Lymph Node Stations Research Articles

Central ligation or partial preservation of the right gastric artery does not seem to affect conduit or anastomotic perfusion during robot-assisted resection of gastroesophageal junction cancer: a randomized clinical trial.

The gastric conduit can be created with partial preservation or a central ligation of the right gastric artery. Central ligation may facilitate complete removal of lymph node (LN) station 3; however, whether this influences conduit and anastomotic perfusion is unknown. Hence this study investigated whether a central ligation of the right gastric artery would affect conduit or anastomotic perfusion compared with partial preservation (local standard) during robot-assisted resection of gastroesophageal junction cancer. Patients scheduled for robot-assisted resection of gastroesophageal junction cancer were randomized to either central ligation or partial preservation of the right gastric artery. Perfusion was assessed using quantified indocyanine green angiography: before gastric mobilization, after conduit formation, and after anastomosis. Hemodynamic variables during surgery and surgical outcomes were recorded. We included 70 patients between June 2020 and October 2021, of whom 5 were excluded from the final analysis. The two patient groups did not differ in conduit (0.07 [interquartile range (IQR), 0.05-0.08] vs. 0.07 u [IQR, 0.05-0.08], P = 0.86) or anastomotic perfusion (0.08 [standard deviation (SD), ±0.02] vs. 0.08 u [SD, ±0.02], P = 0.21), nor did they differ in intraoperative blood loss, anastomotic leaks, postoperative complications, or 1-year survival. However, more LNs were resected in the central ligation group (36 [IQR, 30-44] vs. 28 [IQR, 23-43], P = 0.02). Introducing a central ligation of the right gastric artery did not seem to affect conduit or anastomotic perfusion, compared with partial preservation. However, significantly more LNs were resected.

The Impact of Balloon Use During Endobronchial Ultrasound: A Randomized Pilot Study

Introduction During endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA), a saline-filled balloon placed over the tip of the bronchoscope is used to improve coupling of the ultrasound transducer to the airway wall. However, it is unknown whether it objectively improves image quality or affects procedural outcomes. Our aim is to establish whether the use of a balloon during EBUS impacts image quality, diagnostic yield, procedure duration or complications. Methods A pilot randomized control trial of patients undergoing EBUS-TBNA of mediastinal lymph nodes was performed at a single academic centre. Patients were randomized to use of a saline-filled balloon (versus no balloon use) during EBUS-TBNA of the right lower paratracheal lymph node (station 4R). The EBUS videos were recorded and scored on a 4-point Likert scale by three blinded external reviewers. The primary outcome of this study was ultrasound image quality. Secondary outcomes included diagnostic yield, procedure duration and complications. Results Forty-six patients were randomized. In the balloon group, 61% of patients had an image quality score of “excellent” or “good,” compared to 47% in the no balloon group (p = 0.009). There was no significant difference in diagnostic yield, procedure duration or complications between the groups. Conclusion Inflation of the balloon during EBUS-TBNA at the right lower paratracheal lymph node improves ultrasound image quality but does not impact diagnostic yield, procedure duration or safety. This study provides a framework for additional studies with complete nodal assessment to determine if balloon use has a clinically meaningful benefit on procedural outcomes.

Prognostic significance and risk factors of mediastinal lymph node metastasis in esophagogastric junction cancer: a single-center, retrospective study.

Although the optimal extent of lymph node dissection in esophagogastric junction cancer (EGJC) has been reported, the efficacy of mediastinal lymph node dissection remains unclear. We aimed to identify risk factors for mediastinal lymph node metastasis and its prognostic impact in patients with EGJC. A total of 100 consecutive patients who underwent curative surgery for EGJC were eligible. We examined the rates of metastasis, prognosis, and therapeutic value index at each mediastinal lymph node station. In addition, multivariate analyses were performed to identify risk factors for mediastinal lymph node metastasis. The rates of upper, middle, and lower mediastinal lymph node metastases were 12.0%, 20.7%, and 13.2%, respectively. The 5-year overall survival rate was lower in patients with mediastinal lymph node metastasis than in those without mediastinal lymph node metastasis (11.1% vs. 59.2%, p < 0.01). The therapeutic value index was 0 in patients with upper/middle mediastinal lymph node metastasis, and mediastinal lymph node metastasis was an independent prognostic factor (hazard ratio 6.59, 95% confidence interval [CI] 2.48-17.9, p < 0.01). Additionally, the length of esophageal invasion and the presence of hiatal hernia were independent predictors of mediastinal lymph node metastasis (odds ratio 8.21, 95%CI 1.44-46.8, p = 0.02 and odds ratio 7.13, 95%CI 1.22-41.8, p = 0.03). No survival benefit of mediastinal lymph node dissection was observed. Intensive multidisciplinary treatment could be considered in patients with predicted mediastinal lymph node metastasis, such as those with longer esophageal invasion and those with hiatal hernia.

Lymphadenectomy for Perihilar Cholangiocarcinoma: Therapeutic Benefit of Lymph Node Number and Station

INTRODUCTIONWe sought to characterize the benefit of lymphadenectomy among patients undergoing curative-intent surgery for perihilar cholangiocarcinoma (pCCA) utilizing the therapeutic index. METHODSData on patients who underwent curative-intent resection for pCCA between 2000-2023 were obtained from 8 high-volume international hepatobiliary centers. Multivariable Cox regression analysis was used to assess clinicopathological factors associated with overall survival (OS). The therapeutic index was determined to assess the therapeutic benefit of lymphadenectomy. RESULTSAmong 341 patients, median number of LNs evaluated was 7 (IQR: 4-11). A total of 127 (37.2%) patients underwent lymphadenectomy of station 12 only, while 146 (42.8%) patients had LNs from stations 12 plus 8 ± 13 harvested. On multivariable analysis, lymphadenectomy of stations 12 plus 8 ± 13 was associated with improved OS (referent, station 12 only: HR 0.51, 95%CI 0.32-0.80). The therapeutic index was highest among patients who underwent LN evaluation of stations 12 plus 8 ± 13 (33.1) and had ≥ 6 LNs harvested (26.3). CONCLUSIONSAt the time of surgery of pCCA, lymphadenectomy should include station 12, as well as stations 8 and 13, with the goal to evaluate > 6 LNs to ensure optimal staging and maximize the therapeutic benefit for patients.

Correlation Between the Extent of N1 Lymph Node Station Examination and Prognosis in Stage I Nonsmall Cell Lung Cancer Patients: One Station is Insufficient

BackgroundExamination standards for hilar and intrapulmonary (N1) lymph nodes (LNs) have been debated. The objective of this study was to assess the prognostic significance of the extent of examination for N1 LN stations in patients with pathological stage I nonsmall cell lung cancer (NSCLC). MethodsA total of 1868 patients were identified and divided into 3 groups on the basis of the number of N1 stations examined: group A (≥3 stations), group B (2 stations) and group C (1 station). Moreover, we investigated the prognostic significance of each individual N1 station examined. The primary outcome was 5-year disease-free survival (DFS). ResultsOverall, 1062, 607, and 199 patients were in groups A, B, and C, respectively. The baseline demographic and clinical characteristics were similar among the groups, except for the tumor side. The 5-year DFS rates were comparable between groups A and B (85.1% vs. 82.7%, P = .3), both of which were significantly greater than that of group C (74.4%) (P < .01). Similar results were observed for the corresponding 5-year overall survival rates. The number of N1 stations examined was an independent predictor in multiple analyses. Additionally, the examination of stations 10 and 13 were independent favorable predictors for 5-year DFS. ConclusionFor patients with pathological stage I NSCLC, examination of only 1 N1 station is insufficient. Examinations of a minimum of two N1 stations, including stations 10 and 13, is recommended to obtain the optimal survival benefit.

Enhancing Lymph Node Yield in Gastric Cancer Resection: Impact of Back Table Dissection on Number of Lymph Node Examined.

During gastric cancer resection, back table dissection (BTD) involves examination and separation of lymph node (LN) packets from the surgical specimen based on LN stations, which are sent to pathology as separately labeled specimens. With potential impact on clinical outcomes, we aimed to explore how BTD affects number of LNs examined. A retrospective review of a gastric cancer database was performed, including all cases of gastrectomy with D2 lymphadenectomy from January 2009 to March 2022. Back table dissection and conventional groups were compared using Mann-Whitney U and Fisher's exact tests. Multiple linear regression modeling was used to identify potential predictors of number of LN examined. A total of 174 patients were identified: 39 (22%) BTD and 135 (78%) conventional. More patients in the BTD group underwent neoadjuvant chemotherapy (62% vs 29%, P < .05). Compared to the conventional group, the BTD group had a greater number of LNs examined (42 [26-59] vs 21[15-33], median [IQR], P < .001), lower LN positivity ratio (.01 vs .07, P = .013), and greater number of LNs in patients with BMI >35 (32.5[27.5-39] vs 22[13-27], P = .041). A multiple linear regression model controlling for age, BMI, preoperative N stage, neoadjuvant chemotherapy, surgeon experience, and operative approach identified BTD as a significant positive predictor of number of LN examined (β = 19.7, P = .001). Back table dissection resulted in improved LN yield during gastric cancer resection. As a simple technical addition, BTD helps enhance pathology examination and improve surgeon awareness, which may ultimately translate to improve oncologic outcomes.

EP.07A.10 Concordance Between Lymph Node Station Examination Reported on a Checklist and the Final Pathology Report after Curative Lung Cancer Resection

EP.07A.10 Concordance Between Lymph Node Station Examination Reported on a Checklist and the Final Pathology Report after Curative Lung Cancer Resection

Impact of mediastinal tumor burden and lymphatic spread in locally advanced non-small-cell lung cancer: A secondary analysis of the multicenter randomized PET-Plan trial

PurposeThe aim of this secondary analysis of the prospective randomized phase 2 PET-Plan trial (ARO-2009-09; NCT00697333) was to evaluate the impact of mediastinal tumor burden and lymphatic spread in patients with locally advanced non-small-cell lung cancer (NSCLC). MethodsAll patients treated per protocol (n = 172) were included. Patients received isotoxically dose-escalated chemoradiotherapy up to a total dose of 60–74 Gy in 30–37 fractions, aiming as high as possible while adhering to normal tissue constraints. Radiation treatment (RT) planning was based on an 18F-FDG PET/CT targeting all lymph node (LN) stations containing CT positive LNs (i.e. short axis diameter > 10 mm), even if PET-negative (arm A) or targeting only LN stations containing PET-positive nodes (arm B). LN stations were classified into echelon 1 (ipsilateral hilum), 2 (ipsilateral station 4 and 7), and 3 (rest of the mediastinum, contralateral hilum). The endpoints were overall survival (OS), progression-free survival (PFS), and freedom from local progression (FFLP). ResultsThe median follow-up time (95 % confidence interval [CI]) was 41.1 (33.8 − 50.4) months. Patients with a high absolute number of PET-positive LN stations had worse OS (hazard ratio [HR] = 1.09; 95 % CI 0.99 − 1.18; p = 0.05) and PFS (HR = 1.12; 95 % CI 1.04 − 1.20; p = 0.003), irrespective of treatment arm allocation. The prescribed RT dose to the LNs did not correlate with any of the endpoints when considering all patients. However, in patients in arm B (i.e., PET-based selective nodal irradiation), prescribed RT dose to each LN station correlated significantly with FFLP (HR=0.45; 95 % CI 0.24–0.85; p = 0.01). Furthermore, patients with involvement of echelon 3 LN stations had worse PFS (HR = 2.22; 95 % CI 1.16–4.28; p = 0.02), also irrespective of allocation. ConclusionMediastinal tumor burden and lymphatic involvement patterns influence outcome in patients treated with definitive chemoradiotherapy for locally advanced NSCLC. Higher dose to LNs did not improve OS, but did improve FFLP in patients treated with PET-based dose-escalated RT.

441. EXTENT AND BOUNDARIES OF LYMPH NODE STATIONS DURING MINIMALLY INVASIVE ESOPHAGECTOMY: A SURVEY AMONG DUTCH ESOPHAGEAL SURGEONS

Abstract Background The optimal extent of lymph node dissection (LND), and the anatomical boundaries per lymph node station (LNS) during minimally invasive esophagectomy (MIE) for esophageal cancer remains a topic of debate. This study investigated the opinion of Dutch esophageal cancer surgeons on their routine LND extent and anatomical boundaries per LNS, during MIE. Methods In April 2023, an English web-based cross-sectional survey was conducted. Within all 15 Dutch hospitals performing MIE, two MIE surgeons were asked to participate. The routine LND extent (quantity, specific LNS) for distal esophageal adenocarcinoma, (dis)agreement with the TIGER definition, and anatomical boundaries for each LNS in six directions were inquired. Results Twenty-four Dutch MIE surgeons completed the survey (80% response rate). Consensus on the routine LND extent (85% or more of the participating surgeons) included the left and right paracardial, left gastric artery, celiac trunk, proximal splenic artery, common hepatic artery, subcarinal middle mediastinal paraoesophageal, lower mediastinal paraoesophageal, pulmonary ligament and upper mediastinal paraoesophageal LNSs. Other LNS were not widely considered routine. Although, certain anatomical boundaries were consistent among surgeons, the majority varied, even when agreeing on the TIGER definition. Conclusion Significant variations in surgical practice among Dutch esophageal surgeons, regarding their routine extent of LND and anatomical boundaries of LNSs during MIE were demonstrated. Variation may impact clinical outcomes, hampers uniform treatment strategies, and hinders comparison of performance assessments. This study highlights the need for an international follow-up study towards one uniform defined LND during MIE for esophageal cancer.

549. CLINICAL IMPLICATIONS OF SELECTIVE RIGHT PARATRACHEAL LYMPH NODE DISSECTION IN PATIENTS WITH EARLY-STAGE ESOPHAGEAL CANCER: PROPENSITY-SCORE MATCHED ANAYLSIS

Abstract Background The optimal extent of lymph node dissection in esophageal squamous cell carcinoma (Sqcc) still remains a topic of debate without specifying the lymph node stations. This study aimed to evaluate the clinical impact of selective right paratracheal lymph node (RtPTLN) dissection in patients with esophageal squamous cell carcinoma (SQCC). Methods We included the patients who underwent curative surgery for clinical stage I esophageal SQCC (cT1N0) at our institution between January 2010 and December 2021. Patients who underwent neoadjuvant therapy were excluded. A total of 1,484 patients underwent surgery for esophageal cancer at our institution during the study period. Among these, 658 patients (mean age 63.1±7.7 years, 46 [7.0%] women) were identified, categorized into RtPTLN+ (dissection performed, n = 88) and RtPTLN- (no dissection, n = 570) groups. The RtPTLN+/- groups were matched in a 1:3 ratio using propensity scores. Results Median follow-up was 48.8 (24.2–85.2, interquartile) months. Five-year overall survival (OS, RtPTLN+ vs. RtPTLN-, 75.8% vs. 79.0%, P = 0.38) and recurrence-free survival (RFS, 70.0% vs. 72.5%, P = 0.55) rates showed no significant differences. Propensity-score matching yielded 313 patients: RtPTLN+ (n = 83) and RtPTLN- (n = 230). OS and RFS rates did not significantly differ between RtPTLN+ and RtPTLN- groups (OS: 77.2% vs. 79.9%, P = 0.57; RFS: 72.1% vs. 74.7%, P = 0.79) after adjustment (Figure). Multivariate analysis confirmed that RtPTLN dissection was not a significant predictor for OS or RFS (Table). Conclusion In this propensity-score matched analysis, there was no significant difference in OS and RFS between patients with and without RtPTLN dissection. These findings discreetly suggest that the routine RtPTLN dissection may not be necessary, and selective dissection could be considered acceptable.

237. THE PROGNOSTIC VALUE OF NODAL SKIP METASTASIS IN PATIENTS WITH ESOPHAGEAL CANCER

Abstract Background Nodal skip metastasis (NSM), a common form of lymphatic spread in esophageal cancer (EC), refers to metastatic involvement of distant lymph nodes (LNs) without prior engagement of adjacent LNs. Previous studies examining the association between NSM and survival outcomes in EC patients have yielded inconsistent and even contradictory results. This systematic review and meta-analysis aim to assess the prognostic value of NSM and summarize NSM definitions used in prior studies. Methods Four databases were employed for this meta-analysis. The relationship between NSM and overall survival (OS) was assessed using pooled hazard ratios (HRs) and their 95% confidence intervals (CIs). Sensitivity analysis and funnel plots were utilized to evaluate publication bias. Results This meta-analysis incorporated nine studies, and the pooled results revealed no significant association between NSM and OS (HR = 0.99, 95% CI: 0.75–1.31; P = 0.951). Sub-group analyses based on histological features, method of lymphadenectomy, node staging system, and NSM definitions also failed to identify a significant association between NSM and OS. Conclusions Based on the available evidence, NSM cannot be considered a prognostic factor for EC patients. Future studies examining the prognostic value of NSM should focus on employing three-field lymphadenectomy with an adequate number of harvested LNs. NSM definitions based on lymph node station and anatomical compartment could both serve as feasible classifications for EC.

785. MANAGEMENT OF ESOPHAGEAL CANCER WITH CONCURRENT CERVICAL NODE METASTASIS: A NATIONWIDE POPULATION-BASED COHORT STUDY

Abstract Background In the Netherlands, the standard treatment of locally advanced, resectable esophageal cancer without metastasis is neoadjuvant chemoradiotherapy followed by esophagectomy. There is a small subset of patients that present with concurrent cervical lymph node metastasis (LNM). Historically this was seen as distant metastasis and surgical intervention has usually not been an option for these patients. The contemporary TNM classification now categorizes these lymph node stations as locoregional disease. Our current study aims to describe current treatment paradigms in the Netherlands for patients presenting with esophageal cancer and concurrent cervical LNM. Methods This population-based cohort study utilized data from the Netherlands Cancer Registry (NCR), encompassing patients with locally advanced thoracic esophageal or gastroesophageal junction cancer and concurrent cervical lymph node metastasis. Treatment modalities were categorized into five options: neoadjuvant therapy followed by surgery (Neo + S), definitive chemoradiotherapy (dCRT), chemotherapy with or without radiotherapy &amp;lt; 30 Gray (CT), radiotherapy (RT), and best supportive care (BSC). Overall survival (OS) was assessed using the Kaplan-Meier method and compared via the log-rank test. Hazard rates were computed using Cox proportional hazards regression, with adjustment for confounding achieved through inverse probability of treatment weighting (IPTW). Results Between 2015 and 2021, a cohort of 412 patients was identified from the NCR database. Median survival durations were observed as follows: 24.2 months for Neo + S, 18.0 months for dCRT, 14.5 months for CT, 7.0 months for RT, and 3.2 months for BSC (Figure). A comparison between the Neo + S group and dCRT demonstrated a significant improvement in survival (p=0.02). Further subdivision of the surgical group into neoadjuvant CRT or chemotherapy did not reveal a significant difference in survival (p=0.6). Utilizing IPTW to adjust for confounding factors, Neo + S maintained its survival advantage. Conclusion The retrospective cohort findings suggest that neoadjuvant therapy followed by surgery may represent the optimal approach for managing esophageal cancer patients with cervical LNMs Yet, it's vital to recognize the influence of confounding by indication, which statistical adjustments may not entirely rectify. Furthermore, immortal time bias notably skews results favorably toward surgery. Nevertheless, the results emphasize the importance of considering surgery as a viable option for these patients. These limitations underscore the critical need for a prospective study, prompting the launch of the NODE-II trial.

399. LYMPH NODE METASTATIC PATTERNS AND SENTINEL LYMPH NODES FOR ESOPHAGEAL SQUAMOUS CELL CARCINOMA AFTER DIFFERENT NEOADJUVANT REGIMENS

Abstract Background This study aimed to outline lymph node metastasis patterns in esophageal squamous cell carcinoma (ESCC) patients undergoing neoadjuvant chemoradiotherapy (nCRT) or chemotherapy (nCT), comparing regimens, assessing prognosis impact, and identifying potential sentinel lymph node stations for future individualized dissection. Methods Involving 578 ESCC patients undergoing nCRT (n=303) or nCT (n=275) followed by esophagectomy (2010-2022), we conducted propensity score matching, analyzing 171 pairs. Nodal metastasis patterns and station positivity associations with survival were assessed through univariate and multivariate models, adjusting for clinical factors. Results Among 171 nCRT patients, 36.8% had nodal metastases, 22.8% single-station, 8.2% two-station, and 5.8% ≥3-station occurrences. Specific station positivity correlated with poorer survival. The nCRT group had fewer nodal metastases (36.8% vs 50.3%), common sites being left gastric, right recurrent laryngeal nerve, and paraesophageal region. Increased nodal stations and positive nodes correlated with worse prognosis. In nCRT, mentioned areas were prognostic; in nCT, only left gastric nodal metastases were prognostic. Single and multi-station rates were similar, but nCT had more multi-station disease. For sentinel lymph nodes, positivity in left gastric, paraesophageal, right recurrent laryngeal nerve for nCRT, and subcarinal, left recurrent laryngeal nerve, paratracheal, left gastric, paraesophageal right recurrent laryngeal nerve for nCT, may indicate complex metastasis. Conclusions Over one-third of ESCC patients had post nCRT metastatic lymph nodes. Though nCRT reduced metastasis rates, survival outcomes didn't improve, emphasizing thorough lymph node dissection based on metastasis patterns.

807. A REVISED APPROACH TO THE ESOPHAGOGASTRIC JUNCTION: A MODIFIED SIEWERT CLASSIFICATION

Abstract Background Esophagogastric junction (EGJ) adenocarcinomas are challenging due to their anatomical and histopathological features and treated either as part of the esophagus or stomach cancers. Siewert (S) and Nishi classifications rely on the tumor’s epicenter to guide treatment decisions, which can lead to diagnostic and therapeutic inconsistencies. Moreover, recent studies helped define the optimal extent of lymphadenectomy for EGJ cancers. Here we present our standardized approach to EGJ cancers that integrates these insights, providing a framework to guide clinical decision-making. Methods Our modified classification relies on tumor extent rather than the epicentre, based on endoscopic measurement of the proximal and the distal limits, and the exact location of the EGJ. This approach classifies tumors based on their extent which results into six categories: SI, SI/II, SII, SII/III, SIII, and SI/II/III. Lower esophageal tumors whose distal limit lies between + 1cm and -2cm are classified as I/II. Cardia tumors whose proximal limit falls between those boundaries are II/III. Tumors that span more cephalad than + 1cm and more distally than – 2cm, are I/II/III. For Siewert I, I/II and II tumors, surgical management depends on the extent of esophageal involvement, mainly dictated by the probability of mediastinal basement nodal involvement, as defined by Kurokawa et al (2019). Additionally, a 3-field lymphadenectomy is performed when there is involvement of the cervical or recurrent laryngeal nerve lymph node stations. Results In SI, SI/II, and SI/II/III, with esophageal involvement exceeding 4 cm we favor a transthoracic esophagectomy (TTE) with total thoracic lymphadenectomy. If the involvement is between 1-4 cm, a transhiatal esophagectomy (THE) with lower mediastinal lymphadenectomy is performed. In SII, THE is done for 0-1 cm of involvement; absence of esophageal involvement permits a transhiatal extended total gastrectomy (eTG) with abdominal D2 lymphadenectomy and intra-operative margin status assessment via frozen sections. In SI/II/III and esophageal involvement of more than 4 cm, TTE is required; for esophageal involvement of 1-4 cm, we perform a THE and total gastrectomy with abdominal D2 lymphadenectomy based on distal margin findings. Conclusion This proposed modification to the classification of EGJ adenocarcinomas introduces a comprehensive framework that is tailored to the extent of tumor involvement. By addressing the limitations of existing systems and incorporating current insights, this updated classification aims to improve patient categorization and standardize treatment protocols, potentially leading to enhanced clinical outcomes.

Commission on Cancer Standards for Lymph Node Sampling and Oncologic Outcomes After Lung Resection

BackgroundThe newest Commission on Cancer standards recommend sampling 3 mediastinal and 1 hilar lymph node stations, 3 (N2) 1 (N1), for lung cancer resections. However, the relationship between the Commission on Cancer standards and outcomes has not been thoroughly investigated. MethodsA prospective institutional database was queried for clinical stage I-III lung resections before the implementation of the new standards. The relationship between the 3 (N2) 1 (N1) standard (“guideline concordant”) and outcomes (upstaging, complications, receipt of adjuvant therapy, locoregional/distant recurrence, and survival) was assessed with multivariable models and stratified by stage. ResultsOf 9289 pulmonary resections, 3048 (33%) were guideline concordant and 6241 (67%) were not. Compared with nonconcordant, those that were guideline concordant had higher rates of nodal upstaging (21% vs 13%; odds ratio [OR], 1.32 [95% CI, 1.14-1.51]; P < .001) and in-hospital complications (34% vs 27%; OR, 1.17 [95% CI, 1.05-1.30]; P = .004) but similar adjuvant systemic therapy administration (19% vs 13%; OR, 1.09 [95% CI, 0.95-1.24]; P = .2; 98% chemotherapy). Locoregional and distant recurrences were not significantly improved with guideline concordance across clinical stage I, II, and III subsets. Overall survival was similar in clinical stages I and II, but improved survival was observed for guideline concordant clinical stage III patients (hazard ratio, 0.85 [95% CI, 0.74-0.97]; P = .02). ConclusionsSampling 3 (N2) 1 (N1) was associated with increased upstaging and complications but not with decreased recurrence or mortality in clinical stage I or II patients. Survival was improved for concordant, clinical stage III patients. Further study is indicated to determine the ideal lymph node sampling strategy across heterogeneous lung cancer patients.

489. EVALUATION OF THE ONCOLOGICAL QUALITY OF MINIMALLY INVASIVE TRANSCERVICAL OESOPHAGECTOMY (MICE) USING A CADAVERIC MODEL

Abstract Background Nodal involvement is a well-known factor of poor prognosis for esophageal cancer, but the extent of the lymph node dissection, or the number of the dissected lymph nodes, remains controversial questions. Western guidelines (ESMO and NCCN) suggest accomplishing esophagectomy with en-bloc two-field lymphadenectomy. Minimally Invasive transCervical oEsophagectomy (MICE) is a novel technique for the minimally invasive treatment of esophageal cancer. In the literature, the radicality of this procedure still remains unknown, as evidenced by studies conducted in Eastern countries. This descriptive study explores feasibility of MICE in Western countries using a cadaveric model. Methods A cadaver study was conducted in a real operating room setting, with bilateral lung ventilation induced to replicate a real-life situation. Mediastinal dissection was carried out via single port left transcervical mediastinoscopy. Subsequently, a right thoracoscopy in prone position was performed to access the clearance of the fatty tissue at the anatomical boundaries of the lymph node stations. The finalization of the dissection of the lower mediastinum via transhiatal approach was not performed because it was not in the aim of the study. The extent and the radicality of the dissection were evaluated by an independent external expert. Results Results indicated effectiveness of MICE in dissecting lymph nodes around the lower and middle esophagus, as well as at the subcarinal station. At the upper esophagus level, harvesting was complete on the left side but some residual tissue was found on the right-side at the right recurrent laryngeal nerve and on the right pleura, this result was attributed to technical difficulty. Conclusion The findings suggest that MICE is adequate in accomplish a complete dissection of lymph nodes around the mediastinal esophagus, including a complete subcarinal dissection, adhering to Western lymphadenectomy standards. Further descriptive study on cadaver will help to understand if a more extensive lymphadenectomy is achievable.

A hypothesis on treatment strategy of severe multicentric Castleman disease with continuous renal replacement therapy.

Castleman disease (CD) is a rare lymphoproliferative disorder, with non-specific clinical manifestations, often delayed diagnosis and treatment, which pose a significant challenge in the present times. Patients diagnosed with this disease have poor prognosis due to the limited treatment options. Multicentric CD occurs at multiple lymph node stations and is associated with a proinflammatory response that leads to the development of the so-called 'B symptoms'. IL-6 seems to be a key cytokine involved in various manifestations such as lymphadenopathies, hepatosplenomegaly, and polyclonal hypergammaglobulinemia. Its levels correlate with the activity of the disease. Other consequences of MCD include increased fibrinogen levels leading to deep vein thrombosis and thromboembolic disorders, high hepcidin levels causing anaemia, elevated VEGF levels promoting angiogenesis and vascular permeability, which, along with hypoalbuminemia, induce oedema, ascites, pleural and pericardial effusions, and in severe cases, generalized anasarca. In extreme cases multiple organ failure can occur, often resulting in death. We propose the use of continuous renal replacement therapy (CRRT) in managing severe multicentric CD. Our arguments are based on the principles that CRRT is able to remove IL-6 from circulation thus attenuating the cytokine storm, can influence hepcidin levels, and reduction in oedema, and is often used in multiple organ failure to regain homeostasis control. Therefore, it could be used as a therapy or bridge therapy in severe cases. To sustain our hypothesis with evidence, we have gathered several studies from the literature confirming the successful removal of cytokines, especially IL-6 from circulation, which can be used as a starting point.

What alters prognosis in patients who were operated for lung cancer with lymph node metastasis?

In this study, we investigated the clinical outcomes of patients who underwent surgery with proven lymph node metastasis. Patients who were operated for lung cancer with pN1 or pN2 were examined in the study. The clinicopathological features and survival of the subjects were evaluated according to pN1-pN2 status, presence of neoadjuvant treatment, Positron emission tomography and computed tomography (PET/CT) avidity on mediastinal lymph nodes and specific lymph node stations. The study examines 100 patients operated from January 2016 to December 2021. Number of cases with pN1 and pN2 disease were 45 (45%) and 55 (55%) respectively. Thirty (30%) patients received neoadjuvant treatment. The 5-year overall survival (OS) and disease-free survival (DFS) of the patients were computed as 42.5% and 42.4% correspondingly. The 5-year cancer-related survival was 55.3%. In pN2 cohort, 5-year DFS was 67.9% in the neoadjuvant group and 15.9% in the non-neoadjuvant group (P = 0.042). In non-neoadjuvant group, 5-year DFS was 19.9% in cases with mediastinal PET/CT avidity and 56.3% in patients without mediastinal PET/CT avidity (P = 0.018). In pN2 disease, the presence of subcarinal or paratracheal lymph node metastasis did not create a significant difference in 5-year OS or DFS, but pulmonary ligament lymph node metastasis was found to be linked with worse survival in both 5-year OS (P = 0.005) and DFS (P = 0.017). The main elements related with poor prognosis were absence of neoadjuvant treatment and pulmonary ligament lymph node metastasis in pN2 disease, detecting PET/CT avid mediastinal lymph nodes in non-neoadjuvant group.

Application of tissue pneumoperitoneum technique around lymph nodes in thoracoscopic lung cancer resection.

Thoracoscopic surgery is a primary treatment for lung cancer, with lobectomy and mediastinal lymph node dissection being the predominant surgical approaches for invasive lung cancer. While many thoracic surgeons can proficiently perform lobectomy, thorough and standardized lymph node dissection remains challenging. This study aimed to explore a safer and more efficient surgical method for mediastinal lymph node dissection in lung cancer. A prospective randomized controlled study was conducted, involving 100 patients with right lung cancer who were admitted to our hospital from January 2021 to April 2024 and met the inclusion criteria. These patients were randomly divided into an observation group (tissue pneumoperitoneum technique around lymph nodes group) and a control group (conventional surgery group). Thoracoscopic lobectomy and mediastinal lymph node dissection were performed. Intraoperative and postoperative related indicators were observed to validate the effectiveness and safety of the tissue pneumoperitoneum technique around lymph nodes. The observation group showed a significantly shorter lymph node dissection surgery time compared to the control group, with a statistically significant difference (p < 0.05). The number of lymph nodes dissected in the observation group was significantly higher than that in the control group, with a statistically significant difference (p < 0.05). Although the observation group had slightly more mediastinal lymph node stations dissected than the control group, the difference was not statistically significant (p > 0.05). The total drainage volume within three days postoperatively was comparable between the two groups, with no statistically significant difference (p > 0.05). The observation group had shorter chest tube indwelling time and postoperative hospital stay than the control group, with statistically significant differences (p < 0.05). The incidence of surgical complications was similar between the two groups, and there were no perioperative deaths. The tissue pneumoperitoneum technique around lymph nodes is a more efficient method for mediastinal lymph node dissection in lung cancer, demonstrating safety and feasibility, and is worthy of promotion.

The Relationship Between Nodal Metastases and Primary Location in Stage I Non-Small Cell Lung Cancer

IntroductionThis study examines the relationship between location of the primary tumor and specific nodal metastases in clinical stage 1 non-small cell lung cancer (NSCLC) patients undergoing lobectomy. MethodsWe retrospectively analyzed all lobectomies performed at a single institution, between January 2005 and December 2019, for clinical stage I NSCLC patients. Patients selected for this study were clinically node negative (cN0) by positron emission tomography-computed tomography scan and selectively by endobronchial ultrasound or mediastinoscopy. Cases of postoperative pathologic nodal upstaging were identified among these patients. For each patient upstaged, the specific lymph node stations found to be positive were recorded. Descriptive statistics, chi-squared tests, and Fisher's exact test were utilized to identify independent risk factors for upstaging to specific N1 and N2 lymph node stations. All clinical and pathologic staging information was retrospectively normalized to the International Association for the Study of Lung Cancer 8th Edition TNM Classification. ResultsThe research cohort included 645 patients. The mean age was 68 years (standard deviation ± 9.2), 54% were female, and 88% were White, 11% Black, and 1% other. Twelve percent (n = 75) were upstaged from cN0 to pN1 or pN2 upon final pathologic examination: 41 to pN1 (54.7%) and 34 to pN2 (45.3%). The primary tumor location with the highest rate of nodal upstaging was the left upper lobe (LUL) (12.8%). Tumors in the right middle lobe had the lowest rate of unsuspected nodal metastases (8.8%). Out of all upstaged patients, there were no positive level eight lymph nodes, and only 1 patient with a positive level nine lymph node. Lymph node levels five and six were only positive in LUL primary tumors, a relationship that approached statistical significance (P = 0.0797). No patients with a LUL primary tumor had a positive level seven lymph node. Upstaging at station 12 was significantly associated with the location of the primary tumor, occurring less often in tumors originating in the right upper lobe in comparison to other lobes (P = 0.0288). ConclusionsWe identified relationships between the location of a primary tumor and specific nodal upstaging in patients with clinical stage I NSCLC who undergo lobectomy. We found the following: 1) only 1 patient had a positive level eight or nine lymph node out of 645 patients; 2) only LUL primary tumors demonstrated upstaging to level five or six lymph nodes; and 3) right upper lobe tumors were significantly less likely to be associated with a positive level 12 lymph node.