A Comprehensive Comparison of Different Nodal Subclassification Methods in Surgically Resected Non-Small-Cell Lung Cancer Patients.

INTRODUCTION: The revision of the N descriptor in non-small-cell lung cancer has been widely discussed in the past few years. Many different subclassification methods based on number or location of lymph nodes have been proposed for better distinguishing different N patients. This study aimed to systematically collect them and provide a comprehensive comparison among different subclassification methods in a large cohort. METHOD: Pathological N1 or N2 non-small-cell lung cancer patients undergoing surgical resection between 2005 and 2016 in the Western China Lung Cancer Database were retrospectively reviewed. A literature review was conducted to collect previous subclassification methods. Kaplan-Meier and multivariable Cox analyses were used to examine the prognostic performance of subclassification methods. Decision curve analysis, Akaike's information criterion, and area under the receiver operating curve concordance were also performed to evaluate the standardized net benefit of the subclassification methods. RESULTS: A total of 1625 patients were identified in our cohort. Eight subclassification methods were collected from previous articles and further grouped into subclassification based on number categories (node number or station number), location categories (lymph node zone or chain) or combination of number and location categories. Subclassification based on combination of lymph node location and number tended to have better discrimination ability in multivariable Cox analysis. No significant superiority among the different subclassification methods was observed in the three statistical models. CONCLUSION: Subclassification based on the combination of location and number could be used to provide a more accurate prognostic stratification in surgically resected NSCLC and is worth further validation.

A new basic thoracoscopic surgical skill training and assessment system using automatic scoring techniques.

PURPOSE: We report a new thoracoscopic surgical skill training and assessment system with automatic scoring techniques, the Huaxi Intelligent Thoracoscopic Skill Training and Assessment (HITSTA) system. We also evaluated the discriminative ability of this system compared to our conventional scoring method at our institution. METHODS: We retrospectively collected training data of thoracic board-certified thoracic surgeons at West China Hospital, Sichuan University from January 1, 2018 to January 1, 2019. Surgeons were assessed by HITSTA system and human examiners simultaneously. Total scores were summed from 3 tasks (grasping with delivery, pattern cutting, and suture with knot). Bland-Altman analysis was used to test agreement of scores made by HITSTA system (automatic scoring) and human examiners (manual scoring). Differentiation ability was also compared between the two scoring methods. RESULTS: Thirty-nine surgeons were recruited. Scores made by HITSTA system and human examiners were not consistent. For suture with knot, automatic scoring method could detect the score differences between different training status (trained: 26.92 ± 12.04, untrained: 19.85 ± 11.12; p = 0.026) and training duration (< 10 h: 20.67 ± 15.23, ≥ 10 h: 31.92 ± 5.56; p = 0.003). For total scores, automatic scoring approach could discriminate between different training status (trained: 71.90 ± 12.63; untrained: 61.41 ± 13.87; p = 0.016) and training duration (< 10 h: 65.23 ± 15.31; ≥ 10 h 77.23 ± 6.94; p = 0.046). CONCLUSION: HITSTA system could discriminate the different levels of thoracoscopic surgical skills better than the traditional manual scoring method. Larger prospective studies are warranted to validate the differentiation ability of HITSTA system.

Clinical significance of tumour mutation burden in immunotherapy across multiple cancer types: an individual meta-analysis.

BACKGROUND: Biomarkers for stratifying patients that could benefit from immune checkpoint inhibitors are necessary. Tumour mutation burden has recently become a promising biomarker in cancer, but the associations between tumour mutation burden and outcomes of immune checkpoint inhibitors treatment were not well-documented in present studies. METHODS: We searched PubMed, Web of Science and EMBASE databases up to 1 October 2019. Studies evaluated the association between tumour mutation burden and clinical outcomes were included. Hazard ratios and odds ratios were applied to estimate the association of tumour mutation burden score with overall survival, progression-free survival and response rate, respectively. The best cut-off value was chosen by best discriminated overall survival using Contal and O'Quigley method. RESULTS: Twenty-two studies involving 6171 patients in diverse cancers were included. The individual participant data meta-analysis demonstrated that high tumour mutation burden was associated with better overall survival (HR = 0.57, 95% CI = 0.50-0.64) and progression-free survival (HR = 0.50, 95% CI = 0.40-0.63) and higher response rate. The best cut-off values in each cancer type were 17.7/MB in non-small cell lung cancer, 7.9/MB in bladder cancer, 6.1/MB in melanoma, 12.3/MB in colorectal cancer, 6.9/MB in esophagogastric cancer, 10.5/MB in head and neck cancer. The pooled meta-analysis showed the prognosis value was robust and the sensitivity, specificity and area under the receiver operating characteristic curves in predicting response rates were 0.63, 0.71 and 0.73, respectively. CONCLUSIONS: The present meta-analysis indicates tumour mutation burden is a promising predictor of immune checkpoint inhibitors therapy but the cut-off value differs in different cancers.

Prognostic value of lymph node ratio in non-small-cell lung cancer: a meta-analysis.

BACKGROUND: This meta-analysis aimed to investigate the prognostic value of lymph node ratio in non-small-cell lung cancer. METHODS: We searched systematically for eligible studies in PubMed, Web of Science, Medline (via Ovid) and Cochrane library through 6 November 2018. The primary outcome was overall survival. Disease-free survival and cancer-specific survival were considered as secondary outcomes. Hazard ratio with corresponding 95% confidence interval were pooled. Quality assessment of included studies was conducted. Subgroup analyses were performed based on N descriptors, types of tumor resection, types of lymphadenectomy and study areas. Sensitivity analysis and evaluation of publication bias were also performed. RESULTS: Altogether, 20 cohorts enrolling 76 929 patients were included. Mean Newcastle-Ottawa Scale was 7.65 ± 0.59, indicating the studies' quality was high. The overall result showed non-small-cell lung cancer patients with lower lymph node ratio was associated with better overall survival (HR: 1.946; 95% CI: 1.746-2.169; P < 0.001), disease-free survival (HR: 2.058; 95% CI: 1.717-2.467; P < 0.001) and cancer-specific survival (HR: 2.149; 95% CI: 1.864-2.477; P < 0.001). Subgroup analysis prompted types of lymphadenectomy and the station of positive lymph node have an important effect on the prognosis. No significant discovery was found in sensitivity analysis. CONCLUSION: Patients with lower lymph node ratio was associated with better survival, indicating that lymph node ratio may be a promising prognostic predictor in non-small-cell lung cancer. The type of lymphadenectomy, an adequate examined number and the removed stations should be considered for more accurate prognosis assessment.

Efficiency and safety of TachoSil® in the treatment of postoperative air leakage following pulmonary surgery: a meta-analysis of randomized controlled trials.

OBJECTIVE: There has been still no consensus whether to apply TachoSil® to reduce the incidence of air leakage after pulmonary surgery. We conducted this meta-analysis of randomized controlled trials (RCTs) to identify the efficiency and safety of TachoSil® applied in the prevention of postoperative air leakage following pulmonary surgery. METHODS: We performed a systematic electronic search through EMABSE, PubMed and Web of Science up to March 2018. Summary risk ratio (RR) and weight mean difference (WMD) with corresponding 95% confidence intervals (CI) were calculated to analyze the outcomes. Fixed effect or random effect model was used to pool the estimates. Two independent reviewers assessed the quality of included studies using Cochrane risk-of-bias tool for RCTs. RESULTS: We included six RCTs with a total of 921 patients. Compared with standard treatment (suturing, stapling techniques or electrocautery), TachoSil® was associated with the decreased air leak duration (WMD: -3.32 days; 95% CI: -5.34--1.31; P = 0.001), chest tube duration (WMD: -1.99 days; 95% CI: -3.14--0.84; P = 0.0007), hospital stay (WMD: -1.89 days; 95% CI: -2.42--1.35; P < 0.0001), and incidence of prolonged air leak (RR: 0.57; 95% CI: 0.35-0.92; P = 0.02). No significant difference was found between the two groups regarding the incidence of postoperative complications (RR: 0.86; 95% CI: 0.69-1.06; P = 0.16). CONCLUSIONS: TachoSil® was safe, cost-effective and superior over standard treatment for patients who underwent pulmonary surgery in decreasing incidence of postoperative air leak, air leak duration, chest tube duration and the length of hospital stay.

Video-assisted thoracoscopic surgery versus muscle-sparing thoracotomy for non-small cell lung cancer: a systematic review and meta-analysis.

BACKGROUND: It has been widely accepted that video-assisted thoracoscopic surgery (VATS) lobectomy is superior to conventional open thoracotomy lobectomy in many aspects. However, the direct comparison between VATS and Muscle-sparing thoracotomy (MST) has not been widely conducted. We aimed to compare the perioperative outcomes in non-small cell lung cancer (NSCLC) patients following VATS and MST. METHODS: PubMed, EMBASE, the Cochrane Library and Web of Science were searched for relevant studies. The retrieval time was up to April 24, 2019. Studies investigating the comparison of video-assisted thoracoscopy and muscle-sparing thoracotomy were included in our meta-analysis. Odds ratio and mean differences with 95% confidential interval were applied to determine the effectiveness of dichotomous or continuous variables respectively. RESULTS: A total of 10 studies were included with 1514 patients. Compared with MST, the incidence of postoperative complications in VATS [OR = 0.54; 95%CI(0.4, 0.73); P < 0.001] and the hospital stay [MD = -1.5; 95%CI(- 2.28, - 0.73); P = 0.0001] decreased significantly, chest tube drainage time [MD = -0.71; 95%CI(- 1.18, - 0.24); P = 0.003] were shorter and the intraoperative blood loss [MD = - 43.87; 95%CI(- 73.66, - 14.08); P = 0.004] were less in VATS group. VATS also showed a relatively longer operative time [MD = 17.11; 95%CI(2.38, 31.85); P = 0.02]. However, no significant differences were observed in numbers of resected lymph nodes, postoperative mortality, postoperative pneumonia and postoperative bleeding. CONCLUSION: Compared with MST, VATS was associated with lower incidence of postoperative complications, shorter length of hospital stay, less intraoperative blood loss and less chest tube drainage, which showed that VATS was a comparable method to MST. Meanwhile, these results should be further conformed by more randomized control trials.

High postoperative monocyte indicates inferior Clinicopathological characteristics and worse prognosis in lung adenocarcinoma or squamous cell carcinoma after lobectomy.

BACKGROUND: Peripheral monocyte count is an assessable parameter. Recently, evidence suggested an elevated preoperative monocyte counts predicting poor prognosis in malignancies. The aim of this study was to determine the prognostic effect of early postoperative blood monocyte count in patients with lung adenocarcinoma or squamous cell carcinoma following lobectomy. METHODS: We retrospectively reviewed patients with operated lung adenocarcinoma or squamous cell carcinoma from 2006 to 2011 in Western China Lung Cancer database. Univariate analysis on disease-free survival (DFS) and overall survival (OS) was performed using the Kaplan-Meier and log-rank tests, and multivariate analysis was conducted using the Cox proportional hazards regression model. RESULTS: There were 433 patients enrolled in our analysis. High postoperative elevated monocyte was associated with male gender (P < 0.001), positive smoking history (P = 0.005), and higher N stage (P = 0.002) and higher tumor stage (P = 0.026). Two-tailed log-rank test indicated patients with an early postoperative elevated monocyte count predicted a poor DFS and OS overall (P < 0.001, P < 0.001, respectively) as well as in subgroup analysis, and further presented as a promising independent prognostic factor for both DFS and OS (HR = 2.991, 95%CI: 2.243-3.988, P < 0.001; HR = 2.705, 95%CI: 1.977-3.700, P < 0.001, respectively) on multivariate analysis. However, no significance was detected for preoperative monocyte in multivariate analysis. CONCLUSIONS: Elevated early postoperative peripheral monocyte count was an independent prognostic factor of poor prognosis and inferior clinicopathological features for patients with operable lung adenocarcinoma or squamous cell carcinoma by lobectomy.

Effect of histological subtype on the efficacy of perioperative chemotherapy in pulmonary sarcomatoid carcinoma: a retrospective study based on SEER population.

Background: The efficacy of perioperative chemotherapy (PC) in pulmonary sarcomatoid carcinoma (PSC) is controversial. We conducted this study to investigate the effect of different histological subtypes on the efficacy of PC in PSC patients. Methods: Clinicopathological data of 811 PSC patients of different histological subtypes were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan-Meier method and log-rank test were used to evaluate the effects of PC on the overall survival (OS) and cancer-specific survival (CSS) in different subtypes of PSC patients. Propensity score matching (PSM) was used to reduce potential confounding effects. Subgroup analyses were conducted to further investigate the efficacy of PC in patients with different characteristics. Results: A total of 210 (25.89%) enrolled PSC patients received PC. PC was not associated with OS or CSS benefit in pleomorphic carcinoma, giant cell carcinoma, or spindle cell carcinoma patients, neither before nor after matching. But survival benefit of PC was observed in carcinosarcoma patients both before (5-year OS: 48.79% vs. 38.75%, P=0.01) and after (5-year OS: 51.29% vs. 17.54%, P=0.003) matching. Subgroup analyses showed that in patients whose tumor larger than 4 cm, PC was still associated with improved survival in carcinosarcoma, but not in the other histological subtypes of PSC. Conclusions: The efficacy of PC varies between different subtypes of PSC. Survival benefit of PC was only observed in carcinosarcoma patients, but not in pleomorphic carcinoma, giant cell carcinoma, or spindle cell carcinoma patients. Histological subtype should be considered when treating PSC patients with PC.

A nomogram predicting the risk of extrathoracic metastasis at initial diagnosis of T≤3cmN0 lung cancer.

Background: The risk and risk factors of extrathoracic metastasis at initial diagnosis in T≤3cmN0 lung cancer patients are not fully understood. We aimed to develop a model to predict the risk of extrathoracic metastasis in those patients. Methods: Clinicopathological data of patients were collected from Surveillance, Epidemiology, and End Results (SEER) database. Univariable and multivariable analyses using logistic regression were conducted to identify risk factors. A predictive model and corresponding nomogram were developed based on the risk factors. The model was assessed using the area under the receiver operating characteristic curve (AUC), Hosmer-Lemeshow test, and decision curve. Results: A total of 20,057 T≤3cmN0 patients were enrolled, of whom 251 (1.25%) were diagnosed with extrathoracic metastasis at the initial diagnosis. Aged ≤50 [odds ratio (OR): 2.05, 95% confidence interval (CI): 1.19-3.53, P=0.01] and aged ≥81 [1.65 (1.05-2.58), P=0.03], Hispanic [1.81 (1.20-2.71), P=0.004], location of bronchus [3.18 (1.08-9.35), P=0.04], larger tumor size, pleural invasion, and a history of colorectal cancer [2.01 (1.01-4.00), P=0.046] were independent risk factors. In the training cohort and validation cohort, the AUCs of the developed model were 0.727, 0.728 respectively, and the results of Hosmer-Lemeshow test were P=0.47, P=0.61 respectively. The decision curve showed good clinical meaning of the model. Conclusions: Extrathoracic metastasis at initial diagnosis in T≤3cmN0 lung cancer patients was not rare. The model based on the risk factors showed good performance in predicting the risk of extrathoracic metastasis.

Lymph node dissection of station 8 improves the survival of T≤3 cmN0M0 lung adenocarcinoma patients.

Background: Mediastinal station 8 lymph node dissection (8LND) is recommended by guidelines but not routinely performed in real world clinical practice. This study aimed to investigate the effect of 8LND on the prognosis of pT≤3 cmN0M0 lung adenocarcinoma. Methods: Patients undergoing lobectomy were retrospectively enrolled from West China Hospital from 2011 to 2019. Kaplan-Meier method and log-rank test were used to investigate the effects of 8LND on the progression-free survival (PFS), overall survival (OS), and cancer-specific survival (CSS). Propensity score matching (PSM) was used to reduce the confounding effects. Multivariable analysis was conducted to evaluate the effect of 8LND in the matched patients. Subgroup analyses were conducted to further identify patients who might benefit from 8LND. Results: A total of 1,209 patients were enrolled and 261 (21.59%) patients underwent 8LND. Before PSM, for patients who received 8LND (8LND+ patients) and who did not (8LND- patients), the 5-year PFS was 91.34%, 88.03% (P=0.03) respectively, the 5-year OS was 97.10%, 92.78% (P=0.03) respectively, and the 5-year CSS was 97.67%, 93.59% (P=0.05) respectively. After PSM, 8LND+ patients still had better PFS (P=0.006), OS (P=0.01), and CSS (P=0.03) as compared to 8LND- patients. Multivariable analyses showed that 8LND was associated with lower risk of disease progression [hazard ratio (HR): 0.46; 95% confidence interval (CI): 0.26-0.80; P=0.007], and lower risk of death (HR: 0.33; 95% CI: 0.13-0.85; P=0.02). The survival benefit of 8LND was still found in subgroup analyses in male patients, smokers, patients with a pT2 tumor (≤3 cm), and patients with a poorly differentiated tumor. Conclusions: 8LND could improve the survival of T≤3 cmN0M0 lung adenocarcinoma patients. Routine 8LND is recommended, especially in male, smokers, patients with a pT2 tumor (≤3 cm), and patients with a poorly differentiated tumor.

The Gap in the Thickness: Estimating Effectiveness of Pulmonary Nodule Detection in Thick- and Thin-Section CT Images with 3D Deep Neural Networks.

BACKGROUND AND OBJECTIVES: There is a noticeable gap in diagnostic evidence strength between the thick and thin scans of Low-Dose CT (LDCT) for pulmonary nodule detection. When the thin scans are needed is unknown, especially when aided with an artificial intelligence nodule detection system. METHODS: A case study is conducted with a set of 1,000 pulmonary nodule screening LDCT scans with both thick (5.0mm), and thin (1.0mm) section scans available. Pulmonary nodule detection is performed by human and artificial intelligence models for nodule detection developed using 3D convolutional neural networks (CNNs). The intra-sample consistency is evaluated with thick and thin scans, for both clinical doctor and NN (neural network) models. Free receiver operating characteristic (FROC) is used to measure the accuracy of humans and NNs. RESULTS: Trained NNs outperform humans with small nodules < 6.0mm, which is a good complement to human ability. For nodules > 6.0mm, human and NNs perform similarly while human takes a fractional advantage. By allowing a few more FPs, a significant sensitivity improvement can be achieved with NNs. CONCLUSIONS: There is a performance gap between the thick and thin scans for pulmonary nodule detection regarding both false negatives and false positives. NNs can help reduce false negatives when the nodules are small and trade off the false negatives for sensitivity. A combination of human and trained NNs is a promising way to achieve a fast and accurate diagnosis.

Does surgical margin affect recurrence and survival after sublobar pulmonary resection for lung cancer?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was: How does surgical margin distance affect recurrence and survival after sublobar pulmonary resection for lung cancer? Altogether, 172 papers were found using the search strategy, of which 12 studies with 1946 stage I non-small-cell lung cancer (NSCLC) patients using sublobar resection (wedge resection or segmentectomy) represented to be 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 were tabulated. Overall, 11 cohort studies and 1 prospective study were included. Four cohort studies demonstrated positive prognostic significance of surgical margin with specific cut-off points in each paper (ranged from 9 to 15 mm). Two retrospective studies and 1 prospective study found that a margin-to-tumour ratio of ≥1 was associated with better cytology and prognosis results. Other 5 studies showed that larger margin distance provided a favourable prognosis for NSCLC patients with poor-prognostic factors, including solid-dominant type, high invasive component size and Spread through Air Spaces-positive subtype. After reviewing all the included articles, we conclude that the standard of margin distance of >10 mm or margin-to-tumour ratio ≥ 1 should be recommended for stage I NSCLC patients undergoing sublobar resection, especially in wedge resection. Patients with poor-prognostic factors like solid-predominant tumour or non-lepidic adenocarcinoma may benefit from larger margin distance and the proper margin distance for them still needs to be determined. For Spread through Air Spaces-positive patients, sublobar resection may not be the alternative to lobectomy.

Sentinel lymph node biopsy in head and neck cutaneous melanomas: A PRISMA-compliant systematic review and meta-analysis.

BACKGROUND: Head and neck melanomas (HNMs) behave differently from cutaneous melanomas in other sites, and the efficacy of sentinel lymph node biopsy (SLNB) for patients with HNMs remains controversial. METHODS: Studies on prognosis following SLNB were included. The prognostic role of SLNB and other potential predictors were analyzed using pooled relative risk (RR) or hazard ratio (HR). RESULTS: Pooled statistics showed that SLNB improved overall survival of HNMs patients (HR = 0.845; 95% CI: 0.725-0.986; P = .032). The positive status of SN was proved as a risk factor of poor prognosis in HNMs (HR = 3.416; 95% CI: 1.939-6.021; P < .001). SLNB did not have significant correlation with lower recurrences (RR = .794; 95% CI: 0.607-1.038; P = .091). CONCLUSIONS: SLNB is associated with better overall survival and the SN status is a promising risk factor of poor prognosis for HNMs patients.

Automatic airway tree segmentation based on multi-scale context information.

PURPOSE: Airway tree segmentation plays a pivotal role in chest computed tomography (CT) analysis tasks such as lesion localization, surgical planning, and intra-operative guidance. The remaining challenge is to identify small bronchi correctly, which facilitates further segmentation of the pulmonary anatomies. METHODS: A three-dimensional (3D) multi-scale feature aggregation network (MFA-Net) is proposed against the scale difference of substructures in airway tree segmentation. In this model, the multi-scale feature aggregation (MFA) block is used to capture the multi-scale context information, which improves the sensitivity of the small bronchi segmentation and addresses the local discontinuities. Meanwhile, the concept of airway tree partition is introduced to evaluate the segmentation performance at a more granular level. RESULTS: Experiments were conducted on a dataset of 250 CT scans, which were annotated by experienced clinical radiologists. Through the airway partition, we evaluated the segmentation results of the small bronchi compared with the state-of-the-art methods. Experiments show that MFA-Net achieves the best performance in the Dice similarity coefficient (DSC) in the intra-lobar airway and improves the true positive rate (TPR) by 7.59% on average. Besides, in the entire airway, the proposed method achieves the best results in DSC and TPR scores of 86.18% and 79.31%, respectively, with the consequence of higher false positives. CONCLUSION: The MFA-Net is competitive with the state-of-the-art methods. The experiment results indicate that the MFA block improves the performance of the network by utilizing multi-scale context information. More accurate segmentation results will be more helpful in further clinical analysis.

Lobe-Specific Node Dissection Can Be a Suitable Alternative to Systematic Lymph Node Dissection in Highly Selective Early-Stage Non-Small-Cell Lung Cancer Patients: A Meta-Analysis.

PURPOSE: Whether the lobe-specific lymph node dissection is an alternative to systematic lymph node dissection for early-stage non-small-cell lung cancer remains controversial. An elaborate meta-analysis was conducted to evaluate the effects of lobe-specific lymph node dissection in early-stage patients. METHODS: A systematic literature search was conducted up to February 19, 2020 in PubMed, Ovid, Web of Science, and China National Knowledge Infrastructure databases. The outcomes including overall survival (OS), complications, and recurrence rate were extracted and analyzed. RESULTS: Nine studies including one randomized controlled trial (RCT) and eight retrospective cohort studies with 8499 non-small-cell lung cancer patients were included. The results indicated that lobe-specific lymph node had a lower rate of postoperative complication (relative risk [RR]: 0.83, 95% confidence interval [CI]: 0.72-0.95, P = 0.006). No significant difference was observed between lobe-specific lymph node and systematic lymph node dissection in OS (hazard rate = 1.12, 95% CI: 0.81-1.54, P = 0.501) with high heterogeneity (I2 = 71.9%). CONCLUSION: Lobe-specific lymph node can reach a comparable long-term prognosis in some highly selected patients. However, these results should be viewed cautiously with the existence of high heterogeneity. Due to the high heterogeneity, a strict patient selection process by experienced thoracic surgeons was recommended before validating lobe-specific lymph node.

Electrocautery vs. Stapler in Comparing Safety for Segmentectomy of Lung Cancer: A Meta-Analysis.

Background: Electrocautery and staplers are regarded as the two most common surgical instruments for dissecting the intersegmental plane in segmentectomy. We performed a meta-analysis to compare electrocautery and staplers in terms of their safety and effects. Methods: A systematic search strategy was performed using PubMed, and the retrieval time was up to April 1, 2020. Odds ratio (OR) and mean differences (MDs) with 95% CI were applied to determine the effectiveness of dichotomous or continuous variables, respectively. Results: Six studies including 385 patients were included. The electrocautery had a higher incidence rate of postoperative complication [OR= 1.92, 95% CI (1.12, 3.28), P = 0.02)] and air leak [OR: 3.91, 95% CI (1.64, 9.35), P = 0.002)]. No significant difference was found in the comparison of surgery time, blood loss, and duration of tube days or hospitality days. Conclusions: Our study indicated that patients under segmentectomy were associated with better safety by using stapler than electrocautery in the reduction of postoperative complications.

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

OBJECTIVES: The number of positive lymph node stations has been viewed as a subclassification in the N1 category in the new revision of tumour node metastasis (TNM) staging. However, the survival curve of these patients overlapped with that of some patients in the N2 categories. Our study focused on the prognostic significance of different subclassifications for N1 patients. METHODS: We systematically searched PubMed, Ovid, Web of Science and the Cochrane Library on the topic of N1 lymph node dissection. Hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) were used to assess the prognostic significance of N1 metastases. I2 statistics was used to evaluate heterogeneity among the studies: If significant heterogeneity existed (P ≤ 0.10; I2 >50%), a random effect model was adopted. RESULTS: After a careful investigation, a total of 17 articles were included in the analysis. The results showed that patients with non-small-cell lung cancer with multistation N1 disease have worse survival compared with those with single-station N1 disease (HR 1.53, 95% CI 1.32-1.77; P < 0.001; I2 = 5.1%). No significant difference was observed between groups when we assessed the number of positive lymph nodes (single or multiple) (HR 1.25, 95% CI 0.96-1.64; P = 0.097; I2 = 72.5%). Patients with positive hilar zone lymph nodes had poorer survival than those limited to the intrapulmonary zone (HR 1.80, 95% CI 1.57-2.07; P < 0.001; I2 = 0%). A subgroup analysis conducted according to the different validated lymph node maps showed a stable result. CONCLUSIONS: Our result confirmed the prognostic significance of the N1 subclassification based on station number. Meanwhile, location-based classifications, especially zone-based, were also identified as prognostically significant, which may need further confirmation and validation in the staged population.

Skip metastasis in mediastinal lymph node is a favorable prognostic factor in N2 lung cancer patients: a meta-analysis.

BACKGROUND: Skip metastasis is a common lymph node metastatic pattern in non-small cell lung cancer (NSCLC). The relationship between skip metastasis and specific clinicopathologic factors and the prognostic value of skip metastasis are controversial. METHODS: A systematic search and analysis of skip metastasis in NSCLC was conducted in the databases of PubMed, EMBASE, and Web of Science up to Dec 2019. Summarized hazard ratio (HR), mean difference (MD), and odds ratio (OR) with associated 95% confidence intervals (CI) were evaluated to investigating the relationship between skip metastasis and overall survival (OS), disease-free survival (DFS), recurrence-free survival (RFS) and clinicopathological features in NSCLC. RESULTS: 29 studies with a total of 1,806 skip and 4,670 non-skip N2 patients were included. The upper lobe tumor showed a higher rate of skip metastasis compared with lower lobe one (RR =1.16, 95% CI: 1.00-1.34, P=0.044, I2=39.8%). The presence of skip metastasis correlated with superior overall survival (HR =0.74, 95% CI: 0.66-0.83, P<0.001, I2=48.2%) and DFS or RFS (HR =0.71, 95% CI: 0.61-0.84, P<0.001, I2=18.2%). Further subgroup analyses indicated similar results in articles that reported intrapulmonary lymph node dissection (HR =0.67, 95% CI: 0.57-0.77, P<0.001, I2=0). CONCLUSIONS: The results indicate that the presence of skip metastasis is associated with a marked increase in survival of NSCLC patients compared to patients with non-skip N2 metastasis. These results suggest that skip metastasis might be a distinct subgroup for purposes of N staging of NSCLC patients, and intrapulmonary lymph node assessment is needed.