Improved survival in left non-small-cell N2 lung cancer after more extensive operative procedure

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

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.

Mediastinal lymph nodes: ignore? sample? dissect? The role of mediastinal node dissection in the surgical management of primary lung cancer

The role of mediastinal lymph node dissection (MLND) during the resection of non-small-cell lung cancer is still unclear although most surgeons agree that a minimum of hilar and mediastinal nodes must be examined for appropriate pathological staging. Current surgical practices vary from visual inspection of the mediastinum with biopsy of only abnormal looking nodes to systematic mediastinal node sampling which is to the biopsy of lymph nodes from multiple levels whether they appear abnormal or not to MLND which involves the systematic removal of all lymph node bearing tissue from multiple sites unilaterally or bilaterally within the mediastinum. This review article looks at the evidence and arguments in favour of lymphadenectomy, including improved pathological staging, better locoregional control, and ultimately longer disease-free survival and those against which are longer operating time, increased operative morbidity, and lack of evidence for survival benefit.

Intraoperative staging and surgical management of stage IIIA/N2 non-small cell lung cancer

Staging of the mediastinum is an integral component of the operative treatment of NSCLC. Systematic sampling and systematic lymph node dissection provide similar and accurate staging information. Systematic lymph node dissection is more likely to identify multiple levels of N2 disease, however, and may be associated with improved survival. During surgery for a right lung cancer, at least mediastinal lymph node levels 4 should be sampled or dissected. When removing a left lung cancer, at least nodal levels 5 and 7 should be assessed. Although every effort should be made to identify N2 disease before surgery, if intraoperative metastases to mediastinal lymph nodes are discovered, the planned operation should proceed. Cisplatin-based adjuvant chemotherapy has moderate but proven survival benefit after resection of N2 disease. The role of PORT remains uncertain.

Le bilan préopératoire du cancer bronchique

INTRODUCTION

The overall prognosis of non-small cell carcinoma of the bronchus (NSCLC) remains poor on account of frequently late diagnosis and associated co-morbidity preventing the optimal treatment of the tumour. Surgical resection remains the best curative treatment for limited stage disease.

STATE OF THE ART

The pre-operative assessment should determine whether the extent of the tumour permits complete resection and whether the physiological state of the patient would tolerate the curative resection required. The ultimate goal is to improve 5-year survival. In the case of initial inoperability the assessment should determine whether pre-operative oncological treatment might make an advanced tumour operable (e.g. stage IIIA), or whether targeted medical treatment might improve the patient sufficiently to tolerate an intervention initially judged too risky. The rapid development of the technical modalities available for the assessment requires a continuous review of the current practice guidelines. Positron emission tomography has considerably augmented the accuracy of classical radiological assessment. Nevertheless staging by imaging alone remains imprecise to the extent that invasive examinations are still necessary to provide histological proof of the clinical stage of NSCLC. The techniques for assessing mediastinal invasion are developing rapidly and becoming more accurate and less invasive. Mediastinoscopy enhanced by modern video technology, ultrasound guided endoscopic biopsies and thoracoscopy are complimentary rather than competing techniques. The functional assessment should estimate the operative risk of the proposed pulmonary resection, identify the targeted actions aimed at reducing this risk or, in the absence of such actions, suggest less invasive but less well validated surgical techniques or even palliative treatments. When the operative risk cannot be reduced its precise estimation at least allows the patient to decide whether the risk seems acceptable in relation to the chances of a cure.

VIEWPOINT AND CONCLUSIONS

In the future the pre-operative assessment of NSCLC should improve the detection of micro-metastases in order to optimise the choice of induction and adjuvant therapies. The increasing use of induction chemotherapy before surgical resection can only increase the importance of a detailed assessment for the selection of patients and the evaluation of results.

Surgical exploration of the mediastinum: mediastinoscopy and intraoperative staging

Lung resection remains the therapy of choice offering the greatest potential for cure in non-spread lung cancer. Prognostic importance of lymph-node involvement has been underlined by several studies. So, exploration of the mediastinum is of major importance for defining the therapeutic strategy in a possibly curative setting. Pre-resectional exploration of the mediastinal lymph-nodal status is mandatory to define tumour stage exactly and establish specific therapy. Cervical mediastinoscopy is the primary diagnostic procedure and remains the gold standard in invasive surgical staging. Complementary, parasternal mediastinoscopy, extended mediastinoscopy, and video-assisted thoracoscopy may be performed. These techniques allow accurate assessment of mediastinal lymph-node involvement, resulting in an appropriate judgement as to resectability and possible treatment options. Different techniques are established for intraoperative exploration and staging. In terms of curative surgery of lung cancer we demand accurate staging which is achieved by systematic and complete Lymph-node dissection. So, individually and dependent on primary tumour site, accurate mediastinal staging of Lung cancer should be performed in combination with definitive lung resection.

Prognosis in N2 NSCLC

The prognosis of bronchogenic carcinoma in stage III N2 is poor. Five-year survival ranges between 0 and 5%. Lymph-node involvement itself still is the main prognostic factor. Complete lymphadenectomy improves long-term survival in contrast to lymph-node sampling. Recent studies have indicated that the number of involved lymph nodes could be another prognostic factor. It has also been proved that complete lymphadenectomy is necessary for correct staging. This also applies to preoperative staging prior to neoadjuvant treatment. For this reason exact knowledge of lymph-node anatomy and drainage is required. To achieve assessment and comparison of mediastinal staging and of lymphadenectomy, the number of pathologically examined lymph nodes should be documented. Other prognostic factors within N2 stages are age and T stage. Molecular markers are subject to major investigation. A definite clinical relevance, however, could so far not be verified for any of them.

Skip metastasis in nonsmall cell lung carcinoma

BACKGROUND

Skip metastasis to mediastinal lymph nodes is a prognostic factor for patients with nonsmall cell lung carcinoma (NSCLC). Little is known about the biologic behavior of tumors with noncontinuous spread to the mediastinal lymph nodes. In patients with pN2 skip metastases, micrometastases to N1 lymph nodes, which only mimic skip metastases, have not been investigated.

METHODS

In a retrospective study, the authors analyzed the primary tumor specimens from 45 patients with pN2 NSCLC (18 patients had squamous cell carcinomas, 23 had adenocarcinomas, and 4 had large cell carcinomas). They immunohistochemically evaluated the expression of p21, p53, MUC-1, Bcl-2, c-ErbB-2, and E-cadherin. Survival rates and biomarker expression levels were compared between patients with pN2 disease and infiltration of N1 lymph nodes (without skip metastasis [n = 28]) and patients with pN2 disease without N1 infiltration (with skip metastasis [n = 17]). To evaluate micrometastasis in the pN1 lymph nodes of 17 patients with skip metastases, lymph nodes were stained using the anticytokeratin antibody, AE1/AE3.

RESULTS

The 5-year survival rate of patients with skip metastases was 41%, compared with 14% for patients without skip metastases (P = 0.019). In a multivariate analysis, the incidence of skip metastases did not vary significantly according to gender, age, histology, pT status, or cM status. Three skip-positive patients (17.6%) had micrometastatic tumor involvement of pN1 lymph nodes. After adding these patients to the group of patients without skip metastases, there was still a significant difference in survival between the two groups. p53, MUC-1, c-ErbB-2, and E-cadherin expression levels in primary tumor specimens were not significantly different in patients with continuous metastasis and patients with skip metastases. Patients with skip metastases expressed lower levels of p21 (P = 0.026), whereas Bcl-2 expression levels were considerably higher (P = 0.019) compared with the corresponding levels in patients without skip metastases.

CONCLUSIONS

Patients with NSCLC and pN2 skip metastases have a more favorable prognosis than do patients with pN2 disease without skip metastases. Tumor specimens from these patients exhibit elevated expression of the antiapoptosis gene BCL2 and lower expression levels of p21 relative to patients with pN2 disease without skip metastases. Micrometastases occurred in 3 of 17 (17.6%) patients with pN2 disease and skip metastases diagnosed by routine histopathology.

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.

Inter-observer variability in systematic nodal dissection: comparison of European and Japanese nodal designation

BACKGROUND

Systematic nodal dissection is accepted as an important component of the intrathoracic staging of patients undergoing thoracotomy for lung cancer. Several lymph node maps have been proposed in an attempt to ensure uniformity in designating lymph node stations. The Japan Lung Cancer Society has published detailed definitions for each nodal station adopting the Naruke map. However, since these definitions had not been interpreted into other languages, they have not been universally accepted. The objective of this study was to assess the inter-observer variability in the interpretation of lymph node stations.

METHODS

A total of 424 lymph node stations were removed from 41 patients undergoing thoracotomy for non-small cell lung cancer. All nodal stations were labeled using the Naruke map. As each station was excised, it was designated in a blind fashion by one of two surgeons trained in the UK and one surgeon trained in Japan. The designation accorded to each nodal station was analyzed.

RESULTS

The total concordance was 68.5% (right side 67.0%, left side 69.9%). The concordance rate for individual nodal stations varied from 0% to 100%. Considerable discordance existed between the Japanese and European surgeons in the designation of nodal stations 2, 4, 8 and N1 station 12. In 14 (34.1%) patients, discordance in the labeling of lymph nodes led to disease being categorized as N1 by one observer, whereas the other considered the same nodes to be N2.

CONCLUSIONS

Considerable discordance in the designation of nodal station has been demonstrated. We would expect similar inter-observer variability elsewhere between surgeons, institutions, or countries. More detailed nodal charts and precise, easily understood definitions of nodal stations are needed for intrathoracic staging. The first English version of the Japan Lung Cancer Society staging manual goes some way to address this.

Principles of surgical treatment in localized non-small cell lung cancer

Non-small cell cancer has become the leading cause of cancer-related deaths in women and men in the western hemisphere. Surgical resection remains the mainstay of therapy in stage I and II disease. Surgical therapy has an acceptable morbidity and mortality rate. Analysis of 5-year survival shows 70-75% in experienced centers for stage I and 40% for stage II, including tumors extending to the chest wall. Local and distant recurrence account for the disappointing survival rates after complete resection. In the future, appropriate selection of surgical procedures and effective use of systemic therapies might depend upon the elucidation of prognostic factors that predict recurrence and poor outcome. Thus, parameters need to be identified that characterize those patients preoperatively.

Mediastinal lymph node dissection improves survival in patients with stages II and IIIa non-small cell lung cancer. Eastern Cooperative Oncology Group

BACKGROUND

Mediastinal lymph node dissection (MLND) is an integral part of surgery for non-small cell lung cancer (NSCLC). To compare the impact of systematic sampling (SS) and complete MLND on the identification of mediastinal lymph node metastases and patient survival, the Eastern Cooperative Oncology Group (ECOG) stratified patients by type of MLND before participation in ECOG 3590 (a randomized prospective trial of adjuvant therapy in patients with completely resected stages II and IIIa NSCLC).

METHODS

Eligibility requirements for study entry included a thorough investigation of the mediastinal lymph nodes with either SS or complete MLND. The former was defined as removal of at least one lymph node at levels 4, 7, and 10 during a right thoracotomy and at levels 5 and/or 6 and 7 during a left thoracotomy, while the latter required complete removal of all lymph nodes at those levels.

RESULTS

Three hundred seventy-three eligible patients were accrued to the study. Among the 187 patients who underwent SS, N1 disease was identified in 40% and N2 disease in 60%. This was not significantly different than the 41% of N1 disease and 59% of N2 disease found among the 186 patients who underwent complete MLND. Among the 222 patients with N2 metastases, multiple levels of N2 disease were documented in 30% of patients who underwent complete MLND and in 12% of patients who had SS (p = 0.001). Median survival was 57.5 months for those patients who had undergone complete MLND and 29.2 months for those patients who had SS (p = 0.004). However, the survival advantage was limited to patients with right lung tumors (66.4 months vs 24.5 months, p<0.001).

CONCLUSIONS

In this nonrandomized comparison, SS was as efficacious as complete MLND in staging patients with NSCLC. However, complete MLND identified significantly more levels of N2 disease. Furthermore, complete MLND was associated with improved survival with right NSCLC when compared with SS.

Staging and the surgical management of lung cancer

Small cell lung cancer remains a nonsurgical disease with the majority (80%) of cases presenting in higher stages. The primary treatment modalities for small cell lung cancer are radiation therapy and systemic chemotherapy, often administered concomitantly. This article focuses on the staging and surgical management of non-small-cell lung cancer.

Surgical management of early stage lung cancer

For patients with lung cancer, the greatest hope for cure rests with patients with early stage disease. Surgery has been the standard of care for this group with the best 5-year survival of only 65% being achieved in patients with earliest pathologic Stage IA disease. Using strategies gained from the management of patients with advanced disease, clinicians are investigating the use of perioperative chemotherapy and radiotherapy to improve survival. In addition, biologic and molecular markers are being evaluated to assist in predicting prognosis and to identify those patients at increased risk for recurrent disease. Postoperative surveillance of patients using helical computed tomography (CT) scanning is being investigated to detect early recurrences and second primary lesions. With such treatment and management plans on the horizon, the prognosis of patients with early stage non-small cell lung cancer (NSCLC) may be improved.

[Results of surgical treatment of non-microcytic bronchopulmonary carcinoma in III-A stage]

To analyze results and survival after surgical treatment of various stage III-a subgroups. We reviewed 748 case histories of patients with non-small cell bronchopulmonary carcinoma between January 1970 and December 1991, selecting 121 patients who underwent resection of stage III-a tumors, according to the pathologist's report. Overall survival at 3, 5 and 10 years was 26, 16 and 12%, respectively. The subgroup with better response to treatment was that of patients with T-3 tumors (peripheral), N-0, with survival of 21% at five years. If peribronchial and/or hilar (N-1) nodes were affected, survival was slightly less (16%). If mediastinal adenopathy (N-2) was present, there were no survivors after 3 years. In this same T-3 group, but with neoplastic invasion of the pericardium, mediastinal pleura or principal bronchi, survival after 3 years was nil. The survival rates of peripheral T-3 patients undergoing block resections were 27, 20 and 17% at 3, 5 and 10 years, respectively, 16% at 2 years and 0% at 5, for those with extrapleural resection. Patients with the poorest response to treatment were those with mediastinal nodes (N-2), in whom survival was 17, 12 and 8% at 3, 5 and 10 years, respectively. In the 34 patients received postoperative irradiation of the mediastinum, survival was 16% higher. The survival rates after 5 years were similar for epidermoid carcinoma (18%) and adenocarcinoma (14%). The results of surgical treatment are variable and depend on several factors: extension and extrapulmonary location of lesions, surgical technique used for T-3 tumors and histological type.

The lymphatic pathways of non-small cell lung cancer and their implication in curative irradiation treatment

Using the pre-therapy CT scans of 266 node positive non-small cell lung cancer patients, we analysed the lymphatic pathways and the incidence of lymph node metastases in regional lymph nodes (as described by CT criteria corresponding to the modified mapping scheme of the American Thoracic Society), in order to develop the target volume for curative irradiation treatment. Among the 105 patients with node positive left sided primaries, the incidence of involvement of the ipsilateral supraclavicular lymph nodes was 9.5%, and the incidence of involvement of the contralateral lymph nodes was 3.8%. The incidence of involvement of the contralateral hilar lymph nodes was 4.8%. Among the 161 patients with nodal positive right sided primaries, the incidence of involvement of the ipsilateral supraclavicular lymph nodes was 8.7% and the incidence of involvement of the contralateral lymph nodes was 1.8%. For this group of patients, the incidence of involvement of the contralateral hilar lymph nodes was 3.7%. All patients with involvement of the contralateral hilar lymph nodes died within 2.5 years of diagnosis. In the cases where there was involvement of the supraclavicular lymph nodes, the patients died within 1.6 years. Involvement of the ipsilateral and/or contralateral supraclavicular lymph nodes, and/or the contralateral hilar lymph nodes, is defined as N3 disease, and is included in Stage IIIb. No curative surgery is indicated for these patients. Why therefore should this group of patients be treated with curative intent by irradiation of the primary, ipsilateral and contralateral hilar lymph nodes, as well as mediastinal, ipsilateral and contralateral supraclavicular lymph nodes? The curative radiation treatment volume for lung cancer has to include the primary tumor and the ipsilateral hilar, and the low and high mediastinal lymph nodes, as is indicated for Stage I, II and IIIa disease.

Extended resection for higher-stage non-small-cell lung cancer

This report reviews the results of extended surgical resection for advanced lung cancer (stage IIIa, IIIb, IV) reported in the Anglo-American literature between 1980 and 1993. Complete resection of stage IIIa (T3) tumors with minimal or no nodal involvement resulted in a 5-year survival approaching 40%. Ipsilateral mediastinal nodal involvement (N2) lowered 5-year survival to 10-15% and to near 0% if bulky disease was present. Historically, resection of stage IIIb disease has failed to improve survival. Radiation therapy has decreased local recurrence in advanced-stage disease but has not improved survival. Preliminary results have recently been reported using induction chemotherapy or chemoradiotherapy followed by resection in subsets of patients with stage IIIa and IIIb disease. Induction chemotherapy for bulky N2 (IIIa) disease resulted in major response rates of up to 77% and a 5-year survival of up to 26% after complete resection. Preliminary results of resection of stage IIIb tumors following induction chemotherapy have achieved 2-year survivals of 40%. Metastatic lung cancer (stage IV) with disseminated disease remains virtually incurable with poor response rates to chemotherapy. However, resection of isolated brain metastases (M1 disease) resulted in a 5-year survival near 25%. Resection of other sites of isolated metastatic disease including the adrenal gland is under investigation. The major prognostic factor in these studies has been the ability to completely resect all tumor. To improve resectability rates, induction therapy and radical resections are being combined more frequently. The increased morbidity and mortality of these aggressive approaches requires careful patient selection.