Minimum Number Of Lymph Nodes Research Articles

Abstract PO4-23-01: Imaging tailored axillary approach combined with radiotherapy eliminates axillary lymph node dissection in low-volume axillary disease after neoadjuvant chemotherapy

Abstract ABSTRACT Background Individualized treatment strategies are highlighted for breast cancer patients in the last decades. Therefore aggressive surgical approaches have begun to evolve towards minimally invasive tailored interventions. SLNB is widely used in patients who received neoadjuvant treatment (NAC) and axillary lymph node dissection (ALND) is recommended for patients with axillary residual disease after NAC. In our study, we investigated regional recurrence rates in patients with limited axillary residual disease after NAC who underwent imaging-guided (MR+USG) axillary surgery plus radiotherapy (RT) instead of ALND. Materials and Methods 139 patients whose clinical stages were T1-3 and N1 at the time of diagnosis, who had a clinically good or complete axillary response after neoadjuvant therapy, and who had axillary residue (≤3 pathological lymph nodes) with favorable response to NAC (>50% fibrotic changes) in the final pathological examination were included in the study. The tumor stage and the number of pathological lymph nodes were assessed by USG, MMG, MR, and PET-CT examination (The minimum number of lymph nodes to be removed was determined according to imaging findings). All patients underwent imaging-guided SLNB (blue dye) and imaging-guided palpable lymph node excision. The patients were re-evaluated with their final pathology results in the multidisciplinary councils for suitable further treatments, ALND or RT. Peripheral lymphatic radiotherapy was applied to patients whose radiology and pathology results were compatible and no further surgery was done. The patients whose radiologically detected number of positive nodes was inconsistent with the number of metastases in pathology examination and who were presumed to have the gross residual disease underwent ALND. These patients were excluded from the study. Results The median age was 47 years. The median number of lymph nodes excised was 4. The total number of excised lymph nodes was between 1-3 in 64 (46%) patients and between 4-6 in 62 (45%) patients. 13 (9%) patients had ≥7 lymph nodes. 1 metastatic lymph node was found in all patients with 1 positive lymph node according to imaging findings. Of 41 patients with 2 radiologically positive lymph nodes, 1 metastatic lymph node was found in 17 (41%) patients, 2 metastatic lymph nodes in 22 (53%), and 3 metastatic lymph nodes in 2 (5%) patients respectively. Radiology reported 3 positive lymph nodes in 22 patients, of which 1 metastatic lymph node was found in 8 (36%), 2 metastatic lymph nodes in 10 (45%), and 3 metastatic lymph nodes in 4 (18%). The median follow-up period was 44 months. One patient had breast recurrence at the 31st month and one patient had lymphatic recurrence in the supraclavicular area at the 39th month. Systemic recurrence was noted in 6 (4.3%) patients. No axillary recurrence occurred during the follow-up period. Conclusions Patients with pathological-suspicious ≤ 3 lymph nodes shown by imaging (USG, MR, and PET-CT) who responded to NAC but still have residual disease in the axilla can be safely treated with SLNB(blue dye)+imaging-guided axillary approach and adjuvant RT. This approach eliminates the need for ALND in patients with low-volume residual axillary disease. Table. Patient characteristics Citation Format: Mahmut Muslumanoglu, Baran Mollavelioglu, Selman Emiroglu, Hasan Karanlik, Mustafa Tukenmez, Kamuran Ibis, Aysel Bayram, Ravza Yılmaz, Neslihan Cabıoğlu, Abdullah Igci. Imaging tailored axillary approach combined with radiotherapy eliminates axillary lymph node dissection in low-volume axillary disease after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-23-01.

Defining the Minimal and Optimal Thresholds for Lymph Node Resection and Examination for Intraductal Papillary Mucinous Neoplasm Derived Pancreatic Cancer: A Multicenter Retrospective Analysis.

To establish minimal and optimal lymphadenectomy thresholds for intraductal papillary mucinous neoplasm (IPMN)-derived pancreatic ductal adenocarcinoma (PDAC) and evaluate their prognostic value. Current guidelines recommend a minimum of 12-15 lymph nodes (LNs) in PDAC. This is largely based on pancreatic intraepithelial neoplasia (PanIN)-derived PDAC, a biologically distinct entity from IPMN-derived PDAC. Multicenter retrospective study including consecutive patients undergoing upfront surgery for IPMN-derived PDAC was conducted. The minimum cut-off for lymphadenectomy was defined as the maximum number of LNs where a significant node positivity difference was observed. Maximally selected log-rank statistic was used to derive the optimal lymphadenectomy cut-off (maximize survival). Kaplan-Meier curves and log-rank tests were used to analyze overall survival (OS) and recurrence-free survival (RFS). Multivariable Cox-regression was used to determine hazard ratios (HR) with 95% confidence intervals (95%CI). In 341 patients with resected IPMN-derived PDAC, the minimum number of LNs needed to ensure accurate nodal staging was 10 (P=0.040), whereas ≥20 LNs was the optimal number associated with improved OS (80.3 vs. 37.2mo, P<0.001). Optimal lymphadenectomy was associated with improved OS [HR:0.57 (95%CI 0.39-0.83)] and RFS [HR:0.70 (95%CI 0.51-0.97)] on multivariable Cox-regression. On sub-analysis the optimal lymphadenectomy cut-offs for pancreatoduodenectomy, distal pancreatectomy, and total pancreatectomy were 20 (P<0.001), 23 (P=0.160), and 25 (P=0.008). In IPMN-derived PDAC, lymphadenectomy with at least 10 lymph nodes mitigates under-staging, and at least 20 lymph nodes is associated with the improved survival. Specifically, for pancreatoduodenectomy and total pancreatectomy, 20 and 25 lymph nodes were the optimal cut-offs.

The optimal minimum lymph node count for carcinoembryonic antigen elevated colon cancer: a population-based study in the SEER set and External set

PurposeThe aim of this paper was to clarify the optimal minimum number of lymph node for CEA-elevated (≥ 5 ng/ml) colon cancer patients.MethodsThirteen thousand two hundred thirty-nine patients from the SEER database and 238 patients from the Second Affiliated Hospital of Harbin Medical University (External set) were identified. For cancer-specific survival (CSS), Kaplan-Meier curves were drawn and data were analyzed using log-rank test. Using X-tile software, the optimal cut-off lymph node count was calculated by the maximal Chi-square value method. Cox regression model was applied to perform survival analysis.ResultsIn CEA-elevated colon cancer, 18 nodes were defined as the optimal minimum node. The number of lymph node examined (< 12, 12-17 and ≥ 18) was an independent prognosticator in both SEER set (HR12-17 nodes = 1.329, P < 0.001; HR< 12 nodes = 1.985, P < 0.001) and External set (HR12-17 nodes = 1.774, P < 0.032; HR< 12 nodes = 2.741, P < 0.006). Moreover, the revised 18-node standard could identify more positive lymph nodes compared with the 12-node standard in this population.ConclusionsWith the purpose of favorable long-term survival and accurate nodal stage for CEA-elevated colon cancer patients, the 18-node standard could be regarded as an alternative to the 12-node standard advocated by the ASCO and NCCN guidelines.

OGC P39 Absolute lymph node yield &amp;lt;15 is associated with reduced overall survival in patients undergoing oesophagectomy for oesophageal cancer and is an important quality metric

Abstract Background Surgical resection following neoadjuvant therapy with either chemotherapy or chemoradiotherapy remains the cornerstone of curative management of oesophageal cancer. In spite of this, there remains uncertainty regarding the optimal radicality of lymphadenectomy, and whether increasing lymph node yields confer a true survival benefit. This study aims to assess the impact of lymph node yield and lymph node ratio on survival following surgery for oesophageal cancer, in addition to identifying factors that may influence lymph node yield and radicality of resection. Methods Patients in a single centre undergoing oesophagectomy with curative intent from January 1, 2010 to December 31, 2020 were reviewed. Clinical and pathological variables were assessed, with univariable, multivariable, regression and survival analyses performed as appropriate. Regression with cut-point analysis was used to determine the optimal cut-off for lymph node ratio and for minimum number of nodes resected. Results Three hundred and ninety-seven patients underwent oesophagectomy in the study period, with 288 of these having a minimally invasive operation (MIE). Stage (stage 3 HR: 1.64 (1.02–2.62), p=0.04, stage 4 HR: 2.50 (1.43–5.01), p=0.001), positive margin status (HR: 2.62 (1.57–4.36), p&amp;lt;0.001), lymph node yield &amp;lt;15 (HR: 2.62 (1.57–4.36), p&amp;lt;0.001) and an elevated lymph node ratio (HR: 8.42 (2.85–24.90, p&amp;lt;0.001) predicted survival. Patients undergoing MIE had higher lymph node yields compared with open procedures (30.7 vs 25.3, p&amp;lt;0.001). Patients undergoing neoadjuvant chemoradiation had lower lymph node yields compared with those with no neoadjuvant therapy and those with neoadjuvant chemotherapy (26.4 vs 30.6 vs 36.8 respectively, p&amp;lt;0.001). Cut-point regression analysis determined lymph node ratio of &amp;lt;0.05 was associated with a survival benefit. Cut-point analysis also demonstrated that resecting more than 15 lymph nodes had an associated benefit, and 15 nodes is the minimum that should be resected, consistent with guidelines. Conclusions Lymphadenectomy is a cornerstone of resection of oesophageal cancer. Low lymph node yield and high lymph node ratio are associated with reduced overall survival. A lymph node ratio of &amp;lt;0.05 is associated with significant survival benefit. The minimum number of lymph nodes that should be resected in esophageal cancer is 15, consistent with current guidelines.

Minimum number of necessary lymph nodes for the accurate staging of adenocarcinoma of esophagogastric junction

ObjectiveThis study aims to explore the minimum number of lymph nodes (LNs) necessary for assessing the postoperative staging of adenocarcinoma of esophagogastric junction (AEG). MethodsWe extracted the data of patients from the Surveillance Epidemiology and End Results (SEER) database, who were pathologically diagnosed with AEG between 2000 and 2017. We explored the associations between the number of LNs and overall survival (OS) by univariate and multivariate analyses and determined the proper cutoff value of the number of LNs necessary for accurate postoperative staging. ResultsOf the patients with AEG in the SEER database, 2668 met our inclusion criteria. The total number of regional LNs dissected was found to be significantly associated with survival in analyses stratified by T stage. Univariate and multivariate regression showed that age, grade, positive LNs, number of LNs examined, and T stage were independently associated with OS. For patients with T1-2 tumors, the 5-year survival rate was 58.7%, and patients with more than 11 LNs examined obtained a greater survival benefit. Among patients with T3-4 tumors, the 5-year survival rates were 28.9% and 39.7% for those with 1–16 LNs examined and for those with more than 17 LNs examined, respectively. ConclusionTo accurately determine the pathological stage of patients with AEG, no less than 11 LNs must be resected for patients with stage T1-2 disease, and no less than 16 LNs must be resected for patients with stage T3-4 disease.

Prognostic value of the extent of lymphadenectomy for esophageal cancer-specific survival among T1 patients

BackgroundClinically, there are no clear guidelines on the extent of lymphadenectomy in patients with T1 esophageal cancer. Studying the minimum number of lymph nodes for resection may increase cancer-specific survival.MethodsPatients who underwent esophagectomy and lymphadenectomy at T1 stage were selected from the Surveillance, Epidemiology and End Results Program (United States, 1998–2014). Maximally selected rank and Cox proportional hazard models were used to examine three variables: the number of lymph nodes examined, the number of negative lymph nodes and the lymph node ratio.ResultsApproximately 18% had lymph node metastases, where the median values were 10, 10 and 0 for the number of lymph nodes examined, the number of negative lymph nodes and the lymph node ratio, respectively. All three examined variables were statistically associated with cancer-specific survival probability. Dividing patients into two groups shows a clear difference in cancer-specific survival compared to four or five groups for all three variables: there was a 29% decrease in the risk of death with the number of lymph nodes examined ≥14 vs < 14 (hazard ratio 0.71, 95% confidence interval: 0.57–0.89), a 35% decrease in the risk of death with the number of negative lymph nodes ≥13 vs < 13 (hazard ratio 0.65, 95% confidence interval: 0.52–0.81), and an increase of 1.21 times in the risk of death (hazard ratio 2.21, 95% confidence interval: 1.76–2.77) for the lymph node ratio > 0.05 vs ≤ 0.05.ConclusionsThe extent of lymph node dissection is associated with cancer-specific survival, and the minimum number of lymph nodes that need to be removed is 14. The number of negative lymph nodes and the lymph node ratio also have prognostic value after lymphadenectomy among T1 stage patients.

Evaluation of the prognostic relevance of the recommended minimum number of lymph nodes in colorectal cancer\u2014a propensity score analysis

PurposeNodal status in colorectal cancer (CRC) is an important prognostic factor, and adequate lymph node (LN) staging is crucial. Whether the number of resected and analysed LN has a direct impact on overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS) is much discussed. Guidelines request a minimum number of 12 LN to be analysed. Whether that threshold marks a prognostic relevant cut-off remains unknown.MethodsPatients operated for stage I–III CRC were identified from a prospectively maintained database. The impact of the number of analysed LN on OS, CSS and DFS was assessed using Cox regression and propensity score analysis.ResultsOf the 687 patients, 81.8% had ≥ 12 LN resected and analysed. Median LN yield was 17.0 (IQR 13.0–23.0). Resection and analysis of ≥ 12 LN was associated with improved OS (HR = 0.73, 95% CI: 0.56–0.95, p = 0.033), CSS (HR 0.52, 95% CI: 0.31–0.85, p = 0.030) and DFS (HR = 0.73, 95% CI: 0.57–0.95, p = 0.030) in multivariate Cox analysis. After adjusting for biasing factors with propensity score matching, resection of ≥ 12 LN was significantly associated with improved OS (HR = 0.59; 95% CI: 0.43–0.81; p = 0.002), CSS (HR = 0.34; 95% CI: 0.20–0.60; p < 0.001) and DFS (HR = 0.55; 95% CI: 0.41–0.74; p < 0.001) compared to patients with < 12 LN.ConclusionEliminating biasing factors by a propensity score matching analysis underlines the prognostic importance of the number of analysed LN. The set threshold marks the minimum number of required LN but nevertheless represents a cut-off regarding outcome in stage I–III CRC. This analysis therefore highlights the significance and importance of adherence to surgical oncological standards.

Examining More Lymph Nodes May Improve the Prognosis of Patients With Right Colon Cancer: Determining the Optimal Minimum Lymph Node Count.

ObjectivesThe objective is to determine the optimal minimum lymph node examination number for right colon cancer (RCC) patients.MethodsWe comprehensively analysed the Surveillance, Epidemiology and End Results database data from 2004 to 2016 to determine the 13-year trend in the number of lymph nodes examined among 108,703 left colon cancer and 165,937 RCC patients. 133,137 RCC patients eligible for inclusion were used to determine the optimal minimum for lymph node examination. We used restricted cubic splines to analyse the dose-response relationship between the number of lymph nodes examined and prognosis. X-tiles and decision trees were used to determine the optimal cutoff for the number of lymph nodes based on the survival outcomes of patients with RCC. The Kaplan–Meier method and COX model were used to estimate the overall survival and independent prognostic factors, and a prediction model was constructed. The C-index, calibration curve, net reclassification improvement and integrated discrimination improvement were used to determine the predictive performance of the model, and decision curve analysis was used to evaluate the benefits.ResultsLymph node examinations were common among colon cancer patients over the 13-year study period. It is generally agreed that at least 12 lymph nodes must be examined to ensure proper dissection and accurate staging of RCC; however, the optimal number of lymph nodes to be examined is controversial. The dose-response relationship indicated that 12 was not the optimal minimum number of lymph nodes for RCC patients. X-tile and survival decision-tree analysis indicated that 20 nodes was the optimal number. Survival analysis indicated that <20 nodes examined was a risk factor for poor prognosis, and the classification performance was superior for 20 nodes compared to 12 nodes.ConclusionLymph node examination in RCC patients should be altered. Our research suggests that a 20-node measure may be more suitable for RCC patients.

Significance of accurate hilar and intrapulmonary lymph node examination and prognostication in stage IA\u2013IIA non-small cell lung cancer, a retrospective cohort study

BackgroundThe examination of lymph nodes (LNs) plays an important role in the nodal staging of non-small cell lung cancer (NSCLC). For patients without LN metastasis, the main role of thorough LN examination is accurate staging, which weakens the effect of staging migration. To date, the role of hilar and intrapulmonary (N1) station LNs has not been fully appreciated. In this study, we aimed to confirm the significance of N1 LNs in long-term survival for stage IA–IIA NSCLC patients and to find the minimum number of LN to examine.MethodsThe data of patients who underwent radical lobectomy and were confirmed as having non-metastatic LNs from January 2008 to March 2018 were retrospectively screened. Pathology records were reviewed for the number of LNs examined. The Kaplan-Meier method and Cox regression model were used to identify survival and prognostic factors.ResultsThe median number of resected N1 LNs was 8. The number of patients with 0–2 N1 LNs, 3–5 N1 LNs, 6–8 N1 LNs, 9–11 N1 LNs, and more than 11 N1 LNs examined was 181, 425, 477, 414, and 531, respectively. Sex (P = 0.004), age (P < 0.001), tumor size (P = 0.004), differentiation degree (P = 0.001), and number of N1 LNs examined (P = 0.008) were independent prognostic factors of overall survival. Gender (P = 0.006), age (P = 0.031), tumor size (P = 0.001), differentiation degree (P = 0.001), vascular invasion (P = 0.034), and number of N1 LNs examined (P = 0.007) were independent prognostic factors of disease-free survival. Compared with patients with 0–5 N1 LNs examined, patients with more than 5 N1 LNs examined had better OS (P = 0.015) and had better DFS (P = 0.015) if only a landmark 5-year follow-up was performed.ConclusionIncreasing the number of N1 LN examination might improve the long-term survival of T1-2N0 NSCLC patients. These data indicate that at least 6 N1 nodes examined is an essential part in surgical and pathological management but cannot prove this. This finding should be confirmed in a large, prospective randomized clinical study.

Optimal number of harvested lymph nodes for curatively resected gallbladder adenocarcinoma based on a Bayesian network model.

To identify the optimal range and the minimum number of lymph nodes (LNs) to be examined to maximize survival time of patients with curatively resected gallbladder adenocarcinoma (GBAC). Data were collected from the surveillance, epidemiology, and end results database on patients with GBAC who underwent curative resection between 2004 and 2015. A Bayesian network (BN) model was constructed to identify the optimal range of harvested LNs. Model accuracy was evaluated using the confusion matrix and receiver operating characteristic (ROC) curve. A total of 1268 patients were enrolled in this study. Accuracy of the BN model was 72.82%, and the area under the curve of the ROC for the testing dataset was 78.49%. We found that at least seven LNs should be harvested to maximize survival time, and that the optimal count of harvested LNs was in the range of 7 to 10 overall, with an optimal range of 10 to 11 for N+ patients, 7 to 10 for stage T1-T2 patients, and 7 to 11 for stage T3-T4 patients. According to a BN model, at least seven LNs should be retrieved for GBAC with curative resection, with an overall optimal range of 7 to 10 harvested LNs.

Abstract A054: Sociodemographic disparities in gastric adenocarcinoma: A population-based study

Abstract Background: Gastric cancer is one of the leading causes of cancer-related mortality worldwide, with a global burden of 5.7% new cases each year and 8.2% of cancer-related deaths. Area of residence has been found to affect survival in different cancers but their impact on gastric cancer remains largely unknown. The purpose of this study is to address the potential disparities between the rural and urban populations affected specifically by gastric adenocarcinoma. Methods: We conducted a retrospective study, analyzing different socio-economic factors associated with populations affected by gastric adenocarcinoma between 2004 and 2013. Data was obtained from the National Cancer Database (NCDB). Univariate and multivariable analyses were performed to evaluate overall survival (OS). Different socio-demographic factors, location of residence were included, urban area (UA) or rural area (RA), gender, race, insurance status and marital status were included in the analyses. Results: A total of 88,246 [RA, N=12,365; UA, N=75,881] patients were included in the study. Majority of the study population was white (N = 67,792, 77%) and male (N = 59,574, 68%). Univariate and multivariable analysis showed that RA had the worst OS (univariate - HR=1.08, p&amp;lt;0.001; multivariate HR=1.04; p&amp;lt;0.001) compared to UA. When comparing different racial backgrounds, univariate and multivariable analysis showed Native American and African American population had poor OS when compared to the white population, however, Asian patients tend to have better OS (univariate HR=0.66, multivariable HR=0.68, p&amp;lt;0.01). From quality of care standpoint, UA patients median days to undergo surgery (28 vs. 33; p&amp;lt;0.01) post diagnosis was significantly sooner, with significantly fewer positive margins (6.3% vs. 6.9%; p&amp;lt;0.01) when compared to RA patients. Though, there is no minimum number of lymph nodes examined during resection, but total of 15 or above is an accepted practice. When comparing the lymph node dissection, 19.6% UA patients underwent more than or equal to 15 lymph nodes dissection in comparison to 18.7% patients in RA (p=0.03). Discussion: This study identifies socio-demographic disparities in gastric adenocarcinoma. Access to healthcare, variations in patient care, environmental and lifestyle factors as well as genomic differences are all potential factors that affect the OS. This is consistent with the available literature in gastric cancer, including studies demonstrating survival differences in different populations undergoing surgical treatment in the United States. Based on the above data, it is imperative for future health policy initiatives to address these disparities in an effort to improve OS. Citation Format: Rohit Gosain, Navpreet Rana, Riccardo Lemini, Chong Wang, Sarbajit Mukherjee. Sociodemographic disparities in gastric adenocarcinoma: A population-based study [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr A054.

Metastatic lymph node ratio as better prognostic tool than TNM system in colorectal cancer.

e16128 Background: Colorectal cancer (CRC) is the third leading cause of cancer death in the world. Lymph node metastasis is an important prognostic factor; however, the minimum number of lymph nodes that should be evaluated for adequately categorizing lymph node status is still a controversial theme. The TNM staging system has limitations in defining the pN category. The lymph node ratio (LNR) may be a better prognostic indicator. Objectives: Evaluate the impact on the prognosis of patients operated for CRC, comparing the LNR with the pN category of TNM system. Methods: We studied 1065 patients treated at a General Surgery Department from 01/01/2000 to 08/31/2012. The LNR was separated into 5 categories based on three previously calculated cut-off values: LNR0 (0), LNR1 (0.01-0.17), LNR2 (0.18- 0.41), LNR3 (0.42-0.69) and LNR4 (≥0.70). Results: The results of the univariate analysis indicated significant differences in survival according to age (p &lt; 0.001), tumor size (p &lt; 0.001), serosal invasion (p &lt; 0.001), histological type (p = 0.002), differentiation (p &lt; 0.001), pT (p &lt; 0.001), pN (p &lt; 0.001), LNR (p &lt; 0.001), M (p = 0.001), TNM stage (p &lt; 0.001), venous invasion (p &lt; 0.001). Multivariate analysis confirmed the LRN, pN, age, venous invasion and pT as independent prognostic factors. The survival analysis showed significant differences between the categories of pN (p &lt; .001) and LNR (p &lt; .001). Spearman correlation analysis showed a significant correlation between the total number of dissected lymph nodes and the number of metastatic lymph nodes (rs = 0.167, p &lt; 0.001). The total number of dissected lymph nodes is not significantly correlated with LNR (rs = -0.019, p = 0.550). Conclusions: In this study LNR seems to demonstrate a superior prognostic value when compared to the pN categories, in part due to its greater independence regarding the extent of lymphadenectomy.

Use of Nodal Staging Score in Evaluating the Accuracy of Pathologic Nodal Status in Node-Negative Ampullary Carcinoma

BackgroundThe minimum number of lymph nodes (LNs) that should be resected for accurate nodal staging in patients with ampullary carcinoma (AC) remains controversial. This study aimed to establish a nodal staging score (NSS) to evaluate whether a pathological node-negative AC patient is indeed free of a nodal disease. MethodsA total of 2539 AC patients with stages I–III were retrieved from the Surveillance, Epidemiology and End Result database (design cohort [DC], n = 2382) and First Affiliated Hospital of Sun Yat-sen University (validation cohort [VC], n = 157). NSS was developed to represent the probability that a node-negative patient was correctly staged as a function of the number of examined LNs (ELNs) and pathologic T stage with a beta-binomial model. Its prognostic value in node-negative patients was assessed by survival analysis. ResultsThe probability of missing a metastatic LN decreased as the number of the ELNs increased. NSS was escalated as the number of ELNs increased. For patients with early-stage (T1–T2) and late-stage (T3–T4) tumors, examining 7 and 33 lymph nodes could ensure an NSS of 80.0%, respectively. Multivariate analysis showed that higher NSS was an independent favorable prognostic factor for overall survival in node-negative patients with AC (DC, p < 0.001; VC, p = 0.001). ConclusionsNSS model could be used to evaluate the accuracy of nodal staging and predict the prognosis of node-negative AC patients. It could assist in making clinical strategies in node-negative AC patients.

Accuracy of nodal staging is influenced by sidedness in colon cancer.

Adequate lymph node (LN) sampling is critical for accurate nodal staging in colon cancer (CC), particularly for T3N0 disease as current guidelines recommend considering adjuvant chemotherapy when less than 12 LNs are examined. The impact of sidedness on nodal staging accuracy in patients with T3N0 disease has not been previously studied. Patients with pathologic T3 CC were identified from a prospective multicenter international trial of ultrastaging in CC. The probability of true nodal negativity (TNN) based on the number of LN examined was calculated for right and left CC. These results were then validated in a cohort of patients with similar inclusion criteria selected from the National Cancer Database (NCDB) between 2006 and 2014. Three hundred and seventy patients met the inclusion criteria in the trial cohort; 48% were LN-negative. Of 153,945 patients in the NCDB, 57% were LN-negative. The probability of TNN when 12 LNs were examined was 68% for right and 64% for left CC in the trial cohort and 77% and 72% in the NCDB. The number of LNs needed to achieve any given probability of TNN was significantly different between right and left CC in both the trial (P<0.001) and the NCDB (P<0.001). In both a prospective multicenter trial and the NCDB, sidedness influences the number of LNs needed to predict nodal negativity in CC. Current guidelines regarding the minimum number of LNs needed to accurately stage patients with T3N0 CC may need to be re-evaluated by taking into consideration the tumor sidedness.

Lymph node yield and lymph node density for elective level II-IV neck dissections in laryngeal squamous cell carcinoma patients.

To determine the minimum lymph node yield (LNY) in patients with laryngeal squamous cell carcinoma (LSCCs). This retrospective study was performed in a tertiary care hospital setting and included 42 LSCC patients aged 39-81years (females, n = 2; males, n = 40) who underwent a total or partial laryngectomy and elective bilateral level II-IV neck dissections (unilateral neck dissections: n = 84). The average LNY in the unilateral level II-IV lymph node dissections was 25.9 ± 10, and the average metastatic LNY was 0.9 ± 1.9. The unilateral neck dissections were grouped according to the number of lymph nodes. There was no significant difference between the groups in terms of the metastatic LNY (p = 0.5). The metastatic lymph node density (LND) (metastatic lymph node yield/LNY) was 0.043 for unilateral neck level II-IV neck dissections. A Cox regression analysis revealed no significant relationship between survival and the LNY and LND in bilateral neck dissections (p = 0.4 and p = 0.8, respectively). The results revealed no minimum number of lymph nodes that could reliably detect metastatic lymph nodes in LSCC patients.

Optimal number of lymph nodes to be examined in stage II colon cancer

Objective: to determine the minimum number of lymph nodes (LN) required for accurate prediction of overall survival in patients with stage II colon cancer and to assess the prognostic value of criteria used in the MOSAIC trial. Materials and methods. This retrospective study included patients with stage II colon cancer that underwent surgical treatment in the Department of Proctology and received adjuvant chemotherapy (if needed) in the Department of Clinical Pharmacology and Chemotherapy of N.N. Blokhin National Medical Research Center of Oncology between 2004 and 2013. Overall survival was considered as the main criterion of treatment efficacy. Results. A total of 445 patients met the inclusion criteria; of them, 60 (13.5 %) patients received adjuvant chemotherapy. The receiver operating characteristic (ROC) analysis was employed to evaluate the predictive value of the number of removed LN for disease progression and death in patients with stage II colon cancer. We found that specificity of &gt;80 % was achieved by removing/examining at least 12 LN. The examination of 13 LN increases specificity by another 6 %. Further increase in the number of removed/examined LN (&gt;13) did not significantly improve prognostic accuracy for death from the moment of disease progression. Only the removal of 13 or more LN ensured a significant impact on overall survival (hazard ratio (HR) 0.12; 95 % confidence interval (CI) 0.02—0.91; p = 0.04). At multivariate analysis, the following factors were found to affect overall survival: postoperative complications (HR 2.4; 95 % CI 1.4—4.3; p &lt;0.01), pT4 stage (HR 1.2; 95 % CI 1.003—1.400; р = 0.04), and removal/examination of 13 or more LN(HR 0.1; 95 % CI 0.02—1.01;p = 0.05). However, after the inclusion of the variable reflecting the number of factors form the MOSAIC trail into the multivariate model, the last 2 covariates lost their statistical significance as independent prognostic factors. Conclusion. We recommend removing/examining at least 12 (preferable 13) LN in patients with stage II colon cancer in order to ensure proper staging. For patients with high risk of disease progression (those with &lt;13 LN removed and/or presented a T4 depth of invasion in the intestinal wall), adjuvant chemotherapy should be considered. For routine clinical practice, we recommend assessing the risk of progression using the criteria from the MOSAIC trial for patients with stage II colon cancer.

Prognostic value of lymph node positivity and number of lymph nodes required for accurate staging of pancreatic neuroendocrine tumors.

e15736 Background: The prognostic role of the number of positive lymph nodes (PLNs), as well as the minimum number of lymph nodes needed to accurately stage patients with pancreatic neuroendocrine tumors (pNETs), remain controversial. The aim of this study was to assess the effect of the number of PLNs on prognosis in pNETs and to determine the ideal number of examined lymph nodes (ELNs) for accurate staging of pNETs. Methods: The SEER database was reviewed from 2004 to 2014 for pts with surgically resected, pathologically confirmed pNETs. Pts with missing data for pathological stage, tumor size, ELNs or PLNs were excluded. Kaplan-Meier survival analysis was used to evaluate the association between lymph node involvement and disease-specific survival (DSS). The optimal number of ELNs was identified using the log odds of positive lymph nodes (LODDS). A large single institutional cohort with 203 patients was used for validation. Results: Of the 1,813 patients included, 686 (37.8%) had lymph node-positive disease. Patients with lymph node-positive disease had a significantly worse DSS than those with lymph node-negative disease (Log-rank P &lt; 0.001). Patients with 4 or more positive lymph nodes had a worse DSS compared with those with 1 to 3 positive lymph nodes (Log-rank P &lt; 0.001). In order to capture 95% of pNETs with PLNs at the time of surgery, 12 lymph nodes need to be examined (LODDS: -2.344). Findings were reproducible with the validation cohort. Conclusions: The number of PLNs leads to better prognostic discrimination of lymph node-positive patients with pNETs. The current staging systems may include an N-stage that distinguishes lymph node-positive disease into N1 (1 to 3 PLNs) and N2 (4 or more PLNs) categories. The minimum number of ELNs for accurate staging of pNETs is 12. [Table: see text]

Pathological nodal staging score for rectal cancer patients treated with radical surgery with or without neoadjuvant therapy: a postoperative decision tool.

BackgroundLymph node status can predict the prognosis of patients with rectal cancer treated with surgery. Thus, we sought to establish a standard for the minimum number of lymph nodes (LNs) examined in patients with rectal cancer by evaluating the probability that pathologically negative LNs prove positive during surgery.Patients and methodsWe extracted information of 31,853 patients with stage I–III rectal carcinoma registered between 2004 and 2013 from the Surveillance, Epidemiology, and End Results database and divided them into two groups: the first group was SURG, including patients receiving surgery directly and the other group was NEO, encompassing those underwent neo-adjuvant therapy. Using a beta-binomial model, we developed nodal staging score (NSS) based on pT/ypT stage and the number of LNs retrieved.ResultsIn both cohorts, the false-negative rate was estimated to be 16% when 12 LNs were examined, but it dropped to 10% when 20 LNs were evaluated. In the SURG cohort, to rule out 90% possibility of false staging, 3, 7, 28, and 32 LNs would be necessarily examined in patients with pT1–4 disease, respectively. While in the NEO cohort, 4, 7, 12, and 16 LNs would be included for examination in patients with ypT1–4 disease to guarantee an NSS of 90%.ConclusionBy determining whether a rectal cancer patient with negative LNs was appropriately staged, the NSS model we developed in this study may assist in tailoring postoperative management.

Effects of lymph nodes count on the prognosis of patients with pathologically lymph node-negative hypopharyngeal squamous cell carcinoma

Objective To investigate the relationship between lymph nodes count after selective neck lymph node dissection and the prognosis of patients with pathologically lymph node-negative (pN0) hypopharyngeal squamous cell carcinoma (HPSCC). Methods The clinical data of 96 patients with pN0 HPSCC undergoing selective neck dissection (bilateralⅡ-Ⅳregion) from October 1995 to October 2012 in Shanxi Provincial Cancer Hospital were analyzed retrospectively. The optimal lymph nodes count cutoff values were determined by using the X-tile program in different prognostic groups, and the univariate and multivariate survival analysis in different groups were analyzed by using SPSS 19.0 software. Results A total of 2 116 lymph nodes were detected in this cohort, with a median number of 22 (3-52). Except for the tumor site (P= 0.011), there were no statistical differences in lymph nodes count of patients with different age, gender, history of smoking or drinking, T stage, and differentiation degree (all P > 0.05). Applying 9 and 23 nodes as the cutoff values determined by using X-tile program, all patients could be divided into the high-risk (13 cases, lymph nodes count 3-9), the middle-risk (37 cases, lymph nodes count 10-22) and the low-risk (46 cases, lymph nodes count 23-52) groups. And the 5-year overall survival (OS) rate was 23.1%, 55.9% and 86.0% in the high, middle, low risk groups respectively (χ 2= 21.73, P < 0.001). Multiple-factor analysis showed that lymph nodes count, T stage and degree of tumor differentiation were independent prognostic factors in patients with pN0 HPSCC (all P < 0.05). Further analysis showed that when the cutoff value of lymph nodes count was 9, the patients could be divided into two groups with significantly different prognosis. The 5-year OS rate was 23.1% in the high-risk group and 73.2% in the low-risk group, and the difference was statistically significant (χ 2= 17.87, P < 0.001). Conclusions Lymph nodes count after selective neck lymph node dissection can be used to predict the prognosis of patients with pN0 HPSCC. It is likely that 9 is the minimum number of lymph nodes in pN0 HPSCC patients. Key words: Hypopharyngeal neoplasms; Carcinoma, squamous cell; Lymphatic metastasis; Neck dissection; Prognosis

Prognostic Role of Lymph Node Positivity and Number of Lymph Nodes Needed for Accurately Staging Small-Bowel Neuroendocrine Tumors

Little information is available regarding the minimum number of lymph nodes needed to accurately stage patients when performing a mesenteric lymphadenectomy for small-bowel neuroendocrine tumors. To determine the prognostic role of lymph node positivity and the ideal number of lymph nodes for accurately staging patients with small-bowel neuroendocrine tumors. This case series from the US Neuroendocrine Tumor Study Group, a collaboration among 8 US-based, academic tertiary care referral centers, obtained demographic, perioperative, and pathologic data from the group's database, Social Security Death Index, and publicly available obituaries. All patients in these institutions with small-bowel neuroendocrine tumors who underwent curative-intent surgical resection of a primary tumor between January 1, 2000, and December 31, 2015, were included (n = 199). Patients with duodenal or ampullary tumors, other nonneuroendocrine concurrent malignant neoplasms, mortality of fewer than 30 days after the surgical procedure, and distant metastatic disease were excluded. Data analysis was conducted from September 1, 2017, to December 1, 2017. Primary study outcome was recurrence-free survival. Hypothesis was generated after data collection and data entry into the US Neuroendocrine Tumor Study Group database. Of the 199 patients included, 112 (56.3%) were male and 87 (43.7%) female with a mean (SD) age of 60.3 (12.5) years and a mean (SD) body mass index of 29.5 (6.0). One hundred fifty-four patients (77.4%) had lymph node-positive disease. No difference in 3-year recurrence-free survival was found between patients with lymph node-positive and lymph node-negative disease. Patients with 4 positive lymph nodes had a worse 3-year recurrence-free survival compared with those with 1 to 3 or 0 positive lymph nodes (81.6% vs 91.4% vs 92.1%; P = .01). When examining patients with fewer than 8 resected lymph nodes, no difference in 3-year recurrence-free survival was observed among patients with 4 or more, 1 to 3, or 0 positive lymph nodes (100% vs 93.8% vs 91.7%; P = .87). Retrieval of 8 or more lymph nodes, however, accurately discriminated patients with 4 or more, 1 to 3, or 0 positive lymph nodes (3-year recurrence-free survival: 79.9% vs 89.6% vs 92.9%; P = .05). The findings from this study suggest that, for patients undergoing curative-intent resection of small-bowel neuroendocrine tumors, accurate lymph node staging requires a minimum of 8 lymph nodes for examination, and 4 or more positive lymph nodes are associated with decreased 3-year recurrence-free survival compared with 1 to 3 or 0 positive lymph nodes; a thorough regional lymphadenectomy may be critical for accurate staging and management of this disease.