Factors determining survival in resected N2 lung cancer

Analysis of clinical features and prognostic factors of lung cancer patients: A population-based cohort study

OBJECTIVES

This paper analyses clinical features of lung cancer patients and discusses factors influencing the lung cancer occurrence and prognosis.

METHODS

Patients diagnosed with lung cancer from 1975 to 2016 are analysed based on SEER database. The samples are divided into groups according to the number of positive lymph nodes of LN > 3 and LN ≤ 3. Univariate and multivariate Cox risk models are performed. After balancing the clinicopathological features of the two groups with the propensity score matching (PSM) method, the survival rates of the two groups are compared.

RESULTS

A total of 30 864 patients are included in this study. Kaplan-Meier curves show that the survival rate of patients with LN ≤ 3 is higher than that of patients with LN > 3 (P < 0.0001). Univariate and multivariate Cox proportional risk model analysis suggests that the number of lymph nodes is an independent prognostic risk factor for lung cancer. LN ≤ 3 group shows better OS (HR2.066; 95% CI 1.941-2.199, P < 0.01) and better CSS (HR 2.461; 95% CI 2.304-2.629, P < 0.01). In addition, age at diagnosis, gender, Laterality, Derived AJCC T, 7th ed (2010-2015), Derived AJCC N, 7th ed (2010-2015) and Derived AJCC M, 7th ed, (2010-2015) have also been proved to be potential prognostic factors. A total of 1,851 pairs of patients are screened after 1:1 PSM matching. Patients with LN ≤ 3 have significant improvements in OS and CSS (HR 1.09; 95% CI 1.001-1.187, P < 0.05 and HR 1.127; 95% CI 1.03-1.232, P < 0.001).

CONCLUSION

The number of lymph nodes is an independent prognostic risk factor for lung cancer. Patients with fewer lymph node positives have a better survival prognosis than patients with more lymph nodes.

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.

State of the art in surgery for early stage NSCLC-does the number of resected lymph nodes matter?

Surgery is the treatment of choice in patients with early stage NSCLC. However, the results remain poor in these patients. Lymph node involvement is the main prognostic factor in patients with NSCLC, but there is still no clear definition of the number of nodes required to consider a lymphadenectomy as complete. Although there is no defined minimum number of lymph nodes required for a complete lymphadenectomy, there are some recommendations to perform this procedure, published by different scientific societies. Current practice in thoracic surgery regarding lymphadenectomy, differs on some points from the guidelines recommendations, with data regarding patients with no mediastinal assessment between 30-45% according to some of the published data. Different studies have probed the fact that the probability of finding a positive node increases with the number of lymph nodes analyzed. Therefore, a complete lymphadenectomy provides proper staging, which helps to identify the patient's real prognosis. Several nonrandomized studies and retrospective series have shown that survival increases in the group of patients with a higher number of lymph nodes removed. There is no contraindication to performing a complete lymphadenectomy. The increase in survival in patients with a complete lymphadenectomy may be due to more accurate staging. Therefore, complete lymphadenectomy should be mandatory even in early stage patients.

Long-term survival of patients with pN2 lung cancer according to the pattern of lymphatic spread

BACKGROUND

N2 involvement has dramatic consequences on the prognosis and management of patients with non-small cell lung cancer (NSCLC). N2-NSCLC may present with or without N1 involvement, constituting non-skip (pN1N2) and skip (pN0N2) diseases, respectively. As the prognostic impact of this subclassification is still a matter of debate, we analyzed the prognosis of pN2 patients according to the pN1-involvement and the number of N2-stations concerned.

METHODS

The medical records of consecutive patients who underwent surgery for pN2-NSCLC in 2 French centers between 1980 and 2009 were prospectively collected and retrospectively reviewed. Patients undergoing induction therapy, exploratory thoracotomy, incomplete mediastinal lymphadenectomy, or incomplete resections were excluded. The prognoses of pN1N2 and pN0N2 patients were first compared, and then deciphered according to the number of N2 stations involved (single-station: 1S, multi-station: 2S).

RESULTS

All together, 871 patients underwent first-line complete surgical resection for pN2-NSCLC during the study period, including 258 pN0N2 (29.6%) and 613 pN1N2 (70.4%) patients. Mean follow-up was 72.8±48 months. Median, 5- and 10-year survivals were, respectively, 30 months, 34%, and 24% for pN0N2 and 20 months, 21%, and 14% for pN1N2 patients (p<0.001). Multivariate analysis revealed 3 different prognostic groups; ie, favorable in pN0N2-1S disease, intermediate in pN0N2-2S and pN1N2-1S diseases, and poor in pN1N2-2S disease (p<0.001).

CONCLUSIONS

Among pN2 patients, the combination of N1 involvement (pN0N2 vs pN1N2) and number of involved N2 stations (1S vs 2S) are independent prognostic factors. These results might be taken into consideration to sub-classify the heterogeneous pN2-NSCLC group of patients.

Impact of the 7th TNM staging lung cancer in surgery

Accurate staging of lung cancer is very critical to determine the proper management approach of each patient and to address prognosis issues. In this manuscript, we will discuss the impact of the most recent staging categories (7th TNM staging) on the management of non-small cell lung cancer.

Prognostic factors of resected node-positive lung cancer: location, extent of nodal metastases, and multimodal treatment

Objective: To investigate the prognostic significance of location and extent of lymph node metastasis in resected non-small cell lung cancer (NSCLC), and to weigh up the influence of treatment modalities on survival.

Patients and method: On exploratory analysis, patients were grouped according to location and time of diagnosis of nodal metastasis: group I, pN2-disease in the aortopulmonary region (N=14); group II, pN2-disease at other level (N=30); group III, cN2-disease with response to induction treatment (ypN0; N=21); group IV, cN2-disease without response to induction treatment (ypN1-2; N=27); group V, pN1-disease (N=66).

Results: From 1999 to 2005, 158 patients (median age: 64 years) with node-positive NSCLC were treated at our institution either by neoadjuvant chemo-radiotherapy plus surgery or by surgery plus adjuvant therapy (chemotherapy, radiotherapy, or both). Operative mortality and major morbidity rates were 2% and 15%. Five-year survival rates were 19% for group I, 12% for group II, 66% for group III, 15% for group IV, and 29% for group V (P<.05). On multivariate analysis, time of N+-diagnosis, extent of nodal involvement and therapy approach were significantly linked to prognosis.

Conclusion: The survival of patients with node-positive NSCLC does not depend on anatomical location of nodal disease, but strongly correlates to extent of nodal metastases and treatment modality. Combined therapy approaches including chemotherapy and surgery may improve long-term survival.

The IASLC lung cancer staging project: a proposal for a new international lymph node map in the forthcoming seventh edition of the TNM classification for lung cancer

The accurate assessment of lymph node involvement is an important part of the management of lung cancer. Lymph node "maps" have been used to describe the location of nodal metastases. However, discrepancies in nomenclature among maps used by Asian and Western countries hinder analyses of lung cancer treatment outcome. To achieve uniformity and to promote future analyses of a planned prospective international database, the International Association for the Study of Lung Cancer proposes a new lymph node map which reconciles differences among currently used maps, and provides precise anatomic definitions for all lymph node stations. A method of grouping lymph node stations together into "zones" is also proposed for the purposes of future survival analyses.

Completely resected non-small cell lung cancer: reconsidering prognostic value and significance of N2 metastases

BACKGROUND

Non-small cell lung cancer (NSCLC) mediastinal (N2) metastases are indicators of poor prognosis. Survival rates decrease with increasing number of N2 stations and involved lymph nodes as well as lymph node size and capsular invasion. Our purpose was to elucidate the impact lymph node-related variables on the outcome after surgical resection.

METHODS

We reviewed data of 2344 NSCLC patients who underwent curative resections with mediastinal lymphadenectomy, and 586 (25%) had N2 metastases. We studied the overall survival of N2 patients according to some important covariates.

RESULTS

Metastases involved single N2 stations in 386 patients (66%) and two or more in 200 (34%). Survival was not related with histology or pathologic tumor (pT), but was better when only one N2 station was involved (5-year overall survival 28.5% [median, 24 months] versus 17.2% [median, 14 months] respectively; p = 0.0002. For single N2 stations, capsular rupture, number, and size of lymph nodes were not significant prognostic factors. When the size of lymph node was analyzed (micrometastases, 53; nonbulky, 207; or bulky metastases, 126), overall survival differences between nonbulky and bulky N2 were significant: 5-year overall survival was 34% (median, 28 months) versus 23% (median, 23 months), respectively (p = 0.026). Presence of micrometastases was associated with a poor prognosis: 5-year overall survival of 21.4% (median, 23 months).

CONCLUSIONS

Prognosis was better for patients with single N2 stations when metastatic lymph nodes were not enlarged. However, the presence of lymph nodes micrometastases does not seems associated with a better outcome.

Mediastinal lymphatic drainage from pulmonary lobe based on CT observations of histoplasmosis: implications for minimal N2 disease of non-small-cell lung cancer

PURPOSE

The aim of this study was to assess mediastinal lymphatic drainage patterns from each pulmonary lobe using computed tomographic (CT) observations of calcified primary complex pulmonary histoplasmosis.

MATERIALS AND METHODS

We assessed 400 CT studies of patients with primary complex histoplasmosis consisting of a single lobe pulmonary lesion and mediastinal nodal disease. We assessed the distribution of mediastinal nodal involvement depending on pulmonary lobes for the total number of involved nodes, the number with single-station involvement (which suggests the initial site of involvement), and the number with skip involvement which suggests direct drainage to the mediastinum.

RESULTS

The most commonly involved mediastinal nodal stations from the right upper lobe, left upper lobe, and left lower lobe were the right lower paratracheal node (97%, 74/76), the subaortic node (72%, 49/68), and the left pulmonary ligament node (61%, 66/108), respectively. These nodes were the most common site of skip involvement in each lobe. In the right lower lobe and middle lobe, the subcarinal node was most commonly involved: 62% (65/105) and 81% (35/43), respectively. By contrast, skip involvement was uncommon in the drainage to this node.

CONCLUSION

Our data show a predictable pattern of lobar lymphatic drainage to the mediastinum. This may have implications on the minimal N2 disease of non-small-cell lung cancer.

The IASLC Lung Cancer Staging Project: Proposals for the Revision of the N Descriptors in the Forthcoming Seventh Edition of the TNM Classification for Lung Cancer

INTRODUCTION

Accurate staging of lymph node involvement is a critical aspect of the initial management of nonmetastatic non-small cell lung cancer (NSCLC). We sought to determine whether the current N descriptors should be maintained or revised for the next edition of the international lung cancer staging system.

METHODS

A retrospective international lung cancer database was developed and analyzed. Anatomical location of lymph node involvement was defined by the Naruke (for Japanese data) and American Thoracic Society (for non-Japanese data) nodal maps. Survival was calculated by the Kaplan-Meier method, and prognostic groups were assessed by Cox regression analysis.

RESULTS

Current N0 to N3 descriptors defined distinct prognostic groups for both clinical and pathologic staging. Exploratory analyses indicated that lymph node stations could be grouped together into six "zones": peripheral or hilar for N1, and upper or lower mediastinal, aortopulmonary, and subcarinal for N2 nodes. Among patients undergoing resection without induction therapy, there were three distinct prognostic groups: single-zone N1, multiple-zone N1 or single N2, and multiple-zone N2 disease. Nevertheless, there were insufficient data to determine whether the N descriptors should be subdivided (e.g., N1a, N1b, N2a, N2b).

CONCLUSIONS

Current N descriptors should be maintained in the NSCLC staging system. Prospective studies are needed to validate amalgamating lymph node stations into zones and subdividing N descriptors.

Analysis of risk factors for skip lymphatic metastasis and their prognostic value in operated N2 non-small-cell lung carcinoma

BACKGROUND

The aim of this study is to report a series and to analyze risk factors for skip lymphatic metastasis an their prognostic value in operated N2 non-small-cell lung carcinoma.

METHODS

From 1997 to 2002, 142 patients classified pN2 were included in the study. Tumours were classified according to the TNM classification. Skips metastases were defined by the cases of N2 disease without lobar and interlobar and hilar lymph node involvement. A skip (+) and a skip (-) group were defined. Characteristics of tumours, ganglionar involvement and survival were analysed in both groups.

RESULTS

Forty-two patients fulfilled the criteria for skip metastasis. The average number of mediastinal lymph nodes resected by patient was similar in both groups, whereas more intrapulmonary nodes were dissected in the skip (-) group (4.7 +/- 3 vs 3 +/- 3; p < 0.002). The ratio of involved to resected lymph nodes was 0.47 +/- 0.27 in the skip (-) group vs 0.23 +/- 0.20 in the skip (+) group (p < 0.0001). In the skip (+) group, 85% of the patients presenting with a right upper lobe tumour had involvement of the superior mediastinal lymph nodes against 40% in the skip (-) group. The 5-year survival rate was 48% in the skip (-) group vs 37% in the skip (+) group (p = 0.49). In multivariate analysis, incomplete resection, tumour size, extended resection and pT were significant prognostic factors.

CONCLUSIONS

Skip metastasis are frequent in non-small-cell lung cancer and complete dissection of hilar and mediastinal lymph nodes should remain the surgical standard procedure for this disease. However, skip metastasis are not an independent prognostic factor in survival.

Complete resection via medial sternotomy for non-small cell lung cancer in the right upper lobe

BACKGROUND

Right upper lobectomy with right cervical and bilateral mediastinal lymph node dissection via a median approach was performed for non-small cell lung cancer.

METHODS

From 1995 to 2003, 48 patients aged < or = 70 years underwent resection of cancer in the right upper lobe, including 26 with N0, four with N1 and 18 with N2 disease.

RESULTS

Metastases to the right cervical, highest mediastinal, pretracheal and bilateral tracheobronchial lymph nodes were frequent. There were no operative or hospital deaths. Preoperative accuracy of N-factor diagnosis was only 35.4%. The overall 5-year survival rate was 58.8%. The rate for C-N2 disease (n = 18) was 42.6%, and the rate for p-N2 disease (n = 7) and p-N3 disease (n = 13) was 57.1% and 0%, respectively, using the Kaplan-Meier method.

CONCLUSIONS

Patients without N3 disease have a good prognosis, and extended and systematic radical lymphadenectomy via median sternotomy improves the staging, and possibly the prognosis of pure N2 disease.

Postoperative survival and the number of lymph nodes sampled during resection of node-negative non-small cell lung cancer

STUDY OBJECTIVE

To examine the association between postoperative survival and the number of lymph nodes (LNs) examined during surgery among persons who underwent definitive resection of node-negative (stage IA or stage IB) non-small cell lung cancer (NSCLC).

DESIGN AND SETTING

Information on postoperative survival and the number of LNs examined during surgery for stage I NSCLC treated with definitive surgical resection was retrieved from the population-based Surveillance, Epidemiology and End Results database for the period from 1990 to 2000. The association between survival and the number of LNs was examined using multivariate Cox proportional hazard models with adjustment for age, race, sex, type of surgery performed, and tumor size, grade, and histology.

RESULTS

A total of 16,800 patients were included in the study. The overall survival analysis for patients without radiation therapy (RT) demonstrated that in comparison to the reference group (one to four LNs), patients with five to eight LNs examined during surgery had a modest but statistically significant increase in survival, with a proportionate hazard ratio (HR) of 0.90 and a 95% confidence interval (CI) of 0.84 to 0.97. Similar results for 9 to 12 LNs and 13 to 16 LNs examined produced further increases in survival, with HRs of 0.86 (95% CI, 0.79 to 0.95) and 0.78 (95% CI, 0.68 to 0.90), respectively. There appeared to be no incremental improvement after evaluating > 16 LNs. The corresponding results for lung cancer-specific mortality and for patients receiving RT were not substantially different. The highest median survival (97 months) occurred in patients with 10 to 11 LNs evaluated.

CONCLUSIONS

Our results indicate that patient survival following resection for NSCLC is associated with the number of LNs evaluated during surgery. This is likely due to reduction of staging error: a decreased likelihood of missing positive LNs with an increasing number of LNs sampled. Although we are reluctant to recommend a definitive "optimal number," our data support the conclusion that an evaluation of nodal status should include somewhere from 11 to 16 LNs.

Vascular endothelial growth factor expression in pN2 non-small cell lung cancer: Lack of prognostic value

OBJECTIVE

Although several previous studies have investigated the prognostic significance of vascular endothelial growth factor (VEGF) expression in non-small cell lung (NSCL) cancer, no previous study has concentrated on NSCL cancer with pathologically abnormal mediastinal nodes (pN2).

METHODOLOGY

A total of 60 patients with pN2 NSCL cancer who had undergone a complete resection with a systematic mediastinal lymph node dissection were reviewed retrospectively. Immunohistochemical examination, using antibodies against VEGF, was conducted. The prognostic significance of VEGF expression and clinicopathological factors were analysed.

RESULTS

The overall 5-year survival rate was 21.7%. With respect to clinicopathological factors, single N2 involvement and skip metastasis were significantly associated with patients' survival. Expression of VEGF was found in 35/60 (58.3%) patients. VEGF expression was not related to the clinicopathological parameters examined. There was no relationship between survival rates and patients positive and negative for VEGF. Multivariate analysis showed that single N2 disease was an independent prognostic factor, while VEGF expression was not.

CONCLUSIONS

Although VEGF expression might be important for tumour development and maintenance, no prognostic significance of VEGF expression in pN2 NSCL cancer was found.

Results of surgical intervention for p-stage IIIA (N2) non-small cell lung cancer: acceptable prognosis predicted by complete resection in patients with single N2 disease with primary tumor in the upper lobe

OBJECTIVES

Non-small cell lung cancer with mediastinal lymph node involvement is a heterogeneous entity different from single mediastinal lymph node metastasis to multiple nodes or extranodal disease. The objective of this study was to identify the subpopulation of patients with N2 disease who can benefit from surgical intervention.

METHODS

We reviewed 219 consecutive patients with N2 non-small cell lung cancer treated with a thoracotomy between November 1980 and June 2002 and retrospectively analyzed 154 of those who had p-stage IIIA disease and underwent a complete resection. Age, sex, side (right or left), histology, location (upper or middle-lower lobe), tumor size, c-N factor, and N2 level (single or multiple) were used as prognostic variables.

RESULTS

The 3- and 5-year survivals were 45.3% and 28.1%, respectively, in patients with p-stage IIIA (N2) disease. Survival for those with single N2 non-small cell lung cancer was significantly better than in those with multiple N2 disease (P =.0001), and patients with a tumor in the upper lobe showed a significantly longer survival than those with middle-lower lobe involvement (P =.0467). The 3- and 5-year survivals for patients with single N2 disease with a primary tumor in the upper lobe were 74.9% and 53.5%, respectively. A multivariate analysis with Cox regression identified 5 predictors of better prognosis: younger age, squamous cell carcinoma as determined by histology, primary tumor location in the upper lobe, c-N0 status, and a single station of mediastinal node metastasis.

CONCLUSION

Our results suggest that of the heterogeneity of N2 diseases, patients with single N2 disease with non-small cell lung cancer in the upper lobe are good candidates for pulmonary resection.

Prognostic significance of bcl-2 expression in resected pN2 non-small cell lung cancer

AIMS

The prognosis of non-small cell lung cancer with pathologic mediastinal lymph node involvement (pN2) is poor, we wished to study the expression of p53, bcl-2 by immunohistochemistry in a series of such patients.

METHODS

Clinicopathologic factors were investigated in relation to prognosis in 60 patients with resected pN2 non-small cell lung cancer.

RESULTS

The 5-year survival rate was 21.7%. Positive staining for p53, and bcl-2 was found in 29/60 and 12/60, respectively. Patients with bcl-2 positive tumor had a more favorable survival than those with bcl-2 negative tumor (P=0.0054). The expression of p53 was not related to patients' survival. Multivariate analysis showed that Bcl-2 expression and single N2 station were independent prognostic factors.

CONCLUSIONS

Patients with bcl-2 positive tumors may comprise a favorable prognostic subgroup in pN2 non-small cell lung cancer.

Proposta de metodização da linfadenectomia mediastinal na cirurgia do câncer de pulmão

OBJETIVO: Estabelecer uma padronização anatômica da linfadenectomia mediastinal como complementação à cirurgia do câncer de pulmão. MÉTODO: 1 - Foram enviados para vinte e dois cirurgiões torácicos brasileiros, questionários sobre linfadenectomia mediastinal. 2 - Realizou-se extensa revisão bibliográfica sobre a anatomia dos linfáticos do mediastino e descrições das técnicas de dissecação linfática mediastinal. 3 - Procedeu-se à dissecação do mediastino em cinco cadáveres não formolizados. 4 - Estabelecido os limites anatômicos de cada loja linfonodal foram realizadas vinte e sete fotografias de cada uma das referidas lojas antes e após a dissecação. RESULTADOS: Não houve consenso entre os cirurgiões que responderam ao questionário quanto a realização ou não e quanto à forma de realizar a linfadenectomia do mediastino na cirurgia do câncer pulmonar, significando que a técnica merece uma metodização. Movidos por esta necessidade e baseados na análise dos itens 2, 3 e 4 acima relacionados, propusemos uma metodização da linfadenectomia mediastinal de forma objetiva, definindo claramente os limites anatômicos de cada loja ganglionar no mediastino direito e esquerdo e especificando aquelas a serem abordadas de acordo com o sítio primário da lesão no lobo pulmonar. CONCLUSÃO: É possível definir claramente uma metodização técnica de fácil execução da linfadenectomia mediastinal, baseado em critérios anatômicos.

Completely resected stage IIIA non-small cell lung cancer: the significance of primary tumor location and N2 station

BACKGROUND

The number of N2 stations (single vs multiple N2 stations) is an important prognostic factor in patients with completely resected stage IIIA-N2 non-small cell lung cancer. However, the significance of both the N2 station(s) actually involved and the primary tumor location remains unclear.

METHODS

The database was built with the use of a questionnaire survey on the survival of patients with pathologic stage IIIA-N2 non-small cell lung cancer completely resected between January 1992 and December 1993. The survey was performed by the Japan Clinical Oncology Group as of July 1999. The data include information on the survival and N2 stations of 402 patients.

RESULTS

A frequently metastasized single N2 station was the lower pretracheal station in primary tumors in the right upper lobe, the subaortic station in the left upper lobe, and the subcarinal station in the right middle or lower lobe and the left lower lobe. In multiple N2 stations, the frequency of metastasis of the N2 station observed in a single N2 station was as high as 72% to 89%, and one or two other frequently metastasized stations were added to each group. Regarding the survival of patients with a primary tumor in each lobe except for the left lower lobe, a single N2 station resulted in a significantly better survival than did multiple N2 stations. Furthermore, the overall survivals classified according to each primary site showed a significant difference among the four primary sites (P =.04).

CONCLUSIONS

The primary tumors in each lobe showed a prevalence of N2 station(s). The number of N2 stations is a good prognosticator except in patients with a primary tumor in the left lower lobe. In addition, the site of a primary tumor itself is also considered to influence the survival of the patients.

Survival of patients with resected N2 non-small-cell lung cancer: evidence for a subclassification and implications

PURPOSE

Patients who suffer from non-small-cell lung cancer (NSCLC) with ipsilateral mediastinal lymph node involvement (N2) belong to a heterogeneous subgroup of patients. We analyzed the prognosis of patients with resected N2 NSCLC to propose homogeneous patient subgroups.

PATIENTS AND METHODS

The present study comprised 702 consecutive patients from six French centers who underwent surgical resection of N2 NSCLC. Initially, two groups of patients were defined: patients with clinical N2 (cN2) and those with minimal N2 (mN2) disease were patients in whom N2 disease was and was not detected preoperatively at computed tomographic scan, respectively.

RESULTS

The median duration of follow-up was 52 months (range, 18 to 120 months). A multivariate analysis using Cox regression identified four negative prognostic factors, namely, cN2 status (P <. 0001), involvement of multiple lymph node levels (L2+; P <.0001), pT3 to T4 stage (P <.0001), and no preoperative chemotherapy (P <. 01). For patients treated with primary surgery, 5-year survival rates were as follows: mN2, one level involved (mN2L1, n = 244): 34%; mN2, multiple level involvement (mN2L2+, n = 78): 11%; cN2L1 (n = 118): 8%; and cN2L2+ (n = 122): 3%. When only patients with mN2L1 disease were considered, the site of lymph node involvement according to the American Thoracic Society numbering system had no prognostic significance (P =.14). Preoperative chemotherapy was associated with a better prognosis for those with cN2 (P <.0001). Five-year survival rates were 18% and 5% for cN2 patients treated with and without preoperative chemotherapy, respectively.

CONCLUSION

This study has identified homogeneous N2 NSCLC prognostic subgroups and suggests different therapeutic approaches according to the subgroup profile.

Non-small cell lung cancer: role of surgery for stages I-III

Survival following surgical resection of non-small cell lung cancer (NSCLC) has improved since the 1960s, although the 5-year survival rate remains low. This article provides an overview of the role of surgery for NSCLC stages I-III, with a focus on optimizing long-term survival in those patients with resectable disease. Topics explored include diagnosis and staging, indications for resection, types of resection, and indications for adjuvant therapy. A review of the literature indicates a clear survival advantage for complete resection, and is suggestive of an advantage for mediastinal lymph node dissection (vs lymph node sampling) and neoadjuvant therapy (vs adjuvant therapy).

Lymph node sampling in lung cancer: how should it be done?

OBJECTIVES

Systematic lymph node dissection in radical operation for lung cancer is recognized as an operative procedure which is expected to improve local control. We investigate the most effective method of lymph node dissection or sampling.

METHODS

A retrospectrive study was carried out on 1815 patients who underwent systematic lymph node dissection and complete resection. The lymphatic route of metastatis from each lobe was investigated by examining which nodes had the most likelihood of metastasis, or to find out which is the sentinel lymph node in the case of small sized tumor, suitable for the video assisted thoracic surgery (VATS) approach.

RESULTS

At N2 level, distribution of major metastases from each lobe are as follows: right upper lobe tumor, #3 - 12.3% (80/648) and/or #4 - 8% (52/648); right middle lobe tumor, #3 and/or #7 - 16.4% (13/79); right lower lobe tumor, #7 - 13.7% (52/380); left upper lobe tumor, #5 - 12.3% (60/489) and/or #6 - 6.7% (33/489); and left lower lobe tumor, #7 - 11.9% (26/219). Small sized tumor requires lymph node sampling upon staging, and the lymph node most likely to become the first metastasis, i.e. sentinel node, are as follows: regardless of the location of tumor, #12, #11, and/or #10 in N1 level, which means dissection or sampling within these locations of lymph nodes are prerequisite. In N2 level, #3 and/or #4 in right upper lobe tumor, #3 and/or #7 in right middle lobe tumor, #7 in right lower lobe tumor, #5 and/or #6 in left upper lobe tumor, and, #7 in left lower lobe tumor.

CONCLUSIONS

In clinical T1NO lung cancer, sentinel lymph node sampling should be done first, if the nodes are negative, complete mediastinal lymph node dissection might be omitted. On the other hand, if the sentinel nodes are positive for pathology, complete medistinal lymph node dissection is required for curative resection.

Prognosis of completely resected pN2 non-small cell lung carcinomas: What is the significant node that affects survival?

OBJECTIVE

We analyzed the effect of the station of mediastinal metastasis with regard to the location of the primary tumor on the prognosis in patients with non-small cell lung cancer.

METHODS

Of 956 consecutive patients who underwent operation for primary lung carcinoma between 1986 and 1996, 760 patients (79.5%) were diagnosed as having non- small cell carcinoma and were subjected to complete removal of hilar and mediastinal lymph nodes together with the primary tumor.

RESULTS

The status of lymph node involvement was N0 in 480 patients (63.2%), N1 in 139 patients (18.3%), and N2 in 141 patients (18.6%). The 5- and 10-year survival of patients with N2 disease were 26% and 17%, respectively. Neither cell type nor the extent of procedure was a significant survival determinant. Patients having involvement of subcarinal nodes from upper-lobe tumors had a significantly worse prognosis than those patients with metastases only to the upper mediastinal or aortic nodes (P =.003). Patients with nodal involvement of the upper mediastinum from lower-lobe tumors had a significantly worse survival than those patients with metastases limited to the lower mediastinum (P =.039). Furthermore, patients with involvement of the aortic nodes alone from left upper-lobe tumors had a significantly better survival than those patients with metastasis to the upper or lower mediastinum beyond the aortic region (P =.044).

CONCLUSIONS

When mediastinal metastasis is limited to upper nodes from upper-lobe tumor, to lower nodes from lower-lobe tumor, or to aortic nodes from left upper-lobe tumor, acceptable survival could be expected after radical resection.

Five-year survivors with resected pN2 nonsmall cell lung carcinoma

BACKGROUND

Some patients with resected pN2 lung carcinoma were long term survivors. To determine appropriate therapeutic modalities for the selected patients, the clinicopathologic characteristics of these patients were examined using the actual number of survivors rather than the cumulative survival rate because the cumulative survival rate occasionally is confounded due to patients with short follow-up periods.

METHODS

Between 1981-1990, 178 patients with pN2 nonsmall cell lung carcinoma underwent complete resection with systemic lymph node dissection. The ratios of 5-year survivors to all patients in groups with several clinicopathologic factors were compared.

RESULTS

Gender, the side that was operated on, location of the tumor, histologic type, or surgical procedure were not related to the ratio of 5-year survivors. However, T classification, skip metastasis, and the number of levels involved were associated with the ratio significantly. The authors also found that the location of the involved lymph node(s) affected the ratio.

CONCLUSIONS

Even in the presence of pN2 disease, lung carcinoma patients with T1 tumors, skip metastasis, or single level mediastinal lymph node involvement, especially Level 4, Level 5, or Level 6 lymph nodes, had a relatively favorable prognosis and may be candidates for primary resection.

Survival and prognostic factors in resected N2 non-small cell lung cancer: a study of 140 cases. Leuven Lung Cancer Group

BACKGROUND

The selection of stage IIIA N2 non-small cell lung cancer patients for primary surgical treatment remains controversial.

METHODS

One hundred forty patients with resected non-small cell lung cancer who eventually proved to have pathologic N2 disease were studied with a univariate and multivariate analysis of prognostic factors.

RESULTS

Nineteen patients had a positive mediastinoscopy; the others had a preoperative N0 or N1 stage. Complete resection rate was 80.7%. Five-year survival was 20.8% (95% confidence interval, 17.2% to 24.4%), 32.2% in mediastinoscopy-negative patients. In the univariate analysis, clinical N stage at mediastinoscopy, complete resection, performance status, T stage, number of metastatic levels in adenocarcinoma, and nodal capsule rupture were important factors. In a multivariate model, survival was worse in case of higher T stage (relative risk = 1.43), lower performance status (relative risk = 1.37), involvement of more than one node level (relative risk = 1.68), nonsquamous histology (relative risk = 1.29) and clinical N2 stage (relative risk = 1.43). Long-term survival was unlikely when lactic dehydrogenase or carcinoembryonic antigen levels were elevated.

CONCLUSIONS

In clinical N0 or N1 cancer, complete resection resulted in reasonable survival prospects. In patients with N2 disease discovered at mediastinoscopy, surgical treatment was only worthwhile in case of minimal N2. Several unfavorable prognostic factors could be identified in the univariate analysis and confirmed in a multivariate Cox model.