The number of lymph node metastases as a prognostic factor in patients with N1 non-small cell lung cancer

Number of involved nodal stations predicts survival in small cell lung cancer

BACKGROUND

In small cell lung cancer (SCLC), the pathological N category is identical to it in non-small cell lung cancer (NSCLC) and remains unchanged over a decade. Here we verified the discriminability of number of involved nodal stations (nS) in SCLC and compared its efficacy in predicting survival with currently used pathological nodal (pN) staging.

METHODS

We retrospectively analyzed the patients who received operations and were pathologically diagnosed as SCLC at Shanghai Pulmonary Hospital between 2009 and 2019. X-tile software was adopted to determine optimal cut-off values for nS groups. Kaplan-Meier method and Cox regression analysis were used to compare survival between different groups. Decision curve analysis (DCA) was employed to evaluate the standardized net benefit.

RESULTS

A total of 369 patients were included. The median number of sampled stations was 6 (range 3-11), and the median number of positive stations was 1 (range 0-7). The optimal cutoff for nS groups was: nS0 (no station involved), nS1-2 (one or two stations involved), and nS ≥ 3 (three or more stations involved). Overall survival (OS) and relapse-free survival (RFS) were statistically different among all adjacent categories within the nS classification (p < 0.001, for both OS and RFS between each two subgroups), but survival curves for subgroups in pN overlapped (OS, p = 0.067; RFS, p = 0.068, pN2 vs. pN1). After adjusting for other confounders, nS was a prognostic indicator for OS and RFS. The DCA revealed that nS had improved predictive capability than pN.

CONCLUSIONS

Our cohort study demonstrated that the nS might serve as a superior indicator to predict survival than pN in SCLC and was worth considering in the future definition of the N category.

Survival difference between patients with single versus multiple metastatic lymph nodes and the role of histology in pathological stage II-N1 non-small cell lung cancer

BACKGROUND

Previous studies investigating whether metastatic lymph node count is a relevant prognostic factor in pathological N1 non-small cell lung cancer (NSCLC), showed conflicting results. Hypothesizing that outcome may also be related to histological features, we determined the prognostic impact of single versus multiple metastatic lymph nodes in different histological subtypes for patients with stage II-N1 NSCLC.

METHODS

We performed a retrospective cohort study using data from the Netherlands Cancer Registry, including patients treated with a surgical resection for stage II-N1 NSCLC (TNM 7th edition) in 2010-2016. Overall survival (OS) was assessed for patients with single (pN1a) and multiple (pN1b) metastatic nodes. Using multivariable analysis, we compared OS between pN1a and pN1b in different histological subtypes.

RESULTS

After complete resection of histologically proven stage II-N1 NSCLC, 1309 patients were analyzed, comprising 871 patients with pN1a and 438 with pN1b. The median number of pathologically examined nodes (N1 + N2) was 9 (interquartile range 6-13). Five-year OS was 53% for pN1a versus 51% for pN1b. In multivariable analysis, OS was significantly different between pN1a and pN1b (HR 1.19, 95% CI 1.01-1.40). When stratifying for histology, the prognostic impact of pN1a/b was only observed in adenocarcinoma patients (HR 1.44, 95% CI 1.15-1.81).

CONCLUSION

Among patients with stage II-N1 adenocarcinoma, the presence of multiple metastatic nodes had a significant impact on survival, which was not observed for other histological subtypes. If further refinement as to lymph node count will be considered for incorporation into a new staging system, evaluation of the role of histology is recommended.

Optimal Extent of Neck Dissection for a Head and Neck Lymph Node Metastasis from a Remote Primary Site

BACKGROUND

Despite its rarity and limited documentation, therapeutic neck dissection (ND) for cervical lymph node (LN) metastases from distant primary sites is increasingly practiced, potentially enhancing survival rates. However, the optimal ND extent remains unclear. This study aimed to determine the safety of excluding upper neck levels from ND.

METHODS

We retrospectively analyzed 25 patients who underwent ND for cervical LN metastases from remote primary tumors between 2015 and 2021 (12 with primary lung tumors, four with ovary, three with mammary gland, three with esophagus, two with thymus, and one with colon).

RESULTS

Assessing clinical characteristics and occult metastasis rates, we observed LN metastases predominantly at levels III and IV. Occult metastases occurred in 14 out of 25 patients, primarily at neck levels III and IV (55.0% and 50.0%, respectively). The five-year disease-specific survival rate for all patients was 44.3%. While no statistically significant impact of occult metastasis on prognosis was confirmed, an association between the postoperative LN ratio and poor prognosis was revealed.

CONCLUSIONS

Our findings suggest that prophylactic NDs at levels I, II, and Va may not be essential for managing cervical LN metastases from remote primary malignancies. This could lead to a more tailored and less invasive therapeutic strategy.

N1 lymph node detection in lymph node harvesting in non-small cell lung cancer: Formaldehyde exposure is a drawback?

OBJECTIVE

This study aimed to evaluate the effect of lymph node dissection method on staging results, diagnosis of tumor metastasis in single or multiple N1 lymph nodes and survival rates in patients with non-small cell lung cancer (NSCLC).

METHODS

Patients with NSCLC who underwent anatomic resection between September 2014 and October 2019 were examined prospectively. All patients with similar clinico-demographic characteristics were randomly assigned to either the surgical group (n = 83) or the pathology group (n = 87). Lymph node dissection was performed by the surgeon in the surgical group and by the pathologists after formaldehyde exposure in the pathology group. Data were analyzed according to formaldehyde exposure, N1 positivity, and number of N1 positive lymph nodes.

RESULTS

There were no significant differences in N1 lymph node positivity between the two groups (p = 0.482). On average 9.08 lymph node sampling was performed in the surgical group and 2.39 in the pathology group (p = 0.0001). Multiple lymph node involvement was significantly higher in the surgical group (P = 0.0001) than in the pathology group.

CONCLUSION

It is easier to detect lymph node involvement without introducing formaldehyde into the sample. We recommend that N1 lymph node dissection be performed on fresh specimens to detect more lymph node involvement.

A Systematic Review of Short-Term Outcomes of Minimally Invasive Thoracoscopic Surgery for Lung Cancer after Neoadjuvant Systemic Therapy

BACKGROUND

Minimally invasive surgeries for non-small cell lung cancers (NSCLCs) such as video-assisted thoracoscopic surgeries (VATSs) and robotic-assisted thoracoscopic surgeries (RATSs) have become standard of care for patients needing surgical resection in early stages. The role for neoadjuvant systemic therapy has increased with patients receiving neoadjuvant systemic chemotherapy and immunotherapy. However, there has been some equipoise over the intraoperative and overall outcomes for these patients. Here, we review the current data regarding outcomes of patients undergoing minimally invasive thoracic surgical resection after systemic chemotherapy, immunotherapy, or both.

METHODS

A systematic literature review of randomized controlled trials and observational studies presenting data on patients with NSCLC that underwent neoadjuvant systemic therapy followed by minimally invasive surgery was performed assessing complications, conversion rates, and lymph node yield.

RESULTS

Our search strategy and review of references resulted in 239 publications to screen with 88 full texts assessed and 21 studies included in our final review. VATS had a statistically significant higher lymph node yield in five studies. The reported conversion rates ranged from 0 to 54%. Dense adhesions, bleeding, and difficult anatomy were the most common reported reasons for conversion to open surgeries. The most common complications between both groups were prolonged air leak, arrythmia, and pneumonia. VATS was found to have significantly fewer complications in three papers.

CONCLUSIONS

The current literature supports VATS as safe and feasible for patients with NSCLC after neoadjuvant systemic treatment. Surgeons should remain prepared to convert to open surgeries in those patients with dense adhesions and bleeding risk.

Prognostic Relevance of Negative Lymph Node Count in Resected Stage I-IIIa Small-cell Lung Cancer

OBJECTIVES

The prognostic significance of the negative lymph node (NLN) count has been confirmed in various cancers but not in small-cell lung cancer (SCLC). We aimed to evaluate the correlation between the NLN count and the prognosis of patients with stages I-IIIa SCLC who underwent lobectomy.

METHODS

Data on the clinical characteristics of SCLC patients who underwent lobectomy between 2000 and 2019 were collected from the SEER database and organized based on the X-tile plots to identify the optimal cutoff point for the NLN count. Kaplan-Meier curves and a Cox proportional hazard model were used to evaluate the prognostic factors for overall survival (OS) and lung cancer-specific survival.

RESULTS

Based on the X-tile plot-determined cutoff points of 3 and 7, the participants were grouped into the low (<3), middle (3-7), and high (>7) NLN subgroups for the analysis of OS. Univariable analysis showed that a higher NLN count correlated with more favorable OS and lung cancer-specific survival (both P <0.001). Multivariate analysis demonstrated that, after adjustment for related factors, the NLN count was positively associated with the prognosis and might thus be an independent risk factor for prognosis. Subgroup analyses revealed that, among different LN statuses and varied positive LN counts, the NLN count could predict the prognosis independently.

CONCLUSIONS

Higher NLNs correlated with better survival for patients who underwent lobectomy of stages I-IIIa SCLC. A predictive marker that combines the NLN count with the N stage and positive LN count could provide more prognostic information in SCLC.

Surgical Treatment Outcomes of Patients with Non-Small Cell Lung Cancer and Lymph Node Metastases

This study aimed to investigate the appropriate subgroups for surgery and adjuvant chemotherapy in patients with non-small-cell lung cancer (NSCLC) and nodal metastases. We retrospectively reviewed 210 patients with NSCLC and nodal metastases who underwent surgery and examined the risk factors for poor overall survival (OS) and recurrence-free probability (RFP) using multivariate Cox proportional hazards analysis. Pathological N1 and N2 were observed in 114 (52.4%) and 96 (47.6%) patients, respectively. A single positive node was identified in 102 patients (48.6%), and multiple nodes were identified in 108 (51.4%). Multivariate analysis revealed that vital capacity < 80% (hazard ratio [HR]: 2.678, 95% confidence interval [CI]: 1.483-4.837), radiological usual interstitial pneumonia pattern (HR: 2.321, 95% CI: 1.506-3.576), tumor size > 4.0 cm (HR: 1.534, 95% CI: 1.035-2.133), and multiple-node metastases (HR: 2.283, 95% CI: 1.517-3.955) were significant independent risk factors for poor OS. Tumor size > 4.0 cm (HR: 1.780, 95% CI: 1.237-2.562), lymphatic permeation (HR: 1.525, 95% CI: 1.053-2.207), and multiple lymph node metastases (HR: 2.858, 95% CI: 1.933-4.226) were significant independent risk factors for recurrence. In patients with squamous cell carcinoma (n = 93), there were no significant differences in OS or RFP between those who received platinum-based adjuvant chemotherapy (n = 25) and those who did not (n = 68), at p = 0.690 and p = 0.292, respectively. Multiple-node metastases were independent predictors of poor OS and recurrence. Patients with NSCLC and single-node metastases should be considered for surgery despite N2 disease. Additional treatment with platinum-based adjuvant chemotherapy may be expected, especially in patients with squamous cell carcinoma.

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Overview of Challenges and Opportunities in Revising the Nodal Classification of Lung Cancer

The status of lymph node involvement is a major component of the TNM staging system. The N categories for lung cancer have remained unchanged since the fourth edition of the TNM staging system, partly because of differences in nodal mapping nomenclature, partly because of insufficient details to verify possible alternative approaches for staging. In preparation for the rigorous analysis of the International Association for the Study of Lung Cancer database necessary for the ninth edition TNM staging system, members of the N-Descriptors Subcommittee of the International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee reviewed the evidence for alternative approaches to categorizing the extent of lymph node involvement with lung cancer, which is currently based solely on the anatomical location of lymph node metastasis. We reviewed the literature focusing on NSCLC to stimulate dialogue and mutual understanding among subcommittee members engaged in developing the ninth edition TNM staging system for lung cancer, which has been proposed for adoption by the American Joint Committee on Cancer and Union for International Cancer Control in 2024. The discussion of the range of possible revision options for the N categories, including the pros and cons of counting lymph nodes, lymph node stations, or lymph node zones, also provides transparency to the process, explaining why certain options may be discarded, others deferred for future consideration. Finally, we provide a preliminary discussion of the future directions that the N-Descriptors Subcommittee might consider for the 10th edition and beyond.

Analysis of prognostic factors in pT1-2 N1 lung cancer patients in the light surgical results

Nodal metastasis status is an important parameter affecting the prognosis in lung cancer. Although surgical treatment is possible in most cases of N1 positive non-small cell lung cancer, this group of patients is clinically, radiologically and histologically heterogeneous. The aim of our study is to investigate the prognostic factors affecting survival in patients with pT1-2 N1 who underwent lung resection. From January 2010 to December 2019, patients who underwent lobectomy, bilobectomy or pneumonectomy for pT1-T2 N1 NSCLC in our center were included in the study. The preoperative, intraoperative and postoperative data of the patients were recorded by accessing the patient files and hospital records. The mean follow-up time was 39.8 months. The mean overall survival was 73.8 ± 3.6, and the mean disease-free survival was 67.5 ± 3.8. In multivariate analysis, age, N1 nodal metastasis pattern (occult vs obvious) and histology were found as independent variables affecting survival. In our study, age, histology, and clinical N1 status were found to be independent variables effective on overall survival.

Lymph node metastases outside tumor-bearing lobes and/or segments in non–small cell lung cancer

Objective

Hilar and lung lymph node metastases (N1) are defined as ipsilateral bronchial and intrapulmonary lymph nodes. However, the cleaning standards for ipsilateral bronchial lymph nodes in different lobes and segments within the same lobe in segmentectomy are not clearly defined.

Materials and methods

Sixty-six patients undergoing pulmonary resection for the treatment of lung cancer were evaluated. Intraoperatively visible non-tumor-bearing lobe (NTBL) and post-operatively non-tumor-bearing segment (NTBS) lymph nodes were removed and analyzed. The associations between the NTBL LNs and clinicopathological characteristics were analyzed.

Results

Non-tumor-bearing lobe LNs metastases were found in 8 (12.1%) of the 66 patients, NTBS LNs metastasis were not found (0/13). The presence of NTBL metastases was significantly associated with age (&lt;60 years vs. ≥60 years, P = 0.037), differentiation (Grade 1 well differentiated vs. Grade 2 moderately differentiated vs. Grade 3 poorly differentiated, P = 0.012), CAT-scan-findings of Mediastinal and hilar lymph nodes metastasis (node-positive vs. node-negative, P = 0.022), pN stage (N0 vs. N1 vs. N2, P = 0.003) and p stage (I vs. II vs. III, P = 0.009). Multivariate logistic analysis showed that tumor differentiation (P = 0.048, HR 6.229; 95% CI 1.016–38.181) and pN (P = 0.024, HR 5.099; 95% CI 1.245–20.878) were statistically significant predictors.

Conclusions

Lobar lymph node metastasis of NTBL occurs frequently in patients with NSCLC, but lymph node metastases in NTBS LNs are rare. Advanced age, poorly differentiated and N1 and N2 status of CAT-scan-findings were independent risk factors for the involvement of the NTBL lobar lymph nodes. Although lymph node metastases in NTBS are rare, further investigation of the need to dissect is required.

A Comprehensive Comparison of Different Nodal Subclassification Methods in Surgically Resected Non-Small-Cell Lung Cancer Patients

INTRODUCTION

The revision of the N descriptor in non-small-cell lung cancer has been widely discussed in the past few years. Many different subclassification methods based on number or location of lymph nodes have been proposed for better distinguishing different N patients. This study aimed to systematically collect them and provide a comprehensive comparison among different subclassification methods in a large cohort.

METHOD

Pathological N1 or N2 non-small-cell lung cancer patients undergoing surgical resection between 2005 and 2016 in the Western China Lung Cancer Database were retrospectively reviewed. A literature review was conducted to collect previous subclassification methods. Kaplan-Meier and multivariable Cox analyses were used to examine the prognostic performance of subclassification methods. Decision curve analysis, Akaike's information criterion, and area under the receiver operating curve concordance were also performed to evaluate the standardized net benefit of the subclassification methods.

RESULTS

A total of 1625 patients were identified in our cohort. Eight subclassification methods were collected from previous articles and further grouped into subclassification based on number categories (node number or station number), location categories (lymph node zone or chain) or combination of number and location categories. Subclassification based on combination of lymph node location and number tended to have better discrimination ability in multivariable Cox analysis. No significant superiority among the different subclassification methods was observed in the three statistical models.

CONCLUSION

Subclassification based on the combination of location and number could be used to provide a more accurate prognostic stratification in surgically resected NSCLC and is worth further validation.

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.

Advances in the Treatment of Stage III Non-Small Cell Lung Cancer

Treatment of stage III non-small cell lung cancer (NSCLC) traditionally has involved combinations of chemotherapy, radiation, and surgical resection. Although the multimodality approach remains standard, only a fraction of patients with stage III lung cancer can undergo complete resection, and long-term prognosis remains poor. The PACIFIC trial generated significant enthusiasm when it demonstrated that the programmed death ligand-1 inhibitor, durvalumab, improved survival in patients with unresectable stage III NSCLC after completion of definitive concurrent chemoradiation. This article reviews the indications for traditional therapies in stage III NSCLC and highlights ongoing advances that have led to the incorporation of novel therapeutic agents.

Lobectomy Versus Stereotactic Body Radiotherapy in Healthy Octogenarians With Stage I Lung Cancer

BACKGROUND

Stereotactic body radiation therapy (SBRT) is increasingly being offered for early stage non-small cell lung cancer (NSCLC). We sought to evaluate long-term survival outcomes after lobectomy and SBRT in patients aged 80 years or more with stage I NSCLC.

METHODS

The National Cancer Database was queried for patients with clinical stage IA and IB (size 40 mm or smaller) NSCLC who underwent SBRT or lobectomy. Only patients with no comorbidities were selected. Number of lymph nodes (LN) examined was used to stratify lobectomy patients into 0 LN, 1 to 6 LN, and 7 or more LN. Propensity score analysis was used to adjust treatment groups. Kaplan-Meier and multivariate Cox regression analysis were used for survival analysis.

RESULTS

A total of 8964 patients with stage I NSCLC treated with lobectomy were compared with 286 patients who received SBRT. Using propensity matched pairs, lobectomy (7 LN or more) had significantly improved survival as compared with SBRT (median 74 vs 53.2 months, P < .05); however, no survival differences were observed when 0 LN were sampled (median 53.8 vs 52.3 months, P = .88). In multivariate analysis, lobectomy was associated with significantly improved survival (hazard ratio 0.726; 95% confidence interval; 0.580 to 0.910; P = .005). In addition, age, sex, high grade, and tumor size were independent predictors of survival.

CONCLUSIONS

Among healthy octogenarians with clinical stage I NSCLC who are good surgical candidates, lobectomy offers better survival than SBRT. Adequate LN dissection allows true nodal staging and opportunity for adjuvant treatment when unsuspected nodal metastases are found.

Negative Lymph Node Count Predicts Survival of Resected Non-small Cell Lung Cancer

PURPOSE

The purpose of this study was to explore the association between the negative lymph node (NLN) count and survival, as well as compare the prognostic value of the positive lymph node (PLN) count, lymph node ratio (the PLN count/total lymph nodes examined, LNR), and NLN count in patients with non-small cell lung cancer (NSCLC).

METHODS

We identified patients diagnosed with NSCLC between 2005 and 2011 from the Surveillance, Epidemiology, and End Results database. Outcomes of interest were lung cancer-specific survival (LCSS) and overall survival (OS). Cases were divided into several groups based on the PLN count, NLN count, and LNR. The prognostic significance of the PLN count, NLN count, and LNR models was analyzed with the Kaplan-Meier method and the Cox regression model.

RESULTS

39,959 patients with surgical resection for NSCLC were identified. Univariate analysis demonstrated that a greater count of NLNs was associated with better LCSS (P < 0.001) and OS (P < 0.001). Subgroup analysis showed that the NLN count could predict survival in both node-negative and node-positive patients. Multivariable analysis revealed that the NLN count was an independent prognostic factor for LCSS and OS.

CONCLUSION

The NLN count is an independent prognostic factor of OS and LCSS in patients with NSCLC, as well as the PLN count and LNR. The prognostic value of the PLN count, NLN count, and LNR shows no difference.

Synchronicity of genetic variants between primary sites and metastatic lymph nodes, and prognostic impact in nodal metastatic lung adenocarcinoma

PURPOSE

Nodal positive lung adenocarcinoma includes wide range of survival. Several methods for the classification of nodal-positive lung cancer have been proposed. However, classification considering the impact of targetable genetic variants are lacking. The possibility of genetic variants for the better stratification of nodal positive lung adenocarcinoma was estimated.

METHODS

Mutations of 36 genes between primary sites and metastatic lymph nodes (LNs) were compared using next-generation sequencing. Subsequently, mutations in EGFR and BRAF, rearrangements in ALK and ROS1 were evaluated in 69 resected pN1-2M0 adenocarcinoma cases. Recurrence-free survival (RFS), post-recurrence survival (PRS), and overall survival (OS) were evaluated with respect to targetable variants and tyrosine kinase inhibitor (TKI) therapy after recurrence.

RESULTS

About 90% of variants were shared and allele frequencies were similar between primary and metastatic sites. In 69 pN1-2M0 cases, EGFR/ALK were positive in primary sites of 39 cases and same EGFR/ALK variants were confirmed in metastatic LNs of 96.7% tissue-available cases. Multivariate analyses indicated positive EGFR/ALK status was associated with worse RFS (HR 2.366; 95% CI 1.244-4.500; P = 0.009), and PRS was prolonged in cases receiving TKI therapy (no post-recurrence TKI therapies, HR 3.740; 95% CI 1.449-9.650; P = 0.006). OS did not differ with respect to targetable variants or TKI therapy.

CONCLUSIONS

Cases harbouring targetable genetic variants had a higher risk of recurrence, but PRS was prolonged by TKI therapy. Classification according to the targetable genetic status provides a basis for predicting recurrence and determining treatment strategies after recurrence.

Prognostic Factors of Pathological N1 Non-small Cell Lung Cancer After Curative Resection Without Adjuvant Chemotherapy

BACKGROUND

The aim of this study was to evaluate the outcomes of patients with pathological N1 non-small cell lung cancer who did not receive adjuvant chemotherapy. We attempted to identify those patients for whom adjuvant chemotherapy would be indispensable.

METHODS

Among 132 patients who were diagnosed with pathological N1 lung cancer at a single institution from January 2010 to December 2016 were 32 patients who did not receive adjuvant treatment after curative surgical resection. The surgical and oncological outcomes of these patients were analyzed. Candidate factors for predicting recurrence were analyzed to identify patients at high risk of recurrence.

RESULTS

The median follow-up time for all 32 patients was 1044 days. The 5-year recurrence-free survival (RFS) and disease-specific survival rates of the patients without adjuvant therapy were 50.3% and 77.6%, respectively. By multivariate analysis, tumors with a lepidic growth pattern [hazard ratio (HR) 0.119, p = 0.024] and extralobar lymph node metastasis (HR 6.848, p = 0.015) were significant factors predicting recurrence. The difference between the 5-year RFS rates of patients with tumors with or without a lepidic growth pattern was statistically significant (63.5% vs 40.0%, respectively; p = 0.050). The 5-year RFS rates of patients with intralobar lymph node metastasis versus those with extralobar lymph node metastasis were 63.3% and 18.8%, respectively (p = 0.002).

CONCLUSIONS

Patients with tumors without a lepidic growth pattern or with extralobar lymph node metastasis who do not receive adjuvant chemotherapy have a high recurrence rate after surgery. Therefore, these patients should be encouraged to undergo adjuvant chemotherapy if their overall condition is not a contraindication for chemotherapy.

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.

Hyaluronan-based delivery of therapeutic oligonucleotides for treatment of human diseases

INTRODUCTION

Oligonucleotide therapeutics such as antisense oligonucleotides and siRNA requires chemical modifications and nano-sized carriers to circumvent stability problems in vivo, to reach target tissues, and to overcome tissue and cellular barriers. Hyaluronic acid (HA), already utilized in drug delivery and tissue engineering, possess properties that are useful to solve these problems and achieve full potential of oligonucleotide therapeutics.

AREAS COVERED

Complexes of oligonucleotide therapeutics with HA are discussed in terms of interactions providing the complexes formation and genes targeted by the therapeutics to cure diseases such as cancer, atherosclerosis, liver cirrhosis, and inflammation. The achieved therapeutic effects are rationalized as consequences of biodistribution, cell internalization and endosomal escape provided by HA.

EXPERT OPINION

Design of electrostatic, coordination, and hydrophobic interactions as well as covalent conjugation between oligonucleotide drugs, HA macromolecules and intermediate ligands are crucial for carrier-cargo association and dissociation under different conditions to impart oligonucleotides stability in vivo, their accumulation in diseased organs, cellular uptake, and dissociation in cytoplasm intact. These are the delivery factors that provides eventual complex formation of oligonucleotide therapeutics with their mRNA, microRNA, or protein targets. Elucidation of the impact of structural parameters of oligonucleotide/HA complexes on their therapeutic effect in vivo is important for the future rational design of the delivery agents.

Towards More Structure: Comparing TNM Staging Completeness and Processing Time of Text-Based Reports versus Fully Segmented and Annotated PET/CT Data of Non-Small-Cell Lung Cancer

Results of PET/CT examinations are communicated as text-based reports which are frequently not fully structured. Incomplete or missing staging information can be a significant source of staging and treatment errors. We compared standard text-based reports to a manual full 3D-segmentation-based approach with respect to TNM completeness and processing time. TNM information was extracted retrospectively from 395 reports. Moreover, the RIS time stamps of these reports were analyzed. 2995 lesions using a set of 41 classification labels (TNM features + location) were manually segmented on the corresponding image data. Information content and processing time of reports and segmentations were compared using descriptive statistics and modelling. The TNM/UICC stage was mentioned explicitly in only 6% (n=22) of the text-based reports. In 22% (n=86), information was incomplete, most frequently affecting T stage (19%, n=74), followed by N stage (6%, n=22) and M stage (2%, n=9). Full NSCLC-lesion segmentation required a median time of 13.3 min, while the median of the shortest estimator of the text-based reporting time (R1) was 18.1 min (p=0.01). Tumor stage (UICC I/II: 5.2 min, UICC III/IV: 20.3 min, p < 0.001), lesion size (p < 0.001), and lesion count (n=1: 4.4 min, n=12: 37.2 min, p < 0.001) correlated significantly with the segmentation time, but not with the estimators of text-based reporting time. Numerous text-based reports are lacking staging information. A segmentation-based reporting approach tailored to the staging task improves report quality with manageable processing time and helps to avoid erroneous therapy decisions based on incomplete reports. Furthermore, segmented data may be used for multimedia enhancement and automatization.

Prognostic Impact of Extracapsular Lymph Node Invasion on Survival in Non-small-Cell Lung Cancer: A Systematic Review and Meta-analysis

The extracapsular tumor extension (ECE) of nodal metastasis is an important prognostic factor in different types of malignancies. However, there is a lack of recent data in patients with non-small-cell lung cancer (NSCLC). In addition, the TNM staging system does not include ECE status as a prognostic factor. This systematic review and meta-analysis has been conducted to summarize and pool existing data to determine the prognostic role of ECE in patients with lymph node-positive NSCLC. Two authors performed an independent search in PubMed using a predefined keyword list, without language restrictions with publication date since 1990. Prospective or retrospective studies reporting data on prognostic parameters in subjects with NSCLC with positive ECE or with only intracapsular lymph node metastasis were retrieved. Data were summarized using risk ratios (RR) for the survival with 95% confidence intervals (CI). The data was analyzed using Mix 2 (ref: Bax L: MIX 2.0 - Professional software for meta-analysis in Excel. Version 2.015. BiostatXL, 2016. https://www.meta-analysis-made-easy.com ). There 2,105 studies were reviewed. Five studies covering a total of 828 subjects met the inclusion criteria and were included in the meta-analysis. Two hundred and ninety-eight (35.9%) patients were categorized as ECE+, of whom 54 (18.1%) survived at the end of follow-up. In the ECE-negative group, 257 patients (48.4%) survived by the end of follow-up. Thus, ECE status is associated with a significantly decreased survival rate: pooled RR 0.45 (95% CI 0.35-0.59), Q ₍₄₎ = 4.06, P _value = 0.39, and I ² = 68.00% (95 CI 0.00-79.55%). In conclusion, ECE has a significant impact on survival in NSCLC patients and should be considered in diagnostic and therapeutic decisions in addition to the current TNM staging. Postoperative radiotherapy may be an option in ECE-positive pN1 NSCLC patients.

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 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.

Missed Intrapulmonary Lymph Node Metastasis and Survival After Resection of Non-Small Cell Lung Cancer

BACKGROUND

Pathologic nodal stage is a key prognostic factor for patients with surgically resected lung cancer. We previously described the extent of missed intrapulmonary nodal metastasis in a cohort of patients treated at institutions in metropolitan Memphis, TN. With long-term follow-up, we now quantify the survival impact of missed nodal metastasis.

METHODS

We conducted a prospective cohort study to evaluate inadvertently discarded lymph nodes in re-dissected remnant lung resection specimens from lung cancer patients. Retrieved material was histologically examined and classified as lymph nodes with and without metastasis. Survival information was obtained from hospital cancer registries. We plotted survival distributions with the use of the Kaplan-Meier method and evaluated them with proportional hazards models that controlled for important demographic and clinical factors.

RESULTS

The study included 110 patients who were 54% women and 69% white. Discarded lymph nodes with metastasis were found in 25 patients (23%). Patients with missed lymph node metastasis had an increased risk of death with an unadjusted hazard ratio of 2.0 (p = 0.06) and an adjusted hazard ratio of 1.4 (p = 0.45) compared with patients without missed lymph node metastasis. Patients with more than 2 missed lymph nodes with metastasis had 4.8 times the hazard of death (p = 0.0005) compared with patients without missed lymph node metastasis (adjusted hazard ratio 6.5, p = 0.0001).

CONCLUSIONS

Metastasis to inadvertently discarded intrapulmonary lymph nodes from lung cancer resection specimens was associated with reduced survival. A more rigorous gross dissection protocol for lung cancer resection specimens may provide prognostically useful information.

Systemic delivery of siRNA by hyaluronan-functionalized calcium phosphate nanoparticles for tumor-targeted therapy

In this study, hyaluronan (HA)-functionalized calcium phosphate nanoparticles (CaP-AHA/siRNA NPs) were developed for an injectable and targetable delivery of siRNA, which were prepared by coating the alendronate-hyaluronan graft polymer (AHA) around the surface of calcium phosphate-siRNA co-precipitates. The prepared CaP-AHA/siRNA NPs had a uniform spherical core-shell morphology with an approximate size of 170 nm and zeta potential of -12 mV. The coating of hydrophilic HA improved the physical stability of nanoparticles over one month due to the strong interactions between phosphonate and calcium. In vitro experiments demonstrated that the negatively charged CaP-AHA/siRNA NPs could effectively deliver EGFR-targeted siRNA into A549 cells through CD44-mediated endocytosis and significantly down-regulate the level of EGFR expression. Also, the internalized CaP-AHA/siRNA NPs exhibited a pH-responsive release of siRNA, indicating that the acidification of lysosomes probably facilitated the disassembling of nanoparticles and the resultant ions sharply increased the inner osmotic pressure and thus expedited the release of siRNA from late lysosomes into the cytoplasm. Furthermore, in vivo tumor therapy demonstrated that high accumulation of CaP-AHA/siEGFR NPs in tumor led to a significant tumor growth inhibition with a specific EGFR gene silencing effect after intravenous administration in nude mice xenografted with A549 tumor, along with a negligible body weight loss. These results suggested that the CaP-AHA/siRNA NPs could be an effective and safe systemic siRNA delivery system for a RNAi-based tumor targeted therapy strategy.

Clinical analysis of sixty-four patients with T1aN2M0 stage non-small cell lung cancer who had undergone resection

Background

The aim of this study was to evaluate the clinical features of T1aN2M0 stage non‐small cell lung cancer (NSCLC).

Method

From November 2008 to May 2013, 498 patients with T1a‐stage NSCLC who visited the Shanghai Cancer Center were included in the study. All patients underwent a lobectomy or segmentectomy with systematic nodal resection for primary lung cancer. Analyses of gender, smoking history, primary tumor site, tumor location, tumor size, pathological classification, cancer gene, pleural invasion, number of positive lymph nodes, skip N2, single or multiple station N2, progression‐free survival (PFS), and overall survival (OS) were performed.

Result

There were significant differences in tumor size, tumor size distribution, adenocarcinoma subgroup, and number of positive lymph nodes between patients at T1aN2M0 and T1aN0M0 stages. The most common histology of the T1aN2M0 subgroup was adenocarcinoma. Epidermal growth factor receptor mutations were the most common gene mutation in T1aN2M0 stage NSCLC. There were significant differences in five‐year OS and PFS rates between patients with T1aN2M0, T1aN0M0, and T1aN1M0 stages. Multivariate analyses of mediastinal lymph node metastasis showed that gender, tumor size distribution, and histology type were significant predictive factors. Multivariate analyses of OS and PFS rates in the T1aN2M0 subgroup showed that the number of positive lymph nodes was a significant predictive factor.

Conclusion

Gender, tumor size distribution, and histology type were independent predictors of mediastinal lymph node metastasis in patients with T1a stage. The number of positive lymph nodes was significantly associated with OS and PFS rates in patients with T1aN2M0 stage NSCLC.

Improving the pathologic evaluation of lung cancer resection specimens

Accurate post-operative prognostication and management heavily depend on pathologic nodal stage. Patients with nodal metastasis benefit from post-operative adjuvant chemotherapy, those with mediastinal nodal involvement may also benefit from adjuvant radiation therapy. However, the quality of pathologic nodal staging varies significantly, with major survival implications in large populations of patients. We describe the quality gap in pathologic nodal staging, and provide evidence of its potential reversibility by targeted corrective interventions. One intervention, designed to improve the surgical lymphadenectomy, specimen labeling, and secure transfer between the operating theatre and the pathology laboratory, involves use of pre-labeled specimen collection kits. Another intervention involves application of an improved method of gross dissection of lung resection specimens, to reduce the inadvertent loss of intrapulmonary lymph nodes to histologic examination for metastasis. These corrective interventions are the subject of a regional dissemination and implementation project in diverse healthcare systems in a tri-state region of the United States with some of the highest lung cancer incidence and mortality rates. We discuss the potential of these interventions to significantly improve the accuracy of pathologic nodal staging, risk stratification, and the quality of specimens available for development of stage-independent prognostic markers in lung cancer.

Sublobar resection is equivalent to lobectomy for T1a non-small cell lung cancer in the elderly: a Surveillance, Epidemiology, and End Results database analysis

BACKGROUND

Anatomic lobectomy with mediastinal lymph node dissection is considered the optimal management for early stage non-small cell lung cancer (NSCLC). Limited lung resection may be preferable in the elderly population, who are more likely to have poor pulmonary reserve and multiple comorbidities. Our primary objective was to compare the survival of patients aged ≥ 75 y who underwent sublobar resection or lobectomy for stage IA NSCLC.

MATERIALS AND METHODS

We queried the Surveillance, Epidemiology, and End Results database for patients aged ≥ 75 y who were diagnosed with stage IA NSCLC from 1998-2007. Patients were divided into three groups based on the type of surgery performed (wedge resection, segmentectomy, and lobectomy). Kaplan-Meier analysis and Cox proportional hazard model were used for survival analysis.

RESULTS

A total of 1640 patients were analyzed. Lobectomy was performed in 1051 patients, 119 underwent segmentectomy, and 470 patients had wedge resection. Overall and cancer-specific survival were significantly lower in the wedge resection group as compared with those in lobectomy (P < 0.05). However, for T1a tumors, no significant difference was found in risk adjusted 5-y cancer-specific survival for patients who underwent wedge resection, segmentectomy (hazard ratio, 1.009; 95% confidence interval 0.624-1.631; P = 0.972), or lobectomy (hazard ratio, 0.98; 95% confidence interval, 0.691-1.388; P = 0.908).

CONCLUSIONS

Sublobar resection is not inferior to lobectomy for T1a N0 M0 NSCLC in the elderly and should be considered a viable alternative in this high-risk population.

Are we ready to use biomarkers for staging, prognosis and treatment selection in early-stage non-small-cell lung cancer?

Lung cancer accounts for the majority of cancer-related deaths worldwide. At present, platinum-based therapy represents the standard of care in fit stage II and IIIA non-small cell lung cancer (NSCLC) patients following surgical resection. In advanced disease, personalized chemotherapy and targeted biologic therapy based on histological and molecular tumor profiling have already shown promise in terms of optimizing treatment efficacy. While disease stage is associated with outcome and is commonly used to determine adjuvant treatment eligibility, it is known that a subset of patients with early stage disease experience shorter survival than others with the same clinicopathological characteristics. Improved methods for identifying these individuals, at or near the time of initial diagnosis, may inform the decision to pursue adjuvant therapy options. Among the numerous candidate molecular biomarkers, only few gene-expression profiling signatures provide clinically relevant information, while real-time quantitative polymerase-chain reaction (RT-qPCR) strategy involving relatively small numbers of genes offers a practical alternative with high cross-platform performance. mRNA and/or protein expression levels of excision repair cross-complementation group 1 (ERCC1), ribonucleotide reductase M subunit 1 (RRM1) and breast cancer susceptibility gene 1 (BRCA1) are among the most promising potential biomarkers for early disease and their clinical utility is currently being evaluated in randomized phase II and III clinical trials. This review describes the most promising clinicopathological and molecular biomarkers with predictive and prognostic significance in lung cancer that have been identified through advanced research and which could influence adjuvant and neoadjuvant chemotherapy decisions for operable NSCLC in routine clinical practice.

Classifications of n2 non-small-cell lung cancer based on the number and rate of metastatic mediastinal lymph nodes

BACKGROUND

Subdivisions of N2 non-small-cell lung cancer (NSCLC) cases based on metastatic status of mediastinal and non-mediastinal lymph nodes have been proposed. This study aimed to evaluate N2 disease classification by mediastinal lymph nodes alone.

PATIENTS AND METHODS

We reviewed 187 patients with NSCLC pN1-N2 who were surgically treated to evaluate the proposed classifications: number, rate, nodal zone of metastatic lymph nodes. We evaluated N2 disease classification based on mediastinal lymph nodes alone in 136 pN2 cases.

RESULTS

The number (1-2, 3-5, and 6 ≤) or rate (15%≥, 15%< to 40%>, and 40%≤) classification based on all metastatic lymph nodes was validated by the log-rank test and Cox proportional hazards model. After reclassification by number or rate of metastatic mediastinal lymph nodes alone, a significant difference was maintained among all groups except between the 3-5 and 6 ≤ groups. The 5-year survival rates of the 1-2, 3-5, and 6 ≤ groups were 63.4%, 32.4%, and 18.2%, respectively (1-2 vs. 3-5, P = .015; 3-5 vs. 6 ≤, P = .134). With rate classification, the 5-year survival rates of the 15%≥, 15%-40% (15%< to 40%>), and 40%≤ groups were 56.0%, 27.3%, and 5.04%, respectively (15%≥ vs. 15%-40%, P = .011; 15-40% vs. 40%≤, P = .011). The Spearman's rank correlation coefficient showed a highly significant correlation of metastatic status between mediastinal lymph nodes and all lymph nodes (both P < .001).

CONCLUSION

Classification by number and rate of mediastinal lymph nodes alone enabled subdivision of N2 NSCLC cases. Metastatic status of mediastinal lymph nodes reflects that of all lymph nodes and is prognostic indicators.

Survival analysis of patients with non-small cell lung cancer who underwent surgical resection following 4 lung cancer resection guidelines

Background

To compare survival of patients with non-small cell lung cancer (NSCLC) who underwent surgical resection and lymph node sampling based on guidelines proposed by the American College of Surgeons Oncology Group (ACOSOG), National Comprehensive Cancer Network (NCCN), the OSI Pharmaceutical RADIANT trial, and the International Association for the Study of Lung Cancer (IASLC).

Methods

Medical records of patients with NSCLC who underwent surgical resection from 2001 to 2008 at our hospital were reviewed. Staging was according to the 7^th edition of the AJCC TNM classification of lung cancer. Patients who received surgical resection following the IASLC, ACOSOG, RADIANT or NCCN resection criteria were identified.

Results

A total of 2,711 patients (1803 males, 908 females; mean age, 59.6 ± 9.6 years) were included. Multivariate Cox proportional hazards regression analysis indicated that increasing age, adenosquamous histology, and TNM stage II or III were associated with decreased overall survival (OS). Univariate analysis and log-rank test showed that surgical resection following the guidelines proposed by the IASLC, NCCN, ACOSOG, or RADIANT trial was associated with higher cumulative OS rates (relative to resection not following the guidelines). Multivariate analysis revealed that there was a significant improvement in OS only when IASLC resection guidelines (complete resection) were followed (hazard ratio = 0.84, 95% confidence interval 0.716 to 0.985, P = 0.032).

Conclusions

Surgical resection following the criteria proposed by IASLC, NCCN, ACOSOG, or the RADIANT trial was associated with a higher cumulative OS rate. However, significant improvement in OS only occurred when IASLC resection guidelines were followed.

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

BACKGROUND

It has been proposed that examining a greater number of lymph nodes (LNs) in patients with non-small-cell lung cancer (NSCLC) treated by surgical resection may increase the likelihood of proper staging and affect outcome. Our purpose was to evaluate the interindividual variability and prognostic relevance of the number of LNs harvested during complete pulmonary and mediastinal lymphadenectomy performed for NSCLC.

METHODS

We prospectively collected and retrospectively reviewed the data from 1,095 patients who underwent lung cancer resection in association with systematic lymphadenectomy and pulmonary and mediastinal LN counts from 2004 to 2009. We analyzed the interindividual variability and prognostic impact of the number of LNs on overall survival (OS).

RESULTS

The mean number of harvested pulmonary and mediastinal LNs was 17.4±7.3 (range, 1-65) and was higher in male patients, right lung surgical procedures, lobectomy and pneumonectomy, N2 disease, and pIII stage. The mean number of harvested mediastinal LNs was 10.7±5.6 and was normally distributed (range, 0-49; median, 10). The 5-year survival rate was 53.8%. Overall survival was influenced by the number of involved stations (single-station versus multi-station disease, 5-year survival rates 31.5% versus 16.9%, respectively; p=0.041) but not by the number of harvested LNs, the number of harvested mediastinal LNs, or the number of positive mediastinal LNs.

CONCLUSIONS

After lung cancer resection and complete lymphadenectomy, the number of LNs is subject to normally distributed interindividual variability, with no significant impact on OS. Recommending an optimal number of nodes is therefore arbitrary. Instead, our recommendation is to perform a complete systematic pulmonary and mediastinal lymphadenectomy following established anatomical boundaries.

The impact of a novel lung gross dissection protocol on intrapulmonary lymph node retrieval from lung cancer resection specimens

Although thorough pathologic nodal staging provides the greatest prognostic information in patients with potentially curable non-small cell lung cancer, N1 nodal metastasis is frequently missed. We tested the impact of corrective intervention with a novel pathology gross dissection protocol on intrapulmonary lymph node retrieval. This study is a retrospective review of consecutive lobectomy, or greater, lung resection specimens over a period of 15 months before and 15 months after training pathologist's assistants on the novel dissection protocol. One hundred forty one specimens were examined before and 121 specimens after introduction of the novel dissection protocol. The median number of intrapulmonary lymph nodes retrieved increased from 2 to 5 (P<.0001), and the 75th to 100th percentile range of detected intrapulmonary lymph node metastasis increased from 0 to 5 to 0 to 17 (P=.0003). In multivariate analysis, the extent of resection, examination period (preintervention or postintervention), and pathologic N1 (vs N0) status were most strongly associated with a higher number of intrapulmonary lymph nodes examined. A novel pathology dissection protocol is a feasible and effective means of improving the retrieval of intrapulmonary lymph nodes for examination. Further studies to enhance dissemination and implementation of this novel pathology dissection protocol are warranted.

Size and histologic characteristics of lymph node material retrieved from tissue discarded after routine pathologic examination of lung cancer resection specimens

Redissection of discarded lung resection specimens after routine pathology examination reveals missed lymph node metastasis. We sought to determine if size can be used to grossly select lymph nodes for microscopic examination. This is a prospective cohort study of lymph nodes retrieved from discarded lung resection specimens. The association between size and histologic characteristics of retrieved material was compared by the Wilcoxon-Mann-Whitney test. We retrieved 1094 grossly 'lymph node-like" tissue from 112 remnant lung resection specimens, of which 345 (32%) proved not to be lymph nodes and 71 (9%) of 749 lymph nodes had metastasis. Metastasis was present in discarded nodes in 26 (23%) of 112 patients. The non-lymph node tissue was significantly smaller than lymph nodes (P < .0001); lymph nodes with metastases were significantly larger than those without metastases (P < .0001). However, there was significant size overlap between the 3 types of grossly lymph node-like tissue. Thirty-two percent of nodes with metastasis were less than 1 cm; 15% of patients had at least 1 lymph node less than 1 cm with metastasis. The size difference between lymph nodes with and without metastasis is clinically unhelpful because of broad overlap. Size is insufficiently discriminatory and cannot be relied on to select materials for histologic examination. A third of grossly retrieved material was non-lymph node tissue. This probably occurs during routine pathologic examination and likely contributes to the low N1 lymph node count.

Prognostic significance of the extent of lymph node involvement in stage II-N1 non-small cell lung cancer

BACKGROUND

The non-small cell lung cancer (NSCLC) staging system (published in 2009 in the seventh edition of the cancer staging manuals of the Union for International Cancer Control and American Joint Commission on Cancer) did not include any changes to current N descriptors for NSCLC. However, the prognostic significance of the extent of lymph node (LN) involvement (including the LN zones involved [hilar/interlobar or peripheral], cancer-involved LN ratios [LNRs], and the number of involved LNs) remains unknown. The aim of this report is to evaluate the extent of LN involvement and other prognostic factors in predicting outcome after definitive surgery among Chinese patients with stage II-N1 NSCLC.

METHODS

We retrospectively reviewed the clinicopathologic characteristics of 206 patients with stage II (T1a-T2bN1M0) NSCLC who had undergone complete surgical resection at Shanghai Chest Hospital from June 1999 to June 2009. Overall survival (OS) and disease-free survival (DFS) were compared using Kaplan-Meier statistical analysis. Stratified and Cox regression analyses were used to evaluate the relationship between the LN involvement and survival.

RESULTS

Peripheral zone LN involvement, cancer-involved LNR, smaller tumor size, and squamous cell carcinoma were shown to be statistically significant indicators of higher OS and DFS by univariate analyses. Visceral pleural involvement was also shown to share a statistically significant relationship with DFS by univariate analyses. Multivariate analyses showed that tumor size and zone of LN involvement were significant predictors of OS.

CONCLUSIONS

Zone of N1 LN, LN ratios, and tumor size were found to provide independent prognostic information in patients with stage II NSCLC. This information may be used to stratify patients into groups by risk for recurrence.

Differential prognostic significance of extralobar and intralobar nodal metastases in patients with surgically resected stage II non-small cell lung cancer

OBJECTIVES

We sought to determine the prognostic significance of extralobar nodal metastases versus intralobar nodal metastases in patients with lung cancer and pathologic stage N1 disease.

METHODS

A retrospective review of a prospectively maintained lung resection database identified 230 patients with pathologic stage II, N1 non-small cell lung cancer from 1997 to 2011. The surgical pathology reports were reviewed to identify the involved N1 stations. The outcome variables included recurrence and death. Univariate and multivariate analyses were performed using the R statistical software package.

RESULTS

A total of 122 patients had extralobar nodal metastases (level 10 or 11); 108 patients were identified with intralobar nodal disease (levels 12-14). The median follow-up was 111 months. The baseline characteristics were similar in both groups. No significant differences were noted in the surgical approach, anatomic resections performed, or adjuvant therapy rates between the 2 groups. Overall, 80 patients developed recurrence during follow-up: 33 (30%) of 108 in the intralobar and 47 (38%) of 122 in the extralobar cohort. The median overall survival was 46.9 months for the intralobar cohort and 24.4 months for the extralobar cohort (P < .001). In a multivariate Cox proportional hazard model that included the presence of extralobar nodal disease, age, tumor size, tumor histologic type, and number of positive lymph nodes, extralobar nodal disease independently predicted both recurrence-free and overall survival (hazard ratio, 1.96; 95% confidence interval, 1.36-2.81; P = .001).

CONCLUSIONS

In patients who underwent surgical resection for stage II non-small cell lung cancer, the presence of extralobar nodal metastases at level 10 or 11 predicted significantly poorer outcomes than did nodal metastases at stations 12 to 14. This finding has prognostic importance and implications for adjuvant therapy and surveillance strategies for patients within the heterogeneous stage II (N1) category.

Towards optimal pathologic staging of resectable non-small cell lung cancer

Pathologic nodal staging is the most accurate means of determining prognosis of patients with resectable non-small cell lung cancer (NSCLC), but confusion prevails about the optimal pre-operative and surgical lymph node examination procedures for candidates of curative-intent resection. The landmark American College of Surgeons Oncology Group Z0030 trial revealed no difference in the survival of patients with clinical T1 or T2, N0 or N1 (hilar node-negative), M0 NSCLC who either had a fastidious, pre-defined systematic hilar and mediastinal lymph node sampling procedure, or who received a complete mediastinal lymph node dissection. We place the results of this major trial into a contemporary clinical practice context, and discuss problems associated with apparent misunderstanding of the lessons from this trial, especially in light of evidence of prevailing sub-optimal nodal examination practices. We also discuss evolving knowledge about the origin of the quality gap in pathologic nodal staging and the emerging literature on corrective interventions.

Dual intervention to improve pathologic staging of resectable lung cancer

BACKGROUND

Detection of lymph node metastasis is of immense prognostic value in patients with resectable non-small cell lung cancer (NSCLC), but routine pathologic nodal staging is suboptimal. To determine the impact on the rate of detection of nodal metastasis, we tested dual intervention with a prelabeled lymph node specimen collection kit to improve intraoperative node dissection and a fastidious gross dissection of the lung resection specimen for intrapulmonary lymph nodes.

METHODS

We matched dual-intervention cases with controls staged using standard surgical specimen collection and pathologic examination protocols. Controls were hierarchically matched for extent of resection, laterality, surgeon, pathologist, and T stage. All statistical comparisons were made with exact conditional logistic regression, to account for the matched case-control design.

RESULTS

One hundred dual-intervention cases were matched with 100 controls. The dual interventions resulted in approximately a 3-fold increase in the number of lymph nodes examined and the number of lymph nodes with metastasis detected; they also increased the proportion of patients with lymph node metastasis from 21% to 35% (p = 0.02). There were strong trends toward higher aggregate stage distribution, and eligibility for postoperative adjuvant chemotherapy in the dual-intervention cases.

CONCLUSIONS

The combination of interventions improved the thoroughness and accuracy of pathologic nodal staging. A prospective randomized trial to test the survival impact of the dual interventions is warranted.