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.     

Thoracoscopic mediastinal lymph node dissection for lung cancer

In lung cancer, mediastinum lymphatic spread occurs. We review our technique and experience of thoracoscopic mediastinal lymphnode dissection (MLND). Between 1997 and 2011, 992 patients with primary lung cancer underwent thoracoscopic major pulmonary resection with MLND. Initially we used a combination of electrocautery and clips to divide blood vessels and lymphatic channels; our current technique relies on a vessel sealing system (VSS) which is expeditious and leads to less lymphorrhea. Furthermore, dissection of station 7 nodes is performed after each main bronchus or right intermediate bronchus is taped with a 0 silk suture, which is then brought out of the thorax through the access incision for antero-lateral retraction of the tracheal carina. We dissect between 3 and 4 N2 lymph node stations and a total of approximately 20 N2 lymph nodes. Postoperative complications related to MLND occurred in 35 of 992 patients (3.5%), 15 (1.5%) for recurrent laryngeal nerve injury, 3 (0.3%) for bilateral vagal injury, 14 (1.4%) for chylothorax and 3 (0.3%) for airway injury. However, none were lethal. Thoracoscopic mediastinal dissection is safe and feasible in treating lung cancer. We believe our technique and VSS are very useful for thoracoscopic MLND.     

In patients undergoing lung resection for non-small cell lung cancer, is lymph node dissection or sampling superior?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was 'In patients undergoing lung resection for non-small cell lung cancer, is lymph node dissection or sampling superior?' Altogether 845 papers were found using the reported search, of which 14 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that in stage I tumours there is little difference in survival when performing either mediastinal lymph node dissection (MLND) or lymph node sampling. However, survival is increased when performing MLND in stage II to IIIa tumours. Increased accuracy in staging is not observed with MLND. However, MLND reliably identifies more positive N2 nodes which may offer advantages in postoperative adjuvant treatment in more advanced disease.     

Inframanubrial Parathyroid Glands in Patients with Primary Hyperparathyroidism: Alternatives to Sternotomy

Deep inframanubrial parathyroid tumors have traditionally been excised through a median sternotomy. With the advent of minimally invasive surgical access, we chose to examine the treatment options and outcomes of patients with inframanubrial mediastinal parathyroid tumors. Patients with primary hyperparathyroidism seen at a university medical center over a 12-year period were retrospectively reviewed. The utility of localization studies, methods of treatment, complications, and outcomes were examined in patients with a parathyroid tumor located in the mediastinum inferior to the manubrium. Patients with parathyroid adenomas located at the thoracic inlet were excluded. Sixteen patients with inframanubrial mediastinal tumors were treated during the study period. Altogether, 81% of the patients had undergone at least one prior neck exploration for primary hyperparathyroidism. Preoperative calcium and parathyroid hormone levels were 12.4 ± 0.36 mg/dl and 273 ± 70 pg/ml, respectively. Localization studies identified mediastinal parathyroid adenomas in the following locations: anterior mediastinum (n = 8), middle mediastinum (n = 7), posterior mediastinum (n = 1). Mediastinal computed tomography and technetium-sestamibi scans demonstrated the best sensitivity, 92% and 85%, respectively. Seven patients underwent successful excision of the mediastinal adenoma by transcervical mediastinal exploration with the Cooper retractor. The other patients underwent angiographic ablation (n = 4), anterior mediastinotomy (n = 3), video-assisted thoracoscopy (VATS) (n = 1), and VATS plus thoracotomy (n = 1). The mean hospital stay for the study group was 2.9 ± 0.7 days. The complication rate was 25%. All patients were normocalcemic after a mean follow-up of 15 ± 7 months. Most inframanubrial mediastinal parathyroid tumors can be successfully managed without median sternotomy.     

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.     

Lobectomy with extended lymph node dissection by video-assisted thoracic surgery for lung cancer

Background: Between September 1992 and September 1996, we performed 88 VATS (video-assisted thoracic surgery) lobectomies and two VATS pneumonectomies. Methods: The indications for surgery were 68 cases of lung cancer, nine cases of bronchiectasis, six cases of tuberculosis, and seven cases of benign lesions. Of the 68 cases of lung cancer, 36 were treated by VATS lobectomy with extended lymph node dissection for clinical stage I lung cancer, making full use of recently developed devices for thoracoscopic surgery, such as roticulating endoscissors, miniretractors, endoclips, and harmonic scalpels. Results: Twenty-four lymph nodes were resected on average (range, 10 to 51) by VATS. This number was comparable to lymph nodes resected in open thoracotomy during the same period. Among the 36 patients who underwent extended lymph node dissection, 20 showed no lymph node metastasis postoperatively (stage I), while 16 had N1 or N2 cancer. All patients with stage I cancer have survived 4 to 36 months (median: 17 months) with no signs of recurrence. Conclusions: This survival of stage I lung cancer after VATS is comparable to that of open thoracotomy. We thus believe that VATS lobectomy with extended lymph node dissection can be an alternative to standard posterolateral thoracotomy for stage I lung cancer. Received: 10 May 1996/Accepted: 19 November 1996     

Easier node dissection after chemoradiotherapy for lung cancer with collagen insertion at mediastinoscopy

Objective: Induction chemoradiotherapy followed by anatomical resection is a current therapeutic strategy for non-small-cell lung cancer with mediastinal node involvement. Dense peritracheal fibrosis and sclerosis after chemoradiotherapy cause difficult mediastinal node dissection. We evaluated a novel technique to make the mediastinal node dissection easier after induction therapy. Methods: At the end of mediastinoscopic node biopsy for staging of lung cancer, cotton-type collagen was inserted anterior and lateral to the trachea in patients with pathologically confirmed mediastinal node involve-ment (n=45). The induction therapy consisted of concurrent use of platinum-based chemotherapy and hyperfractionated radiotherapy. After the chemoradiotherapy all patients underwent a pulmonary resection with complete mediastinal node dissection 7–12 weeks after the collagen insertion. Surgical findings of the mediastinum and the time for node dissection were compared with those without collagen insertion at mediastinoscopy after chemoradiotherapy (n=5). Results: All five patients without collagen insertion showed sclerotic and fibrotic change of mediastinal nodes with severe adhesion to the trachea. In 42 of 45 patients with collagen insertion (93.3%) the collagen remained unabsorbed and separated the mediastinal nodes from the trachea. Mediastinal node dissection was easily accomplished by removing mediastinal tissues lateral and anterior to the collagen. The rate of mediastinal node separation was significantly higher with collagen insertion than without (p< 0.0001). The times for node dissection in patients with and without collagen insertion showed no significant difference. Conclusion: Cotton-type collagen insertion at staging mediastinoscopy for lung cancer separates the mediastinal nodes from the trachea and makes the node dissection easier after induction chemoradiotherapy.     

Video-assisted Thoracoscopic Lobectomy Achieves a Satisfactory Long-term Prognosis in Patients with Clinical Stage IA Lung Cancer

We designed a prospective trial to determine the long-term prognosis of video-assisted thoracoscopic (VATS) lobectomy versus conventional lobectomy for patients with clinical stage IA (T1N0M0) lung cancer. Between January 1993 and June 1994, 100 consecutive patients with clinical stage IA non-small cell lung carcinoma underwent either conventional lobectomy through an open thoracotomy (open group; n= 52) or VATS lobectomy (VATS group; n= 48). Lymph node dissections were performed in a similar manner in both groups. No significant differences were observed in the number of dissected lymph nodes between the 2 groups. Pathologic N1 and N2 disease was found in 3 and 1 patients, respectively, from the open group, and in 2 and 1 patients, respectively, from the VATS group. During the follow-up period, distant metastases and local or regional recurrences developed in 7 and 3 of the open group patients, respectively, and in 2 and 3 of the VATS group patients, respectively. Two and one of the open and VATS group patients developed second primary cancers, respectively. The overall survival rates 5 years after surgery were 85% and 90% in the open and VATS groups, respectively (log-rank test, p= 0.74; generalized Wilcoxon test, p= 0.91). VATS lobectomy with lymph node dissection achieved an excellent 5-year survival, similar to that achieved by the conventional approach.     

Clinical feasibility and surgical benefits of video-assisted mediastinoscopic lymphadenectomy in the treatment of resectable lung cancer

Objective: This study was performed to assess the clinical feasibility and surgical outcomes of video-assisted mediastinoscopic lymphadenectomy in the treatment of resectable lung cancer. Methods: Between July 2004 and December 2009, we retrospectively analyzed 108 consecutive video-assisted mediastinoscopic lymphadenectomies in lung cancer patients from a prospectively collected database. Ninety-seven (89.8%) patients underwent combined operation during the same anesthesia and six (5.3%) patients underwent a staged operation for the resection of lung cancer and systematic lymphadenectomy. We reviewed the indication and duration of video-assisted mediastinoscopic lymphadenectomy, its complication, combined or staged operation type, the number of dissected lymph nodes and nodal stations, and pathologic staging of the mediastinal node. Results: Mean operative time of video-assisted mediastinoscopic lymphadenectomy was 39.8 ± 12.3 min (range of 14–85 min). Mean number of resected lymph nodes was 16.0 ± 7.7 (range of 3–37). In video-assisted mediastinoscopic lymphadenectomy, the rates of lymph node dissection of stations 4R, 4L, and 7 were 71.3%, 88.0%, and 100%, respectively, whereas the rates of dissection of lymph nodes in station 2R and 2L were only 22.2% and 17.6%, respectively. There was no operative mortality. We identified five complications of recurrent nerve palsy. Conclusions: Video-assisted mediastinoscopic lymphadenectomy is a clinically feasible procedure with acceptable complication rate and provides more accurate staging of mediastinal node in lung cancer patients. It may be also an excellent supplementary technique used for complete mediastinal node dissection at minimal invasive surgery for cancer resection, especially with left-sided video-assisted thoracoscopic lobectomy.     

Novel retractor for lymph node dissection by video-assisted thoracic surgery

In nonrandomized studies, the video-assisted thoracic surgical (VATS) lobectomy seems to be a safe and effective procedure for treatment of lung cancer. However, there are some difficulties in VATS complete mediastinal lymph node dissection. The presence of the lymph node deep in the mediastinal space necessitates retraction of the surrounding organs. Therefore, we developed a retractor to create enough working space during the VATS procedure. To dissect lymph nodes, we use endoscopic bipolar forceps. These instruments are connected to a special electrosurgical generator to apply bipolar soft coagulation, which enables simultaneous dissection and sealing. Thus, "en bloc" lymph node dissection can be performed during the VATS procedure.     

Omission of mediastinal lymph node dissection in lung cancer: its techniques and diagnostic procedures.

To reduce or omit a mediastinal lymph node dissection in the patients with clinical stage I non-small cell lung cancer (NSCLC), several authors examined the prevalence of metastatic sites of lymph nodes. Because lymphatic drainage usually heads for the upper mediastinum in upper lobe cancer and for the lower mediastinum in lower lobe cancer, upper and lower mediastinal lymph node dissection could be reduced in lung cancers of lower lobe and upper lobe. By using sentinel node (SN) navigation surgery, it is possible to omit mediastinal lymph node dissection. Radiological findings are also useful to determine reduction of mediastinal lymph node dissection. In clinical stage Ia adenocarcinomas that show ground glass opacity (GGO) findings on computed tomography (CT) or negative for fluorodeoxyglucose accumulation on positron emission tomography (PET), mediastinal lymph node dissection can be omitted, because these types of adenocarcinomas rarely metastasize to the lymph nodes. By using these procedures, mediastinal lymph node dissection can be reduced or omitted with little risk of local recurrence.     

T1、T2肺鳞癌及腺癌淋巴结转移特点及其临床意义

目的研究T1、T2肺鳞及腺癌淋巴结转移频度、分布范围及特点,为广泛清扫提供依据。方法按Naruke肺癌淋巴结分布图对254例T1、T2肺鳞癌及腺癌施行了手术切除及广泛肺内、叶间及纵隔淋巴结清扫术并对其进行统计分析。结果清除淋巴结1685组。N1淋巴结转移率20．0％,N2淋巴结转移率为10．2％。T1、T2间淋巴结转移率差异有非常显著性意义(P<0．01)。T1鳞癌无N2转移,N2转移在鳞癌、腺癌分别为22．0％和40．9％,差异有非常显著性意义(P<0．01)。64．3％的鳞癌为某1组N2转移,腺癌≥3组转移占46．2％,跳跃式转移占N2转移的57．5％。N2阳性上叶肺癌下纵隔转移占13．6％,N2阳性的下叶肺癌上纵隔转移占51．6％。结论随着瘤体增大,淋巴结转移频度增加,腺癌比鳞癌淋巴结转移更加活跃,任何部位的肺癌都可跨区域纵隔转移。除T1鳞癌外,只有广泛清扫同侧肺内及纵隔淋巴结才能达到根治。     

非小细胞肺癌淋巴结清扫方式临床研究

目的 比较非小细胞肺癌不同纵隔淋巴结清扫方式间的差异,为规范化开展肺癌淋巴结清扫临床研究提供依据.方法 在202例Ⅰa-Ⅲa期肺癌中进行前瞻性临床对照试验,比较常规清扫(RMLD)和全纵隔骨骼化清扫(SCLD)两种术式,分析手术经过和术后病理分期情况.结果 RMLD 107例,SCLD 95例.两组术前一般情况、临床分期及肺切除方式无明显差异,SCLD组平均扫除淋巴结组数显著高于RMLD组(8.9组对6.2组,P＜0.001),术后总体并发症(14.7%对14.0%,P=0.884)和病死率(2.1%对1.9%,P=0.904)无差异,但SCLD组分别有3例(3.2%)右侧乳糜胸和左侧喉返神经损伤发生.术后病理证实两组组织学类型及分期无明显差异,RNLD和SCLD组pN2分别占27.1%和24.2%(P=0.888),跳跃性纵隔转移率(RMLD 9.3%对SCLD 7.4%,P=0.613)以及纵隔多组转移率(RMLD 15.0%对SCLD 16.8%,P=0.714)亦无明显差异.分析纵隔各组淋巴结转移率发现上叶肺癌下纵隔转移率＜5%,而中、下叶肺癌上、下纵隔转移率均＞10%;cT1病例以及低度恶性肿瘤无一发生纵隔转移.结论 对非小细胞肺癌行常规纵隔清扫可达到与全纵隔骨骼化清扫同样的分期效果,后者手术风险并不高于常规清扫,但应避免右侧乳糜胸和左侧喉返神经损伤的发生;上叶肺癌仅需扫除上纵隔淋巴结而无需常规清扫下纵隔;早早期肺癌以及低度恶性肿瘤没有必要进行常规纵隔清扫.     

One-stage versus two-stage lymph node dissection after investigation of sentinel lymph node in cutaneous melanoma: a comparison of complications, costs, hospitalization times, and operation times

The aim of the study was to evaluate whether complication rate, costs, operation times, and hospitalization times differed in two different patient groups: in group 1, frozen section analysis of the sentinel lymph node and lymph node dissection were carried out in the same operation. In group 2, normal investigation of the sentinel lymph node and lymph node dissection were done in a second operation. One hundred thirty-five patients with cutaneous melanoma were included. Hospitalization times, costs, complication rates, and operation times of two-stage and one-stage lymph node dissection of the draining area after detection of metastases in the sentinel lymph node were retrospectively compared. Lymph node metastasis in the sentinel lymph node was found in 23 patients. In 11 patients, removal of the sentinel lymph node and dissection of the lymph node basin was performed in the same operation. In 12 patients, a two-stage procedure was the treatment of choice. Operation times were not different in the two groups (p=0.87) while two-stage operation patients were hospitalized significantly longer (14.2 ± 9.7 vs 23.9 ± 24 days; p=0.01) and costs were significantly higher (7,836.90 ± 2,397.95 Swiss francs vs 5,279.40 ± 1,994.90 Swiss francs). In addition, more complications were found in the two-stage group.     

The current status of sentinel lymph node mapping in non-small cell lung cancer.

Sentinel lymph node (SLN) mapping has become a common procedure in the treatment of breast cancer and malignant melanoma. Its primary benefit is that it enables surgeons to avoid nontherapeutic lymph node dissection and the complications that follow. There are also several studies of the use of SLN mapping in the treatment of non-small cell lung cancer (NSCLC) reported in the English literature, and all present evidence for the existence of SLNs in NSCLC. Nevertheless, SLN mapping is not widely used in the treatment of NSCLC for several reasons: first, special precautions are required to minimize exposure when radioisotopes are used as tracers; second, it is difficult to detect the blue dyes used as tracers within anthoracotic thoracic lymph nodes; and third, major complications comparable to the arm edema seen in breast cancer or the lymphedema and nerve injury seen in melanoma are not seen with mediastinal lymph node dissection (MLND). To address these issues, new techniques are being developed by groups at several institutes, including our own. We believe that SLN mapping will enable surgeons to more precisely stage NSCLC, after which more sensitive techniques can be employed on a limited amount of tissue to detect occult micrometastatic disease with less cost and effort. SLN mapping can also be applied to video-assisted thoracic surgery (VATS) for NSCLC, enabling surgeons to avoid nontherapeutic and technically difficult MLND often necessary with traditional open surgery. For all of these reasons, we think that SLN mapping will be useful in the treatment of NSCLC, and that further development aimed at making SLN mapping a practical surgical procedure is warranted.     

Thymic metastasis of laryngeal cancer

A 70-year-old man visited the Department of Head and Neck Surgery with a chief complaint of dysphagia. A tumor was observed in the epiglottis and vocal cord, and was diagnosed as squamous cell carcinoma by biopsy. Computed tomography (CT) showed a tumor mainly in the vocal cord. CT scans revealed a tumor centered on the vocal cord, with bilateral cervical lymph node metastases and a well-circumscribed 20-mm tumor in the anterior mediastinum. Fluorodeoxyglucose-positron emission tomography (FDG-PET) showed uptake in the primary lesion, left cervical lymph nodes, and anterior mediastinal tumor, which suggested a lymph node metastasis but did not exclude thymoma. The patient underwent video-assisted thoracic surgery (VATS) resection of the anterior mediastinal tumor with total laryngectomy, total thyroidectomy, and bilateral cervical lymph node dissection. The final pathological diagnosis was laryngeal cancer (glottic cancer, pT4aN2M1, pStage IVC) with thymic metastasis (presenting as an anterior mediastinal tumor). Thymic metastasis of laryngeal cancer is rare, and appears difficult to preoperatively differentiate from other mediastinal tumors.     

T1、T2肺鳞癌及腺癌淋巴结转移特点及其临床意义

目的 研究Ｔ１、Ｔ２肺鳞及腺癌淋巴结转移频度、分布范围及特点,为广泛清扫提供依据。方法 按Ｎａｒｕｋｅ肺癌淋巴结分布图对２５４例Ｔ１、Ｔ２肺鳞癌及腺癌施行了手术切除及广泛肺内、叶间及纵阴淋巴结清扫术并对其进行统计分析。结果 清除淋巴结１６８５组。Ｎ１淋巴结转移率２０．０％,Ｎ２淋巴结转移率为１０．２％。Ｔ１、Ｔ２间淋巴结转移率差异有非常显著性意义（Ｐ〈０．０１）。Ｔ１鳞癌无Ｎ２转移,Ｎ２转移在鳞癌     

A prospective trial of systematic nodal dissection for lung cancer by video-assisted thoracic surgery: can it be perfect?

BACKGROUND: There have been no reports evaluating the completeness of systematic nodal dissection with video-assisted thoracic surgery (VATS). In order to elucidate the completeness of the dissection, we have conducted a prospective trial with patients having primary lung cancer. METHODS: Patients with clinical stage I lung cancer were the candidates for this study. Thoracotomy was performed with a small skin incision of 7 cm to 8 cm in length. Through these small wounds and two trocars, pulmonary resection was performed and then hilar and mediastinal lymph nodes were dissected. After that, a standard thoracotomy was carried out by another surgeon to complete systematic nodal dissection. RESULTS: Video-assisted thoracic surgery lobectomy with lymph node dissection was accomplished in 17 right lung cancer patients and 12 left lung cancer patients. On the right side, the average numbers of resected lymph nodes by VATS and remnant lymph nodes were 40.3 and 1.2, respectively. The average weights of dissected tissues by VATS and remnant tissues were 10.0 g and 0.2 g, respectively. On the left side, there were 37.1 and 1.2 lymph nodes and 8.3 g and 0.2 g of weight of dissected tissues. No nodal involvement was observed in the remnant lymph nodes. CONCLUSIONS: The lymph node dissection with VATS was technically feasible and the remnant ("missed" by VATS) lymph nodes and tissues were 2% to 3%, which seems acceptable for clinical stage I lung cancer.     

Sentinel node sampling limits lymphadenectomy in stage I non-small cell lung cancer.

OBJECTIVE: It is controversial whether a systematic mediastinal lymph node dissection (MLND) needs to be performed in all patients with stage I lung cancer. The present study was done to examine the new sentinel lymph nodes hypothesis based on the lobe of the primary tumor. METHODS: In our first study, the lymph node (LN) metastases were assessed in 291 stage I non-small cell lung cancer (NSCLC) patients who had a major lung resection with a systematic mediastinal lymph node dissection. We evaluated the validity of using our new sentinel lymph nodes method based on the lobe of the primary tumor as follows: the pretracheal (#3), tracheobronchial (#4), and hilar nodes (#10) for right upper lobe tumors; #4, subcarinal (#7), and #10 for middle lobe tumors; the subaortic (#5), paraaortic (#6), and #10 for left upper lobe tumors; and the #7, #10, and interlobar nodes (#11) for tumors in either lower lobes. In the second study, we performed a lobectomy with new sentinel node sampling in 64 patients with preoperative complications. If all of the sampling nodes showed no metastases on frozen section diagnosis, systematic node dissections were not performed. RESULTS: Six of 291 patients in the first study had skip metastases that did not involve the new sentinel nodes; 5 of the 6 patients had macroscopic pleural invasion. Thus, we defined pleural invasion as an exclusion criterion for the second study. In the second study, the median follow-up time was 39 months. Metastatic lymph nodes were detected in 11 of 64 patients. Fifty-three patients (83%) had no metastasis in the sampled nodes, and, therefore, a mediastinal lymph node dissection was not done. The morbidity rate in the sampling group was 36%, and there was no mortality. In the sampling group, local recurrences were observed in two patients, distant metastases in eight, and carcinomatous pleuritis in one; the overall 5-year survival rate was 82%. CONCLUSIONS: We found that it is possible to perform a less invasive lymphadenectomy for patients with stage I lung cancer using intra-operative sampling of new sentinel lymph nodes.