Distribution and Likelihood of Lymph Node Metastasis Based on the Lobar Location of Nonsmall-Cell Lung Cancer

Tumor Location Is an Independent Prognostic Factor in Completely Resected Pathological Stage I Non-Small Cell Lung Cancer: A Multicenter Retrospective Study

Previous studies suggested that the location of the primary tumor in non-small cell lung cancer (NSCLC) is associated with clinical features and prognosis, but results are conflicting. The purpose of this study was to explore tumor location as an independent risk factor of survival for patients with completely resected pathological stage I NSCLC. This was a multicenter retrospective study conducted in Taiwan. Included patients were diagnosed with stage I NSCLC and had undergone primary tumor resection. Variables including tumor location, pathological stage, histological differentiation, and International Association for the Study of Lung Cancer (IASLC) grade were evaluated for predictive ability for disease-free survival (DFS) and overall survival (OS). A total of 208 patients were included, with 123 (59.1%) patients having a primary tumor in the upper and middle lobes. The median duration of follow-up for survivors was 60.5 months. Compared to patients with IASLC Grade 3 disease, patients with Grade 1 disease had significantly longer DFS. Tumor location and IASLC grade were independent predictors for OS in multivariate analysis. Specifically, patients with NSCLC in the lower lobe and patients who are histologically classified as IASLC Grade 3 may have poorer prognosis and require greater attention to improve outcomes.

The prognostic significance of right paratracheal lymph node dissection numbers in right upper lobe non-small cell lung cancer

BACKGROUND

The number of dissected lymph nodes is closely related to the prognosis of patients with non-small cell lung cancer. This study explored the optimal number of right paratracheal lymph nodes dissected in right upper non-small cell lung cancer patients and its impact on prognosis.

METHODS

Patients who underwent radical surgery for right upper lobe cancer between 2012 and 2017 were retrospectively enrolled. The optimal number of right paratracheal lymph nodes and the relationship between the number of dissected right paratracheal lymph nodes and the prognosis of right upper non-small cell lung cancer were analysed.

RESULTS

A total of 241 patients were included. The optimal number of dissected right paratracheal lymph nodes was 6. The data were divided according to the number of dissected right paratracheal lymph nodes into groups RPLND + (≥ 6) and RPLND- (< 6). In the stage II and III patients, the 5-year overall survival rates were 39.0% and 48.2%, respectively (P = 0.033), and the 5-year recurrence-free survival rates were 32.8% and 41.8%, respectively (P = 0.043). Univariate and multivariate analyses revealed that among the stage II and III patients, ≥ 6 right paratracheal dissected lymph nodes was an independent prognostic factor for overall survival (HR = 0.53 95% CI 0.30-0.92 P = 0.025) and recurrence-free survival (HR = 1.94 95% CI 1.16-3.24 P = 0.011).

CONCLUSIONS

Resection of 6 or more right paratracheal lymph nodes may be associated with an improved prognosis in patients with right upper non-small cell lung cancer, especially in patients with stage II or III disease.

Preservation vs. dissection of inferior pulmonary ligament for thoracoscopic upper lobectomy: a prospective randomized controlled trial

OBJECTIVES

The proper procedure for inferior pulmonary ligament (IPL) during upper lobectomy remains a topic of debate. To address this matter, we carried out a trial comparing the clinical outcomes of IPL preservation versus IPL dissection during thoracoscopic upper lobectomy (TUL).

METHODS

Patients undergoing thoracoscopic left/right upper lobectomy (TLUL/TRUL) were assigned to either the dissection group (Group D) or the preservation group (Group P). Our primary objective was to quantify and compare the alterations in postoperative residual bronchial angle and lung volume changes between the two groups. Our secondary objective encompassed the assessment of various other intraoperative and postoperative outcomes.

RESULTS

Following adherence to the inclusion and exclusion criteria, we enrolled 100 patients (41 left and 59 right) in Group P and 108 patients (41 left and 67 right) in Group D for the study. Our findings revealed that in TLUL, Group P was able to reduce the degree of postoperative residual bronchial angle change (P < 0.05). Conversely, the situation was distinct for TRUL. We found no notable disparity between the two groups (P > 0.05) with regard to alterations in lung volume or the occurrence of postoperative complications-except for the duration of postoperative hospital stay (P < 0.05).

CONCLUSIONS

Our study suggests IPL preservation especially for TLUL when compared to TRUL, which have important implications for the clinical management of patients undergoing upper lobectomy.

The Role of Lymphadenectomy in Early-Stage NSCLC

Lung cancer remains the leading cause of cancer-related death worldwide. The involvement of lymph nodes by the tumor has a strong impact on survival of patients. For this reason, lymphadenectomy plays a crucial role in the staging and prognosis of NSCLC, to define the most appropriate therapeutic strategies concerning the stage of the disease. To date, the benefit, in terms of survival, of the different extents of lymphadenectomy remains controversial in the scientific community. It is recognized that metastatic involvement of mediastinal lymph nodes in lung cancer is one of the most significant prognostic factors, in terms of survival, and it is therefore mandatory to identify patients with lymph node metastases who may benefit from adjuvant therapies, to prevent distant disease and local recurrences. The purpose of this review is to evaluate the role of lymphadenectomy in early-stage NSCLC in terms of efficacy and accuracy, comparing systematic, sampling, and lobe-specific lymph node dissection and analyzing the existing critical issue, through a search of the most relevant articles published in the last decades.

Lobe-specific lymph node dissection in early-stage non-small-cell lung cancer: An overview

Lymph node dissection is a vital part of surgical treatment for early-stage non-small cell lung cancer (NSCLC). Lobectomy with systematic lymph node dissection (SLND) still remains the gold standard surgical treatment for early-stage NSCLC patients. However, an increasing number of studies have demonstrated that lobe-specific lymph node dissection (L-SLND) can be used as an alternative therapy for SLND in carefully selected patients with early-stage NSCLC. However, there are no currently available evidences of review summarizing the role of L-SLDN in treating early-stage NSCLC. Therefore, we performed this literature review by summarizing the existing literatures on the lymph node drainage pattern, definition, scope and role of L-SLND in patients with early-stage NSCLC, aiming to provide evidence for the application of L-SLND in patients with early-stage NSCLC.

Mathematical models for intraoperative prediction of metastasis to regional lymph nodes in patients with clinical stage I non-small cell lung cancer

It remains challenging to determine the regions of metastasis to lymph nodes during operation for clinical stage I non-small cell lung cancer (NSCLC). This study aimed to establish intraoperative mathematical models with nomograms for predicting the hilar-intrapulmonary node metastasis (HNM) and the mediastinal node metastasis (MNM) in patients with clinical stage I NSCLC. The clinicopathological variables of 585 patients in a derivation cohort who underwent thoracoscopic lobectomy with complete lymph node dissection were retrospectively analyzed for their association with the HNM or the MNM. After analyzing the variables, we developed multivariable logistic models with nomograms to estimate the risk of lymph node metastasis in different regions. The predictive efficacy was then validated in a validation cohort of 418 patients. It was confirmed that carcinoembryonic antigen (>5.75 ng/mL), CYFRA211 (>2.85 ng/mL), the maximum diameter of tumor (>2.75 cm), tumor differentiation (grade III), bronchial mucosa and cartilage invasion, and vascular invasion were predictors of HNM, and carcinoembryonic antigen (>8.25 ng/mL), CYFRA211 (>2.95 ng/mL), the maximum diameter of tumor (>2.75 cm), tumor differentiation (grade III), bronchial mucosa and cartilage invasion, vascular invasion, and visceral pleural invasion were predictors of MNM. The validation of the prediction models based on the above results demonstrated good discriminatory power. Our predictive models are helpful in the decision-making process of specific therapeutic strategies for the regional lymph node metastasis in patients with clinical stage I NSCLC.

Membranous nephropathy in a patient with pulmonary tuberculosis infection and lung adenocarcinoma: a case report

We report a case of membranous nephropathy (MN) in a patient with tuberculosis infection and lung adenocarcinoma. A 50-year-old Filipino woman underwent a renal biopsy for the evaluation of proteinuria and hematuria. Immunofluorescence analysis revealed positive staining of IgG in the glomerular basement membrane and mesangial matrices, while electron microscopy demonstrated the presence of sub-epithelial deposits, suggesting MN. To screen for secondary causes of MN, we conducted a computed tomography (CT) scan of the chest and abdomen, which revealed a ground-glass opacity in the middle lobe of the right lung and an enlarged paraaortic lymph node. A T-SPOT test was positive, suggesting the possibility of a latent tuberculosis infection, as she was asymptomatic. A follow-up chest CT scan showed persistent presence of the ground-glass opacities, suggesting a non-infectious cause. Video-assisted thoracoscopic resection of the middle right lobe and partial resection of the lower right lobe were performed because the possibility of lung cancer could not be excluded. Notably, pathological analysis of the lung revealed adenocarcinoma in the middle lobe and epithelioid granuloma in the lower lobe, suggesting an active tuberculosis infection. One month after surgery, anti-tuberculosis treatment was initiated. Thereafter, her proteinuria, which had increased to 6 g/gCre preoperatively, began to decrease. Five months after surgery, the patient achieved complete remission. The speed of remission suggests that tuberculosis likely played a primary role in the etiology of MN. Our case underscores the importance of screening tests for infections and malignancies in patients with MN, even if suggestive symptoms are absent.

Lobe-specific lymph node dissection in stage IA non-small-cell lung cancer: a retrospective cohort study

OBJECTIVES

To investigate lymph node (LN) metastasis according to tumour location and assess the impact of lobe-specific LN dissection on survival in stage IA non-small-cell lung cancer (NSCLC).

METHODS

We retrospectively analysed the data of patients with clinical stage IA NSCLC treated with lobectomy and systematic LN dissection at Asan Medical Center (Seoul, Korea) between June 2005 and April 2017. Patients who received neoadjuvant therapy had multiple primary tumours or missed the follow-up during the first postoperative year were excluded. The patients were divided into five groups according to involved lung lobes: right upper lobe (RUL), right middle lobe (RML), right lower lobe (RLL), left upper lobe (LUL) and left lower lobe (LLL), which were further divided into subgroups according to LN station metastasis. Overall survival (OS) and the incidence of metastasis were calculated for each subgroup. Efficacy indices (EIs) were calculated to determine the correlation between each lung lobe and LN station, and the impact of the dissection of these stations on survival.

RESULTS

A total of 1202 patients were analysed. The 5-year OS in the RUL, RML, RLL, LUL and LLL groups was 74%, 88%, 78%, 80% and 75%, respectively. The incidence of single LN station metastasis was 11%, 10%, 10%, 16% and 14%, respectively. The lobe-specific LNs for RUL, RML, RLL, LUL and LLL were stations 2/3/4, 4/7, 2/4/7, 4/5/6 and 6/7/9, respectively. Moreover, the LN stations with high EIs for RUL, RML, RLL, LUL and LLL were 4, 7, 7, 5 and 7, respectively. In the RUL group, the incidence of metastasis to stations 2, 3 and 4 was 2.3%, 0.5% and 7.6%, and the EI was 0.8, 0.3 and 4.3, respectively. In RML, the incidence of metastasis to stations 4 and 7 was 4% and 6%, and the EI was 1.3 and 2.4, respectively. In RLL, the incidence of metastasis to stations 2, 4 and 7 was 4.4%, 5.6% and 8.3%, and the EI was 1.3, 1.4 and 3.3, respectively. In LUL, the incidence of metastasis to stations 4, 5 and 6 was 1.4%, 11.8% and 2.5%, and the EI was 0.4, 7.1 and 0.5, respectively. In LLL, the incidence of metastasis to stations 6, 7 and 9 was 1.1%, 5.7% and 1.7%, and the EI was 0.6, 2.3 and 0.5, respectively. Furthermore, the OS of patients with lobe-specific LN metastasis was statistically significantly different from that of the non-lobe-specific LN metastasis group with P-values of <0.001 for RUL, 0.002 for RML, 0.002 for RLL, 0.001 for LUL and 0.003 for LLL.

CONCLUSIONS

Our findings support the use of lobe-specific LN dissection in stage IA NSCLC. When LN stations with high EI were negative, LN metastasis in other stations was unlikely. The incidence of LN metastasis beyond lobe-specific LN stations was ∼1% in all subgroups. Dissection of non-lobe-specific LNs may not improve the OS; however, prospective randomized controlled trials are needed to modify the standard approach.

Surgical Consideration Based on Lymph Nodes Spread Patterns in Patients with Peripheral Right Middle Non-small Cell Lung Cancer 3 cm or Less

BACKGROUND

The optimal extent of lung resection and lymph nodes dissection for peripheral early-stage right middle non-small cell lung cancer (NSCLC) still remains controversial. In this study, we analyzed the patterns of lymph nodes metastasis (LNM) of patients with peripheral right middle NSCLC ≤ 3 cm, aiming to provide evidences for surgical choice for early-stage peripheral right middle lobe NSCLC.

METHODS

We retrospectively investigated the clinical and pathological data of patients diagnosed with peripheral right middle lobe NSCLC ≤ 3 cm between January 2015 and December 2019. The LNM patterns were analyzed by tumor size.

RESULTS

A total of 60 patients were included for analysis. The tumor size was preoperatively divided as follows: ≤ 1 cm (13 patients); > 1 cm but ≤ 2 cm (36 patients); > 2 cm but ≤ 3 cm (11 patients). Fifty-four patients were categorized as N0 group, 1 patient as N1 group, and 5 patients as N2 group. In the upper zone, 3 patients were found to have LNM. In the subcarinal zone, another 3 patients had LNM. But the lymph nodes of all these patients were negative in the lower zone. In station 10, 1 patient (1.67%) was found to have LNM, while in station 11-13, 2 patients (3.33%) were found to have LNM.

CONCLUSION

For the right middle lobe peripheral NSCLC ≤ 1 cm, sublobar resection with lymph node sampling may be a feasible treatment. For cancers > 1 cm but ≤ 2 cm, lobectomy with lobe-specific lymph node dissection (especially station 2R and 4R) may be a preferred choice. For tumors > 2 cm but ≤ 3 cm, lobectomy with systematic lymph node dissection may still be the standard of care.

New N1/N2 classification and lobe specific lymphatic drainage: Impact on survival in patients with non-small cell lung cancer treated with surgery

OBJECTIVE

to validate the proposed N descriptor revision on a large cohort of patients and assess the impact of tumour location on the distribution pattern of lymph node metastases for patients with NSCLC.

METHODS

This is a retrospective review of a consecutive series of patients who had anatomical lung resections. Systematic lymph node dissection was done for all patients.

RESULTS

Between January 2009 and December 2019 2566 patients had surgical resection for NSCLC. 448 patients (17.5%) had histologically confirmed lymph node metastases: 257 (57.4 %) had pN1 and 191 pN2. Median age of the study population was 69.1 years. Overall survival (OS) for study population was 37.3 months with 5-year survival rate of 35.7 %. The survival analysis of the N subgroups showed the pN2 patients had a median OS of 27.9 months vs. 41.7 months for pN1 patients (p = 0.013). Analysis as per the new proposal of the N subgroups N1a vs N1b vs N2a1 vs N2a2 vs N2b showed that median survival OS was 41.7 vs. 39.2 mo vs. 33.3 mo vs. 28.9 mo vs. 24.6 mo (p = 0.099). There was statistically significant difference in survival between N2 patients with skip metastasis and N2 patients without skip metastases: OS 32.2 (95 % CI: 16.8-47.6) months vs. 24.2 months (p = 0.024). On multivariate analysis only pathological N (p = 0.011) and the new proposed N classification (p = 0.006) were independent prognostic factors for survival.

CONCLUSIONS

N1 and N2 disease are heterogeneous groups and require further stratification. The number of N2 lymph node stations involved and the presence or not of N1 disease translated to significant differences in survival and therefore have to be included in N staging.

ACR Appropriateness Criteria® Noninvasive Clinical Staging of Primary Lung Cancer

Lung cancer is the leading cause of cancer-related deaths in both men and women. The major risk factor for lung cancer is personal tobacco smoking, particularly for small-cell lung cancer (SCLC) and squamous cell lung cancers, but other significant risk factors include exposure to secondhand smoke, environmental radon, occupational exposures, and air pollution. Education and socioeconomic status affect both incidence and outcomes. Non-small-cell lung cancer (NSCLC), including adenocarcinoma, squamous cell carcinoma, and large cell carcinoma, comprises about 85% of lung cancers. SCLC accounts for approximately 13% to 15% of cases. Prognosis is directly related to stage at presentation. NSCLC is staged using the eighth edition of the tumor-node-metastasis (TNM) criteria of the American Joint Committee on Cancer. For SCLC the eighth edition of TNM staging is recommended to be used in conjunction with the modified Veterans Administration Lung Study Group classification system distinguishing limited stage from extensive stage SCLC. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Early removal of chest tubes leads to better short-term outcome after video-assisted thoracoscopic surgery lung resection

Background

Currently, some studies have shown that early removal of a chest tube after video-assisted thoracoscopic surgery (VATS) lobectomy is safe and can shorten the length of hospital stay. The purpose of our study was to retrospectively analyze the association between early chest tube removal and hospital stay in patients who have undergone lobectomy.

Methods

This retrospective analysis included patients undergoing different types of lung resections including lobectomy and wedge resection. Consecutive patients who underwent VATS lobectomy or wedge resection (March 2018 to April 2019) for lung tumor were analyzed. Patients were divided into two groups according to the drainage time: those in whom the chest tube was removed within 48 hours and the traditional management group.

Results

All 931 patients were included. After propensity score matching (PSM). There are no statistically significant differences between the two groups. Compared with the traditional management group, the hospital stay in the early removal group was significantly shorter (5.05±2.27 vs. 7.17±3.03; P<0.001). Regarding complications, compared with the traditional management group, the rates of both lung infection and no complication in the early removal group were less (0.2% vs. 2.3%, 93.0% vs. 91.1%; P=0.005), and the necessity of re-operation was also less (0% vs. 1.2%; P<0.001). Regarding both pleural effusion and thoracentesis, a slight increase in the patient number was observed in the early removal group compared with the traditional management group (4.7% vs. 4.0%, 1.2% vs. 0.9%; P=0.005).

Conclusions

Compared with the traditional management group, early removal of the chest tube after VATS lobectomy and wedge resection is safe and feasible, and could decrease morbidity and postoperative complications, importantly, resulting in a shorter hospital stay.

[Analysis of lymphatic drainage pathways using infrared fluorescence in patients with lung cancer]

OBJECTIVE

To develop a method for analysis of lymphatic drainage pathways from the lobe of the lung affected by non-small cell lung cancer (NSCLC) using infrared fluorescence.

MATERIAL AND METHODS

A study enrolled patients with NSCLC who underwent anatomic resection of the lung with systematic lymph node dissection and preliminary intraoperative peritumoral injection of indocyanine green conjugate with human albumin. Registration of fluorescence in regional lymph nodes (LN) was carried out immediately after excision of specimen using the FLUM-808 instrumental system.

RESULTS

Infrared fluorescence was observed in 117 hilar and mediastinal lymph nodes from 43 patients (2.7 nodes per a patient). Comparison of localization of fluorescent LN with localization of tumor in various lobes established significant variability of lymphatic drainage pathways.

CONCLUSION

The developed method of infrared fluorescent evaluation of lymphatic drainage in patients with NSCLC confirms the necessity of systematic lymph node dissection for adequate staging.

Effect of inferior pulmonary ligament division on residual lung volume and function after a right upper lobectomy

OBJECTIVES

The requirement to divide an inferior pulmonary ligament (IPL) during an upper lobectomy has not been standardized. We evaluated the influence of the division of an IPL after a lobectomy of the right upper lobe.

METHODS

We evaluated 52 patients with lung cancer who underwent a video-assisted thoracoscopic lobectomy of the right upper lobe at Asan Medical Center between January 2011 and April 2014. These cases were stratified by division of the IPL or not, i.e. a preservation group (group P, n = 21) and a division group (group D, n = 31). The angle between the bronchus intermedius and the right middle lobe bronchus and the lung volume were measured using computed tomography. The results of the pulmonary function tests and the prevalence of complications were also reviewed.

RESULTS

The prevalences of atelectasis (P = 0.538), dead space (P = 0.084) and pleural effusion (P = 0.538) were not statistically different. The postoperative volumetric change of the right middle lobe (group P, -27 ± 97 ml; group D, -29 ± 111 ml; P = 0.950) and of the right lower lobe (group P, 397 ± 293 ml; group D, 335 ± 294 ml; P = 0.459) did not show statistical differences. The change in the bronchial angle was not statistically different between the groups (group P, -26.3 ± 13.7°; group D, -26.7 ± 13.6°; P = 0.930). The patients in group D experienced a greater loss in forced vital capacity than those in group P (group P, -0.16 ± 0.26 l; group D, -0.42 ± 0.33 l; P = 0.007), but the loss in the forced expiratory volume in 1 s was not significant (P = 0.328).

CONCLUSIONS

An IPL division does not produce significant differences in lung volume, bronchial angle change or prevalence of complications other than loss of forced vital capacity.

[The technique of thoracic lymph node dissection]

Systematic mediastinal, hilar and interlobar lymph node dissection is required in the S3 guidelines for the treatment of operable lung cancer. The lymph node involvement is considered one of the key prognostic factors. The type of lymph node resection is repeatedly the subject of controversially discussion. Lymph node dissection is essential for staging, prognosis, survival and recurrence rate. It should be standardized as a compartmental dissection with en bloc resection of lymph nodes including surrounding fat and connective tissue. Thus, exact knowledge of the anatomy of the thoracic organs with their peculiarities and high anatomical variability is necessary.

Impact of Different Types of Lymphadenectomy Combined With Different Extents of Tumor Resection on Survival Outcomes of Stage I Non-small-cell Lung Cancer: A Large-Cohort Real-World Study

Background: To investigate the prognostic impact of different types of lymphadenectomy with different extents of tumor resection on the outcomes of stage I non-small-cell lung cancer (NSCLC).

Methods: Patients were classified into lobectomy and sublobectomy groups, and then each group was subdivided according to the types of lymphadenectomy. The end points of the study were overall survival (OS) and disease-free survival (DFS). Propensity score matched (PSM) comparative analysis and univariate and multivariate Cox regression analyses were performed.

Result: A total of 1,336 patients were included in the current study. Lobectomy was associated with better OS and DFS. In the lobectomy group, lobectomy with bilateral mediastinal lymphadenectomy (BML) was associated with better OS than lobectomy with systematic nodal dissection (SND) or lobe-specific systematic node dissection (L-SND). Lobectomy with SND or L-SND was associated with better OS than lobectomy with systematic nodal sampling (SNS) or selected lymph node biopsy (SLNB). Additionally, lobectomy with BML or SND was associated with better DFS than lobectomy with L-SND or SNS or SLNB. After PSM, compared with lobectomy with SNS or SLNB, lobectomy with SND resulted in more favorable OS and DFS. There was no survival difference between different types of lymphadenectomy for patients who underwent sublobectomy. A multivariable analysis revealed independent associations of lobectomy with BML or SND with better OS and DFS compared with those of lobectomy with SNS or SLNB.

Conclusion: This study reveals an association of lobectomy with more systematic and complete lymph node dissection, such as BML or SND, with better prognosis in stage I NSCLC patients.

Systematic mediastinal lymph node dissection outcomes and conversion rates of uniportal video-assisted thoracoscopic lobectomy for lung cancer

BACKGROUND

To evaluate the systematic mediastinal lymph node (LN) dissection outcomes and conversion rates of uniportal video-assisted thoracoscopic surgery (UVATS).

METHODS

Patients with non-small-cell lung cancer who underwent video-assisted thoracoscopic surgery (VATS) and systematic mediastinal LN dissection between January 2015 and January 2017 were retrospectively reviewed. We categorized the patients into two groups according to the different surgical approaches. Patients' clinical data were collected and compared. The index of estimated benefit from LN dissection was used to evaluate the therapeutic value of LN dissection for each station.

RESULTS

A total of 453 patients underwent VATS, including 197 patients in the UVATS group and 256 patients in the triportal VATS (TVATS) group. There were no significant differences in the 1-, 2- and 3-year survival rates of these two groups (P > 0.05). There were no statistically significant differences in the operative time, numbers and stations of LNs, numbers and stations of N2 LNs, conversion rate or postoperative complications. The UVATS group had less intraoperative blood loss, a shorter duration of hospital stay, less chest tube drainage and a shorter duration of chest tube drainage than the TVATS group (P < 0.05). The conversion rates in the UVATS and TVATS groups were 5.1% and 4.3%, respectively, and the difference was not significant. The same degree of LN sampling was achieved in both groups.

CONCLUSION

UVATS permits the same degree of LN sampling as TVATS without a difference in the conversion rate.

Location of stage I-III non-small cell lung cancer and survival rate: Systematic review and meta-analysis

BACKGROUND

The association between the location of non-small cell lung cancer (NSCLC) and prognosis is a debated issue. Some studies have provided evidence of better prognosis of upper lobe tumors than lower to middle lobe tumors, while other studies have reported contrasting conclusions. The aim of this study was to further assess this association through a systematic review and meta-analysis.

METHODS

Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched up to 27 January 2017. Patients pathologically diagnosed with stage I-III NSCLC with three or five-year survival data were included. The main meta-analysis compared differences in survival rates according to the primary tumor location using the Mantel-Haenszel method with a random effect model. Sensitivity analysis was conducted according to lymph node metastasis, tumor node metastasis stage, staging method, and treatment modality.

RESULTS

Ten clinical studies and 35 570 patients were recruited. Patients with tumors in the upper lobes had a higher rate of five-year survival compared to those with tumors in non-upper lobes (odds ratio [OR] 1.31, 95% confidence interval [CI] 1.15-1.49). Similarly, the three-year survival rate was high in patients with tumors in the upper lobes (OR 1.99, 95% CI 1.02-3.86) and low in those with lower lobe tumors (OR 0.31, 95% CI 0.12-0.77).

CONCLUSIONS

Stage I-III NSCLC located in the upper lobes showed higher five-year survival rates compared to other tumor locations.

Survival rates after lobectomy versus sublobar resection for early-stage right middle lobe non-small cell lung cancer

Background

Lung cancer in the right middle lobe has a poorer prognosis than tumors located in other lobes. The optimal surgical procedure for early‐stage non‐small cell lung cancer (NSCLC) in the right middle lobe has not yet been elucidated. The aim of this study was to compare survival rates after lobectomy and sublobar resection for early‐stage right middle lobe NSCLC.

Methods

Patients who underwent lobectomy or sublobar resection for stage IA right middle lobe NSCLC tumors ≤ 2 cm between 2004 and 2014 were identified from the Surveillance, Epidemiology and End Results database of 18 registries. Cox regression model analysis was used to evaluate the prognostic factors. The lung cancer‐specific survival (LCSS) and overall survival (OS) rates between the two groups were compared.

Results

A total of 861 patients met our criteria, including 662 (76.9%) patients who underwent lobectomy and 199 (23.1%) patients who underwent sublobar resection. No statistical differences in LCSS and OS rates were identified between the groups of patients with stage IA right middle lobe NSCLC ≤ 1 cm. For tumors > 1–2 cm, lobectomy was associated with more favorable LCSS and OS rates compared to sublobar resection.

Conclusion

Lobectomy and sublobar resection deliver a comparable prognosis for patients with stage IA right middle lobe NSCLC ≤ 1 cm. For tumors > 1–2 cm, lobectomy showed better survival rates than sublobar resection.

Incidence of occult pN2 disease following resection and mediastinal lymph node dissection in clinical stage I lung cancer patients

Objectives

Early clinical stage (T1 and T2) non-small cell lung cancer (NSCLC) is commonly treated with anatomic lung resection and lymph node sampling or dissection. The aims of this study were to evaluate the incidence and the distribution of occult N2 disease according to tumour location and the short- and long-term outcomes.

Methods

We performed a retrospective review of patients with clinical stage I NSCLC who underwent anatomic lung resection and lymphadenectomy. Mediastinal lymphadenectomy (ML) was defined as resection of at least 2 mediastinal stations, always including station 7 lymph nodes. Patients who had a lobe-specific lymphadenectomy were excluded.

Results

One thousand six hundred and sixty-seven consecutive patients met inclusion criteria and were included. Overall, 9% (146/1667) of the patients had occult pN2 disease. At multivariable analysis, adenocarcinoma histology and vascular invasion were independently associated with greater risk of occult pN2 disease. In left and right upper lobe tumours, station 7 nodes were involved in 5 and 13% of pN2 positive cases, respectively. Station 5 and station 2/4 nodes were involved in 29 and 18% of left and right lower lobe pN2 tumours, respectively. There was no postoperative mortality, and postoperative morbidity was 28%. The median overall survival was 77.4 months. N0 patients had a median overall survival of 83.7 months vs 48.0 months and 37.9 months in N1 and N2 populations, respectively ( P  < 0.001).

Conclusions

Sixteen percent of pN2 patients had mediastinal lymph node metastasis beyond the lobe-specific lymphatic drainage. We recommend a complete lymphadenectomy be performed, even in clinical stage I NSCLC.

Selective lymph node dissection in early-stage non-small cell lung cancer

Lymph node dissection is a vital part of surgical treatment in early-stage non-small cell lung cancer (NSCLC). Removal of metastatic lymph nodes while preservation of intact lymph nodes are equally important. For hospitalized early-stage patients with limited lymph node metastasis, the operation treatment should be made according to some rules such as lobe-specific lymph node drainage pattern. In order to prevent unnecessary surgical trauma in early-stage patients, a minimally invasive approach with selective lymph node excision is preferred for more clinical benefits. This review summarizes the existing findings on lobe-specific lymph node drainage pattern and we hope to provide guidance for selective lymph node dissection (SLND). Furthermore, we include information on histologic views, a tumor marker and protocols of SLND, with hope to inspire creative research and clinical trials in this field.

A Model Predicting Lymph Node Status for Patients with Clinical Stage T1aN0-2M0 Nonsmall Cell Lung Cancer

Background:

Lymph node status of patients with early-stage nonsmall cell lung cancer has an influence on the choice of surgery. To assess the lymph node status more correspondingly and accurately, we evaluated the relationship between the preoperative clinical variables and lymph node status and developed one model for predicting lymph node involvement.

Methods:

We collected clinical and dissected lymph node information of 474 patients with clinical stage T1aN0-2M0 nonsmall cell lung cancer (NSCLC). Logistic regression analysis of clinical characteristics was used to estimate independent predictors of lymph node metastasis. The prediction model was validated by another group.

Results:

Eighty-two patients were diagnosed with positive lymph nodes (17.3%), and four independent predictors of lymph node disease were identified: larger consolidation size (odds ratio [OR] = 2.356, 95% confidence interval [CI]: 1.517–3.658, P < 0.001,), central tumor location (OR = 2.810, 95% CI: 1.545–5.109, P = 0.001), abnormal status of tumor marker (OR = 3.190, 95% CI: 1.797–5.661, P < 0.001), and clinical N1–N2 stage (OR = 6.518, 95% CI: 3.242–11.697, P < 0.001). The model showed good calibration (Hosmer–Lemeshow goodness-of-fit, P < 0.766) with an area under the receiver operating characteristics curve (AUC) of 0.842 (95% [CI]: 0.797–0.886). For the validation group, the AUC was 0.810 (95% CI: 0.731–0.889).

Conclusions:

The model can assess the lymph node status of patients with clinical stage T1aN0-2M0 NSCLC, enable surgeons perform an individualized prediction preoperatively, and assist the clinical decision-making procedure.

[Advances in Lymph Node Metastasis and the Modes of Lymph Node Dissection in Early Stage Non-small Cell Lung Caner]

目前，肺癌已是全球范围内发病率及死亡率最高的恶性肿瘤，非小细胞肺癌（non-small cell lung cancer, NSCLC）约占肺癌80%。手术治疗在早期NSCLC治疗中占主导地位，而淋巴结分期及手术中清扫程度直接影响着患者术后生活质量及患者的预后。解剖性肺叶切除加系统性淋巴结清扫一直以来被认为是NSCLC的标准手术方式，但对早期NSCLC患者纵隔淋巴结清扫程度问题上一直存在较大争议，精确评估区域淋巴结的转移及淋巴结清扫的程度是影响患者围手术期并发症和预后的重要因素。对于早期肺癌行肺叶特异性或选择性淋巴结清扫已逐渐为国内外学者接受，并可能成为临床Ⅰ期NSCLC患者标准淋巴结清扫方式。

Therapeutic value of lymph node dissection for right middle lobe non-small-cell lung cancer

BACKGROUND

Superior mediastinal and #11i lymph node (LN) metastases are adverse prognostic factors in patients with middle lobe lung cancer. We aimed to clarify the benefit of thorough lymphadenectomy by LN station or zone in middle lobe non-small-cell lung cancer (NSCLC).

METHODS

Among 295 patients who underwent pulmonary resection and thorough lymphadenectomy for primary right middle lobe (RML) NSCLC at two institutions, we enrolled 68 patients (33 men, 35 women) and retrospectively studied their data. We divided each N1 location (i.e., #10, #11s and #11i) into N1(-)N2(+) and N1(+)N2(+) and divided the #12m location into N1(+)N2(-), N1(-)N2(+) and N1(+)N2(+).

RESULTS

Interlobar node involvement was rare in pN1 NSCLC when compared with that in other N1 nodes. Lymph node dissection (LND) was beneficial when the hilar zone (HZ)/interlobar zone (IZ) LNs were located at the intermediate point of the upper zones (UZs) and subcarinal zones (SCZs), with the therapeutic benefit at the SCZ being 2.8-fold higher than that at the UZ and 9.7-fold higher than that at the lower zone (LZ). Furthermore, LND evidently had greater therapeutic value for the SCZ than the UZ, which was compatible with skip N2 metastases.

CONCLUSIONS

For middle lobe NSCLC, mediastinal LND should be considered a priority in the SCZ than in the UZ. Moreover, the HZ/IZ is central to unfavourable prognoses in patients with pN2 middle lobe NSCLC.

Lymph node metastasis according to primary tumor location in T1 and T2 stage non-small cell lung cancer patients

BACKGROUND

To evaluate the pattern of lymph node metastasis (LNM) according to primary tumor location in T1 and T2 stage non-small cell lung cancer (NSCLC) patients.

METHODS

The data of 1916 NSCLC patients with LNM who underwent surgery with systematic nodal resection between November 2008 to December 2014 were included in the study. Analyses of tumor location, pathological T stage, and nodal metastasis were performed.

RESULTS

In T1a stage patients, superior mediastinum, aortopulmonary, and inferior mediastinum lymph node metastases were observed in primary tumors present in the right upper lobe (RUL), left upper lobe (LUL) and right middle lobe (RML), respectively. In T1b-stage patients, superior mediastinum, aortopulmonary, and inferior mediastinum lymph node metastases were observed in the RML, LUL, and right lower lobe (RLL), respectively. In patients with T2a-stage, superior mediastinum, aortopulmonary and inferior mediastinum lymph node metastases were observed in the RUL, LUL, and RLL, respectively. However, in T2b-stage patients, RUL, LUL and RML locations were associated with superior mediastinum, aortopulmonary, and inferior mediastinum lymph node metastases, respectively. Multivariable logistic regression showed that T stage was significantly associated with mediastinal and intrapulmonary lymph node metastases. In addition, tumor location was significantly associated with N2 station LNM.

CONCLUSION

LNM varied according to tumor location and T-stage, which are independent factors influencing N2 station LNM.

Dosimetric evaluation of the feasibility of stereotactic body radiotherapy for primary lung cancer with lobe-specific selective elective nodal irradiation

More than 10% of all patients treated with stereotactic body radiotherapy (SBRT) for primary lung cancer develop regional lymph node recurrence. We evaluated the dosimetric feasibility of SBRT with lobe-specific selective elective nodal irradiation (ENI) on dose-volume histograms. A total of 21 patients were treated with SBRT for Stage I primary lung cancer between January 2010 and June 2012 at our institution. The extents of lobe-specific selective ENI fields were determined with reference to prior surgical reports. The ENI fields included lymph node stations (LNS) 3 + 4 + 11 for the right upper lobe tumors, LNS 7 + 11 for the right middle or lower lobe tumors, LNS 5 + 11 for the left upper lobe tumors, and LNS 7 + 11 for the left lower lobe tumors. A composite plan was generated by combining the ENI plan and the SBRT plan and recalculating for biologically equivalent doses of 2 Gy per fraction, using a linear quadratic model. The V20 of the lung, D(1cm3) of the spinal cord, D(1cm3) and D(10cm3) of the esophagus and D(10cm3) of the tracheobronchial wall were evaluated. Of the 21 patients, nine patients (43%) could not fulfill the dose constraints. In all these patients, the distance between the planning target volume (PTV) of ENI (PTVeni) and the PTV of SBRT (PTVsrt) was ≤2.0 cm. Of the three patients who developed regional metastasis, two patients had isolated lymph node failure, and the lymph node metastasis was included within the ENI field. When the distance between the PTVeni and PTVsrt is >2.0 cm, SBRT with selective ENI may therefore dosimetrically feasible.

[Advances of mediastinal lymph node metastasis and the extent of lymph node dissection in patients with stage T1 non-small cell lung cancer]

肺癌是我国发病率和死亡率最高的恶性肿瘤。非小细胞肺癌（non-small cell lung cancer, NSCLC）约占肺癌80%。临床上，早期NSCLC以手术治疗为主要治疗方式，淋巴结分期及手术中清扫程度直接影响着患者的预后。不同肺叶原发NSCLC的淋巴结转移区域存在一定规律。解剖性肺叶切除加系统性淋巴结清扫一直以来被认为是NSCLC的标准手术方式，但近年来T1期NSCLC手术中纵隔淋巴结清扫的程度存在较大争议，选择性淋巴结清扫已逐渐被大多数学者所重视。

Is the lymphatic drainage of lung cancer lobe-specific? A surgical appraisal

OBJECTIVES

Nowadays, early-stage lung cancers are more frequently encountered. Selective lymph node (LN) dissection based on lobe-specific lymphatic pathway has been proposed. Our aim was to study nodal involvement according to tumour location.

METHODS

We reviewed 1779 lobectomized patients and analysed their pathological characteristics according to tumour location: Group 1 (G1), right upper lobe; Group 2 (G2), right middle lobe; Group 3 (G3), right lower lobe; Group 4 (G4), left upper division; Group 5 (G5), lingula; Group 6 (G6), left lower lobe. The pN status was recorded for each group to analyse the lymphatic spread of non-small-cell lung cancer (NSCLC) according to tumour location.

RESULTS

The numbers and proportions of lobectomies in each group were 613 patients in G1 (59.2%), 64 in G2 (6.4%), 359 in G3 (34.6%), 404 in G4 (54.3%), 54 in G5 (7.3%) and 286 in G6 (38.4%). The rates of pN2 involvement were similar, whatever the group was, even when deciphering single- and multistation diseases. on the right side, single-station N2 disease was mainly found in the superior mediastinum (SM) for G1 (95%), and in the inferior for G3 (90%). On the left side, single-station N2 was mainly found in the SM in G4 (94%), and the inferior in G6 (48%). Whatever the side, in case of two-station involvement, both mediastina were concerned in 40% (in G4) to 81% of the case (in G3). Long-term survival rates were different in skip metastasis, single- and multistation involvement, but not between lobes.

CONCLUSIONS

Tumour location is not a predictor of nodal metastasis pattern. In surgical treatment of NSCLC, complete systematic mediastinal LN dissection remains the only acceptable procedure from an oncological point of view.

Lobe-specific mediastinal nodal dissection is sufficient during lobectomy by video-assisted thoracic surgery or thoracotomy for early-stage lung cancer

BACKGROUND

Lobectomy with complete mediastinal lymphadenectomy is considered standard for patients with early-stage non-small cell lung cancer (NSCLC). However, the benefits of complete lymphadenectomy are unproven. There is evidence suggesting a predictable pattern of mediastinal nodal drainage. This study analyzed the frequency and pattern of mediastinal nodal disease and its impact on outcome in patients with early-stage NSCLC.

METHODS

Patients with clinical N0/N1 NSCLC staged with CT scans and PET scans were identified. Disease involvement of resected nodal stations was recorded. Patterns of recurrence in patients who underwent lobectomy with complete mediastinal systematic lymph node sampling (SLNS) were compared with those who underwent lobe-specific mediastinal SLNS.

RESULTS

From July 2004 to April 2011, 370 patients were identified. Complete SLNS was performed in 282 patients. Fifteen patients (5.3%) in the group with complete SLNS were found to have N2 disease after pathologic evaluation. Patients with left-sided tumors were more likely to have pathologic N2 disease than were patients with right-sided tumors (P = .03). Only one patient (0.36%) had positive N2 disease in the distal mediastinum while skipping lobe-specific mediastinal nodes. In addition, patients with complete SLNS had a rate of recurrence similar to that of the group that had lobe-specific mediastinal evaluation (20.6% vs 18.2%, P = .68).

CONCLUSIONS

Mediastinal N2 metastases follow predictable lobe-specific patterns in patients with negative preoperative CT scans and PET scans. Lobe-specific N2 nodal evaluation results in a recurrence rate similar to that of complete mediastinal evaluation. Lobe-specific mediastinal nodal evaluation appears acceptable in patients with early-stage NSCLC.

The use and misuse of positron emission tomography in lung cancer evaluation

This article discusses the potential benefits and limitations of positron emission tomography (PET) for characterizing lung nodules, staging the mediastinum, identifying occult distant metastasis, determining prognosis and treatment response, guiding plans for radiation therapy, restaging during and after treatment, and selecting targets for tissue sampling. The key findings from the medical literature are presented regarding the capabilities and fallibilities of PET in lung cancer evaluation, including characterization of pulmonary nodules and staging in patients with known or suspected non-small-cell lung cancer. The discussion is limited to PET imaging with fluorodeoxyglucose.

Endoscopic ultrasonography/fine-needle aspiration and endobronchial ultrasonography/fine-needle aspiration for lung cancer staging

This article reviews different techniques available for diagnosis and staging of patients with non-small cell lung cancer (NSCLC). The advantages and disadvantages of each staging method are highlighted. The role of the gastroenterologist in NSCLC staging is explored. A new algorithm is proposed for the staging of NSCLC that incorporates endoscopic and endobronchial ultrasonography for mediastinal staging in patients with intrathoracic disease.

Pulmonary lymphatic drainage to the mediastinum based on computed tomographic observations of the primary complex of pulmonary histoplasmosis

BACKGROUND

In the primary infection of pulmonary histoplasmosis, pulmonary lesions are commonly solitary and associated with hilar and/or mediastinal nodal diseases, which spontaneously resolve, resulting in calcifications in individuals with normal cellular immunity.

PURPOSE

To assess the lymphatic drainage to the mediastinum from each pulmonary segment and lobe using computed tomographic (CT) observations of a calcified primary complex pulmonary histoplasmosis and predict which patients with N2 disease that would benefit from surgery.

MATERIAL AND METHODS

We collected 585 CT studies of patients with primary complex histoplasmosis consisting of solitary calcified pulmonary lesions and calcified hilar and/or mediastinal nodal disease. Using the N stage criteria of non-small cell lung cancer, we assessed the distribution of the involved hilar and mediastinal nodes depending on the pulmonary segment of the lesion, with a focus on skip involvement. We also assessed the correlation between the incidence of N1 and skip N2 involvement and the mean number of involved mediastinal nodal stations in the non-skip N2 and skip N2 groups.

RESULTS

Skip involvement was common in the apical segment (9/45, 20.0%), posterior segment (7/31, 22.6%), and mediolbasal segment (13/20, 65.0%) in the right lung, and in the apicoposterior segment (7/55, 12.7%), lateral basal segment (6/26, 23.1%), and posterobasal segment (16/47, 34.0%) in the left lung. The incidence of skip involvement in each segment showed a significant inverse correlation with that of N1 involvement (r = -0.51, P <0.05) in both lungs. The mean number of involved mediastinal nodal stations in the non-skip N2 and skip N2 groups in all segments of both lungs were 1.4 (434/301) and 1.2 (93/77), and the former was significantly greater than the latter (P <0.01).

CONCLUSION

Our data showed a predictable pattern of segmental and lobar lymphatic drainage to the mediastinum and suggested that skip involvement could represent the initial mediastinal node involvement via direct lymphatic drainage.

[Progress of lymphadenectomy on lung cancer surgery]

淋巴道转移是肺癌最主要的转移途径，也是影响肺癌患者预后的主要因素之一。目前，淋巴结清扫已成为标准肺癌手术的重要组成部分。但是到目前为止，对于不同病理类型、不同病理分期、不同肺叶的肺癌而言，术中淋巴结的清扫方式及范围仍存在一定的争议。本文拟就目前肺癌手术中淋巴结清扫的临床意义、清扫方式、清扫范围的研究新进展进行综述。

Tumor location is not an independent prognostic factor in early stage non-small cell lung cancer

BACKGROUND

Conventional thoracic surgical teaching suggests a worse outcome for lower lobe lung cancers. It is unclear whether this is due to stage migration or whether lobar location is an independent negative prognostic factor.

METHODS

We performed a retrospective review of our institutional database of patients undergoing resection for pathologic stage I or stage II lung cancer between Jan 2000 and December 2006. Survival analysis was used to compare outcomes in various groups using the log-rank test. Logistic regression analysis was used to compare the primary dependent variables; age, size, and location of tumor (both laterality and lobe), histology (adenocarcinoma, squamous, large cell, or neuroendocrine and others) and type of resection (wedge, lobectomy or segmentectomy, and pneumonectomy).

RESULTS

A total of 841 patients met the inclusion criteria. The mean age of patients was 64.9 years, mean tumor size 3.3 cm, and, 144 patients had N1 disease. The three-year and five-year survivals for stage I tumors were 346 of 478 (72.4%) and 277 of 497 (55.7%), respectively. There was no difference in survival based upon lobar location. The three-year and five-year survivals for stage II tumors were 81 of 175 (46.3%) and 39 of 150 (26%), respectively, and lobar location did not influence survival. Logistic regression analysis showed that for stage I tumors increasing age and having undergone a pneumonectomy were associated with worse survival, and for stage II tumors increasing age and adenocarcinoma histology were associated with worse survival.

CONCLUSIONS

Tumor location within the lung does not predict survival in pathologic stage I/II non-small cell lung carcinoma. Increasing age, adenocarcinoma histology, and pneumonectomy as the resection may lead to worse long-term survival.

Joint use of cervical mediastinoscopy and video-assisted thoracoscopy for the evaluation of mediastinal lymph nodes in patients with non-small cell lung cancer

OBJECTIVE

To evaluate the efficacy of the joint use of cervical mediastinoscopy and video-assisted thoracoscopy for the sampling of mediastinal lymph nodes in patients with non-small cell lung cancer (NSCLC) and candidates for pulmonary resection.

METHODS

Sixty-two patients diagnosed with NSCLC were submitted to cervical mediastinoscopy and video-assisted thoracoscopy. The samples obtained (from paratracheal chains, anterior and posterior subcarinal chains, paraesophageal chains and pulmonary ligament) were submitted to frozen section analysis. The following variables were also evaluated: age; gender; weight loss; diagnostic method; tomographic findings; histological type; staging; and location and size of the primary tumor.

RESULTS

In 11 patients, mediastinoscopy showed no involvement of the subcarinal chain, whereas such involvement was identified when video-assisted thoracoscopy was used: positive predictive value = 88.89% (95% CI: 51.75-99.72); negative predictive value = 94.34% (95% CI: 84.34-98.82); prevalence = 17.74% (95% CI: 9.2-29.53); sensitivity = 72.73% (95% CI: 39.03-93.98); and specificity = 98.77% (95% CI: 93.31-99.97). In 60% of the patients with involvement of the posterior subcarinal chain, the primary tumor was in the right inferior lobe. (p = 0.029)

CONCLUSIONS

The joint use of cervical mediastinoscopy and video-assisted thoracoscopy for the evaluation of posterior mediastinal lymph nodes proved to be an efficacious method. When there is no access to posterior chains by means of ultrasound with transbronchial or transesophageal biopsy, which dispenses with general anesthesia, this should be the method of choice for the correct evaluation of mediastinal lymph nodes in patients with NSCLC.

N2 disease in T1 non-small cell lung cancer

BACKGROUND

The optimal management strategy for mediastinal staging in early-stage non-small cell lung cancer (NSCLC) is not clearly defined. The true prevalence of mediastinal lymph node metastases (N2 disease) in resected pathologic T1 (pT1) NSCLC must be known to define the role of invasive mediastinal staging in these patients.

METHODS

Data of patients with pT1 lesions resected at Mayo Clinic between 1998 and 2006 were retrospectively reviewed. Patients with N2 disease were identified from pathology and operative reports. We reviewed demographics, radiologic data, and surgical procedures for those with pathologic T1 N2 NSCLC.

RESULTS

We identified 968 cases of pT1 lesions, 59 with pN2 disease (6.1%). For those with T1 N2 disease, the primary lung lesion was peripheral in 18 (31%) and central in 41 (69%). Of these, 36 had negative non-invasive mediastinal staging (3.7%) and were incidentally discovered. The most frequently affected lymph node station was 7 in 22 patients (37%), followed by 5,6 in 18 (31%). Mediastinoscopy found positive lymph nodes in 3 of 16 patients (19%) in which it was performed. Overall 5-year survival for pT1 N2 incidentally discovered during mediastinal lymph node dissection at the time of lung resection was 46% (95% confidence interval, 31% to 68%).

CONCLUSIONS

True pT1 NSCLC harbors a relatively low rate of N2 disease. The rate of occult N2 disease not observed on noninvasive preoperative mediastinal staging is even lower. For patients with T1 NSCLC and negative mediastinal imaging, routine mediastinoscopy results in a low yield of occult N2 disease discovery.