration were correlated to overall survival (OS) by the Kaplan-Meier product-limit method. The log-rank test was used to assess differences between subgroups. A multivariable Cox proportional hazard model was developed using stepwise regression to compare the prognostic power of different factors.

RESULTS

The final analysis was conducted on 480 adenocarcinoma/squamous cell carcinoma patients. Five-year OS (5YOS) resulted 53.9%. No significant differences in OS were detected comparing pN1 vs. pN2 patients or stage IIB vs. stage IIIA-B patients. Univariable confirmed as favourable prognostic factors young age (P<.001), T1-2 tumors (P=.030), number of resected nodes≥10 (P=.040), lymph node ratio (P=.026). Multivariable analysis confirmed as independent negative prognostic factors T≥3 (HR:1.385, 95%CI:1.037-1.851, P=.027) and age≥68 years (HR1.637, 95%CI:1.245-2.152).

CONCLUSION

Patients with N1 involvement or skip metastases present a similar prognosis, suggesting that N2 involvement in these cases may be related to a direct lymphatic drainage to the mediastinal stations.

Prognostic value of lymph node ratio in stage III non-small-cell lung cancer: A retrospective cohort study

A growing number of studies have found that the lymph node ratio (LNR) is an important indicator of prognosis in non-small-cell lung cancer (NSCLC). Impact analysis for LNR was performed for survival in patients undergoing surgery for stage III NSCLC compared to the surveillance, epidemiology and end results databank. Clinicopathological variables, such as cancer-specific survival (CSS), were taken from the surveillance epidemiology and end result databank of stage III NSCLC patients who underwent surgery, and the LNR threshold stratification of NSCLC patients was computed by X-tile. CSS was assessed by the Kaplan-Meier method with CSS-independent risk factors calculated by multivariate Cox regression analysis. In total, 7011 lung cancer patients were included. Multifactorial analysis showed that LNR and positive node category had predictive value for stage III NSCLC. In patients with stage IIIA NSCLC, Kaplan-Meier analysis demonstrated that patients with T1-2N2 stage had clearly superior CSS than those with T3-4N1 stage (P < .001), which conflicted with the results from the assessment of primary tumor, lymph nodes, and metastasis/N stage. The cutoff values for LNR were 0.31 and 0.59. Kaplan-Meier analysis demonstrated that the CSS was substantially better in patients with LNR-low than in those with LNR-medium or LNR-high (P < .001), which was also proven by multivariate competing risk regression. Subgroup analysis suggested that the survival advantage of a lower LNR was achieved in all subgroups (sex, race, etc). In stage III NSCLC, the LNR is a valuable factor for assessing prognosis, in which a higher LNR indicates a worse prognosis.

Impact of skip mediastinal lymph node metastasis on outcomes after resection for primary lung cancer

OBJECTIVES

Patients with non-small cell lung cancer and nodal disease are a heterogeneous group with varied patterns of disease. The aim of this study was to assess long-term outcomes of patients with skip N2 disease in comparison to those with N1 or non-skip N2 disease.

MATERIALS AND METHODS

A retrospective review of 445 patients undergoing anatomical lung resection for primary lung cancer between 2012 and 2019 with post-operative histological confirmation of nodal disease was undertaken. Log rank analysis was used to assess differences in estimated median overall survival according to nodal status. Multivariable Cox regression analysis was performed to determine whether skip N2 disease was independently associated with overall survival.

RESULTS

Mean patient age was 67.0 years (standard deviation ± 9.2 years) and 48.1% (n = 214) were male. In total, 20.7% (n = 92) of patients had N1 disease, 32.1% (n = 143) had skip N2 disease and 47.2% (n = 210) had non-skip N2 disease. Post-operative upstaging took place in 33.0% (n = 147) of patients. Median follow-up time was 35 months (interquartile range 14-68 months). Skip N2 patients had significantly longer estimated median overall survival in comparison to their non-skip N2 counterparts (47 months vs 28 months, log rank analysis p = 0.029) and non-skip N2 disease remained independently associated with reduced overall survival after multivariable analysis (hazard ratio 1.421, 95% confidence interval 1.060-1.907, p = 0.019).

CONCLUSION

Skip N2 disease is a positive prognostic factor for patients with N2 lung cancer, suggesting that lung cancer staging guidelines should consider separating N2 disease into additional subgroups in order to improve prognostic accuracy.

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.

Prognostic impact of lymph node spreading pattern in N2 NSCLC patients

BACKGROUND

One-third of non-small cell lung cancer (NSCLC) patients are diagnosed with locally advanced disease. Long-term survival in stage IIIA/B-N2 remains poor; this may also be due to lymph node spreading pattern. Therefore, we compared the overall survival of stage IIIA/B-N2 patients with superior mediastinal lymph nodes (SML) with infracarinal- or inferior mediastinal lymph nodes (IML) and with multilevel disease (MLD).

RESEARCH DESIGN AND METHODS

One-, three-and five-year survival rates were measured. Kaplan-Meier curves and Cox proportional hazards model assessed survival and were used to identify prognostic factors.

RESULTS

We reviewed data of stage IIIA/B-N2 patients (n = 129) who underwent surgery for NSCLC between 2012 and 2020. Patients with SML (n = 62) were compared to ILM (n = 37) and MLD (n = 30). SML patients showed significantly better one- (SML: 95.2% vs. IML: 78.6% vs. MLD: 69.4%, p = 0.03), three- (78.8% vs. 27.7 vs. 13.3%; p = <0.001) and five-year (61.1% vs. 17.1 vs. 3%; p < 0.001) survival rates, than IML and MLD patients. Kaplan-Meier curves showed prolonged overall survival for SML patients (log-rank SML, ILM, MLD p < 0.0001).

CONCLUSIONS

This study showed significantly better long-term survival of SML patients than IML and MLD patients. The long-term survival of ILM and MLD patients was equally poor.

The postoperative prognosis of skip-N2 metastasis is favorable in small-cell lung carcinoma patients with pathological N2 classification: a propensity-score-adjusted retrospective multicenter study

Background

The study on skip-N2 metastasis in small-cell lung cancer (SCLC) is lacking. Therefore, this study aimed to explore the prognostic significance of skip-N2 metastasis based on a multicenter cohort.

Methods

We collected 176 SCLC patients with pathological categories T1-4N1-2M0 from four hospitals in China. Survival curves were drawn through the Kaplan-Meier method and compared by the log-rank test. The Cox regression method was used to calculate the hazard ratio (HR) and 95% confidence interval of the characteristics for cancer-specific survival (CSS). Two propensity-score methods were used to reduce the bias, including the inverse probability of treatment weighting (IPTW) and propensity-score matching (PSM).

Results

This multicenter database included 64 pN1 patients, 63 non-skip-N2 cases, and 49 skip-N2 cases. Skip-N2 and the non-skip-N2 patients had gap CSS rates (skip-N2 no versus yes: 41.0% versus 62.0% for 1-year CSS, 32.0% versus 46.0% for 2-year CSS, and 20.0% versus 32.0% for 3-year CSS). After PSM, there were 32 pairs of patients to compare survival differences between N2 and skip-N2 diseases, and 34 pairs of patients to compare prognostic gaps between N1 and skip-N2 diseases, respectively. The results of IPTW and PSM both suggested that skip-N2 cases had better survival outcomes than the non-skip-N2 cases (IPTW-adjusted HR = 0.578; PSM-adjusted HR = 0.510; all log-rank p < 0.05). Besides, the above two analytic methods showed no difference in prognoses between pN1 and skip-N2 diseases (all log-rank p > 0.05).

Conclusions

Skip-N2 patients were confirmed to have a better prognosis than non-skip-N2 patients. Besides, there was no survival difference between pN1 and skip-N2 cases. Therefore, we propose that the next tumor-node-metastasis staging system needs to consider the situation of skip metastasis with lymph nodes in SCLC.

Preoperative and postoperative nomograms for predicting early recurrence of hepatocellular carcinoma without macrovascular invasion after curative resection

BACKGROUND

Postoperative early recurrence (ER) is a major obstacle to long-term survival after curative liver resection (LR) in patients with hepatocellular carcinoma (HCC). This study aimed to establish preoperative and postoperative nomograms to predict ER in HCC without macrovascular invasion.

METHODS

Patients who underwent curative LR for HCC between January 2012 and December 2016 were divided into training and internal prospective validation cohorts. Nomograms were constructed based on independent risk factors derived from the multivariate logistic regression analyses in the training cohort. The predictive performances of the nomograms were validated using the internal prospective validation cohort.

RESULTS

In total, 698 patients fulfilled the eligibility criteria. Among them, 265 of 482 patients (55.0%) in the training cohort and 120 of 216 (55.6%) patients in the validation cohort developed ER. The preoperative risk factors associated with ER were age, alpha-fetoprotein, tumor diameter, and tumor number, and the postoperative risk factors associated with ER were age, tumor diameter, tumor number, microvascular invasion, and differentiation. The pre- and postoperative nomograms based on these factors showed good accuracy, with concordance indices of 0.712 and 0.850 in the training cohort, respectively, and 0.754 and 0.857 in the validation cohort, respectively. The calibration curves showed optimal agreement between the predictions by the nomograms and actual observations. The area under the receiver operating characteristic curves of the pre- and postoperative nomograms were 0.721 and 0.848 in the training cohort, respectively, and 0.754 and 0.844 in the validation cohort, respectively.

CONCLUSIONS

The nomograms constructed in this study showed good performance in predicting ER for HCC without macrovascular invasion before and after surgery. These nomograms would be helpful for doctors when determining treatments and selecting patients for regular surveillance or administration of adjuvant therapies.

A Novel and Effective Model to Predict Skip Metastasis in Papillary Thyroid Carcinoma Based on a Support Vector Machine

INTRODUCTION

Skip metastasis, referred to as lymph node metastases to the lateral neck compartment without involvement of the central compartment, is generally unpredictable in papillary thyroid carcinoma (PTC). This study aims to establish an effective predictive model for skip metastasis in PTC.

METERIALS AND METHODS

Retrospective analysis was performed of clinical samples from 18192 patients diagnosed with thyroid cancer between 2016 to 2020. The First Affiliated Hospital of Wenzhou Medical University. The lateral lymph node metastasis was occureed in the training set (630 PTC patients) and validation set (189 PTC patients). The univariate and multivariate analyses were performed to detect the predictors of skip metastasis and the support vector machine (SVM) was used to establish a model to predict skip metastasis.

RESULTS

The rate of skip metastasis was 13.3% (84/631). Tumor size (≤10 mm), upper location, Hashimoto's thyroiditis, extrathyroidal extension, absence of BRAFV600E mutation, and less number of central lymph node dissection were considered as independent predictors of skip metastasis in PTC. For the training set, these predictors performed with 91.7% accuracy, 86.4% sensitivity, 92.2% specificity, 45.2% positive predictive value (PPV), and 98.9% negative predictive value (NPV) in the model. Meanwhile, these predictors showed 91.5% accuracy,71.4% sensitivity, 93.1% specificity, 45.5% PPV, and 97.6% NPV in validation set.

CONCLUSION

This study screened the predictors of the skip lateral lymph node metastasis and to establish an effective and economic predictive model for skip metastasis in PTC. The model can accurately distinguish the skip metastasis in PTC using a simple and affordable method, which may have potential for daily clinical application in the future.

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.

Survival Analysis in Single N2 Station Lung Adenocarcinoma: The Prognostic Role of Involved Lymph Nodes and Adjuvant Therapy

BACKGROUND

Prognostic factors in patients with single mediastinal station (sN2) involvement continues to be a debated issue.

METHODS

Data on 213 adenocarcinoma patients with sN2 involvement and who had undergone complete anatomical lung resection and lymphadenectomy, were retrospectively reviewed. Clinical and pathological characteristics together with adjuvant therapy (AD) and node (N) status classifications (number of resected nodes (#RN), number of metastatic nodes (#MN), and node ratio (#MN/#RN = NR) were analyzed.

RESULTS

Univariable analysis confirmed that age (0.009), #MN (0.009), NR (0.003), #N1 involved stations (p = 0.003), and skip metastases (p = 0.005) were related to overall survival (OS). Multivariable analysis confirmed, as independent prognostic factors, age <66 years and NR with a three-year OS (3YOS) of 78.7% in NR < 10% vs. 46.6% in NR > 10%. In skip metastases, NR (HR 2.734, 95% CI 1.417-5.277, p = 0.003) and pT stage (HR2.136, 95% CI 1.001-4.557, p = 0.050) were confirmed as independent prognostic factors. AD did not influence the OS of patients with singular positive lymph nodes (p = 0.41), while in patients with multiple lymph nodes and AD, a significantly better 3YOS was demonstrated, i.e., 49.1% vs. 30% (p = 0.004). In patients with N2 + N1 involvement, age (p = 0.002) and AD (p = 0.022) were favorable prognostic factors.

CONCLUSIONS

Adenocarcinoma patients with single N2 station involvement had a favorable outcome in the case of skip metastases and low NR. Adjuvant therapy improves survival with multiple nodal involvement, while its role in single node involvement should be clarified.

Minimal invasive surgery in locally advanced N2 non-small cell lung cancer

Locally advanced lung cancer, defined by nodal involvement in upper mediastinal stations (N2) (stage IIIA–N2), includes a wide spectrum of patients with multiple therapeutic alternatives. Such heterogeneity is explained, at least in part, by tumor size and magnitude of mediastinal nodal involvement. In this setting, many variants can influence the prognosis, such as the specific nodal stations compromised, the burden of mediastinal disease, and the presence of skip metastasis. In the surgical field, the advent of minimally invasive techniques, including video-assisted thoracoscopic and robotic surgery, have revolutionized the management of early-stage lung cancer, but implementations of these approaches in the locally advanced setting have been erratic. This review attempts to highlight the most relevant scientific data of the surgical management of locally advanced lung cancer patients, analyzing not only the medical evidence but also the cost-effectiveness and accessibility.

Perioperative comparison of video-assisted thoracic surgery and open lobectomy for pT1-stage non-small cell lung cancer patients in China: a multi-center propensity score-matched analysis

Background

Compared with open surgery, video-assisted thoracic surgery (VATS) has innovated the concept of the minimally invasive approach for non-small cell lung cancer (NSCLC) patients in past decades. This present study aimed to compare the perioperative and lymph node dissection outcomes between VATS lobectomy and open lobectomy for pathological stage T1 (pT1) NSCLC patients from both surgical and oncologic perspectives.

Methods

This was a retrospective multicenter study. Patients who underwent surgical resection for pT1 NSCLC between January 2014 and September 2017 were retrospectively reviewed from 10 thoracic surgery centers in China. Perioperative and lymph node dissection outcomes of pT1 NSCLC patients who accepted VATS or open lobectomies were compared by propensity score matching (PSM) analysis.

Results

Of the 11,360 patients who underwent surgery for pT1 NSCLC, 7,726 were enrolled based on the selection criteria, including 1,222 cases of open lobectomies and 6,504 cases of VATS lobectomies. PSM resulted in 1,184 cases of open lobectomies and 1,184 cases of VATS lobectomies being well matched by common prognostic variables, including age, sex, and surgical side. VATS lobectomy led to better perioperative outcomes, including less blood loss (133.5±200.1 vs. 233.3±318.4, P<0.001), lower blood transfusion rate (2.4% vs. 6.4%, P<0.001), shorter postoperative hospital stay (8.6±5.7 vs. 10.1±5.1, P<0.001), less chest drainage volume (1,109.5±854.0 vs. 1,324.1±948.8, P<0.001), and less postoperative complications (4.9% vs. 8.2%, P<0.001). However, open lobectomy had better lymph node dissection outcomes than VATS, with increased lymph node dissection numbers (16.1±9.4 vs. 13.7±7.7, P<0.001) and more positive lymph nodes being dissected (1.5±3.9 vs. 1.1±2.5, P=0.002). Compared with VATS, open lobectomy harvested more lymph node stations (5.5±1.9 vs. 5.2±1.8, P=0.001), including more pathological N2 (pN2) lymph node stations (3.4±1.4 vs. 3.1±1.3, P<0.001).

Conclusions

VATS lobectomy was associated with better perioperative outcomes, such as less blood loss, lower blood transfusion rate, shorter postoperative hospital stay, less chest drainage volume and less postoperative complications. Open lobectomy has improved lymph node dissection outcomes, as more lymph nodes and positive lymph nodes were dissected for pT1 NSCLC patients during surgery.