Subcarinal lymph node in upper lobe non-small cell lung cancer patients: is selective lymph node dissection valid?

Dual-Region Computed Tomography Radiomics-Based Machine Learning Predicts Subcarinal Lymph Node Metastasis in Patients with Non-small Cell Lung Cancer

BACKGROUND

Noninvasively and accurately predicting subcarinal lymph node metastasis (SLNM) for patients with non-small cell lung cancer (NSCLC) remains challenging. This study was designed to develop and validate a tumor and subcarinal lymph nodes (tumor-SLNs) dual-region computed tomography (CT) radiomics model for predicting SLNM in NSCLC.

METHODS

This retrospective study included NSCLC patients who underwent lung resection and SLNs dissection between January 2017 and December 2020. The radiomic features of the tumor and SLNs were extracted from preoperative CT, respectively. Ninety machine learning (ML) models were developed based on tumor region, SLNs region, and tumor-SLNs dual-region. The model performance was assessed by the area under the curve (AUC) and validated internally by fivefold cross-validation.

RESULTS

In total, 202 patients were included in this study. ML models based on dual-region radiomics showed good performance for SLNM prediction, with a median AUC of 0.794 (range, 0.686-0.880), which was superior to those of models based on tumor region (median AUC, 0.746; range, 0.630-0.811) and SLNs region (median AUC, 0.700; range, 0.610-0.842). The ML model, which is developed by using the naive Bayes algorithm and dual-region features, had the highest AUC of 0.880 (range of cross-validation, 0.825-0.937) among all ML models. The optimal logistic regression model was inferior to the optimal ML model for predicting SLNM, with an AUC of 0.727.

CONCLUSIONS

The CT radiomics showed the potential for accurately predicting SLNM in NSCLC patients. The ML model with dual-region radiomic features has better performance than the logistic regression or single-region models.

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.

A multicenter propensity score-matched analysis of lymphadenectomy in N1-positve lung cancer

OBJECTIVES

Selective mediastinal lymph node dissection based on lobe-specific metastases is widely recognized in daily practice. However, the significance of mediastinal lymph node dissection for N1-positive tumors has not been elucidated.

METHODS

We retrospectively reviewed 359 patients with N1-positive lung cancer who underwent lobectomy with systematic mediastinal lymph node dissection (systematic lymph node dissection) (n = 150) and lobe-specific mediastinal lymph node dissection (lobe-specific lymph node dissection) (n = 209). The operative and postoperative results and their propensity score-matched pairs were compared. The factors affecting survival were assessed using competing risk and multivariable analyses.

RESULTS

The cumulative incidence of recurrence and the cumulative incidence of cancer-specific death were not significantly different between systematic and lobe-specific lymph node dissection in entire cohort. In the propensity score-matched cohort (83 pairs), systematic lymph node dissection tended to detect N2 lymph node metastasis more frequently (55.4 vs. 41%, P = 0.087). Eleven patients (13.2%) in the systematic lymph node dissection group had a metastatic N2 lymph node 'in the systematic lymph node dissection field' that lobe-specific lymph node dissection did not dissect. The oncological outcomes between patients undergoing systematic lymph node dissection (5-year cumulative incidence of recurrence, 62.1%; 5-year cumulative incidence of cancer-specific death, 27.9%) and lobe-specific lymph node dissection (5-year cumulative incidence of recurrence, 60.1%; 5-year cumulative incidence of cancer-specific death, 23.3%) were similar. The propensity score-adjusted multivariable analysis for cumulative incidence of recurrence revealed that the prognosis associated with systematic lymph node dissection was comparable with the prognosis with lobe-specific lymph node dissection (hazard ratio, 1.17; 95% confidence interval, 0.82-1.67; P = 0.37).

CONCLUSIONS

The extent of lymph node dissection can affect accurate pathological staging; however, it was not associated with survival outcome in the treatment of N1-positive lung cancer.

Radioisotope-Guided Excision of Mediastinal Lymph Nodes in Patients with Non-Small Cell Lung Carcinoma: Feasibility and Clinical Impact

BACKGROUND

Intraoperative localisation of nodal disease in non-small cell lung cancer (NSCLC) can be challenging. Lymph node localisation via radiopharmaceuticals is used in many conditions; we tested the feasibility of this approach in NSCLC.

METHODS

NSCLC patients were prospectively recruited. Intraoperative peri-tumoral injections of [99mTc]Tc-albumin nanocolloids were performed, followed by removing the tumour and locoregional lymph nodes. These were examined ex vivo with a gamma probe and labelled sentinel lymph nodes (SLNs) if they showed any activity or non-sentinel lymph nodes (nSLNs) if they did not. Thereafter, the surgical field was scanned with the probe; any further radioactive lymph node was removed and labelled as "extra" SLNs (eSLNs). All specimens were sent to histology, and metastatic status was recorded.

RESULTS

48 patients were enrolled, and 290 nodal stations were identified: 179 SLNs, 87 nSLNs, and 24 eSLNs. A total of 44 nodal metastases were identified in 22 patients, with 36 of them (82%) located within SLNs. Patients with nSLNs metastases had at least a co-existing positive SLN. No metastases were found in eSLNs.

CONCLUSIONS

The technique shows high sensitivity for intraoperative nodal metastases identification. This information could allow selective lymphadenectomies in low-risk patients or more aggressive approaches in high-risk patients.

Preclinical Lymph Node Model for Intraoperative Molecular Imaging of Cancer

Purpose

Lymph node(LN) dissection is part of most oncologic resections. Intraoperatively identifying a positive LN(+ LN), that harbors malignant cells, can be challenging. We hypothesized that intraoperative molecular imaging(IMI) using a cancer-targeted fluorescent prober can identify + LNs. This study aimed to develop a preclinical model of a + LN and test it using an activatable cathepsin-based enzymatic probe, VGT-309.

Procedures

In the first model, we used peripheral blood mononuclear cells (PBMC), representing the lymphocytic composition of the LN, mixed with different concentrations of human lung adenocarcinoma cell line A549. Then, they were embedded in a Matrigel® matrix. A black dye was added to mimic LN anthracosis. Model two was created using a murine spleen, the largest lymphoid organ, injected with various concentrations of A549. To test these models, we co-cultured A549 cells with VGT-309. Mean fluorescence intensity(MFI) was. An independent sample t-test was used to compare the average MFI of each A549:negative control ratio.

Results

A significant difference in MFI from our PBMC control was noted when A549 cells were 25% of the LN (p = 0.046) in both 3D cell aggregate models-where the LNs native parenchyma is replaced and the one where the tumor grows over the native parenchyma. For the anthracitic equivalents of these models, the first significant MFI compared to the control was when A549 cells were 9% of the LN (p = 0.002) in the former model, and 16.7% of the LN (p = 0.033) in the latter. In our spleen model, we first noted significance in MFI when A549 cells were 16.67% of the cellular composition.(p = 0.02).

Conclusions

A + LN model allows for a granular evaluation of different cellular burdens in + LN that can be assessed using IMI. This first exvivo + LN model can be used in preclinical testing of several existing dyes and in creating more sensitive cameras for IMI-guided LN detection.

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.

Lobe-specific lymph node dissection in early-stage non-small-cell lung cancer: An overview

Lymph node dissection is a vital part of surgical treatment for early-stage non-small cell lung cancer (NSCLC). Lobectomy with systematic lymph node dissection (SLND) still remains the gold standard surgical treatment for early-stage NSCLC patients. However, an increasing number of studies have demonstrated that lobe-specific lymph node dissection (L-SLND) can be used as an alternative therapy for SLND in carefully selected patients with early-stage NSCLC. However, there are no currently available evidences of review summarizing the role of L-SLDN in treating early-stage NSCLC. Therefore, we performed this literature review by summarizing the existing literatures on the lymph node drainage pattern, definition, scope and role of L-SLND in patients with early-stage NSCLC, aiming to provide evidence for the application of L-SLND in patients with early-stage NSCLC.

Lobe-specific nodal dissection with intraoperative frozen section analysis for clinical stage-I non-small cell lung cancer: a validation study by propensity score matching

OBJECTIVE

Lobe-specific nodal dissection (LND) is increasingly used for non-small cell lung cancer (NSCLC) in Japan; however, its treatment validity remains unclarified. Since 2013, LND has been used as a standard procedure for clinical stage-I (c-stage-I) NSCLC at our institution. We aimed to evaluate its validity using intraoperative frozen section analysis (FSA) for c-stage-I NSCLC.

METHODS

The participants comprised patients with NSCLC who underwent LND between 2013 and 2016 (n = 307) or systematic nodal dissection (SND) between 2002 and 2013 (n = 367) for c-stage-I disease. FSA was routinely performed in LND to examine at least three stations. Outcomes were compared between the LND and SND groups. Patients in whom LND was converted to SND due to metastasis on FSA of the sampled lymph node were still categorized into the LND group, i.e., intention-to-treat analysis. The prognostic impact was compared using propensity score matching.

RESULTS

The rate of conversion from LND to SND was 10.4%. Of the patients converted to SND, 12.5% had metastases outside the LND area. False-negative N2 results were detected in only 0.7% of the LND group patients after FSA. After matching, each group had 220 patients. There were no significant between-group differences in the lymph-node recurrence rate (7% vs. 6%), 5-year recurrence-free survival (80.1% vs. 79.0%), and overall survival (90.4% vs. 90.3%).

CONCLUSIONS

LND with intraoperative FSA is a valid modality that could serve as a standard surgical procedure for c-stage-I NSCLC. Intraoperative FSA may lower the residual lymph-node metastasis risk in LND.

Permissible Outcomes of Lobe-Specific Lymph Node Dissection for Elevated Carcinoembryonic Antigen in Non-Small Cell Lung Cancer

Background and Objectives: Lobe-specific nodal dissection (L-SND) is currently acceptable for the dissection of early-stage non-small cell lung cancer (NSCLC) but not for cancers of more advanced clinical stages. We aimed to assess the efficacy of L-SND, compared to systemic nodal dissection (SND). Materials and Methods: We retrospectively collected the clinical data of patients with carcinoembryonic antigen (CEA) abnormality who underwent complete resection of NSCLC via lobectomy or more in addition to either SND or L-SND at two cancer-specific institutions from January 2006 to December 2017. Results: A total of 799 patients, including 265 patients who underwent SND and 534 patients who underwent L-SND, were included. On multivariate analysis, thoracotomy, more than lobectomy, cN1-2, advanced pathological stage, adjuvant treatment, and EGFR or ALK were strongly associated with SND. No significant differences were found in overall survival, disease-free survival, and overtime survival after propensity adjustment (p = 0.09, p = 0.11, and p = 0.50, respectively). There were no significant differences in local (p = 0.16), regional (p = 0.72), or distant (p = 0.39) tumor recurrence between the two groups. Conclusions: SND did not improve the prognosis of NSCLC patients with CEA abnormality. Complete pulmonary resection via L-SND seems useful for NSCLC patients with CEA abnormality.

Systematic Versus Lobe-Specific Mediastinal Lymphadenectomy for Hypermetabolic Lung Cancer

BACKGROUND

The optimal extent of lymph node dissection (LND) for hypermetabolic tumors that are associated with high rates of nodal disease, recurrence, or mortality has not been elucidated.

METHODS

We reviewed 375 patients who underwent lobectomy with lymphadenectomy for clinical T2-3 N0-1 M0 hypermetabolic non-small cell lung cancer (NSCLC) [maximum standard uptake value (SUVmax) ≥ 6.60] via a multicenter database. Extent of LND was classified into systematic mediastinal LND (systematic LND) and lobe-specific mediastinal LND (lobe-specific LND). Postoperative outcomes after lobectomy with systematic LND (n = 128) and lobe-specific LND (n = 247) were analyzed for all patients and their propensity-score-matched pairs.

RESULTS

Cancer-specific survival (CSS) and recurrence-free interval (RFI) of the systematic LND group were not significantly different from those of the lobe-specific LND group in the nonadjusted whole cohort. In the propensity-score-matched cohort (101 pairs), systematic LND dissected significantly more lymph nodes (20.0 versus 16.0 nodes, P = 0.0057) and detected lymph node metastasis more frequently (53.5% vs. 33.7%, P = 0.0069). Six (5.9%) patients in the systematic LND group had a metastatic N2 lymph node "in the systematic LND field" that lobe-specific LND could not dissect. The systematic LND group tended to have better prognosis than the lobe-specific LND group (5-year CSS rates, 82.6% versus 69.6%; 5-year RFI rates, 56.6% vs. 47.3%).

CONCLUSIONS

Systematic LND was found to harvest more metastatic lymph nodes and provide better oncological outcome than lobe-specific LND in a cohort of hypermetabolic NSCLC patients.

Surgery for right upper lobe lung cancer in a patient with bridging bronchus

A 70-year-old man with back pain presented with a tumor invading the chest wall of his right upper lobe. Three-dimensional computed tomography revealed an aberrant right lower bronchus originating from the left main bronchus. Open thoracotomy right upper lobectomy with combined resection of the chest wall was performed under ventilation for the left and right lower lobes. The aberrant bronchus was defined as a bridging bronchus, a rare congenital anomaly. For such cases, careful planning is necessary to manage ventilation during operation. The area and extent of lymph node dissection are debatable.

New N1/N2 classification and lobe specific lymphatic drainage: Impact on survival in patients with non-small cell lung cancer treated with surgery

OBJECTIVE

to validate the proposed N descriptor revision on a large cohort of patients and assess the impact of tumour location on the distribution pattern of lymph node metastases for patients with NSCLC.

METHODS

This is a retrospective review of a consecutive series of patients who had anatomical lung resections. Systematic lymph node dissection was done for all patients.

RESULTS

Between January 2009 and December 2019 2566 patients had surgical resection for NSCLC. 448 patients (17.5%) had histologically confirmed lymph node metastases: 257 (57.4 %) had pN1 and 191 pN2. Median age of the study population was 69.1 years. Overall survival (OS) for study population was 37.3 months with 5-year survival rate of 35.7 %. The survival analysis of the N subgroups showed the pN2 patients had a median OS of 27.9 months vs. 41.7 months for pN1 patients (p = 0.013). Analysis as per the new proposal of the N subgroups N1a vs N1b vs N2a1 vs N2a2 vs N2b showed that median survival OS was 41.7 vs. 39.2 mo vs. 33.3 mo vs. 28.9 mo vs. 24.6 mo (p = 0.099). There was statistically significant difference in survival between N2 patients with skip metastasis and N2 patients without skip metastases: OS 32.2 (95 % CI: 16.8-47.6) months vs. 24.2 months (p = 0.024). On multivariate analysis only pathological N (p = 0.011) and the new proposed N classification (p = 0.006) were independent prognostic factors for survival.

CONCLUSIONS

N1 and N2 disease are heterogeneous groups and require further stratification. The number of N2 lymph node stations involved and the presence or not of N1 disease translated to significant differences in survival and therefore have to be included in N staging.

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.

Nodal Involvement Pattern in Clinical Stage IA Non-Small Cell Lung Cancer According to Tumor Location

PURPOSE

The purpose of this study was to investigate lymph node involvement pattern in clinical stage IA non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

Clinical stage ⅠA NSCLC patients who underwent lobectomy and lymph node resection were included in this retrospective study. Mediastinal lymph node involvement was distinguished by different lobes and tumor size.

RESULTS

From 2000 to 2015, a total of 759 patients were identified: 282 (37.2%) with tumors in the right upper lobe (RUL), 183 (24.1%) in the left upper lobe (LUL), 124 (16.3%) in the right lower lobe (RLL), 103 (13.6%) in the left lower lobe (LLL), and 67 (8.8%) in the right middle lobe (RML). Patients with tumor size ≤1 cm accounted for 19.6%, >1 and ≤2 cm for 47.8%, >2 and ≤3 cm for 32.5%. Patients with pN1 accounted for 8.2%, and pN2 for 12.5%. Among patients with pN2, the inferior mediastinum was involved in 9.7% of RULs and 17.4% of LULs; the superior mediastinum was involved in 52.2% of RLLs and 36.4% of LLLs. Mediastinal lymph node metastasis was found in 13.2% of patients with size >1 and ≤2 cm, and 19.0% of >2 and ≤3 cm. Patients with tumors ≤1 cm had no N2 lymph node involved.

CONCLUSION

Selective lymph node dissection based on tumor location is not recommended in clinical stage ⅠA NSCLC, and systemic lymph node dissection should be performed for NSCLC with size >1 cm.

Is lobe specific lymph node dissection adequate for cN0-1 non-small cell lung cancer?

Purpose

This study aims to explore whether lobe specific lymph node dissection (LND) is adequate for cN0–1 non-small cell lung cancer (NSCLC) or not.

Methods

Among 5613 cN0–1 NSCLC patients, 394 cases (7.0%) with pN2 were enrolled and the distribution of mediastinal lymph node metastasis was analyzed. The included patients were divided into the non-lobe specific lymph node metastasis (NLSLNM) group and the lobe specific lymph node metastasis (LSLNM) group. The clinicopathological characteristics were compared between two groups and multivariable analysis was performed to find independent factors predicting NLSLNM.

Results

The incidence of pN2 cases deserved serious attention. The proportion of upper zone lymph node metastases was not rare in right (55.0%) and left (35.7%) lower lobe tumors. The proportion of subcarinal zone lymph node involvement was also high in right (21.8%) and left (25.8%) upper lobe tumors. Multivariable analysis showed that elevated carcinoembryonic antigen (CEA) level (P = 0.034), right lower lobe (RLL) tumors (P = 0.022) and station 11 involvement (P = 0.030) were independent risk factors for NLSLNM.

Conclusion

Systematic LND seems to be superior to lobe specific LND in the assessment of lymph node status and high CEA level, RLL tumors and station 11 involvement are predictors for NLSLNM.

[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。

Assessment of non-lobe-specific lymph node metastasis in clinical stage IA non-small cell lung cancer

BACKGROUND

The rationality of selective mediastinal lymph node dissection based on lobe-specific metastasis is still controversial. The correlation of lymph node metastasis in lobe-specific lymphatic drainage regions (LSDRs) and non-LSDRs has not been widely reported. The purpose of this study was to investigate the variables affecting nodal metastasis in non-LSDRs and to further evaluate the rationality of selective lymphadenectomy in clinical stage IA non-small cell lung cancer (NSCLC) patients.

METHODS

The clinicopathological information of 316 patients with clinical stage IA NSCLC who underwent lobectomy with systematic lymph node dissection between June 2014 and June 2018 was retrospectively collected for analysis.

RESULTS

The overall lymph node metastasis rate was 19.3%. For 35 patients with positive LSDR lymph nodes, the non-LSDR lymph node metastasis rate was 31.4%. Only one patient (0.4%) among 281 patients with negative LSDR lymph nodes had nodal spread in non-LSDRs. Univariate analysis identified that solid consistency, worse differentiation, and positive status in LSDRs were unfavorable predictive variables of lymph node metastasis in non-LSDRs. Multivariate analysis showed that nodal metastasis in LSDRs was the only independent predictor of nodal involvement in non-LSDRs (P < 0.001).

CONCLUSION

For patients with clinical stage IA NSCLC, non-LSDR lymph node metastasis mainly depends on the involvement of the LSDR lymph node. Our observations may indicate the potential implications for the reasonable management of lymphadenectomy in stage IA NSCLC patients.

Prediction of lymph node status in completely resected IIIa/N2 small cell lung cancer: importance of subcarinal station metastases

Background

The aim of this study was to determine the prognostic value of lymph node status in patients with pathologic N2 (pN2) stage IIIA small cell lung cancer (SCLC).

Methods

A total of 163 consecutive pN2 stage IIIA SCLC patients who underwent pulmonary resections and systematic lymphadenectomies at Shanghai Chest Hospital between January 2006 and June 2014 were enrolled. We retrospectively analyzed the potential clinicopathologic factors that influenced survival, including the node levels (single or multiple-station) and the node-spreading patterns (skip N2 or non-skip N2). The prognostic significance was examined by Cox regression analysis.

Results

The median overall survival (OS) was 23.7 months. Multiple-station lymph node metastasis indicated a poorer prognosis than single-station involvement (p = 0.003). Skip metastasis did not appear to influence survival (p = 0.099). With respect to the station of lymph node metastasis, the OS was only related to the involvement of the subcarinal node, regardless of tumor location (p < 0.05). Multivariate analysis showed two statistically significant risk factors for survival, including multiple-station lymph node and subcarinal node metastasis (hazard ratio [HR] = 1.76, 95% confidence interval [CI]:1.11–2.78, p = 0.015; HR = 1.61, 95% CI: 1.03–2.50, p = 0.036, respectively).

Conclusions

Multiple-station N2 metastasis and involvement of the subcarinal node predicted poor prognosis in pN2 stage IIIA SCLC patients, which may profoundly influence therapeutic decisions.

Lymph node metastasis in Chinese patients with clinical T1 non-small cell lung cancer: A multicenter real-world observational study

Background

Approximately 8.3–15.9% of patients with clinical stage I non‐small cell lung cancer are subsequently shown to have lymph node metastasis. However, the clinical characteristics of patients with lymph node metastasis in China are not fully understood.

Methods

This is a multicenter retrospective analysis of pathological T1 non‐small cell lung cancer patients who underwent surgical resection from 2 January 2014 to 27 December 2017. Clinical and pathological information was collected with the assistance of the Large‐scale Data Analysis Center of Cancer Precision Medicine‐LinkDoc database. The clinical and pathological factors associated with lymph node metastasis were analyzed by univariate and multivariate logistic regression.

Results

A total of 10 885 participants (51.6% women; 15.3% squamous cell carcinoma) were included in the analysis. The median age was 60.0 years (range 12.9–86.6 years). A total of 1159 patients (10.6%) had metastases in mediastinal nodes (N2), and 640 patients (5.9%) had metastasis in pulmonary lymph nodes (N1). Most patients had T1b lung cancer (4766, 43.8%). Of the patients, 3260 (29.9%) were current or former smokers. The univariate and multivariate analyses showed that younger age, squamous cell carcinoma, poor differentiation, larger tumor size, carcinoembryonic antigen level ≥5 ng/mL, and vascular invasion (+) were significantly associated with higher percentages of lymph node metastases (P < 0.001 for all).

Conclusion

This real‐world study showed the significant association of lymph node metastasis with age, tumor size, histology and differentiation, carcinoembryonic antigen levels, and status of vascular invasion. Female patients with T1a adenocarcinoma in the right upper lobe barely had lymph node metastasis.

Upfront surgery in patients with clinical skip N2 lung cancer based on results of modern radiological examinations

Background

Direct lymphatic drainage from a primary tumor to the right paratracheal or aortic window lymph nodes is often noted in pN2 disease. This multi-institutional retrospective study investigated the outcomes of upfront surgery in patients with clinical skip N2 disease (N2 disease without N1 disease) and a tumor in the right upper lobe or left upper segment based on results of modern radiological examinations, including positron emission tomography (PET).

Methods

We identified 143 patients with cN2 disease who underwent upfront surgery in 12 institutions under the Thoracic Surgery Study Group of Osaka University between January 2006 and December 2013. Among 143 patients, 94 who underwent PET were analyzed. We classified these patients into Group A (n=39; clinical skip N2 disease and a tumor in the right upper lobe or left upper segment) and Group B (n=55; other).

Results

The median follow-up was 56.5 months. Among the 94 patients, 50 (53.2%) had skip N2 disease and 65 (69.1%) had a tumor in the right upper lobe or left upper segment. The 5-year overall survival (OS) rates of the 94 patients with cN2 disease was 47.9%. The 5-year OS rates for the cN2pN0/1 (n=22) and cN2pN2 (n=70) groups were 74.9% and 41.2%, respectively (P=0.034). The univariate analysis of OS revealed no significant differences in age, sex, histology, carcinoembryonic antigen (CEA) level, tumor size, PET findings, and number of metastatic lymph nodes when these parameters were dichotomized. A significantly better 5-year OS rate was observed in Group A than in Group B (64.0% vs. 37.0%; P=0.039). The multivariate analysis of OS revealed that Group A was a significantly prognostic factor (P=0.030).

Conclusions

Patients with cN2 disease in Group A had a more favorable prognosis. Upfront surgery may be a treatment option for such selected patients with non-small lung cancer in the specific group.

Clinical Significance of 4L Lymph Node Dissection in Left Lung Cancer

Purpose

To investigate the prognostic impact of 4L lymph node (LN) dissection in left lung cancer and to analyze the relative risk factors for 4L LN metastasis.

Patients and Methods

We retrospectively collected data from 657 patients with primary left lung cancer who underwent surgical pulmonary resection from January 2005 to December 2009. One hundred thirty-nine patients underwent 4L LN dissection (4LD+ group); the other 518 patients did not receive 4L LN dissection (4LD− group). Propensity score weighting was applied to reduce the effects of observed confounding between the two groups. Study end points were disease-free survival (DFS) and overall survival (OS).

Results

The metastasis rate of station 4L was 20.9%, which was significantly higher than those of station 7 (14.0%; P = .048) and station 9 (9.8%; P < .001). Station 4L metastasis was associated with most other LN station metastases in univariate analysis, but only station 10 LN metastasis was an independent risk factor for 4L LN metastasis (odds ratio, 0.253; 95% CI, 0.109 to 0.588; P = .001) in multivariate logistic analysis. The 4LD+ group had a significantly better survival than the 4LD− group (5-year DFS, 54.8% v 42.7%; P = .0376; 5-year OS, 58.9% v 47.2%; P = .0200). After allowing potential confounders in multivariate survival analysis, dissection of 4L LN retained its independent favorable effect on DFS (hazard ratio, 1.502; 95% CI, 1.159 to 1.947; P = .002) and OS (hazard ratio, 1.585; 95% CI, 1.222 to 2.057; P = .001). Propensity score weighting further confirmed that the 4LD+ group had a more favorable DFS ( P = .0014) and OS ( P < .001) than the 4LD− group.

Conclusion

Station 4L LN involvement is not rare in left lung cancer, and dissection of the 4L LN station seems to be associated with a more favorable prognosis as compared with those who did not undergo this dissection.

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.

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.

[Surgical Treatment of Small Pulmonary Nodules Under Video-assisted Thoracoscopy (A Report of 129 Cases)]

背景与目的

影像技术的发展导致肺部微小结节尤其是肺磨玻璃结节（ground-glass opacity, GGO）检出逐年增多，但术前定性困难。本研究探讨肺部微小结节的临床诊断及微创手术治疗的必要性和可行性、病理诊断，微创切除及淋巴结切除的手术方式。

方法

对2013年12月-2016年11月接受电视胸腔镜手术（video-assisted thoracic surgery, VATS）治疗并有明确病理诊断的共129例患者的临床资料回顾性分析。所有患者术前行薄层计算机断层扫描（computed tomography, CT）扫描，其中21个微小结节术前行CT引导下Hook-wire定位，并根据病理性质及患者身体状况采用不同手术方式。

结果

共129个微小结节，实性结节（solid pulmonary nodule, SPN）37个，恶性比例是24.3%（9/37），术后病理结果为：肺原发性鳞状细胞癌3个，浸润性腺癌（invasive adenocarcioma, IA）3个，转移癌2个，小细胞肺癌（small cell lung cancer, SCLC）1个，错构瘤16个，其他炎症等良性病变12个；49个混合性GGO（mixed ground-glass opacity, mGGO）的恶性比例是63.3%（31/49），术后病理结果为：IA 19个，微浸润腺癌（micro invasive adenocarcioma, MIA）6个，原位腺癌（adenocarcioma in situ, AIS）4个，非典型性腺瘤样增生（atipical adenomatous hyperplasia, AAH）1个，SCLC 1个，炎症等良性病变18个；43个纯GGO（pure ground-glass opacity, pGGO）的恶性比例是86.0%（37/43），术后病理结果为：AIS 19个，MIA 6个，IA 6个，AAH 6个，炎症等良性病变6个；GGO总的恶性比例是73.9%（68/92）。52个良性病变均采用VATS肺楔形切除；原发性非小细胞肺癌（non-small cell lung cancer, NSCLC）共73例，VATS肺叶切除和淋巴结清扫33例，VATS肺楔形切除和选择性淋巴结切除6例，VATS肺段切除和选择性淋巴结切除6例，VATS肺楔形切除28例；2个转移癌和2个SCLC，采用VATS肺楔形切除术。另有6例患者术中冰冻病理存在误差，其中2例选择二次手术行肺叶切除和淋巴结清扫。45例有淋巴结病理结果NSCLC只有两例以SPN为表现的IA出现纵隔淋巴结转移，其余均未出现淋巴结转移。术后随访1个月-35个月，平均（15.1±10.2）个月，无复发及转移。

结论

肺部微小结节尤其是GGO，是恶性病灶的概率大，应积极外科处理；围手术期应与患者及家属充分告知冰冻病理结果存在误差可能性，避免医疗纠纷。

Subcarinal Lymph Nodes Should be Dissected in All Lobectomies for Non-Small Cell Lung Cancer-Regardless of Primary Tumor Location

BACKGROUND

Mediastinal staging is of paramount importance for planning of treatment in non-small cell lung cancer (NSCLC). Single institution reports recently claimed that subcarinal lymph node dissection during resection of upper lobe NSCLC could be spared. We used a complete national lung cancer registry to investigate patterns of unsuspected mediastinal lymph node involvement after lobectomy.

METHODS

During an 11-year period (2004 to 2014) 5,577 consecutive patients who underwent operations for NSCLC were investigated for unsuspected mediastinal lymph node involvement (N2 disease) discovered at final histopathology. The analysis excluded patients with clinical N2 disease. We used a national registry to extract information for each patient about tumor location, histopathology, clinical and pathologic TNM stage, preoperative imaging modalities, and type of invasive mediastinal staging.

RESULTS

Mediastinal lymph node dissection was performed in 5,577 patients during the operation, and unsuspected N2 disease was discovered in 612 (11.0%), and 193 (3.5%) had subcarinal metastasis. Subcarinal N2 disease was significantly more common in patients with lower-lobe or middle-lobe cancers compared with upper-lobe cancers (5.8% vs 1.6%, p < 0.01). Preoperative invasive mediastinal staging was performed in 73.4% (4,097 of 5,577) of all patients and significantly more frequently in patients who eventually had N2 disease (87.3% [534 of 612], p < 0.01) as well subcarinal N2 disease (89.6% [173 of 193], p < 0.01).

CONCLUSIONS

Subcarinal lymph node metastases were common despite frequent use of preoperative invasive mediastinal staging in lower-lobe, middle-lobe, and upper-lobe NSCLC. Subcarinal lymph nodes should be dissected or sampled routinely during operations for NSCLC to avoid understaging-regardless of preoperative invasive mediastinal staging and tumor location.

Lymph node metastasis according to primary tumor location in T1 and T2 stage non-small cell lung cancer patients

BACKGROUND

To evaluate the pattern of lymph node metastasis (LNM) according to primary tumor location in T1 and T2 stage non-small cell lung cancer (NSCLC) patients.

METHODS

The data of 1916 NSCLC patients with LNM who underwent surgery with systematic nodal resection between November 2008 to December 2014 were included in the study. Analyses of tumor location, pathological T stage, and nodal metastasis were performed.

RESULTS

In T1a stage patients, superior mediastinum, aortopulmonary, and inferior mediastinum lymph node metastases were observed in primary tumors present in the right upper lobe (RUL), left upper lobe (LUL) and right middle lobe (RML), respectively. In T1b-stage patients, superior mediastinum, aortopulmonary, and inferior mediastinum lymph node metastases were observed in the RML, LUL, and right lower lobe (RLL), respectively. In patients with T2a-stage, superior mediastinum, aortopulmonary and inferior mediastinum lymph node metastases were observed in the RUL, LUL, and RLL, respectively. However, in T2b-stage patients, RUL, LUL and RML locations were associated with superior mediastinum, aortopulmonary, and inferior mediastinum lymph node metastases, respectively. Multivariable logistic regression showed that T stage was significantly associated with mediastinal and intrapulmonary lymph node metastases. In addition, tumor location was significantly associated with N2 station LNM.

CONCLUSION

LNM varied according to tumor location and T-stage, which are independent factors influencing N2 station LNM.

[Clinical Study of Surgical Treatment of Non-small Cell Lung Cancer 10 mm or Less in Diameter Under Video-assisted Thoracoscopy]

背景与目的

早期原发性非小细胞肺癌（non-small cell lung cancer, NSCLC）的手术切除及淋巴结切除的合理方式存在较大争议，本研究旨在探讨直径≤10 mm的原发NSCLC的微创切除及淋巴结切除的手术方式。

方法

对2013年7月-2016年3月在我院接受电视胸腔镜手术（video-assisted thoracic surgery, VATS）治疗并有明确病理诊断为NSCLC的共46例患者的临床资料进行回顾性分析。所有患者术前行薄层计算机断层扫描（computed tomography, CT），实性结节5例，混合性磨玻璃结节（mixed ground-glass opacity, mGGO）23例，纯磨玻璃结节（pure ground-glass opacity, pGGO）18例。根据患者具体情况采用不同术式，包括VATS肺叶切除和系统性淋巴结清扫，VATS肺楔形切除和选择性淋巴结切除，VATS肺段切除和选择性淋巴结切除，或仅采用VATS肺楔形切除。其中7例术前行CT引导下Hook-wire定位。

结果

VATS肺叶切除和系统性淋巴结清扫23例（mGGOs 15例，pGGOs 4例，实性结节4例），只有1例实性腺癌结节出现N2淋巴结转移，VATS肺楔形切除和选择性淋巴结切除5例（mGGOs 2例，pGGOs 3例）和VATS肺段切除和选择性淋巴结切除4例（mGGOs 2例，pGGOs 2例）均无淋巴结转移，仅采用VATS肺楔形切除14例（mGGOs 4例，pGGOs 9例，实性结节1例）。7例Hook-wire定位均成功。围手术期无重大并发症，随访1个月-26个月，平均（13.7±8.7）个月，无复发及转移。

结论

直径≤10 mm以mGGO和pGGO为表现的原发性NSCLC淋巴结转移率低，术中可以不进行淋巴结的清扫，实性结节应选择性淋巴结切除或系统性淋巴结清扫。高龄和心肺功能差的患者可以选择楔形切除或肺段切除。术前运用Hook-wire定位安全有效，可为VATS提供便利。

Boundary between N1 and N2 Lymph Node Descriptors in the Subcarinal Zone in Lower Lobe Lung Cancer: A Brief Report

INTRODUCTION

In the International Association for the Study of Lung Cancer (IASLC) lymph node (LN) map, some LNs in the subcarinal space defined as #10 (N1) in the Naruke map were changed to #7 (N2). We aimed to validate the boundary between N1 and N2 in the subcarinal zone.

METHODS

We reviewed the records of 399 consecutive patients who had undergone complete resection for lower lobe non-small cell lung cancer. Involved lymph node stations were classified as N1 by both maps (N1 group), N1 by the Naruke map but reclassified as N2 by the IASLC map (#10 [subcarinal] group), and N2 by both maps (N2 group). The survival rates among these groups were compared using Kaplan-Meier and log-rank analyses.

RESULTS

LNs were classified as N0, N1, and N2 in 268, 67, and 64 patients, respectively, on the IASLC map and as N1 and N2 in 82 and 49 patients, respectively, on the Naruke map. The 5-year disease-free survival rates were 81.7% for N0, 50.9% for N1, 33.3% for the #10 (subcarinal) group, and 24.4% for N2. The rates of the N1 and #10 (subcarinal) groups were significantly different (p = 0.027), but those of the N2 and #10 (subcarinal) groups were not (p = 0.78). On multivariate analysis, metastatic disease in the LNs of #10 in the subcarinal space was an independent prognostic factor for patients classified as N1 on the Naruke map (hazard ratio = 2.47, 95% confidence interval: 1.17-4.85, p = 0.019).

CONCLUSION

All lymph nodes in the subcarinal space should be defined as #7 (N2) for prognosis.

A lobe-specific lymphadenectomy protocol for solitary pulmonary nodules in non-small cell lung cancer

BACKGROUND

We want to establish a lobe-specific mediastinal lymphadenectomy protocol for solitary pulmonary nodules (SPNs) in non-small cell lung cancer (NSCLC).

METHODS

We retrospectively analyzed 401 patients with pathological diagnoses of NSCLC who underwent lobectomy, bilobectomy, or pneumonectomy with systematic lymphadenectomy from March 2004 to June 2011 in our hospital. All of the patients enrolled had a SPN preoperatively. Information about the primary tumor location, lymph node metastasis, and other baseline data were collected. Stepwise logistic regression was used to identify the key factors indicating non-regional mediastinal lymph node metastases (NRM).

RESULTS

Of the primary tumors, 117, 39, 74, 104, and 67 were in the right upper lung (RUL), right middle lung (RML), right lower lung (RLL), left upper lung (LUL), and left lower lung (LLL), respectively. Stepwise regression showed that #2,4, #10,11, and #10,11 as well as #7 was the key lymph node station for RUL, LUL, and lower lobes: #2,4 [odds ratio (OR)=28.000, 95% confidence interval (CI): 2.917-268.790, P=0.004] for RUL, #10,11 (OR=31.667, 95% CI: 2.502-400.833, P=0.008) for LUL, #10,11 (OR=19.540, 95% CI: 4.217-90.541, P<0.001) and #7 (OR=7.395, 95% CI: 1.586-34.484, P=0.011) for lower lobes, respectively. Patients with tumors >2 cm rarely had NRM without primary regional mediastinal involvement.

CONCLUSIONS

With rigid consideration, a lobe-specific lymphadenectomy is feasible in practice. This protocol can be used when the lobe-specific key nodes are negative in intraoperative frozen sections, especially for NSCLC diagnosed as SPN <2 cm preoperatively.

Outcomes of initial surgery in patients with clinical N2 non-small cell lung cancer who met 4 specific criteria

PURPOSE

The role of surgery for patients with non-small cell lung cancer (NSCLC) with clinical mediastinal lymph node metastasis (N2) remains controversial. We specified 4 criteria for performing initial surgery in these patients (single-station N2, non-bulky N2, N2 with regional mode of spread, and N2 without N1) and examined the outcomes to validate the treatment options.

METHODS

Between September 2002 and December 2010, of 1290 patients who underwent complete resection for NSCLC, 808 patients underwent initial standard resection, including 779 patients with cN0-1 and 29 with cN2. We compared the outcomes, and evaluated patients with cN2-pN2.

RESULTS

The median follow-up was 45.5 months (3-119 months). Seventy (9.0 %) and 24 (82.8 %) patients had p-N2 in the cN0-1 and cN2 groups, respectively (p < 0.0001). The 5-year disease-free survival (DFS) rates in the cN0-1 and cN2 groups were 73.3 and 50.6 %, respectively (p = 0.0053), and the 5-year overall survival (OS) rates were 81.3 and 71.1 %, respectively (p = 0.051). The 5-year DFS and OS of patients with cN2-pN2 were 52.5 and 72.6 %, respectively.

CONCLUSIONS

Patients with clinical N2 disease based on our criteria represent a highly specific group with a favorable prognosis. Resection should therefore be the initial treatment for these patients.

Risk factors for recurrence after complete resection of pathological stage N2 non-small cell lung cancer

Background

Tumor recurrence is the most common cause of treatment failure, especially after complete resection of pathological stage N2 non-small cell lung cancer (NSCLC). In this study, we investigated the clinicopathological characteristics in order to identify independent risk factors for postoperative recurrence.

Methods

Between January 2001 and December 2013, 96 patients who underwent surgical resection for pathological N2 NSCLC were retrospectively reviewed. Recurrence-free survival (RFS) was calculated by the Kaplan-Meier method to explore risk factors, while the Cox proportional hazard model was used to assess independent predictors.

Results

The median and five-year RFS rates were 15 months and 27.4%, respectively. Univariate analysis showed a significantly poorer prognosis for non-regional N2 metastasis, more than three metastatic N2 lymph nodes, multiple N2 station, and multiple N2 zone involvement. Multivariate analysis demonstrated that non-regional N2 metastasis (hazard ratio [HR] 1.857, 95% confidence interval [CI] 1.061–3.249, P = 0.030) and more than three metastatic N2 lymph nodes (HR 2.555, 95% CI 1.164–5.606, P = 0.019) were independent risk factors for RFS. Additionally, the incidence of non-regional N2 metastasis was higher in patients with a primary tumor in the left lower (57.1%) or right lower lobe (48.1%), followed by left upper (31.8%), right middle (14.3%) and right upper lobe (7.7%).

Conclusion

The combination of the distribution and number of metastatic N2 lymph nodes provides a more accurate prediction for N2 NSCLC regarding recurrence. Non-regional N2 metastasis could occur with a primary tumor in any lobe, but occurs more frequently in the lower lobe.

Lobe-specific mediastinal nodal dissection is sufficient during lobectomy by video-assisted thoracic surgery or thoracotomy for early-stage lung cancer

BACKGROUND

Lobectomy with complete mediastinal lymphadenectomy is considered standard for patients with early-stage non-small cell lung cancer (NSCLC). However, the benefits of complete lymphadenectomy are unproven. There is evidence suggesting a predictable pattern of mediastinal nodal drainage. This study analyzed the frequency and pattern of mediastinal nodal disease and its impact on outcome in patients with early-stage NSCLC.

METHODS

Patients with clinical N0/N1 NSCLC staged with CT scans and PET scans were identified. Disease involvement of resected nodal stations was recorded. Patterns of recurrence in patients who underwent lobectomy with complete mediastinal systematic lymph node sampling (SLNS) were compared with those who underwent lobe-specific mediastinal SLNS.

RESULTS

From July 2004 to April 2011, 370 patients were identified. Complete SLNS was performed in 282 patients. Fifteen patients (5.3%) in the group with complete SLNS were found to have N2 disease after pathologic evaluation. Patients with left-sided tumors were more likely to have pathologic N2 disease than were patients with right-sided tumors (P = .03). Only one patient (0.36%) had positive N2 disease in the distal mediastinum while skipping lobe-specific mediastinal nodes. In addition, patients with complete SLNS had a rate of recurrence similar to that of the group that had lobe-specific mediastinal evaluation (20.6% vs 18.2%, P = .68).

CONCLUSIONS

Mediastinal N2 metastases follow predictable lobe-specific patterns in patients with negative preoperative CT scans and PET scans. Lobe-specific N2 nodal evaluation results in a recurrence rate similar to that of complete mediastinal evaluation. Lobe-specific mediastinal nodal evaluation appears acceptable in patients with early-stage NSCLC.

Selective mediastinal lymphadenectomy without intraoperative frozen section examinations for clinical stage I non-small-cell lung cancer: retrospective study of 403 cases

OBJECTIVE

The extent of mediastinal lymphadenectomy for clinical stage I non-small-cell lung cancer (NSCLC) remains controversial. This study explored the value of selective mediastinal lymphadenectomy from the clinical viewpoint.

METHODS

From 2005 to 2008, a total of 403 patients diagnosed clinically as having stage I NSCLC underwent lobectomy and mediastinal lymph node dissection. Among them, 309 underwent complete mediastinal lymphadenectomy, and the other 94 underwent selective mediastinal lymphadenectomy. We compared the perioperative parameters and overall survival statistics for the two groups retrospectively.

RESULTS

The two groups had no significant differences in sex, pathology, tumor location, or preoperative staging. The selective mediastinal lymphadenectomy group had an older average age, with a much higher rate of patients >70 years of age (p = 0.016). Also, the patients were apt to undergo thoracoscopic lobectomy (p = 0.044). This group had shorter operating times and less intraoperative bleeding. No significant differences in total drainage volume, length of hospital stay, or complication rates were found between the two groups. The mean follow-up periods were 35.8 ± 13.7 vs. 34.6 ± 17.2 months. Local and distant recurrence rates were 25.6 % vs. 30.9 %, respectively (p = 0.560). The 3-year and 5-year overall survival rates were 83.0 % and 74.6 % vs. 75.1 % and 68.5 %, respectively (p = 0.216).

CONCLUSIONS

For patients with clinical stage I NSCLC, selective mediastinal lymphadenectomy can reduce the trauma caused by the procedure, especially for elderly patients and those with co-morbidities. Survival was acceptable and was no worse than that after complete mediastinal lymphadenectomy. Our results need to be confirmed by prospective randomized controlled studies.

Prognostic role of station 3A mediastinal nodes for non-small-cell lung cancers

OBJECTIVES

Station 3A nodes have been commonly neglected in surgical practice. This retrospective study collected information on the incidence and risk factors of Station 3A node to ascertain the prognostic role of 3A nodal involvement.

METHODS

A total of 180 consecutive pN2 (stage IIIa) non-small-cell lung cancer (NSCLC) cases who underwent systemic lymphadenectomy and contained Station 3A nodes were enrolled. Survival rates were calculated according to the final pathology of Station 3A lymph node: Station 3A node (+) and Station 3A node (-). Statistical analysis was conducted using Kaplan-Meier and Cox regression models.

RESULTS

Station 3A nodal metastasis was validated in 32 cases, and the incidence of Station 3A node involvement was 17.8%. Station 3A nodes involvement was strongly associated with the metastatic status of Station 4R nodes and histological nature of pulmonary cancer. The overall 3-year survival was 53% and median survival time was 40.6 months. The 3-year survival difference was significant between Station 3A node (-) and Station 3A node (+) (63 vs 22%, χ(2) = 16.426, P < 0.001). Moreover, the overall 3-year survival was closely related with the number of involved nodal zones (χ(2) = 31.156, P < 0.001). Multivariate analysis showed two statistically significant risk factors for survival including metastasis of Station 3A node and the number of positive nodal zones (hazard ratios [HR]: 2.702; 95% confidence intervals [CI]: 1.008-7.242; P = 0.027; and HR: 7.404; 95% CI: 3.263-16.936, P < 0.001, respectively).

CONCLUSIONS

The involvement of Station 3A lymph nodes predicts poor prognosis of right-sided stage pIIIa-N2 NSCLC patients. Therefore, systemic lymphadenectomy for right-sided cancers should include Station 3A nodes when ascertaining a complete resection.

Retrospective analysis of nodal spread patterns according to tumor location in pathological N2 non-small cell lung cancer

BACKGROUND

The purpose of the present study was to determine the nodal spread patterns of pN2 non-small cell lung cancer (NSCLC) according to tumor location, and to attempt to evaluate the possible indications of selective lymph node dissection (SLND).

METHODS

We retrospectively analyzed nodal spread patterns in 207 patients with NSCLC of less than 5 cm with N2 involvement.

RESULTS

The tumor location was right upper lobe (RUL) in 79, middle lobe in 12, right lower lobe (RLL) in 40, left upper division (LUD) in 41, lingular division in 11, and left lower lobe (LLL) in 24. Both RUL and LUD tumors showed a higher incidence of upper mediastinal (UM) involvement (96 and 100%, respectively) and a lower incidence of subcarinal involvement (15 and 10%, respectively) than lower lobe tumors (UM; RLL 60%, LLL 42%; subcarinal: RLL 60%, LLL 46%, respectively). Among the patients with 24 right UM-positive RLL and 10 left UM-positive LLL tumors, 2 showed negative hilar, subcarinal, and lower mediastinal involvement, and cT1, suggesting that UM dissection may be unnecessary in lower lobe tumors with no metastasis to hilar, subcarinal, and lower mediastinal nodes on frozen sections according to the preoperative T status. Among the patients with 12 subcarinal-positive RUL and 4 subcarinal-positive LUD tumors, one showed negative hilar or UM involvement, suggesting that subcarinal dissection may be unnecessary in RUL or LUD tumors with no metastasis to hilar and UM nodes on frozen sections.

CONCLUSIONS

The present study appears to provide one of the supportive results regarding the treatment strategies for tumor location-specific SLND.

Recurrence of mediastinal node cancer after lobe-specific systematic nodal dissection for non-small-cell lung cancer

OBJECTIVES

The standard surgical treatment for patients with non-small-cell lung cancer (NSCLC) is lobectomy with systematic nodal dissection (SND). Lobe-specific patterns of nodal metastases have been recognized, and lobe-specific SND (L-SND) has been reported. We performed L-SND depending on patient-related factors, such as age or the presence of diabetes or respiratory dysfunction, or in the context of specific tumour-related factors, such as the presence of a tumour with a wide area of ground-glass opacity.

METHODS

Between September 2002 and December 2008, 335 consecutive patients with clinical and intraoperative N0 NSCLC underwent curative lobectomies at Shizuoka Cancer Center Hospital. Among these 335 patients, 206 underwent SND (Group A) and 129 underwent L-SND. Of the 129 patients undergoing L-SND, 98 underwent L-SND due to patient-related factors (Group B) and 31 underwent L-SND due to tumour-related factors (Group C).

RESULTS

There were no significant differences in morbidity or blood loss between patients undergoing SND or L-SND, but there was a significant difference in the mean operative times. The 5-year disease-free survival (5-DFS) and 5-year overall survival (5-OS) of patients in Group C were 100%. Although the patients in Group B showed no significant difference in 5-DFS and 5-OS compared with Group A, patients in Group B had significantly more initial recurrence of mediastinal node cancer than did the Group A patients (P = 0.0050).

CONCLUSIONS

The recurrence of mediastinal node cancer in patients undergoing L-SND was significantly greater than that in those undergoing SND.