Number of mediastinal lymph nodes in non-small cell lung cancer: a Gaussian curve, not a prognostic factor

The prognostic significance of right paratracheal lymph node dissection numbers in right upper lobe non-small cell lung cancer

BACKGROUND

The number of dissected lymph nodes is closely related to the prognosis of patients with non-small cell lung cancer. This study explored the optimal number of right paratracheal lymph nodes dissected in right upper non-small cell lung cancer patients and its impact on prognosis.

METHODS

Patients who underwent radical surgery for right upper lobe cancer between 2012 and 2017 were retrospectively enrolled. The optimal number of right paratracheal lymph nodes and the relationship between the number of dissected right paratracheal lymph nodes and the prognosis of right upper non-small cell lung cancer were analysed.

RESULTS

A total of 241 patients were included. The optimal number of dissected right paratracheal lymph nodes was 6. The data were divided according to the number of dissected right paratracheal lymph nodes into groups RPLND + (≥ 6) and RPLND- (< 6). In the stage II and III patients, the 5-year overall survival rates were 39.0% and 48.2%, respectively (P = 0.033), and the 5-year recurrence-free survival rates were 32.8% and 41.8%, respectively (P = 0.043). Univariate and multivariate analyses revealed that among the stage II and III patients, ≥ 6 right paratracheal dissected lymph nodes was an independent prognostic factor for overall survival (HR = 0.53 95% CI 0.30-0.92 P = 0.025) and recurrence-free survival (HR = 1.94 95% CI 1.16-3.24 P = 0.011).

CONCLUSIONS

Resection of 6 or more right paratracheal lymph nodes may be associated with an improved prognosis in patients with right upper non-small cell lung cancer, especially in patients with stage II or III disease.

Role of Pathologic Single-Nodal and Multiple-Nodal Descriptors in Resected Non-Small Cell Lung Cancer

BACKGROUND

The eighth edition of lung cancer nodal staging assignment includes the location of lymph node metastasis, but does not include single-nodal and multiple-nodal descriptors.

RESEARCH QUESTION

Do the single-nodal and multiple-nodal statuses stratify the prognosis of patients with non-small cell lung cancer (NSCLC)?

STUDY DESIGN AND METHODS

Using the National Cancer Database, we analyzed patients with pathologically staged N1 and N2 NSCLC. Nodal descriptors were classified into pathological single N1 (pSingle-N1), pathological multiple N1 (pMulti-N1), pathological single N2 (pSingle-N2), and pathological multiple N2 (pMulti-N2). Survival analysis was performed using the Kaplan-Meier method and multivariable Cox regression models.

RESULTS

In the general analysis cohort, 24,531, 22,256, 8,528, and 21,949 patients with NSCLC demonstrated pSingle-N1, pMulti-N1, pSingle-N2, and pMulti-N2 disease, respectively. Patients with pMulti-N1 and pMulti-N2 disease showed a shorter survival than those with pSingle-N1 and pSingle-N2 disease, respectively (hazard ratio, 1.22 [P < .0001] for N1 and 1.39 [P < .0001] for N2). After adjusting age, sex, and histologic findings, the hazard ratio for pSingle-N2 compared with pMulti-N1 disease was 1.05 (P = .0031). Patients with pN1 disease were categorized by metastatic lymph node count (1, 2, 3, ≥ 4), showing significant prognostic differences among groups (P < .0001). In the sensitivity analysis cohort (limited to R0 resection, lobectomy, or more; survival ≥ 30 days; ≥ 10 examined lymph nodes; and without neoadjuvant therapy; n = 34,904) and the external validation cohort (n = 708), analyses supported these results.

INTERPRETATION

Patients with NSCLC with one metastatic lymph node, whether in N1 or N2 stations, showed better survival than those with more than one lymph node involved. Patients with NSCLC with a single-skip N2 lymph node metastasis showed survival similar to patients with multiple N1 lymph nodes, and the number of lymph nodes involved in N1 resections up to four or more was sequentially prognostic.

Significance of metastatic lymph nodes ratio in overall survival for patients with resected nonsmall cell lung cancer: a retrospective cohort study

OBJECTIVE

The tumor, node and metastasis stage is widely applied to classify lung cancer and is the foundation of clinical decisions. However, increasing studies have pointed out that this staging system is not precise enough for the N status. In this study, we aim to build a convenient survival prediction model that incorporates the current items of lymph node status.

METHODS

We performed a retrospective cohort study and collected the data from resectable nonsmall cell lung cancer (NSCLC) (IA-IIIB) patients from the Surveillance, Epidemiology, and End Results database (2006-2015). The x-tile program was applied to calculate the optimal threshold of metastatic lymph node ratio (MLNR). Then, independent prognostic factors were determined by multivariable Cox regression analysis and enrolled to build a nomogram model. The calibration curve as well as the Concordance Index (C-index) were selected to evaluate the nomogram. Finally, patients were grouped based on their specified risk points and divided into three risk levels. The prognostic value of MLNR and examined lymph node numbers (ELNs) were presented in subgroups.

RESULTS TOTALLY,

40853 NSCLC patients after surgery were finally enrolled and analyzed. Age, metastatic lymph node ratio, histology type, adjuvant treatment and American Joint Committee on Cancer 8th T stage were deemed as independent prognostic parameters after multivariable Cox regression analysis. A nomogram was built using those variables, and its efficiency in predicting patients' survival was better than the conventional American Joint Committee on Cancer stage system after evaluation. Our new model has a significantly higher concordance Index (C-index) (training set, 0.683 v 0.641, respectively; P < 0.01; testing set, 0.676 v 0.638, respectively; P < 0.05). Similarly, the calibration curve shows the nomogram was in better accordance with the actual observations in both cohorts. Then, after risk stratification, we found that MLNR is more reliable than ELNs in predicting overall survival.

CONCLUSION

We developed a nomogram model for NSCLC patients after surgery. This novel and useful tool outperforms the widely used tumor, node and metastasis staging system and could benefit clinicians in treatment options and cancer control.

Surgeon experience influence lymphadenectomy during VATS lobectomy: National VATS database results

OBJECTIVES

Aim of this study is to identify the factors that may influence the lymphadenectomy during VATS anatomical lung resection with particular interest on operator experience.

MATERIALS AND METHODS

Clinical and pathological data from the prospective VATS Italian nationwide registry were reviewed and analysed. Patients with incomplete data regarding tumor and surgical characteristics, GGO, or with distant metastases were excluded. Patients clinical data, tumor characteristics, operation information and surgeon experience were collected and compared to resected lymph nodes number (#RN), resected N2 nodes number (#N2RN) and resected N2 stations number. A multivariable model was built using logistic regression analysis. Surgeon experience was categorized considering the number of VATS major anatomical resection and years after residency.

RESULTS

The final analysis was conducted on 3727 patients. The median #RN and #N2RN were 11 (1-51) and 5 (0-41). Regarding the analysed outcomes, #N2RN > 6 resulted in 1812 (48.8%)cases, #RN > 10 in 2124 (57.0%)cases and more than 3 N2 stations were harvested in 1447 (38.8%)patients. First operator experience with number of VATS lobectomies>50 (p < 0.001), operator seniority after residency5-10years (p < 0.001), cTNM II/III(p = 0.017), lobectomy/bilobectomy vs segmentectomy (p < 0.001), and upper/middle lobe tumor location (p < 0.005)resulted significantly associated to #N2RN > 6 at the multivariable analysis. First operator experience with number of VATS lobectomies>50 (p < 0.001), operator seniority after residency5-10years (p < 0.001) and lobectomy/bilobectomy (p < 0.001) resulted significantly associated to #RN > 10 at the multivariable analysis.

CONCLUSIONS

Our study showed that lymphadenectomy during VATS lobectomy is influenced by tumor factors such as cTstage and tumor location but also by operator experience, with a higher number of resected lymph nodes in surgeons with a high number of VATS procedures and years after residency compared to surgeons with less experience.

Influencing Factors on the Quality of Lymph Node Dissection for Stage IA Non-Small Cell Lung Cancer: A Retrospective Nationwide Cohort Study

Lymphadenectomy is an essential part of complete surgical operation for non-small cell lung cancer (NSCLC). This retrospective, multicenter cohort study aimed to identify factors that influence the lymphadenectomy quality. Data were obtained from the Polish Lung Cancer Study Group Database. The primary endpoint was lobe-specific mediastinal lymph node dissection (L-SMLND). The study included 4271 patients who underwent VATS lobectomy for stage IA NSCLC, operated between 2007 and 2022. L-SMLND was performed in 1190 patients (27.9%). The remaining 3081 patients (72.1%) did not meet the L-SMLND criteria. Multivariate logistic regression analysis showed that patients with PET-CT (OR 3.238, 95% CI: 2.315 to 4.529; p < 0.001), with larger tumors (pT1a vs. pT1b vs. pT1c) (OR 1.292; 95% CI: 1.009 to 1.653; p = 0.042), and those operated on by experienced surgeons (OR 1.959, 95% CI: 1.432 to 2.679; p < 0.001) had a higher probability of undergoing L-SMLND. The quality of lymphadenectomy decreased over time (OR 0.647, 95% CI: 0.474 to 0.884; p = 0.006). An analysis of propensity-matched groups showed that more extensive lymph node dissection was not related to in-hospital mortality, complication rates, and hospitalization duration. Actions are needed to improve the quality of lymphadenectomy for NSCLC.

Number of involved nodal stations: a better lymph node classification for clinical stage IA lung adenocarcinoma

Background

With the popularization of lung cancer screening, more early-stage lung cancers are being detected. This study aims to compare three types of N classifications, including location-based N classification (pathologic nodal classification [pN]), the number of lymph node stations (nS)-based N classification (nS classification), and the combined approach proposed by the International Association for the Study of Lung Cancer (IASLC) which incorporates both pN and nS classification to determine if the nS classification is more appropriate for early-stage lung cancer.

Methods

We retrospectively reviewed the clinical data of lung cancer patients treated at the Cancer Hospital, Chinese Academy of Medical Sciences between 2005 and 2018. Inclusion criteria was clinical stage IA lung adenocarcinoma patients who underwent resection during this period. Sub-analyses were performed for the three types of N classifications. The optimal cutoff values for nS classification were determined with X-tile software. Kaplan‒Meier and multivariate Cox analyses were performed to assess the prognostic significance of the different N classifications. The prediction performance among the three types of N classifications was compared using the concordance index (C-index) and decision curve analysis (DCA).

Results

Of the 669 patients evaluated, 534 had pathological stage N0 disease (79.8%), 82 had N1 disease (12.3%) and 53 had N2 disease (7.9%). Multivariate Cox analysis indicated that all three types of N classifications were independent prognostic factors for prognosis (all P < 0.001). However, the prognosis overlaps between pN (N1 and N2, P = 0.052) and IASLC-proposed N classification (N1b and N2a1 [P = 0.407], N2a1 and N2a2 [P = 0.364], and N2a2 and N2b [P = 0.779]), except for nS classification subgroups (nS0 and nS1 [P < 0.001] and nS1 and nS >1 [P = 0.006]). There was no significant difference in the C-index values between the three N classifications (P = 0.370). The DCA results demonstrated that the nS classification provided greater clinical utility.

Conclusion

The nS classification might be a better choice for nodal classification in clinical stage IA lung adenocarcinoma.

Impact of the Number of Harvested Lymph Nodes on Long-Term Survival in Node-Negative Non-Small-Cell Lung Cancer: Based on Clinical Stage But Not Pathological Stage

BACKGROUND

We aimed to investigate the impact of the number of harvested lymph nodes (LNs) on the overall survival (OS) and disease-free survival (DFS) of patients with clinical node-negative (cN0) non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

A total of 2247 patients with cN0 NSCLC between 2001 and 2014 were included. Scatter plots of hazard ratios from Cox proportional hazards models against the number of harvested LNs were created, and curves were fitted using a LOWESS smoother. Chow test was used to determine the cut-off points for the optimal number of harvested LNs. Long-term survival was compared between groups divided by the cut-off points.

RESULTS

The increasing numbers of harvested LNs and N2 level LNs were independent factors favoring OS and DFS. Seventeen LNs and 10 N2 level LNs were determined as the optimal cut-off points. The patients with ≥17 harvested LNs had a better OS (P = .001) and DFS (P = .002), while the patients with ≥10 harvested N2 level LNs also had a better OS (P < .001) and DFS (P = .001). The increasing numbers of harvested LNs and N2 level LNs were independent prognostic factors associated with prolonged OS and DFS only in patients with clinical T2 (cT2) NSCLC.

CONCLUSIONS

The increasing numbers of harvested LNs and N2 level LNs were associated with better OS and DFS in cN0 NSCLC patients that were suitable for lobectomies. At least 17 LNs and 10 N2 level LNs were required to be harvested, especially in cT2 patients.

Type of lymphadenectomy does not influence survival in pIa NSCLC patients who underwent VATS lobectomy: Results from the national VATS group database

INTRODUCTION

Stage Ia presents an optimal survival rate after surgical resection, but the type of lymphadenectomy to use in these patients is still debated. The aim of this study is evaluate if one type of lymphadenectomy adopted influences survival in patients who underwent VATS lobectomy for stage Ia NSCLC.

METHODS

Clinical and pathological data from pIa patients in the prospective VATS Italian nationwide registry were reviewed and analysed. Patients and tumour characteristics,type of lymphadenectomy (sampling or radical nodal dissection,MRLD), were collected and correlated to Overall Survival(OS) and Disease free Survival(DFS). The Kaplan-Meier product-limit method was used to estimate OS and DFS and the log-rank test was adopted to evaluate the differences between groups. A propensity match was performed to reduce bias due to the retrospective study design.

RESULTS

The final analysis was conducted on 2039 patients, 179 died during follow-up,recurrence rate was 13%. MRLD was performed in 1287(63.1%)patients. The univariable analysis identified as favourable prognostic factors for OS the female sex(p = 0.023), low ECOG-score(0.008),low SUVmax(p < 0.001), GGO appearance(p < 0.001), pT < 2 cm(p = 0.002) and low tumour grading(p = 0.002). The multivariable analysis confirmed as independent prognostic factors low ECOG-score(p = 0.012), low SUVmax(p < 0.001) and low tumour grading(p < 0.001). Analysing survival in patients with solid/sub-solid nodules and after propensity score matching for pTdimension and number of N2 resected lymphnodes, no OS differences were present comparing sampling vs MRLD.

CONCLUSION

Survival in pIa patients seems to be determined by patient and tumour characteristics such as performance status,grading and SUVmax. Type of lymphadnectomy did not seem to be correlated with OS in these patients.

Prognostic Impact of Examined Mediastinal Lymph Node Count in Clinical N0 Non-Small Cell Lung Cancer

OBJECTIVES

The number of examined mediastinal lymph nodes (mLNs) could represent the quality of mediastinal lymphadenectomy for non-small cell lung cancer (NSCLC). This study aimed to evaluate the prognostic impact of the number of examined individual mLNs in patients with resectable NSCLC.

METHODS

We retrospectively evaluated 1,420 patients with clinical-stage IA-IIB, N0 NSCLC who underwent complete resection by lobectomy, which involved hilar and mLN dissection, between 2008 and 2016. We investigated the threshold number of examined mLNs that had prognostic significance and evaluated their effects on the risk of mLN recurrence.

RESULTS

In a respective multivariable analysis according to the number of examined mLNs, examining ≥3 mLNs (reference [ref.] mLNs ≤2) achieved statistical significance and had the best prognosis (hazard ratio [HR], 0.68; p = 0.013). In the multivariable analyses for each pathological N (pN) stage, ≥3 examined mLNs (ref. mLNs ≤2) was an independent prognostic factor in pN1 disease (HR, 0.32, p = 0.002), but not in pN0 or pN2 disease. The cumulative incidence of mLN recurrence was significantly lower in patients with ≥3 examined mLNs (ref. mLNs ≤2, HR, 0.27; p = 0.008) in pN1 disease. Patients with ≥3 examined mLNs had higher upstaging rates to pN2 than those with ≤2 examined mLNs.

CONCLUSIONS

Examining ≥3 mLNs contributed to a favorable prognosis and low mLN recurrence risk in patients with clinical stage I-II, N0 NSCLC. Our findings can serve as a benchmark for the number of required mLNs to be examined.

Oncological Outcomes of Robotic Lobectomy and Radical Lymphadenectomy for Early-Stage Non-Small Cell Lung Cancer

Background: While the thoracotomy approach was considered the gold standard until two decades ago, robotic surgery has increasingly strengthened its role in lung cancer treatment, improving patients’ peri-operative outcomes. In this study, we report our experience in robotic lobectomy for early-stage non-small cell lung cancer, with particular attention to oncological outcomes and nodal upstaging rate. Methods: We retrospectively reviewed patients who underwent lobectomy and radical lymphadenectomy at our Institute between 2016 and 2020. We selected 299 patients who met the inclusion criteria of the study. We analyzed the demographic features of the groups as well as their nodal upstaging rate after pathological examination. Then, we analyzed disease-free and overall survival of the entire enrolled patient population and we compared the same oncological outcomes in the upstaging and the non-upstaging group. Results: A total of 299 patients who underwent robotic lobectomy were enrolled. After surgery, 55 patients reported nodal hilar or mediastinal upstaging. The 3-year overall survival of the entire population was 82.8%. The upstaging group and the non-upstaging group were homogeneous for age, gender, smoking habits, clinical stage, tumor site, tumor histology. The non-upstaging group had better OS (p = 0.004) and DFS (p < 0.0001). Conclusion: Our results show that robotic surgery is a safe and feasible approach for the treatment of early-stage NSCLC, especially for its accuracy in mediastinal lymphadenectomy. The oncological outcomes were encouraging and consistent with previous findings.

The impact of pathology grossing protocol measures to improve pathologic nodal staging in lung cancer

OBJECTIVE

Accurate assessment of lymph node (LN) status is essential for proper staging of resected lung cancer specimens. Here, we assessed pathology-centric interventions to increase the number of peribronchial LNs identified and evaluated in anatomic lung cancer resection specimens as part of a quality improvement initiative.

MATERIALS AND METHODS

All non-small cell lung cancer (NSCLC) anatomic resection specimens from 2017 to 2020 were evaluated, comprising two years pre-intervention and one year post-intervention. We instituted 3 measures to increase peribronchial LN yield: 1) educational grossing sessions for pathology assistants and residents, 2) directions to submit additional peribronchial tissue if no LNs were identified grossly, and 3) a hard-stop prior to sign-out by the attending pathologist if no peribronchial LNs were identified.

RESULTS

Of the total 227 resection specimens for NSCLC, 107/151 (70.9%) of specimens prior to the intervention had peribronchial LNs identified, whereas after the intervention significantly more (66/76, 86.8%, p < 0.01) specimens had peribronchial LNs identified. In addition, the mean number of peribronchial LNs identified significantly increased from 2.7 ± 3.3 pre-intervention to 4.3 ± 4.0 post-intervention (p < 0.001). Further analysis revealed a strong correlation between peribronchial LN metastases with both overall tumor size and invasive component size (for adenocarcinomas), correlation coefficient 0.974, p < 0.0001.

CONCLUSION

Establishing focused grossing measures by pathology led to a significant increase in the number of peribronchial LNs identified and assessed during histopathologic evaluation of anatomic lung cancer resection specimens. Larger tumors are more likely to have occult peribronchial LN metastases, which may warrant more aggressive peribronchial LN assessment for larger tumors.

[Surgery for small-cell lung cancer]

Small-cell lung cancer (SCLC) is a high-grade neuroendocrine carcinoma, metastatic at the time of initial diagnosis in 70% of cases. Within the 30% of localised tumours only 5% of patients are eligible for surgical treatment according to the recommendations of learned societies. These recommendations are mainly based on old phase II and III randomised prospective trials and more recent registry studies. Surgical care is only possible within a multimodal treatment and essentially concerns small-sized tumours without involvement of hilar or mediastinal lymph nodes. As with non-small cell lung cancer (NSCLC), lobectomy with radical lymph node removal is the recommended procedure to achieve complete tumour resection. Patient selection for surgery includes age, performance status and comorbidity factors. Adjuvant chemotherapy combining Platinum salts and Etoposide for resected stage I tumours is recommended by ASCO, ACCP and NCCN. The precise sequence of neo-adjuvant or adjuvant treatments remains controversial because of the large heterogeneity in clinical practice reported in the studies and the context at the time of SCLC discovery. The 5-year survival rate of patients with early stage disease (pT1-2N0M0) treated by lobectomy and adjuvant chemotherapy is between 30% and 58%, which validates the primary place that surgery must have in these early forms. There is certainly little or even no place for such a therapeutic sequence in locally advanced stages (T3-T4 or N2). However, the stage heterogeneity, as in NSCLC, makes final conclusions difficult. In fact, some registry studies with pairing scores reported a median survival of more than 20 months in N2 SCLC. So, all files of SCLC must be evaluated in a multidisciplinary meeting in order to find the optimal solution for patients with rare and heterogeneous tumours.

The influence of the number of lymph nodes removed on the accuracy of a newly proposed N descriptor classification in patients with surgically-treated lung cancer

INTRODUCTION

The International Association for the Study of Lung Cancer has proposed a new classification of N descriptor based on the number of metastatic lymph nodes (LNs) stations, including skip metastasis. The aim of the study was to determine the effect of removed LNs on the adequacy of this new classification.

MATERIALS AND METHODS

The material was collected retrospectively based on the database of the Polish Lung Cancer Group, including information on 8016 patients with non-small cell lung cancer operated in 23 thoracic surgery centers in Poland. The material covered the period from January 2005 to September 2015. We divided patients into two groups: ≤6LNs and >6LNs removed.

RESULTS

In the whole group, an average of 13.4 nodes and 4.54 nodal stations were removed. 5-year survivals in the >6LNs group vs ≤ 6LNs group were: 62.3% and 55.1% (N0), 44.5% and 35.9% (N1a), 34.1% and 31,7% (N1b), 37.3% and 26.3% (N2a1), 32.4% and 26.7% (N2a2), 29.4% and 29.2% (N2b1), and 22.0% and 23.0% (N2b2), respectively. Comparing these groups, we detected significant differences at N0 (p < 0.001) and N2a1 (p = 0.022). In the ≤6LNs group, the survival curves for N2a1, N2a2, N2b1, and N2b2 overlapped (p > 0.05). In the >6LNs group, the survival curves were significantly different between grades, with survival for N2a1 better than N1b (p = 0.232).

CONCLUSION

The proposed classification N descriptor is potentially better at differentiating patients into different stages. The accuracy of the classification depends on the number of lymph nodes removed. Therefore, the extent of lymphadenectomy has a significant impact on the staging of surgically-treated lung cancer.

Alternative methods of lymph node staging in lung cancer: a narrative review

The nodal status indicator in non-small cell lung cancer is one of the most crucial prognostic factors available. However, there are still many arguments among scientists regarding whether the currently used nodal status descriptor should be changed in the forthcoming editions of the Tumor Node Metastasis classification or whether it is precise enough and should be maintained as is. We reviewed studies concerning nodal factor classifications to evaluate their accuracy in non-small cell lung cancer patients and to address the previously mentioned challenge. We reviewed the PubMed database regarding the following classifications: ongoing 8^th edition of the Tumor Node Metastasis classification, number of positive lymph nodes, number of negative lymph nodes, number of dissected lymph nodes, lymph node ratio, nodal chains, log odds of positive lymph nodes, zone-based classification and one that is based on the number of lymph node stations involved. Moreover, we analysed data regarding various combinations of these classifications. Our analysis showed that the present nodal staging may not accurately categorize every lung cancer patient. The number of positive lymph nodes and lymph node ratio or the log odds of positive lymph nodes (as the mathematical modification of lymph node ratio) are more legitimate, as they possess very robust data and should be considered initially as additional factors that can be incorporated in ongoing nodal staging systems. Forthcoming non-small cell lung cancer staging systems could benefit from the addition of quantitative-based parameters. Additionally, the minimal extent of lymphadenectomy should be established as staging benefits from it. International, prospective validation studies need to be performed to optimize the cut-off values and prognostic groups and to confirm the superiority of the newly suggested descriptors in non-small cell lung cancer nodal staging.

Trends and Outcomes in Minimally Invasive Surgery for Locally Advanced Non-Small-Cell Lung Cancer With N2 Disease

Few studies examine outcomes by surgical approach in non-small-cell lung cancer (NSCLC) with N2 disease. We examined time trends in surgical approach and outcomes among patients undergoing minimally invasive (MIS, robotic and video-assisted thoracoscopic surgery [VATS]) vs open lobectomy in this patient population. We performed a retrospective analysis of patients from the National Cancer Database diagnosed with clinical Stage IIIA-N2 NSCLC from 2010 to 2016. We examined the yearly proportion of MIS vs open resections. Multivariable regression was used to assess the association of surgical approach with length of stay, unplanned readmissions, 30-day and 90-day mortality. Multivariable Cox proportional hazards modeling was used to assess the association of surgical approach with 5-year overall mortality. We identified 5741 patients who underwent lobectomy for Stage IIIA-N2 NSCLC (459 robotic, 1403 VATS, 3879 open). From 2010 to 2016, the proportion of minimally invasive procedures increased from 20% to 45%. MIS patients, on average, stayed 1 day less in the hospital (95% confidence interval [CI] 0.7, 1.5) and had lower odds of 90-day (odds ratio [OR] 0.74; 95% CI 0.54, 0.99) and 5-year mortality (OR 0.82; 95% CI 0.75, 0.91), compared to open resections. There was no difference in odds of readmission by surgical approach (OR 0.97; 95% CI 0.71, 1.33). Among MIS procedures, robotic resections had lower odds of 90-day mortality (OR 0.42; 95% CI 0.18, 0.97) than VATS. Among patients undergoing lobectomy for locally advanced N2 NSCLC robotic and VATS techniques appear safe and effective compared to open surgery and may offer short- and long-term advantages.

Numbers and Stations: Impact of Examined Lymph Node on Precise Staging and Survival of Radiologically Pure-Solid NSCLC: A Multi-Institutional Study

Objectives

To determine the optimal number of examined lymph nodes (ELNs) and examined node stations (ENSs) in patients with radiologically pure-solid NSCLC and to investigate the impact of ELNs and ENSs on accurate staging and long-term survival.

Methods

Data from six institutions in the People’s Republic of China on resected c-stage Ⅰ to Ⅱ NSCLCs presenting as pure-solid tumors were analyzed for the impact of ELNs and ENSs on nodal upstaging, stage migration, recurrence-free survival, and overall survival by using multivariate models. The correlations between different end points and ELNs or ENSs were fitted with a smoother (using Locally Weighted Scatterplot Smoothing tool), and the structural break points were determined by the Chow test.

Results

Both ELNs and ENSs were identified as prognostic factors for overall survival (ENS: hazard ratio [HR], 0.697; 95% confidence interval [CI]: 0.590–0.824; p < 0.001; ELN: HR, 0.945; 95% CI: 0.909–0.983; p = 0.005) and recurrence-free survival (ENS: HR, 0.863; 95% CI: 0.791–0.941; p = 0.001; ELN: HR, 0.960; 95% CI: 0.938–0.981; p < 0.001). Intraoperative ELNs and ENSs were found to be associated with postoperative nodal upstaging. Cut point analysis revealed an optimal cutoff of 16 LNs and five node stations for patients with c-stage Ⅰ to Ⅱ pure-solid NSCLCs, which were examined in our multi-institutional cohort.

Conclusions

Both ELNs and ENSs are associated with more accurate node staging and better long-term survival. We recommend 16 LNs and five stations as the cut point for evaluating the quality of LN examination for c-stage Ⅰ to Ⅱ patients with radiologically pure-solid NSCLCs.

Novice training: The time course for developing competence in single port video-assisted thoracoscopic lobectomy

The competency in video-assisted thoracoscopic (VATS) lobectomy is expected to be achieved after surgeons practiced 30 to 50 cases according to previous reports. Does single port video-assisted thoracoscopic (SPVATS) lobectomy have a steeper learning curve and being harder to perform correctly, leading to long development times and high defect rates?From January, 2014 to February, 2017, 8 individual surgeons (3 were novices, 5 were pioneers in SPVATS surgery) submitted their cases chronologically to evaluate the learning curve of SPVATS lobectomy. Operating time (OT) was set as a surrogate marker for surgical competency. Postoperative outcomes and OT between the 2 groups were compared using propensity score matching (1:1 nearest neighbor). The learning curve for OT was evaluated using the cumulative sum (CUSUM) method.In the entire study cohort, a total of 356 cases were included (93 in junior consultant group [group A], 263 in senior consultant group [group B]). There were no significant differences between the 2 groups in operative time, conversion rate, postoperative complication rate, 30 and 90 days mortality rate. After propensity-score matching (86 pairs), operative time was longer in group A (214.33 ± 62.18 vs 183.62 ± 61.25 minutes, P = .001). Two-year overall survival rate was similar among 2 groups (P = .409). Competency was reached after junior surgeon completed 30th case of SPVATS lobectomy.SPVATS lobectomy is safe for the novice surgeon who wants to adopt this new surgical approach under well-developed training program. The learning curves for competence in SPVATS lobectomy are similar to VATS lobectomy in our series.

How many lymph nodes should be dissected in esophagectomy with or without neoadjuvant therapy to get accurate staging?

It is essential to dissect an adequate number of lymph nodes (LNs) to ensure staging accuracy during esophagectomy with or without neoadjuvant therapy. We developed a statistical model to quantify the probability of precise nodal staging based on previous studies. Esophageal cancer patients who underwent esophagectomy were retrospectively reviewed in the Surveillance, Epidemiology, and End Results database. A β-binomial distribution was adopted to estimate the number of understaged patients based on the numbers of positive and examined LNs. Using 6,252 patients, we estimated a 90% confidence of accurate N0 staging could be achieved by examining 17 LNs without neoadjuvant therapy. To obtain similar accuracy in N1 and N2, 20 and 25 LNs should be examined. For patients with neoadjuvant therapy, 18, 19, and 28 LNs could achieve the same accuracy. Staging accuracy was a significant prognostic factor. We found when 90% confidence had been achieved, patient survival did not improve with more LNs examined and the ratio and log odds of positive LNs did not have significant prognostic values. The statistical model we developed for precise staging in patients with different N stages is of great value in guiding lymphadenectomy. It provided risk assessment for underestimated LN metastases and guided subsequent adjuvant treatment.

Nodal size ranking as a predictor of mediastinal involvement in clinical early-stage non-small cell lung cancer

In non-small cell lung cancer (NSCLC) patients, the recommended minimum requirement for an endoscopy-based mediastinal staging procedure is sampling the largest lymph node (LN) in right and left inferior paratracheal, and subcarinal stations. We aimed to analyze the percentage of cases where the largest LN in each mediastinal station was malignant in a cohort of NSCLC patients with mediastinal metastases diagnosed in the lymphadenectomy specimen. Furthermore, we investigated the sensitivity of a preoperative staging procedure in a hypothetical scenario where only the largest LN of each station would have been sampled.Prospective data of patients with mediastinal nodal metastases diagnosed in the lymphadenectomy specimens were retrospectively analyzed. The long-axis diameter of the maximal cut surface of all LNs was measured on hematoxylin and eosin-stained sections.Seven hundred seventy five patients underwent operation and 49 (6%) with mediastinal nodal disease were included. A total of 713 LNs were resected and 119 were involved. Sixty seven nodal stations revealed malignant LNs: in these, the largest LN was malignant in 39 (58%). In a "per patient" analysis, a preoperative staging procedure that sampled only the largest LN would have attained a sensitivity of 0.67; and if the largest and the second largest were sampled, sensitivity would be 0.87.In patients with NSCLC, nodal size ranking is not reliable enough to predict malignancy. In clinical practice, regardless of the preoperative staging method, systematic thorough sampling of all visible LNs is to be recommended over selective random samplings.

[Thoracic lymphatic system-principles, characteristics and advice for the practice]

The lymphatic system of the lungs is complex. To maintain an effective gas exchange there is a need for a dense lymphatic network. The alveolae have no lymphatic vessels. There is no segment-specific lymph drainage. For both lungs there are fixed bronchopulmonary lymph nodes but the number and size of the lymph nodes are variable. There are seven mediastinal lymph node chains that vary in extent, each of which acts as an independent functional unit. The accurate assessment of the nodal status needs a simple reproducible nodal map. The division into compartments or zones makes this easier. Mediastinal lymph node metastases without involvement of bronchopulmonary lymph nodes are possible. The development mechanism of this skip metastasizing is multifactorial.

[The technique of thoracic lymph node dissection]

Systematic mediastinal, hilar and interlobar lymph node dissection is required in the S3 guidelines for the treatment of operable lung cancer. The lymph node involvement is considered one of the key prognostic factors. The type of lymph node resection is repeatedly the subject of controversially discussion. Lymph node dissection is essential for staging, prognosis, survival and recurrence rate. It should be standardized as a compartmental dissection with en bloc resection of lymph nodes including surrounding fat and connective tissue. Thus, exact knowledge of the anatomy of the thoracic organs with their peculiarities and high anatomical variability is necessary.

[Rationale of thoracic lymph node dissection in pulmonary metastasectomy]

The goal of metastasectomy is a R0 resection. Depending of the tumor entity the prevalence of lymph node metastases in pulmonary metastasectomy can be up to 45%; however, systematic lymph node dissection is not yet established as a fixed component of metastasectomy. Although there is a high prevalence of lymph node metastases and the increase in the prevalence with a higher number of lung metastases, it remains unclear if a systematic lymph node dissection should be part of pulmonary metastasectomy. For this reason, the goal of this review was to evaluate the rationale of systematic lymph node dissection in pulmonary metastasectomy based on the currently available literature. Furthermore, it was investigated whether patients with additional thoracic lymph node metastases should be excluded per se from pulmonary metastasectomy, even though positive lymph node metastases might be associated with a lower but nevertheless good long-term survival after resection.

Feasibility of nodal classification for non-small cell lung cancer by merging current N categories with the number of involved lymph node stations

Introduction

The aim of this study was to assess the prognoses of patients with non‐small cell lung cancer (NSCLC) according to the current nodal (N) categories of the tumor, node and metastasis (TNM) classification and the number of involved lymph node stations.

Methods

Five hundred and seventy patients with NSCLC underwent surgery from 1 January 2005 to 31 December 2009 and were analysed retrospectively. Postoperative overall survival was analysed according to two nodal classifications: the current N0, N1, N2 and N3 categories and those based on the number of involved nodal stations: N0, N1a (single N1), N1b (multiple N1), N2a1 (single N2 without N1), N2a2 (single N2 with N1), N2b1 (multiple N2 without N1) and N2b2 (multiple N2 with N1).

Results

Five‐year survival rates were 76.1%, 53.4% and 26.3% for N0, N1 and N2, respectively (P < 0.001). When survival was analysed by the number of involved nodal stations, the groups with significant differences were maintained; otherwise, they were merged, and new codes were assigned as follows for exploratory analyses: NA (N0), NB (N1a), NC (N1b, N2a (i.e., N2a1 and N2a2) and N2b1) and ND (N2b2). Five‐year survival rates were 76.1%, 60.0%, 39.1%, and 11.4% for NA, NB, NC and ND, respectively, and there were significant differences among them. This N classification was an independent prognostic factor in multivariate analyses.

Conclusion

Pending prospective and international validation, it is practical to merge the current N categories with the number of involved lymph node stations when evaluating the postoperative prognosis of NSCLC patients.

Mid-term survival outcome of single-port video-assisted thoracoscopic anatomical lung resection: a two-centre experience

OBJECTIVES

Single-port video-assisted thoracoscopic surgery (SPVATS) anatomical resection has been shown to be a feasible technique for lung cancer patients. Whether SPVATS has equivalent or better oncological outcomes for lung cancer patients remains controversial. The purpose of this study was to evaluate the perioperative and mid-term survival outcomes of SPVATS in 2 different medical centres.

METHODS

We retrospectively reviewed patients who underwent SPVATS anatomical resections between January 2014 and February 2017 in Coruña University Hospital's Minimally Invasive Thoracic Surgery Unit (Spain) and Chang Gung Memorial Hospital (Taiwan). Survival outcomes were assessed by pathological stage according to the American Joint Committee on Cancer (AJCC) 7th and 8th classifications.

RESULTS

In total, 307 patients were enrolled in this study. Mean drainage days and postoperative hospital stay were 3.90 ± 2.98 and 5.03 ± 3.34 days. The overall 30-day mortality, 90-day morbidity and mortality rate were 0.7%, 20.1% and 0.7%, respectively. The 2-year disease-free survival and 2-year overall survival of the cohort were 80.6% and 93.4% for 1A, 68.8% and 84.6% for 1B, 51.0% and 66.7% for 2A, 21.6% and 61.1% for 2B, 47.6% and 58.5% for 3A, respectively, following the AJCC 7th classification. By the AJCC 8th classification, these were 92.3% and 100% for 1A1, 73.7% and 91.4% for 1A2, 75.2% and 93.4% for 1A3, 62.1% and 85.9% for 1B, 55.6% and 72.7% for 2A, 47.1% and 64.2% for 2B and 42.1% and 60.3% for 3A.

CONCLUSIONS

Our preliminary results revealed that SPVATS anatomical resection achieves acceptable 2-year survival outcomes for early-stage lung cancer and is consistent with AJCC 8th staging system 2-year survival data. For advanced stage non-small-cell lung cancer patients, further evaluation is warranted.

New revisions and current issues in the eighth edition of the TNM classification for non-small cell lung cancer

In the eighth edition of the TNM classification of lung cancer, the prognostic impact of tumor size is emphasized as a descriptor of all T categories. Especially in lung cancer where tumor size is 5 cm or less, the 1-cm cutoff point significantly differentiated the survival outcome. In addition, the new staging categories were assigned, namely, Tis (adenocarcinoma in situ) and T1mi (minimally invasive adenocarcinoma). Furthermore, the measurement of a radiological solid component size excluding the ground glass opacity component or pathological invasive size without a lepidic component was proposed for deciding the cT/pT categories for lung adenocarcinoma. The N descriptors were kept the same as in the eventh edition on the whole, however, quantification of nodal disease had a prognostic impact based on the number of nodal stations involved in the eighth edition, i.e. N1a as a single N1 station, N1b as a multiple N1 station, N2a1 as a single N2 station without N1 (skip metastasis), N2a2 as a single N2 station with N1 disease, and N2b as a multiple N2 station. In the M descriptors, subclassification was performed based on the location or numbers of distantly metastatic lesions, i.e. M1a as any intrathoracic metastases, M1b as a single distant metastatic lesion in one organ, and M1c as multiple distant metastases in either a single organ or multiple organs. Survival analysis of the eighth edition of the TNM classification clearly separated the distinct groups, however, unsolved issues still remain that should be discussed and further revised for the forthcoming TNM staging system.

The number of resected lymph nodes is associated with the long-term survival outcome in patients with T2 N0 non-small cell lung cancer

Objective

For the patients with pathologic T2 N0 non-small cell lung cancer (NSCLC), the extent of lymph node (LN) removal required for survival is controversial. We aimed to explore the prognostic significance of examined LNs and to identify how many nodes should be examined.

Methods

We reviewed 549 patients who underwent pulmonary or pneumonectomy surgery or plus lymphadenectomy who were confirmed as T2 stage and LN negative by postoperative pathological diagnosis. According to Martingale residuals of the Cox model, the patients were classified into four groups by the number of examined LNs (1-2 LNs, 3-7 LNs, 8-11 LNs, and ≥12 LNs). Kaplan-Meier analysis and Cox regression analysis were used to evaluate the association between survival and the number of examined LNs.

Result

Compared with the 1-2 LNs, 3-7 LNs, and 8-11 LNs groups, the survival was significantly better in the ≥12 LNs group. The 5-year cancer-specific survival rate was 60.5% for patients with 1-2 negative LNs, compared with 68.7%, 72.6%, and 78.4% for those with 3-7, 8-11, and >11 LNs examined, respectively. The 7-year cancer-specific survival rate was 52.9% for patients with 1-2 negative LNs, compared with 63.7%, 63.8%, and 70.8% for those with 3-7, 8-11, and >11 LNs examined, respectively (P=0.045). There was a significant drop in mortality risk with the examination of more LNs. The lowest mortality risk occurred in those with 32 or more LNs examined. Multivariate analysis showed that age and the number of examined LNs were strong independent predictors of survival.

Conclusion

The number of examined LNs is a strong independent prognostic factor. Our study demonstrates that patients with T2 N0 NSCLC should have at least 12 LNs examined and that the results of this study may provide information for the optimal number of resected LNs in surgery.

Impact of examined lymph node counts on survival of patients with stage IA non-small cell lung cancer undergoing sublobar resection

Background

The correlation between the number of examined lymph nodes (ELNs) and lung cancer-specific survival (LCSS) of stage IA non-small cell lung cancer (NSCLC) patients, who underwent sublobar resection in which lymph node (LN) sampling was relatively restricted as compared with standard lobectomy remains unclear.

Methods

Patients from the Surveillance, Epidemiology, and End Results database with stage IA NSCLC who underwent sublobar resection were categorized based on ELN count (1-6 vs. ≥7; the cut point 7 was identified by Cox model).

Results

Collectively, 3,219 patients with a median follow-up time of 37 months were included in this study (G1: 1-6 ELN, n=2,410; G2: ≥7 ELN, n=809). The 5-year LCSS rate of the G1 and G2 cohorts were 75% and 83%, respectively. Cox analysis suggested that the LCSS of G1 cohort patients was lower as compared with the G2 cohort [hazard ratio (HR) =1.530; 95% confidence interval (CI): 1.240-1.988, P<0.001). Propensity score analysis also showed decreased survival of the matched G1 cohort (HR =1.499; 95% CI: 1.176-1.911; P=0.001).

Conclusions

The data suggested the ELNs ≤6 were associated with poor prognoses. Adequate LN sampling is essential even for stage IA NSCLC patients undergoing sublobar resection.

[The Argument and Consensus of Lymphadenectomy on Lung Cancer Surgery]

淋巴结转移是肺癌的重要转移途径，淋巴结清扫术已成为肺癌的标准术式，同时也决定着肺癌的分期、预后及治疗策略。在临床实践中肺癌淋巴结的清扫方式各有不同，从选择性的淋巴结采样到扩大的淋巴结清扫，目前各种清扫方式存在着很大的争议，本文就目前的纵隔淋巴结清扫方式的共识及争议进行综述，为今后开展多中心临床研究提供参考。

Mediastinal staging by videomediastinoscopy in clinical N1 non-small cell lung cancer: a prospective multicentre study

A quarter of patients with clinical N1 (cN1) non-small cell lung cancer (NSCLC) based on positron emission tomography-computed tomography (PET-CT) imaging have occult mediastinal nodal involvement (N2 disease). In a prospective study, endosonography alone had an unsatisfactory sensitivity (38%) in detecting N2 disease. The current prospective multicentre trial investigated the sensitivity of preoperative mediastinal staging by video-assisted mediastinoscopy (VAM) or VAM-lymphadenectomy (VAMLA).Consecutive patients with operable and resectable (suspected) NSCLC and cN1 after PET-CT imaging underwent VAM(LA). The primary study outcome was sensitivity to detect N2 disease. Secondary endpoints were the prevalence of N2 disease, negative predictive value (NPV) and accuracy of VAM(LA).Out of 105 patients with cN1 on imaging, 26% eventually developed N2 disease. Invasive mediastinal staging with VAM(LA) had a sensitivity of 73% to detect N2 disease. The NPV was 92% and accuracy 93%. Median number of assessed lymph node stations during VAM(LA) was 4 (IQR 3-5), and in 96%, at least three stations were assessed.VAM(LA) has a satisfactory sensitivity of 73% to detect mediastinal nodal disease in cN1 lung cancer, and could be the technique of choice for pre-resection mediastinal lymph node assessment in this patient group with a one in four chance of occult-positive mediastinal nodes after negative PET-CT.

Nodal management and upstaging of disease: initial results from the Italian VATS Lobectomy Registry

BACKGROUND

VATS lobectomy is an established option for the treatment of early-stage NSCLC. Complete lymph node dissection (CD), systematic sampling (SS) or resecting a specific number of lymph nodes (LNs) and stations are possible intra-operative LN management strategies.

METHODS

All VATS lobectomies from the "Italian VATS Group" prospective database were retrospectively reviewed. The type of surgical approach (CD or SS), number of LN resected (RN), the positive/resected LN ratio (LNR) and the number and types of positive LN stations were recorded. The rates of nodal upstaging were assessed based on different LN management strategies.

RESULTS

CD was the most frequent approach (72.3%). Nodal upstaging rates were 6.03% (N0-to-N1), 5.45% (N0-to-N2), and 0.58% (N1-to-N2). There was no difference in N1 or N2 upstaging rates between CD and SS. The number of resected nodes was correlated with both N1 (OR =1.02; CI, 1.01-1.04; P=0.03) and N2 (OR =1.02; CI, 1.01-1.05; P=0.001) upstaging. Resecting 12 nodes had the best ability to predict upstaging (6 N1 LN or 7 N2 LN). The finding of two positive LN stations best predicted N2 upstaging [area under the curve (AUC) of receiver operating characteristic (ROC) =0.98].

CONCLUSIONS

Nodal upstaging (and, indirectly, the effectiveness of intra-operative nodal management) cannot be predicted based on the surgical technique (CD or SS). A quantitative assessment of intra-operative LN management may be a more appropriate and measurable approach to justify the extension of LN resection during VATS lobectomy.

Impact of Examined Lymph Node Count on Precise Staging and Long-Term Survival of Resected Non-Small-Cell Lung Cancer: A Population Study of the US SEER Database and a Chinese Multi-Institutional Registry

Purpose We investigated the correlation between the number of examined lymph nodes (ELNs) and correct staging and long-term survival in non-small-cell lung cancer (NSCLC) by using large databases and determined the minimal threshold for the ELN count. Methods Data from a Chinese multi-institutional registry and the US SEER database on stage I to IIIA resected NSCLC (2001 to 2008) were analyzed for the relationship between the ELN count and stage migration and overall survival (OS) by using multivariable models. The series of the mean positive LNs, odds ratios (ORs), and hazard ratios (HRs) were fitted with a LOWESS smoother, and the structural break points were determined by Chow test. The selected cut point was validated with the SEER 2009 cohort. Results Although the distribution of ELN count differed between the Chinese registry (n = 5,706) and the SEER database (n = 38,806; median, 15 versus seven, respectively), both cohorts exhibited significantly proportional increases from N0 to N1 and N2 disease (SEER OR, 1.038; China OR, 1.012; both P < .001) and serial improvements in OS (N0 disease: SEER HR, 0.986; China HR, 0.981; both P < .001; N1 and N2 disease: SEER HR, 0.989; China HR, 0.984; both P < .001) as the ELN count increased after controlling for confounders. Cut point analysis showed a threshold ELN count of 16 in patients with declared node-negative disease, which were examined in the derivation cohorts (SEER 2001 to 2008 HR, 0.830; China HR, 0.738) and validated in the SEER 2009 cohort (HR, 0.837). Conclusion A greater number of ELNs is associated with more-accurate node staging and better long-term survival of resected NSCLC. We recommend 16 ELNs as the cut point for evaluating the quality of LN examination or prognostic stratification postoperatively for patients with declared node-negative disease.

Can mathematics replace anatomy to establish recommendations in lung cancer surgery?

The greater the number of lymph node (LN) sampled (NLNsS) during lung cancer surgery, the lower the risk of underestimating the pN-status and the better the outcome of the pN0-patients due to stage-migration. Thus, regarding LN sampling "to be or not to be", number is the question. Recent studies advocate removing 10 LNs. The most suitable NLNsS is unfortunately impossible to establish by mathematics. A too high NLNsS variability exists, based on anatomy, surgery and pathology. The methodology may vary according to Inter-institutional differences in the surgical approach regarding LN inspection and number sampling. The NLNsS increases with the type of resection: sublobar, lobectomy or pneumonectomy. Concerning pathology, one LN may be divided into several pieces, leading to number overestimation. The pathological examination is limited by the number of slices analyzed by LN. The examined LNs can arbitrarily depend on the probability of detecting nodal metastasis. In fact, the only way to ensure the best NLNsS and the best pN-staging is to remove all LNs from the ipsilateral mediastinal and hilar LN-stations as they are discovered by thoroughly dissecting their anatomical locations. In doing so, a deliberate lack of harvest of LNs is unlikely, number turns out not to be the question anymore and a low NLNsS no longer means incomplete surgery. This prevents from judging as incomplete a complete LN dissection in a patient with a small NLNsS and from considering as complete a true incomplete one in a patient with a great NLNsS. Precise information describing the course of the operation and furnished in the surgeon's reports is also advisable to further improve the quality of LN-dissection, which ultimately might be beneficial in the long-term to patients. However, that procedure is of limited interest in pN-staging if LNs are not thoroughly examined and also described by the pathologist.

Impact of lymph node management on resectable non-small cell lung cancer patients

BACKGROUND

A surgical lung resection with systematic mediastinal lymph node (LN) dissection is recommended by the National Comprehensive Cancer Network guideline. However, the effective number of dissected LNs, stations and positivity is still controversial. The aim of this study is to identify the impact of total numbers, LN stations and positivity of dissected LNs on tumor recurrence and overall death in resectable non-small cell lung cancer (NSCLC).

METHODS

This prognostic study used a retrospective data collection design. Adult patients with clinical resectable NSCLC who underwent pulmonary resection and mediastinal lymphadenectomy at Chiang Mai University between June 2000 and June 2012 were enrolled in this study. A multilevel mixed-effects parametric survival model was used to identify the effect of numbers, LN stations and positivity of dissected LNs to tumor recurrence and mortality.

RESULTS

The average number of dissected LNs was 22.7±12.8. Tumor recurrence was found in 51.3% and overall mortality was 43.3%. The number of dissected LNs was a prognostic factor for tumor recurrence [HR 0.98, 95% confidence interval (CI): 0.96-0.99]. There was a significant difference at the cut-pointed value of 11 dissected LNs for tumor recurrence (HR 2.22, 95% CI: 1.26-3.92). Dissection less than 11 nodes and less than 5 stations indicated a poor prognostic factor for tumor recurrence: for 3-4 stations (HR 3.01, 95% CI: 1.22-7.42) and for 1-2 stations (HR 1.96, 95% CI: 1.04-3.72). The positivity of dissected LNs was also a prognostic factor for tumor recurrence and overall mortality (HR 1.01, 95% CI: 1.01-1.02 and HR 1.01, 95% CI: 1.01-1.03, respectively).

CONCLUSIONS

Eleven or more LN dissection with at least 5 stations influenced recurrent-free survival. Systematic LN dissection (SLND) should be performed not only to identify the positivity of dissected LNs but also to determine an accurate tumor nodal stage. A larger cohort should be further conducted to support these findings.

Lymph node dissection after pulmonary resection for lung cancer: a mini review

An accurate staging of a malignant disease is imperative in order to plan pre- and post-operative therapy, define prognosis and compare studies. According to the European Society of Thoracic Surgeons (ESTS) guidelines a systematic lymph node (LN) dissection is recommended in all cases of pulmonary resection for non-small cell lung cancer (NSCLC). The current lung cancer staging system considers the lymphatic stations involved but not the number of LNs. Up to date, published scientific studies on hilar and mediastinal lymphadenectomy mainly have been regarded the type of LN dissection procedure after pulmonary resection (selected LN biopsy, LN sampling, systematic nodal dissection, lobe specific nodal dissection and extended LN dissection) focusing particularly on the comparison between mediastinal LN dissection (MLND) and mediastinal LN sampling (MLNS). Recently, further investigations have been concentrated on surgical approach (videothoracoscopic vs. thoracotomic approach) used to perform pulmonary resection and following LN dissection in order to achieve a complete mediastinal lymphadenectomy. This short synthesis aims to present the current experiences in this setting.

Survival Implications of Variation in the Thoroughness of Pathologic Lymph Node Examination in American College of Surgeons Oncology Group Z0030 (Alliance)

BACKGROUND

Accurate pathologic nodal staging mandates effective collaboration between surgeons and pathologists. The American College of Surgeons Oncology Group Z0030 trial (ACOSOG Z0030) tightly controlled surgical lymphadenectomy practice but not pathologic examination practice. We tested the survival impact of the thoroughness of pathologic examination (using the number of examined lymph nodes as a surrogate).

METHODS

We re-analyzed the mediastinal lymph node dissection arm of ACOSOG Z0030, using logistic regression and Cox proportional hazards models.

RESULTS

Of 513 patients, 435 were pN0, 60 were pN1, and 17 were pN2. The mean number of mediastinal lymph nodes examined was 13.5, 13.1, and 17.1; station 10 lymph nodes were 2.4, 2.7, and 2.6; station 11 to 14 nodes were 4.6, 6.1, and 6.7; and total lymph nodes were 19.7, 21.3, and 25.4 respectively. The pN category and histologic evaluation were associated with increased number of examined intrapulmonary lymph nodes. Patients with pN1 had more non-hilar N1 nodes than patients with pN0, patients with N2 had more N2 nodes examined than patients with pN0 or pN1. Patients with pN0 had better survival with examination of more N1 nodes; patients with pN1 had better survival with increased mediastinal nodal examination; the likelihood of discovering N2 disease was significantly associated with increased examination of mediastinal and non-hilar N1 lymph nodes.

CONCLUSIONS

Despite rigorously standardized surgical hilar/mediastinal lymphadenectomy, the number of lymph nodes examined was associated with the likelihood of detecting nodal metastasis and survival. This may indicate an effect of incomplete pathologic examination.

Comparison of three-dimensional and two-dimensional visualization in video-assisted thoracoscopic lobectomy

BACKGROUND

Video-assisted thoracoscopic surgery (VATS) lobectomy has emerged as a safe and effective technique for treating early-stage lung cancer. Novel three-dimensional, high-definition (3D HD) imaging has removed this technical obstacle and is increasingly used in laparoscopic surgery. We compared our initial experience of 3D HD VATS with standard two-dimensional (2D) HD VATS to identify the advantages and disadvantages of 3D HD visualization in VATS.

METHODS

The data of consecutive patients diagnosed with lung cancer who underwent 2D or 3D thoracoscopic lobectomy or bilobectomy at the Guangdong Lung Cancer Institute from July 2013 to October 2014 were retrospectively analyzed. Operation duration, estimated blood loss, length of postoperative stay, major complications, and mortality were recorded for each patient.

RESULTS

In total, 359 patients were enrolled in the study. Lobectomy was performed in 339 patients and bilobectomy in 20; the 3D HD system was used for 178 of the 359 patients, and the 2D HD system for 181. Tumor size, distribution of the resected lobes, and the demographic characteristics of the patients were matched between the two groups. The mean operative time for 3D VATS was 163 minutes (range 60-330), whereas 2D VATS required 184 minutes (range 75-360; P < 0.001). The volume of blood loss was 109 and 144 mL in the 3D and 2D VATS groups, respectively (P = 0.064).

CONCLUSIONS

The new-generation 3D HD imaging system is feasible and safe for thoracic lobectomy. The 3D system required a shorter operative duration.

Selection for adjuvant chemotherapy in completely resected stage I non-small cell lung cancer: external validation of a Chinese prognostic risk model

BACKGROUND

The ability to sub-stratify survival within stage I is an important consideration as it is assumed that survival is heterogeneous within this sub-group. Liang et al. recently published a nomogram to predict post-operative survival in patients undergoing lung cancer surgery. The aim of our study is external validation of their published nomogram in a British cohort focusing on stages IA and IB to determine applicability in selection of adjuvant chemotherapy within stage I.

METHODS

Patient variables were extracted and the score individually calculated. Receiver operative characteristics curve (ROC) was calculated and compared with the original derivation cohort and the discriminatory ability was further quantified using survival plots by splitting our (external) validation cohort into three tertiles and Kaplan Meier plots were constructed and individual curves tested using Cox regression analysis on Stata 13 and R 3.1.2 respectively.

RESULTS

A total of 1,238 patients were included for analysis. For all patients from stage IA to IIB the mean (SD) score was 9.95 (4.2). The ROC score comparing patients who died versus those that remained alive was 0.62 (95% CI: 0.58 to 0.67). When divided into prognostic score tertiles, survival discrimination remained evident for the entire cohort, as well as those for stage IA and IB alone. The P value comparing survival between the middle and highest score with baseline (low score) was P=0.031 and P=0.034 respectively.

CONCLUSIONS

Our results of external validation suggested lower survival discrimination than reported by the original group; however discrimination between survival remained evident for stage I.

The impact of tumor size on the association of the extent of lymph node resection and survival in clinical stage I non-small cell lung cancer

INTRODUCTION

Lymph node evaluation for node-negative non-small cell lung cancer (NSCLC) is associated with long-term survival but it is not clear if smaller tumors require as extensive a pathologic nodal assessment as larger tumors. This study evaluated the relationship of tumor size and optimal extent of lymph node resection using the National Cancer Data Base (NCDB).

MATERIALS AND METHODS

The incremental survival benefit of each additional lymph node that was evaluated for patients in the NCDB who underwent lobectomy for clinical Stage I NSCLC from 2003 to 2006 was evaluated using Cox multivariable proportional hazards regression modeling. The impact of tumor size was assessed by repeating the Cox analysis with patients stratified by tumor size ≥2 cm vs <2 cm.

RESULTS

A median of 7 [interquartile range: 4,11] lymph nodes were examined in 13,827 patients who met study criteria. Following adjustment, the evaluation of each additional lymph node demonstrated a significant survival benefit through 11 lymph nodes. After grouping patients by tumor size, patients with tumors <2 cm demonstrated a significant survival benefit for the incremental resection of each additional lymph node through 4 lymph nodes while patients with tumors ≥2 cm had a significant survival benefit through 14 lymph nodes.

CONCLUSION

Pathologic lymph node evaluation is associated with improved survival for clinically node-negative NSCLC, but the extent of the necessary evaluation varies by tumor size. These results have implications for guidelines for lymph node assessment as well as the choice of surgery vs other ablative techniques for clinical stage I NSCLC.

Radiologic Predictors for Clinical Stage IA Lung Adenocarcinoma with Ground Glass Components: A Multi-Center Study of Long-Term Outcomes

Objective

This study was to define preoperative predictors from radiologic findings for the pathologic risk groups based on long-term surgical outcomes, in the aim to help guide individualized patient management.

Methods

We retrospectively reviewed 321 consecutive patients with clinical stage IA lung adenocarcinoma with ground glass component on computed tomography (CT) scanning. Pathologic diagnosis for resection specimens was based on the 2011 IASLC/ATS/ERS classification of lung adenocarcinoma. Patients were classified into different pathologic risk grading groups based on their lymph node status, local regional recurrence and overall survival. Radiologic characteristics of the pulmonary nodules were re-evaluated by reconstructed three-dimension CT (3D-CT). Univariate and multivariate analysis identifies independent radiologic predictors from tumor diameter, total volume (TV), average CT value (AVG), and solid-to-tumor (S/T) ratio. Receiver operating characteristic curves (ROC) studies were carried out to determine the cutoff value(s) for the predictor(s). Univariate cox regression model was used to determine the clinical significance of the above findings.

Results

A total of 321 patients with clinical stage IA lung adenocarcinoma with ground glass components were included in our study. Patients were classified into two pathologic low- and high- risk groups based on their distinguished surgical outcomes. A total of 134 patients fell into the low-risk group. Univariate and multivariate analyses identified AVG (HR: 32.210, 95% CI: 3.020–79.689, P<0.001) and S/T ratio (HR: 12.212, 95% CI: 5.441–27.408, P<0.001) as independent predictors for pathologic risk grading. ROC curves studies suggested the optimal cut-off values for AVG and S/T ratio were-198 (area under the curve [AUC] 0.921), 2.9 (AUC 0.996) and 54% (AUC 0.907), respectively. The tumor diameter and TV were excluded for the low AUCs (0.778 and 0.767). Both the cutoff values of AVG and S/T ratio were correlated with pathologic risk classification (p<0.001). Univariate Cox regression model identified clinical risk classification (RR: 3.011, 95%CI: 0.796–7.882, P = 0.095) as a good predictor for recurrence-free survival (RFS) in patients with clinical stage IA lung adenocarcinoma. Statistical significance of 5-year OS and RFS was noted among clinical low-, moderate- and high-risk groups (log-rank, p = 0.024 and 0.010).

Conclusions

The AVG and the S/T ratio by reconstructed 3D-CT are important preoperative radiologic predictors for pathologic risk grading. The two cutoff values of AVG and S/T ratio are recommended in decision-making for patients with clinical stage IA lung adenocarcinoma with ground glass components.

Recurrence Risk Factors Analysis for Stage I Non-small Cell Lung Cancer

Lung cancer is the leading cause of cancer-related death worldwide. Even early-stage patients might encounter disease recurrence with relative high risk. Effective postoperative therapy is based on an accurate assessment of treatment failure after surgery. The aim of this study is to construct a disease-free survival (DFS) prediction model and stratify patients into different risk score groups.A total of 356 pathological stage I patients (7th American Joint Committee on Cancer) who underwent lung resection from January 2005 through June 2011 were retrospectively reviewed. Of these patients, 63 patients were eliminated for this study. A total of 293 p-stage I patients were included for further univariate and multivariate analysis. Clinical, surgical, and pathological factors associated with high risk of recurrence were analyzed, including age, gender, smoking status, additional primary malignancy (APM), operation method, histology, visceral pleural invasion, angiolymphatic invasion, tumor necrosis, and tumor size.Of the 293 p-stage I non-small cell lung cancer (NSCLC) patients examined, 143 were female and 150 were male, with a mean age of 62.8-years old (range: 25-83-years old). The 5-year DFS and overall survival rates after surgery were 58.9% and 75.3%, respectively. On multivariate analysis, current smoker (hazards ratio [HR]: 1.63), APM (HR: 1.86), tumor size (HR: 1.54, 2.03), nonanatomic resections (HR: 1.81), adenocarcinoma histology (HR: 2.07), visceral pleural invasion (HR: 1.54), and angiolymphatic invasion (HR: 1.53) were found to be associated with a higher risk of tumor recurrence. The final model showed a fair discrimination ability (C-statistic = 0.68). According to the difference risk group, we found patients with intermediate or higher risk group had a higher distal relapse tendency as compared with low risk group (P = 0.016, odds ratio: 3.31, 95% confidence interval: 1.21-9.03).Greater than 30% of disease recurrences occurred after surgery for stage I NSCLC patients. That is why we try to establish an effective DFS predicting model based on clinical, pathological, and surgical covariates. However, our initial results still need to be validated and refined into greater population for better application in clinical use.

The impact of positive nodal chain ratio on individualized multimodality therapy in non-small-cell lung cancer

This study aimed to analyze the prognostic significance of the positive nodal chain ratio (NCR) in non-small-cell lung cancer (NSCLC). A total of 208 pIIIa-N2 NSCLC patients who underwent complete surgical resections with a systematic nodal dissection were enrolled. The median values of NCR and the positive lymph node ratio (LNR) were used to grouping patients. The differences of overall survival (OS) and disease-free survival (DFS) between the different groups were compared. The median values of NCR and LNR were 0.31 and 0.45, respectively. The patients were separated into group A (NCR ≤0.45 and LNR ≤0.31; 91 cases), group B (NCR ≤0.45 and LNR >0.31 or NCR >0.45 and LNR ≤0.31; 51 cases), and group C (NCR >0.45 and LNR >0.31; 66 cases) according to their combined LCR and LNR values. Groups A, B, and C exhibited significantly different prognoses (5-year OS: 43.7, 25.2, and 12.3 %, respectively, p < 0.0001; 5-year DFS: 30.4, 23.3, and 8.6 %, respectively, p < 0.0001). Multivariate analyses revealed that this novel grouping method based on the combination of NCR and LNR was an independent prognostic factor for 5-year OS and 5-year DFS in pIIIa-N2 NSCLC. In group C, patients who received no postoperative treatment, adjuvant chemotherapy alone, or chemoradiotherapy exhibited different 5-year OS rates (0.0, 11.6, and 37.5 %, respectively, p = 0.003) and 5-year DFS rates (0.0, 7.5, and 25.0 %, respectively, p = 0.009). Therefore, postoperative chemoradiotherapy may significantly improve the prognosis of patients displaying NCR >0.45 and LNR >0.31. NCR combined with LNR may be more effective to guide individualized multimodality therapy including postoperative chemoradiotherapy for pIIIa-N2 NSCLC.

Prognostic value of metastatic N1 lymph node ratio and angiolymphatic invasion in patients with pathologic stage IIA non-small cell lung cancer

With regard to pathologic stage IIA (pIIA) non-small cell lung cancer (NSCLC), there is a paucity of literature evaluating the risk factors for disease-free survival (DFS) and overall survival (OS). The aim of this study was to identify the prognostic factors of DFS and OS in patients with NSCLC pIIA.We performed a retrospective review of 98 stage II patients (7th edition of the American Joint Committee on Cancer) who underwent lung resection from January 2005 to February 2011. Of these, 23 patients were excluded for this study because of loss of follow-up or different substage, and 75 patients with pIIA were included for further univariate and multivariate analysis. Risk factors for DFS and OS were analyzed, including age, gender, smoking history, operation method, histology, differential grade, visceral pleural invasion, angiolymphatic invasion, and metastatic N1 lymph node ratio (LNR).Of the 75 patients with pIIA NSCLC who were examined, 29 were female and 46 were male, with a mean age of 61.8 years (range: 34-83 years). The average tumor size was 3.188 cm (range: 1.10-6.0 cm). Under univariate analysis, angiolymphatic invasion and metastatic N1 LNR were risk factors for DFS (P = 0.011, P = 0.007). Under multivariate analysis, angiolymphatic invasion and metastatic N1 LNR were all independent risk factors for DFS, while adjuvant chemotherapy and higher metastatic N1 LNR were independent prognostic factors for OS.For patients with pIIA, higher metastatic N1 LNR and angiolymphatic invasion were related to poor DFS. In addition to DFS, higher metastatic N1 LNR was also a poor prognostic factor for OS rates and adjuvant therapy effectiveness. Clinical physicians should devise different postsurgical follow-up programs depending on these factors, especially for patients with high risk.