Prognostic variability among nonsmall cell lung cancer patients with pathologic N1 lymph node involvement

Validation Study for the N Descriptor of the Newly Proposed Ninth Edition of the TNM Staging System Proposed by the International Association for the Study of Lung Cancer

INTRODUCTION

The aim of this study was to validate the discriminatory ability and clinical utility of the N descriptor of the newly proposed ninth edition of the TNM staging system for lung cancer in a large independent cohort.

METHODS

We retrospectively analyzed patients who underwent curative surgery for NSCLC between January 2004 and December 2019. The N descriptor of patients included in this study was retrospectively reclassified based on the ninth edition of the TNM classification. Survival analysis was performed using the log-rank test and Cox proportional hazard model to compare adjacent N categories.

RESULTS

A total of 6649 patients were included in this study. The median follow-up period was 54 months. According to the newly proposed ninth edition N classification, 5573 patients (83.8%), 639 patients (9.6%), 268 patients (4.0%), and 169 patients (2.5%) were classified into the clinical N0, N1, N2a, and N2b categories and 4957 patients (74.6%), 744 patients (11.2%), 567 patients (8.5%), and 381 patients (5.7%) were classified into the pathologic N0, N1, N2a, and N2b categories, respectively. The prognostic differences between all adjacent clinical and pathologic N categories were highly significant in terms of both overall survival and recurrence-free survival.

CONCLUSIONS

We validated the clinical utility of the newly proposed ninth edition N classification for both clinical and pathologic stages in NSCLC. The new N classification revealed clear prognostic separation between all categories (N0, N1, N2a, and N2b) in terms of both overall survival and recurrence-free survival.

The number of metastatic lymph nodes is more predictive of prognosis than location-based N stage for nonsmall cell lung cancer: a retrospective cohort study

BACKGROUND

The eighth edition of nodal classification is defined only by the anatomical location of metastatic lymph nodes and has limited prognostic discrimination power. The authors aimed to evaluate the prognostic significance and discriminatory capability of the number of metastatic lymph nodes (nN) in resected nonsmall cell lung cancer.

MATERIALS AND METHODS

Patients with stage IA to IIIB resected nonsmall cell lung cancer between 1 January 2009 and 31 December 2013 were analyzed as a Chinese cohort. The optimal thresholds for the nN classification were determined by the X-tile. The receiver operating characteristic curve, net reclassification improvement and standardized net benefit calculated by decision curve analysis was estimated to quantify the nN classification's performance in prognostic stratification. External validation in the surveillance, epidemiology, and end results database was performed to test the robustness of the nN classification.

RESULTS

Both cohorts showed a stepwise prognosis deterioration with increasing nN. One to three, four to six, and more than six were selected as optimal thresholds of nN classification in the Chinese cohort, which included 4432 patients, then validated in the SEER cohort ( n =28 022 patients). Multivariate Cox analysis showed the nN classification was an independent predictive factor for overall survival in both cohorts (Chinese cohort and SEER cohort: N 0 vs. N 1-3 , P <0.001; N 0 vs. N 3-6 , P <0.001; N 0 vs. N >6 , P <0.001). And prognostic discriminatory capability was improved in the nN classification compared with location-based N classification [5-year NRI score, 0.106 (95% CI: 0.049-0.132) and 5-year time-independent AUC, 0.593 (95% CI: 0.560-0.625) vs. 0.554 (95% CI: 0.520-0.588), P <0.001].

CONCLUSIONS

The nN classification tended to be a superior prognostic indicator than the location-based N classification. The number of metastatic lymph nodes should be considered in the future revision of the TNM system.

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.

A multi-kernel and multi-scale learning based deep ensemble model for predicting recurrence of non-small cell lung cancer

Predicting recurrence in patients with non-small cell lung cancer (NSCLC) before treatment is vital for guiding personalized medicine. Deep learning techniques have revolutionized the application of cancer informatics, including lung cancer time-to-event prediction. Most existing convolutional neural network (CNN) models are based on a single two-dimensional (2D) computational tomography (CT) image or three-dimensional (3D) CT volume. However, studies have shown that using multi-scale input and fusing multiple networks provide promising performance. This study proposes a deep learning-based ensemble network for recurrence prediction using a dataset of 530 patients with NSCLC. This network assembles 2D CNN models of various input slices, scales, and convolutional kernels, using a deep learning-based feature fusion model as an ensemble strategy. The proposed framework is uniquely designed to benefit from (i) multiple 2D in-plane slices to provide more information than a single central slice, (ii) multi-scale networks and multi-kernel networks to capture the local and peritumoral features, (iii) ensemble design to integrate features from various inputs and model architectures for final prediction. The ensemble of five 2D-CNN models, three slices, and two multi-kernel networks, using 5 × 5 and 6 × 6 convolutional kernels, achieved the best performance with an accuracy of 69.62%, area under the curve (AUC) of 72.5%, F1 score of 70.12%, and recall of 70.81%. Furthermore, the proposed method achieved competitive results compared with the 2D and 3D-CNN models for cancer outcome prediction in the benchmark studies. Our model is also a potential adjuvant treatment tool for identifying NSCLC patients with a high risk of recurrence.

Updated Prognostic Factors in Localized NSCLC

Lung cancer is the most common cause of cancer mortality worldwide, and non-small cell lung cancer (NSCLC) represents 80% of lung cancer subtypes. Patients with localized non-small cell lung cancer may be considered for upfront surgical treatment. However, the overall 5-year survival rate is 59%. To improve survival, adjuvant chemotherapy (ACT) was largely explored and showed an overall benefit of survival at 5 years < 7%. The evaluation of recurrence risk and subsequent need for ACT is only based on tumor stage (TNM classification); however, more than 25% of patients with stage IA/B tumors will relapse. Recently, adjuvant targeted therapy has been approved for EGFR-mutated resected NSCLC and trials are evaluating other targeted therapies and immunotherapies in adjuvant settings. Costs, treatment duration, emergence of resistant clones and side effects stress the need for a better selection of patients. The identification and validation of prognostic and theranostic markers to better stratify patients who could benefit from adjuvant therapies are needed. In this review, we report current validated clinical, pathological and molecular prognosis biomarkers that influence outcome in resected NSCLC, and we also describe molecular biomarkers under evaluation that could be available in daily practice to drive ACT in resected NSCLC.

Anatomical location and number of metastatic lymph nodes for prognosis of non-small cell lung cancer

Background

The nodal classification of lung cancer is determined by the anatomical location of metastatic lymph nodes (mLNs). However, prognosis can be heterogeneous at the same nodal stage, and the current classification system requires improvement. Therefore, we investigated the correlation between the number of mLNs and prognosis in patients with non-small cell lung cancer.

Methods

Using a multicenter database in Japan, we retrospectively reviewed the records of patients who underwent complete resection for lung cancer between 2010 and 2016. Kaplan-Meier curves were used to determine recurrence-free and overall survival. Multivariate analyses were performed using the Cox proportional hazards model.

Results

We included 1,567 patients in this study. We could show a statistically significant difference in recurrence-free survival between pN2 patients with 1 mLN and pN2 patients with ≥2 mLNs (P=0.016). Patients with a combination of pN1 (≥4 mLNs) plus pN2 (1 mLN) had a poorer prognosis than pN1 patients (1-3 mLNs) (P=0.061) and a better prognosis than pN2 patients (≥2 mLNs) patients (P=0.007). Multivariate analysis showed that the number of mLNs was independently associated with cancer recurrence in patients with pN1 and pN2 disease (P=0.034 and 0.018, respectively).

Conclusions

Nodal classification that combines anatomical location and the number of mLNs may predict prognosis more accurately than the current classification system. Our study provides the concept that supports the subdivision of nodal classification in the upcoming revision of the tumor, node, and metastasis staging system.

Prognostic significance of the N1 classification pattern: a meta-analysis of different subclassification methods

OBJECTIVES

The number of positive lymph node stations has been viewed as a subclassification in the N1 category in the new revision of tumour node metastasis (TNM) staging. However, the survival curve of these patients overlapped with that of some patients in the N2 categories. Our study focused on the prognostic significance of different subclassifications for N1 patients.

METHODS

We systematically searched PubMed, Ovid, Web of Science and the Cochrane Library on the topic of N1 lymph node dissection. Hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) were used to assess the prognostic significance of N1 metastases. I2 statistics was used to evaluate heterogeneity among the studies: If significant heterogeneity existed (P ≤ 0.10; I2 >50%), a random effect model was adopted.

RESULTS

After a careful investigation, a total of 17 articles were included in the analysis. The results showed that patients with non-small-cell lung cancer with multistation N1 disease have worse survival compared with those with single-station N1 disease (HR 1.53, 95% CI 1.32-1.77; P < 0.001; I2 = 5.1%). No significant difference was observed between groups when we assessed the number of positive lymph nodes (single or multiple) (HR 1.25, 95% CI 0.96-1.64; P = 0.097; I2 = 72.5%). Patients with positive hilar zone lymph nodes had poorer survival than those limited to the intrapulmonary zone (HR 1.80, 95% CI 1.57-2.07; P < 0.001; I2 = 0%). A subgroup analysis conducted according to the different validated lymph node maps showed a stable result.

CONCLUSIONS

Our result confirmed the prognostic significance of the N1 subclassification based on station number. Meanwhile, location-based classifications, especially zone-based, were also identified as prognostically significant, which may need further confirmation and validation in the staged population.

Application of N Descriptors Proposed by the International Association for the Study of Lung Cancer in Clinical Staging

Background Patients with N1 or N2 non-small cell lung cancer exhibit prognostic heterogeneity. To refine the current N staging system, new N stages were proposed by the International Association for the Study of Lung Cancer. However, those proposed new N stages have not been validated. Purpose To evaluate the prognostic performance of the proposed N descriptors for clinical staging. Materials and Methods Participants with non-small cell lung cancer without distant metastasis from January 2010 to December 2014 were retrospectively included. Each patient's clinical N (cN) stage was assigned to one of seven categories (cN0, cN1a, cN1b, cN2a1, cN2a2, cN2b, cN3). The 5-year overall survival rates were estimated with the Kaplan-Meier method. The adjusted hazard ratios (HRs) and their 95% CIs were estimated by using a multivariable Cox proportional hazard model. Ad hoc analyses according to lymph node (LN) size were performed. Results A total of 1271 patients (median age, 66 years; interquartile range, 59-73 years; 812 men) were included. The 5-year overall survival rates were 77.3%, 53.7%, 36.0%, 29.2%, 34.4%, 18.0%, and 12.4% for stages cN0, cN1a, cN1b, cN2a1, cN2a2, cN2b, and cN3, respectively. Patients with cN2b disease had a worse prognosis than patients with cN2a disease (HR, 1.53; 95% CI: 1.06, 2.22; P = .02). There was no prognostic difference between cN1b and cN1a (HR, 1.13; 95% CI: 0.61, 2.09; P = .71); however, there was a difference between cN1 subgroups when stratified by LN size (≥2 cm; HR, 2.26; 95% CI: 1.16, 4.44; P = .02). Within cN2a disease, there were no differences between cN2a1 and cN2a2 (HR, 0.98; 95% CI: 0.61, 1.56; P = .93) or between subgroups according to LN size (HR, 0.74; 95% CI: 0.40, 1.37; P = .34). Conclusion A survival difference was observed between single- and multistation involvement among cN2 disease. The number of involved lymph node stations in patients with cN1 disease and the presence of skip metastasis in patients with cN2 disease were not associated with survival differences. © RSNA, 2021 Online supplemental material is available for this article.

Number of metastatic lymph nodes and zones as prognostic factors in non-small-cell lung cancer

OBJECTIVES

Characterizing pathological nodes (pNs) by location alone is sometimes inadequate as patients with pN1 or pN2 non-small-cell lung cancer (NSCLC) show prognostic heterogeneity. We aimed to assess the relationship of the number of metastatic lymph nodes (LNs) and zones with prognosis in NSCLC patients.

METHODS

We analysed 1393 patients who underwent lobectomy with mediastinal LN dissection for NSCLC at the Osaka International Cancer Institute between January 2006 and December 2015. Patients were classified into 3 groups according to the number of LNs: n1-3, n4-6 and n7-. We investigated the relationship of prognosis with the number of metastatic LNs and metastatic zones.

RESULTS

In the multivariable analyses, the number of metastatic LNs and zones were not independent factors for overall survival or recurrence-free survival in patients with pN1 disease after adjustment for age, sex, tumour histology and tumour diameter. However, n4-6 (ref. n1-3) was an independent prognostic factor for overall survival [hazard ratio (HR) 4.148, P < 0.001] in those with pN2 disease. There were no significant differences in overall survival and recurrence-free survival between pN1 (HR 0.674, P = 0.175) and pN2n1-3 disease (HR 1.056, P = 0.808). Moreover, patients with pN2 disease with a higher number of metastatic zones had a poor prognosis for recurrence-free survival [3 zones (ref. 1): HR 1.774, P = 0.051, and 4 zones (ref. 1): HR 2.173, P < 0.047].

CONCLUSIONS

The number of metastatic LNs and metastatic zones were useful prognostic factors in NSCLC patients. The findings could help in establishing a new pN classification.

Prognostic impact of extranodal extension in patients with pN1-N2 lung adenocarcinoma

PURPOSE

Lymph node involvement is one of the important prognostic factors of patients with lung adenocarcinoma. In the tumor, node, and metastasis classification, lymph node involvement is categorized only according to the anatomical station and not the involvement pattern. The aim of this study was to investigate which morphological pattern of lymph node involvement affects the prognosis of patients with surgically resected lung adenocarcinoma.

METHODS

We retrospectively reviewed 168 consecutive patients who underwent surgical resection for primary lung adenocarcinoma with lymph node involvement. The morphological patterns of lymph node involvement (tumor area, number of metastatic lymph nodes, presence of necrosis, and extranodal extension) were histologically examined. The relationships between the patterns of lymph node involvement, clinicopathological features, and survival of patients were analyzed.

RESULTS

Eighty patients had N1 disease, and 88 patients had N2 disease. Univariate analysis revealed that invasive size, history of adjuvant chemotherapy, and presence of extranodal extension were significant prognostic factors in N1 patients, and vascular invasion, pleural invasion, presence of epidermal growth factor receptor mutation, history of adjuvant chemotherapy, and presence of extranodal extension were significant prognostic factors in N2 patients. In a bivariate analysis including other clinicopathological factors and patterns of lymph node involvement, the presence of extranodal extension was significantly associated with poor 3-year overall and recurrence-free survival of both N1 and N2 patients.

CONCLUSIONS

In patients who underwent surgical resection for lung adenocarcinoma with lymph node involvement, the extranodal extension was the most important prognostic factor among morphological lymph node involvement patterns.

Recommended Change in the N Descriptor Proposed by the International Association for the Study of Lung Cancer: A Validation Study

INTRODUCTION

The International Association for the Study of Lung Cancer recently proposed a new N descriptor by combining the location of metastatic lymph nodes (LNs), nN (single-station versus multiple-station), and absence versus presence of skip metastasis as pN1a, pN1b, pN2a1, pN2a2 and pN2b. This study aimed to evaluate the discriminatory ability and prognostic performance of the proposed N descriptor in a large independent NSCLC cohort.

METHODS

We analyzed 1228 patients who underwent major pulmonary resection for pathological N1 or N2 NSCLC between 2004 and 2014. Survival analysis using the Cox proportional hazard model was performed to assess the prognostic significance of the N descriptor.

RESULTS

From 2004 to 2014, a total of 7437 patients were operated on for NSCLC. Patients pathologically confirmed as having N1 (n = 732) or N2 (n = 496) disease after surgery were included. The median total number of dissected LNs was 24 (range 10-83), and the median number of involved LNs was 2 (range 1-40). The 5-year overall survival rates were 62.6%, 57.0%, 64.7%, 48.4%, and 42.8% for stages N1a, N1b, N2a1, N2a2, and N2b, respectively. Analysis of overall and recurrence-free survival revealed that N2a1 is not sufficiently distinguished from N1a and N1b. In terms of overall survival, N1b is not sufficiently distinguished from N2a2.

CONCLUSION

On the basis of the N descriptor proposed by the International Association for the Study of Lung Cancer, some of the prognostic implications of the five groups overlapped. It would be better to classify similar prognostic groups into three or four groups to divide the group. A large-scale prospective study is needed to validate these N descriptors.

Detection of lymph node metastasis in lung cancer patients using a one-step nucleic acid amplification assay: a single-centre prospective study

BACKGROUND

The use of one-step nucleic acid amplification (OSNA) allows for lymph node (LN) metastasis to be detected rapidly and accurately. We conducted a prospective single-centre clinical trial to evaluate OSNA assay in detecting LN metastasis of lung cancer.

PATIENTS AND METHODS

A total of 705 LNs from 160 patients with clinical stage IA to IVA lung cancer were included in this study. The LNs were divided and submitted to routine histological diagnosis and OSNA assay and the results were compared. We also examined keratin 19 expression of different histological types lung primary tumours.

RESULTS

When the cut-off value was set to 250 copies/µl, the concordance rate between the two methods was 96.17% and the sensitivity 97.14%. Discordant results were observed in 27 LNs of 21 patients. Most of these discordant results were molecular micrometastasis expressing a very low number of copies with negative histology. Most thoracic tumours were positive for keratin 19.

CONCLUSIONS

Our data show that the OSNA assay might be a useful and sensitive method to diagnose LN metastasis in lung cancer and could be applied to intraoperative decision-making in personalised lung cancer surgery based on LN status and a more accurate staging of patients.

Prognostic Impact of the Number of Metastatic Lymph Nodes on the Eighth Edition of the TNM Classification of NSCLC

INTRODUCTION

Current nodal staging of NSCLC is defined only by anatomical location of lymph nodes (LNs). The aim of this study is to investigate prognostic impacts of the number of metastatic LNs by stratifying the present N classification.

METHODS

We analyzed 1989 patients with NSCLC who underwent complete resection by lobectomy or pneumonectomy involving dissection of the hilar and mediastinal LNs from 2003 to 2012. We classified patients according to the number of metastatic nodes and stations and their current category of metastatic LNs. We analyzed the overall survival in each group and assessed the survival impact of the combination of them.

RESULTS

In the multivariate analyses of all patients, pathological N1 (pN1) (reference [ref.] pN2) and single-node metastasis (ref. multiple-node) were independent prognostic factors whereas single-station metastasis (ref. multiple-station) was not. In the respective multivariate analyses of pN1 and pN2 disease, multiple-node metastasis (ref. single-node) was an independent prognostic factor in pN1 disease (hazard ratio: 1.41, p = 0.04), but not in pN2 disease. Investigation for other boundaries of a number of metastatic LNs of three or more (ref. one to two), four or more (ref. one to three), and five or more (ref. one to four) found that all of them were independent prognostic factors in both pN1 and pN2 diseases.

CONCLUSIONS

The number of metastatic LNs had a strong impact on survival in addition to the current pN classification. To clarify its prognostic impact, further study is needed in other datasets including patients treated by nonsurgical modalities.

Prognostic value of lymph node ratio in patients with pathological N1 non-small cell lung cancer: a systematic review with meta-analysis

BACKGROUND

Non-small cell lung cancer (NSCLC) patients with N1 disease have variable outcomes, and additional prognostic factors are needed. The number of positive lymph nodes (LNs) has been proposed as a prognostic indicator. However, the number of positive LNs depends on the number of LNs examined from the resection specimen. The lymph node ratio (LNR) can circumvent this limitation. The purpose of this study is to evaluate LNR as a predictor of survival and recurrence in patients with pathologic N1 NSCLC.

METHODS

We systematically reviewed studies published before March 17, 2016, on the prognostic value of LNR in patients with pathologic N1 NSCLC. The hazard ratios (HRs) and their 95% confidence intervals (CIs) were used to combine the data. We also evaluated heterogeneity and publication bias.

RESULTS

Five studies published between 2010 and 2014 were eligible for this systematic review with meta-analysis. The total number of patients included was 6,130 ranging from 75 to 4,004 patients per study. The combined HR for all eligible studies evaluating the overall survival (OS) and disease-free survival (DFS) of N1 LNR in patients with pathologic N1 NSCLC was 1.53 (95% CI: 1.22-1.85) and 1.64 (95% CI: 1.19-2.09), respectively. We found no heterogeneity and publication bias between the reports.

CONCLUSIONS

LNR is a worthy predictor of survival and cancer recurrence in patients with pathological N1 NSCLC.

Prognostic impact of bulky swollen lymph nodes in cN1 non-small cell lung cancer patients

OBJECTIVE

The aim of this study was to analyze clinicopathological backgrounds and prognosis of clinical N1 non-small cell lung cancer and clarify the difference between bulky and non-bulky cN1 diseases.

METHODS

We reviewed 110 patients with completely resected cN1 non-small cell lung cancer and examined the prognostic impact of lymph node size. We classified the swollen lymph nodes into two groups based on their size on chest computed tomography: short-axis diameter ≥20 mm (=bulky group) or <20 mm (=non-bulky group).

RESULTS

The bulky group consisted of 10 patients, and the non-bulky group comprised 100 patients. There was no significant difference in the upstaging rate to pathological N2 between the bulky and non-bulky groups (31% vs. 30%; P = 0.63). The 5-year recurrence-free survival rate and 5-year overall survival rate of both groups did not differ significantly (P = 0.36, P = 0.30, respectively). Our results suggested the possibility that the size of the swollen lymph nodes had no impact on the prognosis in cN1 non-small cell lung cancer patients. In comparison of surgical procedure, pneumonectomy was performed in the bulky group more frequently than the non-bulky group (70% vs. 19%; P < 0.01).

CONCLUSIONS

Bulky cN1 disease was not different from non-bulky disease in the prognosis and the upstaging rate to pN2. Curative resection should be indicated to resectable bulky cN1 disease as with non-bulky disease, with careful pre-operative evaluation and preparation considering the possibility of pneumonectomy.

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.

Lymphatic microvessel density combined with CT used in the diagnosis of mediastinal and hilar lymph node metastasis of non-small cell lung cancer

BACKGROUND AND AIMS

Lymphatic microvessel density (LMVD) has been demonstrated to correlate with tumor metastasis. The purpose of this study is to determine whether the criteria combining LMVD with computed tomography (CT) could improve the diagnostic accuracy of lymph node (LN) metastasis in non-small cell lung cancer (NSCLC).

METHODS

Ninety four patients with NSCLC who had chest CT scans preoperatively and LMVD tested by immunohistochemistry postoperatively were randomized into two groups: the training set (n = 66) and the test set (n = 28). Cut-off point of LMVD was selected to separate the LN metastasis-predictive positive and negative groups. On the basis of LMVD levels, chest CTs of the training set were re-analyzed and hypothetical criteria for LN metastasis diagnosis were established. Diagnostic characteristics for LN metastasis were tested by using the combined criteria in the test set as compared to those of CT alone.

RESULTS

There was a significantly positive correlation between LMVD and LN metastasis (p <0.01). For sensitivity, specificity, positive predictive value (PPV) and negative predictive values (NPV), accuracy was 67, 81, 75, 81 and 79% for the combined criteria, respectively. Diagnostic efficacy of the combined criteria was significantly higher than that of CT only (p <0.05).

CONCLUSIONS

Diagnosis of LN metastasis using a combination of LMVD and CT is superior to the CT-only diagnosis. In future clinical trials, it is necessary to evaluate the efficacy of adjuvant therapy for the selection of patients according to the combined criteria.

Which is the better prognostic factor for resected non-small cell lung cancer: the number of metastatic lymph nodes or the currently used nodal stage classification?

INTRODUCTION

This retrospective study was conducted to evaluate the prognostic significance of the number of metastatic lymph nodes (nN) in resected non-small cell lung cancer (NSCLC) in comparison with the currently used pathologic nodal (pN) category in the staging system.

METHODS

A total of 1659 patients who underwent potentially curative resection for NSCLC from 2000 to 2006 were included in this study. The association between the nN and survival was explored, and the results were compared with those using the location-based pN stage classification.

RESULTS

The patients were divided into four categories according to the number of metastatic nodes: nN0, absence of metastatic nodes; nN1, metastasis in one to two nodes; nN2, metastasis in three to six nodes; and nN3, metastasis in seven or more nodes. The 5-year overall survival for nN0, nN1, nN2, and nN3 was 89.2%, 65.1%, 42.1%, and 22.4%, respectively (p < 0.001). The nN category could be used to subdivide pN1 and pN2 patients into two (nN1 and nN2) and three (nN1, nN2, and nN3) prognostically distinct subgroups, respectively. Multivariate analysis showed the nN category was an independent prognostic factor for resected NSCLC. The difference in overall survival between pN1 and pN2 was not significant (55.4% versus 47.8%, p = 0.245). Patients in each nN category could not be subdivided into different prognostic subgroups according to the pN classification.

CONCLUSIONS

The nN category in this study was shown to be a better prognostic determinant than the location-based pN stage classification.

Gene immunotherapy for non-small cell lung cancer

Historically, limited results have been observed with immunity in non-small cell lung cancer (NSCLC). In the last 5 years, however, several immune-stimulating products have demonstrated enhancement of tumor antigen recognition through activation of dendritic cell-involved processes. Moreover, clinical benefit has been demonstrated in subsets of patients, justifying ongoing phase III investigation. Results of key gene immunotherapies being tested in NSCLC are reviewed. Preliminary results in advanced NSCLC suggest evidence of well-tolerated immune activation with suggested evidence of clinical benefit with respect to survival and response.