Mediastinal Lymph Node Metastasis Research Articles

Comparison of diagnostic value of quantitative parameters from FAPI and FDG PET/CT in the detection of mediastinal lymph node metastasis in non-small cell lung cancer

Comparison of diagnostic value of quantitative parameters from FAPI and FDG PET/CT in the detection of mediastinal lymph node metastasis in non-small cell lung cancer

The ninth edition of TNM staging for lung cancer: precise staging for precise diagnosis and treatment

The ninth edition of TNM staging for lung cancer has been announced at the 2023 World Lung Cancer Congress and implemented from January 1, 2024. Te focus of the ninth TNM staging change is dividing N2 into N2a and N2b, as well as M1c into M1c1 and M1c2. Although the T staging has not changed, it has played an important role in verifying the eighth edition of the T staging. The subdivision of stage N2 has led some patients with ⅢA of the eighth edition to experience ascending or descending stages, which will more accurately help to assess the condition and prognosis of patients with mediastinal lymph node metastasis, as well as the design of related clinical studies. Modifying the M1c staging will help define oligometastasis and explore new treatment models in the future. The ninth edition of the TNM staging system provides a more detailed division of different tumor loads, but there is no clear explanation for the staging of lung cancer after neoadjuvant therapy. Further data analysis is needed, and it is expected to be answered in the tenth edition of TNM staging.

A Single-center Experience of Radiotherapy in Pediatric Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Chest Wall.

To evaluate the treatment results, prognostic parameters, and treatment-related toxicity in patients with Ewing sarcoma (ES)/primitive neuroectodermal tumor (PNET) of the chest wall who underwent surgery, chemotherapy, and radiotherapy (RT) in a tertiary referral center. The data of 24 patients under 18 years of age with a histologic diagnosis of ES/PNET in the chest wall that received RT in our department between February 2003 and July 2020 were retrospectively evaluated. RT was applied to the primary site±whole involved chest wall and to the whole lung in patients with lung metastasis. The median age was 8.5 years (range: 1.5 to 17y), 15 (63%) patients were female and 9 were male (37%). The tumor localization was extrathoracic in 18 (75%) and intrathoracic in 6 (25%) patients. Mediastinal lymph node and distant metastasis (DM) was present in 5 (21%) and 4 (16%) cases at diagnosis, respectively. The median follow-up after RT was 47 months (range: 11 to 162mo). The 2-year and 5-year overall survival, event-free survival, local recurrence-free survival, and pleural recurrence-free survival were 83% and 48%, 48% and 42%, 74% and 48%, and 61% and 52%, respectively. The overall local control rate was 83% and the pleural control rate was 67%. RT was well tolerated, with 1 case of grade 3 acute dermatitis and 1 case of grade 3 subacute radiation pneumonitis. Late toxicity was observed in 3 (13%) cases. Long-term survival can be achieved with extended-field RT even in patients with ES/PNET of the chest wall with DM. The low toxicity rates allow us to draw the conclusion that RT with modern techniques is an effective and safe treatment modality for these patients.

Occult SMARCA4-Deficient Undifferentiated Carcinoma Unmasked by 68Ga-FAPI-46 PET/CT.

SMARCA4-deficient undifferentiated tumors (SMARCA4-dUT) are rare and aggressive neoplasms commonly found in male smokers and portend a poor prognosis. In this case, we reported 18F-FDG and 68Ga-FAPI-46 PET/CT findings in an occult SMARCA4-dUT located in the left pulmonary hilum along with mediastinal lymph node metastases. 68Ga-FAPI-46 PET/CT showed superiority over 18F-FDG for detecting SMARCA4-dUT lesions. This case highlighted that 68Ga-FAPI-46 PET/CT may be a promising imaging modality in the evaluation of SMARCA4-dUT, particularly for detecting the occult SMARCA4-dUT arising in uncommon sites.

Omitting Lymph Node Dissection for Small Ground-Glass Opacity–Dominant Tumors

BackgroundThe purpose of this study was to determine the optimal extent of lymph node dissection required in patients with small (≤3 cm) radiologically ground-glass opacity–dominant, peripheral, non-small cell lung cancer tumors. MethodsThe study analyzed the clinicopathologic findings and surgical outcomes of 988 patients with radiologic, ground-glass opacity–dominant non-small cell lung cancer without lymph node involvement who underwent complete resection of the primary tumor between 2010 and 2020. Patients were followed up for 54.5 months (median). Kaplan-Meier curves and the log-rank test were used in statistical analyses of the prognosis. ResultsMedian age, whole tumor size, solid tumor size, and maximum standardized uptake values were 68 years, 1.7 cm, 0.4 cm, and 0.9, respectively. Sixty percent of the cohort was female (n = 590). Wedge resection, segmentectomy, and lobectomy were performed in 206, 372, and 410 patients, respectively. A total of 982 of 988 (99%) tumors were adenocarcinomas. One patient had hilar lymph node involvement; however, no mediastinal lymph node metastasis or hilar or mediastinal lymph node recurrence was detected. The 5-year overall survival rate was 96.5% (95% CI, 94.8%-97.7%). Excellent survival outcomes were achieved regardless of procedure (wedge resection, 94.7% [95% CI, 89.1%-97.5%]; segmentectomy, 96.9% [95% CI, 93.7%-98.5%]; and lobectomy, 97.1% [95% CI, 94.4%-98.5%]). ConclusionsOmitting lymph node dissection may be acceptable with curative intent for small tumors with radiologic ground-glass opacity dominance. Appropriate surgical procedures such as wedge resection, segmentectomy, or lobectomy can provide satisfactory outcomes in patients with indolent tumors if surgical margins are secured.

An Investigation of the Relationship Between 18F-FDG PET/CT Parameters of Primary Tumors and Lymph Node Metastasis in Resectable Non-small Cell Lung Cancer.

Mediastinal lymph node metastasis is an important prognostic factor in non-small cell lung cancer (NSCLC) patients without distant metastases. 18F-2-fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) is recommended for detecting and staging lymph nodes and distant metastases in NSCLC patients. This study aims to investigate whether maximum standardized uptake (SUVmax), mean standardized uptake (SUVmean), metabolic tumor volume (MTV), and tumor lesion glycolysis (TLG) values of the primary tumor measured by 18F-FDG PET/CT in resectable NSCLC can predict preoperative lymph node metastasis. This retrospective study included eighty NSCLC patients who underwent preoperative Positron Emission Tomography/Computed Tomography (PET/CT) for diagnosis and staging. The patients were stage I-III and had no distant metastases. Tumor metabolic parameters such as SUVmax, SUVmean, MTV, and TLG at PET/CT imaging were measured for preoperative diagnosis and staging, and the postoperative pathology results of the patients were examined. The pathology results divided patients into two groups; with and without lymph node metastasis. The groups were compared with student's t-test and chi-square test with regard to 18F-FDG PET/CT tumor metabolic parameters and other parameters. Fifteen (18.8%) patients were female, and 65 (81.3%) were male. According to the postoperative pathology results, while 30 (37.5%) patients had lymph node metastasis, 50 (62.5%) did not. There was a significant difference between the groups regarding tumor SUVmax and SUVmean values (p = 0.036, p = 0.045). Overall survival in the N0 group was significantly higher than in the N1 + N2 group (p = 0.034); median survival was 30.2 months in N0 group cases and 27.3 months in N1 and N2 groups. SUVmax and SUVmean values are significantly higher in patients with lymph node metastases than in patients without lymph node metastases, and this finding may provide useful information for predicting lymph node metastasis in patients with resectable NSCLC.

Assessment of risk factors of lymph node metastasis and prognosis of Siewert II/III adenocarcinoma of esophagogastric junction: A retrospective study.

Adenocarcinoma of the esophagogastric junction (AEG) has a high incidence, and the extent of lymph node dissection (LND) and its impact on prognosis remain controversial. This study aimed to explore the risk factors for lymph node metastasis (LNM) and prognosis in Siewert II/III AEG patients. A retrospective review of 239 Siewert II/III AEG patients surgically treated at Beijing Friendship Hospital from July 2013 to December 2022 was conducted. Preoperative staging was conducted via endoscopy, ultrasound gastroscopy, CT, and biopsy. Depending on the stage, patients received radical gastrectomy with LND and chemotherapy. Clinicopathological data were collected, and survival was monitored semiannually until November 2023. Utilizing logistic regression for data analysis and Cox regression for survival studies, multivariate analysis identified infiltration depth (OR = 0.038, 95% CI: 0.011-0.139, P < .001), tumor deposit (OR = 0.101, 95% CI: 0.011-0.904, P = .040), and intravascular cancer embolus (OR = 0.234, 95% CI: 0.108-0.507, P < .001) as independent predictors of LNM. Lymph nodes No. 1, 2, 3, 4, 7, 10, and 11 were more prone to metastasis in the abdominal cavity. Notably, Siewert III AEG patients showed a higher metastatic rate in nodes No. 5 and No. 6 compared to Siewert II. Mediastinal LNM was predominantly found in nodes No. 110 and No. 111 for Siewert II AEG, with rates of 5.45% and 3.64%, respectively. A 3-year survival analysis underscored LNM as a significant prognostic factor (P = .001). Siewert II AEG patients should undergo removal of both celiac and mediastinal lymph nodes, specifically nodes No. 1, 2, 3, 4, 7, 10, 11, 110, and 111. Dissection of nodes No. 5 and No. 6 is not indicated for these patients. In contrast, Siewert III AEG patients do not require mediastinal LND, but pyloric lymphadenectomy for nodes No. 5 and No. 6 is essential. The presence of LNM is associated with poorer long-term prognosis. Perioperative chemotherapy may offer a survival advantage for AEG patients.

Interventional treatment of hilar and mediastinal lymph node metastases

Interventional treatment of hilar and mediastinal lymph node metastases

Expression of Concern: Comparison of 18F-FDG PET/CT and DWI for detection of mediastinal nodal metastasis in non-small cell lung cancer: A meta-analysis.

Expression of Concern: Comparison of 18F-FDG PET/CT and DWI for detection of mediastinal nodal metastasis in non-small cell lung cancer: A meta-analysis.

Role of invasive mediastinal nodal staging in survival outcomes of patients with non-small cell lung cancer and without radiologic lymph node metastasis: a retrospective cohort study

Lung cancer diagnostic guidelines advocate for invasive mediastinal nodal staging (IMNS), but the survival benefits of this approach in patients with non-small cell lung cancer (NSCLC) without radiologic evidence of lymph node metastasis (rN0) remain uncertain. We aimed to investigate the impact of IMNS in patients with rN0 NSCLC by comparing the long-term survival between patients who underwent IMNS and those who did not (non-IMNS). In this retrospective cohort study, we included patients with NSCLC but without radiologic evidence of lymph node metastasis from the Registry for Thoracic Cancer Surgery and the clinical data warehouse at the Samsung Medical Centre, Republic of Korea between January 2, 2008 and December 31, 2016. We compared the 5-year overall survival (OS) rate as the primary outcome after propensity score matching between the IMNS and non-IMNS groups. The age, sex, performance statue, tumor size, centrality, solidity, lung function, FDG uptake in PET-CT, and histological examination of the tumor before surgery were matched. A total of 4545 patients (887 in the IMNS group and 3658 in the non-IMNS group) who received curative treatment for NSCLC were included in this study. By the mediastinal node dissection, the overall incidence of unforeseen mediastinal node metastasis (N2) was 7.2% (317/4378 patients). Despite the IMNS, 67% of pathological N2 was missed (61/91 patients with unforeseen N2). Based on propensity score matching, 866 patients each for the IMNS and non-IMNS groups were assigned. There was no significant difference in 5-year OS and recurrence-free survival (RFS) between two groups: 5-year OS was 73.9% (95% confidence interval, CI: 71%-77%) for IMNS and 71.7% (95% CI: 68.6%-74.9%; p=0.23), for non-IMNS (hazard ratio, HR 0.90, 95% CI: 0.77-1.07), while 5-year RFS was 64.7% (95% CI: 61.5%-68.2%) and 67.5% (95% CI: 64.3%-70.9%; p=0.35 (HR 1.08, 95% CI: 0.92-1.27), respectively. Moreover, the timing and locations of recurrence were similar in both groups. IMNS might not be required before surgery for patients with NSCLC without LN suspicious of metastasis. Further randomised trials are required to validate the findings of the present study. None.

Lymph node metastases in middle and upper mediastinum of Siewert type II adenocarcinoma: A real-world retrospective study.

To explore whether the upper and/or middle mediastinal nodes (UMMN) should be dissected in Siewert type II adenocarcinoma (AC) according to the incidence of lymph node metastasis. Additionally, to investigate the association between the length of esophageal involvement (LEI) and the UMMN metastases. A cohort with Siewert type II AC who were operated on by a surgical team that routinely treated esophagogastric junction (EGJ) tumors with esophagectomy and extended lymphadenectomy were assessed retrospectively. The primary endpoint of the research was the metastasis rate of UMMN. A total of 94 patients with EGJ tumor from July 2018 to September 2022 were enrolled. Station 106recR (6.4%, 6/94) was the only station among upper mediastinal nodes (UMN) that presented positive nodes. Middle mediastinal nodes (MMN) metastases of station 107, 109 and station 108 were 2.1% (2/94) and 5.0% (4/80), respectively. Among the 11 patients with MMN or UMN metastases, 63.6% (7/11) had lesser than seven metastatic nodes, and 54.5% (6/11) had a pathological N stage ≤2. LEI >3 cm (p = 0.042) showed a higher risk for MMN metastases in univariable logistic analysis. However, no independent risk factor for mediastinal node metastases was detected. This study demonstrated that the incidence of positive MMN and UMN is relatively low in resectable Siewert type II AC, which indicated that it is not necessary to perform a routine dissection upon these stations. LEI >3 cm might be associated with higher risk for mediastinal node metastasis. Certain patients could benefit from extended lymphadenectomy since most of the patients with positive MMN or UMN have a limited number of metastatic nodes.

Evaluating Mediastinal Lymph Node Metastasis of Non-Small Cell Lung Cancer Using Mono-exponential, Bi-exponential, and Stretched-exponential Models of Diffusion-weighted Imaging.

To explore and compare the diagnostic values of mono-exponential, bi-exponential, and stretched-exponential diffusion-weighted imaging (DWI) parameters of primary lesions and lymph nodes (LNs) to predict mediastinal LN metastasis in patients with non-small cell lung cancer. Sixty-one patients with non-small cell lung cancer underwent preoperative magnetic resonance imaging, including multiple b-value DWI. The DWI parameters, including apparent diffusion coefficient (ADC) from a mono-exponential model, true diffusion (D) coefficient, pseudo-diffusion (D*) coefficient, and perfusion fraction (f) from a bi-exponential model, distributed diffusion coefficient (DDC) and intravoxel diffusion heterogeneity index (α) from a stretched-exponential model of primary tumors and LNs and the size characteristics of LNs, were measured and compared. Multivariate logistic regression analysis was used to establish models for predicting mediastinal LN metastasis. Receiver operating characteristic analysis was applied to evaluate diagnostic performances. The DWI parameters of primary tumors showed no statistical significance between LN metastasis-positive and LN metastasis-negative groups. Nonmetastatic LNs had significantly higher ADC, D, DDC, and α values compared with metastatic LNs (all P < 0.05). The short-dimension, long-dimension, and short-long dimension ratio of metastatic LNs was significantly larger than those of nonmetastatic ones (all P < 0.05). The D value showed the best diagnostic performance among all DWI-derived single parameters, and the short dimension of LNs performed the same among all the size variables. Furthermore, the combination of DWI parameters (ADC and D) and the short dimension of LNs can significantly improve diagnostic efficiency. The ADC, D, DDC, and α from the mono-exponential, bi-exponential, and stretched-exponential models were demonstrated efficient in differentiating benign from metastatic LNs, and the combination of ADC, D, and short dimension of LNs may have a better diagnostic performance than DWI or size-derived parameters either in combination or individually.

Sphericity of lymph nodes using 3D-CT predicts metastasis in lung cancer patients

BackgroundThe presence of mediastinal lymph node metastasis is important because it is related to the treatment and prognosis of lung cancer. Although prevalently used, evaluation of lymph nodes is not always reliable. We introduced sphericity as a criterion for evaluating morphologic differences between metastatic and nonmetastatic nodes.MethodsWe reviewed the cases of 66 patients with N2 disease and of 68 patients with N0-1 disease who underwent lobectomy with mediastinal dissection between January 2012 and December 2021. The sphericity of the dissected station lymph nodes, which represents how close the node is to being a true sphere, was evaluated along with the diameter and volume. Each parameter was obtained and evaluated for ability to predict metastasis.ResultsMetastatic lymph nodes had a larger short-axis diameter (average: 8.2 mm vs. 5.4 mm, p < 0.001) and sphericity (average: 0.72 vs. 0.60, p < 0.001) than those of nonmetastatic lymph nodes. Short-axis diameter ≥ 6 mm and sphericity ≥ 0.60 identified metastasis with 76.2% sensitivity and 70.2% specificity (AUC = 0.78, p < 0.001) and 92.1% sensitivity and 53.9% specificity (AUC = 0.78, p < 0.001), respectively. For lymph nodes with a short-axis diameter ≥ 5 mm, sphericity ≥ 0.60 identified metastasis with 84.1% sensitivity and 89.3% specificity.ConclusionBy using 3D-CT analysis to examine sphericity, we showed that metastatic lymph nodes became spherical. Our method for predicting lymph node metastasis based on sphericity of lymph nodes with a short-axis diameter ≥ 5 mm could do so with higher sensitivity than the conventional method, and with acceptable specificity.

The impact of the highest mediastinal lymph node metastasis on postoperative recurrence and survival in non-small cell lung cancer patients

Objective: To examine whether the highest mediastinal lymph node (HMLN) metastasis had an influence on postoperative recurrence and survival among non-small cell lung cancer (NSCLC) patients with pN2 lymph node metastasis. Methods: A total of 261 patients who underwent radical resection of lung cancer and systematic lymph node dissection in the Department of Thoracic Surgery of Peking University First Hospital from January 2007 to December 2016 were retrospectively analyzed. There were 180 males and 81 females, aged (61.5±9.4) years (range: 31 to 83 years). There were 128 cases of HMLN-positive and 133 cases of HMLN-negative. They were pathologically confirmed N2 stage NSCLC and postoperative recurrence and survival were followed up. The Kaplan-Meier method was used to calculate disease-free survival (DFS) and overall survival (OS) curves according to whether HMLN metastasize or not. The Cox proportional hazards regression model was used for the prognostic analysis. Results: The median DFS and the median OS of the whole group were 28 months and 44 months, respectively. The median DFS in HMLN-positive and HMLN-negative patients was 19 months and 33 months, respectively (P=0.005). The median OS of HMLN-positive and HMLN-negative group was 37 months and 49 months, respectively (P=0.005). Multivariate analysis showed that pneumonectomy and visceral pleural invasion were independent risk factors for both postoperative OS (HR=1.85, 95%CI: 1.25 to 2.72, P=0.002; HR=1.82, 95%CI: 1.30 to 2.56, P=0.007) and DFS (HR=1.61, 95%CI: 1.10 to 2.35, P=0.014; HR=1.77, 95%CI: 1.27 to 2.46,P=0.001). HMLN metastasis and lymphovascular invasion were independent risk factors for only postoperative DFS (HR=1.39, 95%CI: 1.03 to 1.87, P=0.030; HR=1.40, 95%CI: 0.99 to 1.81, P=0.042). Conclusions: For patients of pN2 stage NSCLC, both postoperative recurrence and long-term survival were significantly worse in the HMLN metastatic group. In addition, pneumonectomy and visceral pleural invasion were unfavorable factors that affected both recurrence and overall survival. HMLN metastasis and lymphovascular invasion could shorten the postoperative time for DFS.

Lymph node dissection in small peripheral lung cancer: Supplemental analysis of JCOG0802/WJOG4607L

ObjectiveThe optimal region of lymph node dissection (LND) during segmentectomy in patients with small peripheral non–small cell lung cancer requires clarification. Through a supplemental analysis of the Japan Clinical Oncology Group (JCOG) 0802/West Japan Oncology Group (WJOG) 4607L, we investigated the associated factors, distribution, and recurrence pattern of lymph node metastases (LNMs) and proposed the optimal LND region. MethodsOf the 1106 patients included in the JCOG0802/WJOG4607L, 1056 patients with LNDs were included in this supplemental analysis. We investigated the distribution and recurrence pattern of LNMs along with the radiologic findings (with ground-glass opacity, part-solid tumor; without ground-grass opacity component, pure-solid tumor). ResultsThe radiologic findings were the only significant factor for LNMs. Of 533 patients with part-solid tumors, 8 (1.5%) had LNMs. Further, only 3 (0.5%) patients had pN2 disease, and no patients had interlobar LNMs from nonadjacent segments. Of the 523 patients with pure-solid tumors, 55 (10.5%) had LNMs, and 28 (5.4%) had pN2 disease. Five patients had metastases to nonadjacent interlobar lymph nodes (LNs). Two (2.0%) patients with S6 tumors had upper mediastinal LNMs. In addition, the incidence of mediastinal LN recurrence in patients with S6 lung cancer was greater in those who underwent selective LND than those who underwent systematic LND (P = .0455). ConclusionsNonadjacent interlobar and mediastinal LND have little impact on pathologic nodal staging in patients with part-solid tumors. In contrast, selective LND is recommended at least for patients with pure-solid tumors.

Foreign Body Reaction Mimicking Lymph Node Metastasis is Not Rare After Lung Cancer Resection.

Mediastinal lymphadenopathies with high 18-fluorodeoxyglucose uptake in patients previously operated on for lung cancer are alarming for recurrence and necessitate invasive diagnostic procedures. Peroperative placement of oxidized cellulose to control minor bleeding may lead to a metastasis-like image through a foreign body reaction within the dissected mediastinal lymph node field at postoperative examinations. In this study, we investigated clinicopathological features and the frequency of foreign body reaction mimicking mediastinal lymph node metastasis. Patients who underwent surgery for lung cancer between January 2016 and August 2021 and who were subsequently evaluated for mediastinal recurrence with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) were included. Patients were grouped according to the results of EBUS-TBNA as metastasis, foreign body, and reactive. Clinicopathological features of these patients were compared and characteristics of patients in the foreign body group were scrutinized. EBUS-TBNA was performed on a total of 34 patients during their postoperative follow-up due to suspicion of mediastinal recurrence. EBUS-TBNA pathological workup revealed metastasis in 18 (52.9%), foreign body reaction in 10 (29.4%) and reactive lymph nodes in 6 (17.6%) patients. Mean maximum standardized uptake value (SUVMax) for metastasis group and foreign body group were 9.39 ± 4.69 and 5.48 ± 2.54, respectively (p = 0.022). Time interval between the operation and EBUS-TBNA for the metastasis group was 23.72 ± 10.48 months, while it was 14.90 ± 12.51 months in the foreign body group (p = 0.015). Foreign body reaction mimicking mediastinal lymph node metastasis is not uncommon. Iatrogenic cause of mediastinal lymphadenopathy is related to earlier presentation and lower SUVMax compared with metastatic lymphadenopathy.

Patterns of the lymph node metastasis and the influencing factors in esophagogastric junction cancers.

A retrospective analysis of 214 cases of esophagogastric junction cancers (EGJCs) in Kunming, Yunnan Province, was conducted to investigate the lymph node metastasis (LNM) pattern for EGJCs and its associated risk factors (RFs), as well as the predictive value of common clinical metabolic indicators for it. The clinical data of 214 patients diagnosed with EGJCs by electronic gastroscope and postoperative pathology between 2013 and 2021at the First Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, and the Second Affiliated Hospital of Kunming Medical University were retrospectively examined. Preoperative gastroscopy, imaging, biochemical data, and postoperative pathological findings analysis in EGJCs were statistically analyzed to determine the RFs of LNM. At presentation, 92.5% of EGJCs were progressive malignancies, including 68.2% LNMs, 79.5% abdominal lymph nodes (ALN), 20.1% mediastinal lymph nodes (MLN), and 27.1% distal metastases. The ratio of Siewert subtypes was approximately 2:11:7 (type I to type II to type III). In terms of age, disease duration at initial presentation, history, tumor length, pathological biopsy histology, degree of differentiation, depth of infiltration, LNM status, MLN metastasis, and surgical route, the differences between the three Siewert subgroups were statistically significant (p<0.05). Multifactor analysis revealed that the proportion of patients aged <65at the time of consultation was significantly more significant in Siewert II and Siewert III than in Siewert I. Significantly more patients than in Siewert I had <2 months of disease duration at the time of their first consultation. The proportion of patients with tumors <3 Cm in length was significantly higher than in Siewert I. For the RFs analysis of LNM, Siewert staging (type I and type II), depth of infiltration, and distant metastasis were the independent RFs for LNM. The depth of infiltration and family history of the tumor were the independent RFs for ALN metastasis, and the number of lymph nodes cleared in the abdominal and mediastinal regions was a protective factor for ALN metastasis. Siewert staging(type I and type II), infiltration depth, invasion of the esophagus by the tumor, tumor length, and distant metastasis were independent risk factors for MLN metastasis. Among the metabolic variables evaluated, BMI was an independent RF for LNM, fasting glucose was an independent RF for ALN metastasis, and triacylglycerol was a protective factor for MLN metastasis. EGJCs are frequently advanced at presentation, characterized by minimal differentiation and a high incidence of LNM. The Siewert subtype is concentrated near the stomach. Different Siewert subtypes exhibit distinct clinicopathological characteristics. LNM and MLN metastasis risk are considerably higher in type I tumors compared to types II and III. There is a strong correlation between LNM and MLN metastasis and distant metastasis in EGJCs, so Siewert I is more aggressive and associated with a worse prognosis. EGJCs have numerous RFs associated with LNM, and there are similarities and differences in the RFs affecting their LNM, ALN metastases, and MLN metastases, which are related to their unique anatomical features. There is a close relationship between metabolic factors and EGJCs with some predictive value.

362. AUTOMATED DETECTION OF UPPER MEDIASTINAL LYMPH NODES METASTASIS OF ESOPHAGEAL SQUAMOUS CANCER USING BERT ON COMPUTED TOMOGRAPHY

Abstract Upper mediastinal lymph node (LN) metastasis is the extremely frequent metastasis lymph node site and dissection of this site of lymph node harbors a high risk of recurrent laryngeal nerve injury. Prediction of LN metastasis before dissection is necessary for personalized therapy. We developed a pre-training unsupervised deep learning model based on Bidirectional Encoder Representation from Transformers (BERT) to extract features from pre-operational CT images and detect patients with LN metastasis. A total of 3769 esophageal cancer patients from 2012 to 2020 with complete post-surgical pathology in our institute were included in this study, 823 of which had upper mediastinal LN metastasis. The extracted features of CT images were labeled with the LN metastasis status of the corresponding patients and then divided into training and validation groups (7:3) for training. In order to keep balancing of the positive and negative ratio in the test dataset, 800 patients were randomly selected from the validation group (1:1). The BERT-based pretrained learning model achieved a AUROC of 0.651 on detection of upper mediastinal LN metastasis. The specificity of this model could reach up to 0.732. Our model can be used to improve diagnostic ability of upper mediastinal LN metastasis before surgery.

395. SURGICAL PROCEDURE AND PERIOPERATIVE OUTCOME OF TRANSMEDIASTINAL ESOPHAGECTOMY FOR ESOPHAGOGASTRIC JUNCTION CANCER

Abstract Background We started performing mediastinal lymph node dissection by a laparoscopic transhiatal approach (LTHA) in 2009. To date, 548 patients had undergone our method during various esophageal surgical procedures, including esophagogastric junction cancer (EGJC). Furthermore, we started performing single-port mediastinoscopic cervical approach in 2014, and developed a simple technique for transmediastinal esophagectomy (TME) without thoracic approach (435 cases). Seventy five patients with EGJC were treated by TME. Methods Left single-port mediastinoscopic cervical approach was performed with pneumomediastinum. Mainly for advanced SCC, upper mediastinal lymph node dissection including recurrent laryngeal nerve LNs was performed with intraoperative monitoring using NIM system. Next, LTHA was performed for en bloc mediastinal lymph node dissection. The esophageal hiatus was opened, and working space was secured by Long Retractors. The posterior plane of the pericardium was extended. The posterior side of LNs was then separated. Finally, while lifting LNs like a membrane, they were resected from bilateral mediastinal pleura. Reconstruction with narrow gastric conduit was performed through substernal tract. Results Patients with EGJC performed TME were analyzed (n = 75, SCC/Adeno/Others = 37/35/3). Upper mediastinal lymph node metastasis was found in 13 cases (SCC/Adeno = 6/7), middle mediastinal lymph node metastasis was found in 10 cases (SCC/Adeno = 3/7), and all of them had advanced tumors. Their perioperative outcome was compared with those performed the right thoracotomy (n = 41). The operative time and bleeding were decreased by TME. The number of resected mediastinal lymph nodes, pR0 rate, and mediastinal recurrence in TME group were not inferior to the right thoracotomy group. In 93.3% of patients treated by TME, extubation was performed at 0 POD. Postoperative respiratory complication was decreased by TME (TME:6.7%, thoracotomy:17.1%). Conclusions This procedure, TME, resulted in a good surgical view, safe en-bloc mediastinal lymph node dissection, and the decrease of postoperative respiratory complications in patients with EGJC.

Impact of skip mediastinal lymph node metastasis on outcomes after resection for primary lung cancer

ObjectivesPatients with non-small cell lung cancer and nodal disease are a heterogeneous group with varied patterns of disease. The aim of this study was to assess long-term outcomes of patients with skip N2 disease in comparison to those with N1 or non-skip N2 disease. Materials and MethodsA retrospective review of 445 patients undergoing anatomical lung resection for primary lung cancer between 2012 and 2019 with post-operative histological confirmation of nodal disease was undertaken. Log rank analysis was used to assess differences in estimated median overall survival according to nodal status. Multivariable Cox regression analysis was performed to determine whether skip N2 disease was independently associated with overall survival. ResultsMean patient age was 67.0 years (standard deviation ± 9.2 years) and 48.1% (n = 214) were male. In total, 20.7% (n = 92) of patients had N1 disease, 32.1% (n = 143) had skip N2 disease and 47.2% (n = 210) had non-skip N2 disease. Post-operative upstaging took place in 33.0% (n = 147) of patients. Median follow-up time was 35 months (interquartile range 14–68 months). Skip N2 patients had significantly longer estimated median overall survival in comparison to their non-skip N2 counterparts (47 months vs 28 months, log rank analysis p = 0.029) and non-skip N2 disease remained independently associated with reduced overall survival after multivariable analysis (hazard ratio 1.421, 95% confidence interval 1.060–1.907, p = 0.019). ConclusionSkip N2 disease is a positive prognostic factor for patients with N2 lung cancer, suggesting that lung cancer staging guidelines should consider separating N2 disease into additional subgroups in order to improve prognostic accuracy.