Node Staging System Research Articles

37. Understanding the clinical utility and prognostic implications of the new AJCC8 staging system for cutaneous squamous cell carcinoma: A survey of head and neck cancer specialists

Background: In order to have clinical relevance and assist in treatment decisions, a cancer staging system must stratify patients into prognostically meaningful groups; outcomes should be homogenous within groups, but distinct between them (AJCC8, 2017). The staging system for head and neck cutaneous squamous cell carcinoma (HNcSCC) in the AJCC 8, has been criticised for its lack of homogeneity and distinctiveness, with no difference in survival between pT2 and pT3 tumours, nor between stage III and stage IV disease. The nodal staging system is likewise a poor predictor of patient outcomes. In addition, the AJCC8 staging system for cutaneous SCC is similar to that of mucosal SCC, despite the vastly different biological behaviour of these diseases. Aim: To understand the experience of head and neck cancer surgeons, pathologists, radiation and medical oncologists in using the AJCC8 in routine management of HNcSCC patients. Method: A literature review was undertaken to: (1) determine the prognostic utility of HNcSCC AJCC8 staging system, (2) identify tumour factors which may influence the staging system, and (3) identify avenues to improve the staging system. An eighteen-part online questionnaire was administered to surgeons, surgical pathologists, oncologists, and radiation oncologists, designed to elicit their views on the prognostic utility of this staging system. Results and discussion: Literature review using the terms ‘head and neck’, ‘cutaneous SCC’, ‘prognosis’ and ‘AJCC’ yielded over 200 results pertaining to the prognostic features of HNcSCC, with fewer than 20 peer-reviewed, indexed manuscripts directly relevant to the prognostic performance of the AJCC8 HNcSCC staging system. The evidence suggests that the omission of prognostically important characteristics (such as patient immunosuppression, depth of invasion, perineural invasion, extent of extranodal extension, and soft-tissue metastases) may contribute to the poor predictive performance of the staging system. The questionnaire is being currently circulated and the Results will be provided.

Comparison of different lymph node staging systems in patients with node-positive cervical squamous cell carcinoma following radical surgery.

Objective: We compared the prognostic accuracy of four lymph node (LN) staging systems - the 2018 International Federation of Gynecology and Obstetrics (FIGO) stage, number of positive lymph node (PLN), metastatic lymph node ratio (LNR), and log odds of positive lymph nodes (LODDS) systems - in patients with node-positive cervical squamous cell carcinoma (CSCC) following radical surgery and explored the optimal choice for clinical applications.Materials and methods: Data were retrospectively collected from 928 node-positive CSCC patients who underwent radical surgery between 2006 and 2014 in our center. Tree-based recursive partitioning was applied to split variables (PLN, LNR, and LODDS) into low-risk and high-risk groups. The log-rank test was used to compare survival curves, and Cox regression analysis was performed to identify prognostic factors. The relative discriminative abilities of the different staging systems were assessed using Harrell's concordance index (C index) and the Akaike information criterion (AIC).Results: The mean number of PLNs was 3.8 (range: 1-44 nodes). According to the 2018 FIGO staging system, 831 patients had stage IIIC1, and 97 had stage IIIC2. For the PLN system, 761 patients were included in the low-risk group, and 167 were included in the high-risk group. For the LNR system, 658 patients were included in the low-risk group, and 270 were included in the high-risk group. The low-risk LODDS group included 694 patients, while the high-risk LODDS group included 234 patients. All four staging systems had a significant influence on patients' progression-free survival (PFS, P < 0.001) and overall survival (OS, P < 0.001). Univariate analysis and multivariate Cox analysis adjusted for significant factors indicated that the four staging systems were significant prognostic factors for PFS and OS. Among them, the PLN system was noted to have the best prognostic performance for both PFS (C index: 0.582; AIC: 8213.33) and OS (C index: 0.624; AIC: 8433.80).Conclusion: The PLN system seemed to be the most accurate LN staging method for predicting node-positive CSCC following radical surgery.

Proposal of the minimal number of retrieved regional lymph nodes for accurate staging of distal bile duct cancer and clinical validation of the three-tier lymph node staging system (AJCC 8th edition).

The minimal required number of retrieved lymph nodes (MNRLNs) to enable accurate staging of distal bile duct (DBD) adenocarcinoma remains unclear. The three-tier 8th N staging system of the American Joint Committee on Cancer (AJCC) for DBD adenocarcinoma has been recently released. The present study is aimed at proposing the MNRLNs for accurate staging and validating the 8th N stage. Between 1991 and 2015, patients with pathologically confirmed DBD adenocarcinoma who underwent pancreatoduodenectomy were enrolled. MNRLN was calculated via a log-rank test based on cut-off values. The concordance index (C-index) was utilized to compare the discrimination capability of the two- and three-tier N stages. A total of 780 patients were enrolled. Lymph node (LN) positivity and 5-year overall survival (5-YOS) rates stabilized and significant survival differences between node-negative and -positive patients were observed when≥12 LNs were retrieved. 5-YOS rates between each 8th N stage significantly differ (N0 vs. N1, P=0.037; N1 vs. N2, P=0.003). The C-index of the 8th N stage was higher than that of the 7th (0.59 vs. 0.57). For accurate staging, at least 12 LNs should be retrieved. The three-tier N staging system is valid for clinical practice and has a more accurate prognostic predictability than the two-tier system.

Modified lymph node ratio improves the prognostic predictive ability for breast cancer patients compared with other lymph node staging systems

BackgroundMetastatic regional lymph nodes (LN) is a strong predictor of worse long-term outcome. Therefore, different LN staging systems have been proposed in recent years. In this study, we proposed a modified lymph node ratio (mLNR) as a new lymph node staging system and then compared the prognostic performance of mLNR with American Joint Committee on Cancer N stage, lymph node ratio (LNR) and log odds of metastatic lymph nodes in breast cancer patients. MethodsBreast cancer patients who underwent surgery between 2004 and 2012 were identified from the Surveillance, Epidemiology, and End Results database. Restricted cubic spline functions were calculated to characterize the association between variables and the risk of death. The Cox proportional hazards models were constructed to assess the predictive ability of different lymph node staging systems using the Akaike’s Information Criterion (AIC) and Harrell’s concordance index (C-index). ResultsA total of 264,096 breast cancer patients were enrolled and 187,785 (71.1%) patients had a limited number of LNs harvested. In the limited LN harvest cohort, the prognostic performance of LNR decreased and mLNR could greatly solve this problem. In addition, among the entire cohort, mLNR modeled as a continuous value had the best predictive ability (AIC: 922021.9 and C-index: 0.727) than other lymph node staging systems. ConclusionsThe predictive ability of LNR is restricted by a limited LN harvest. However, mLNR shows superiority to LNR and other lymph node staging systems especially in a limited LN harvest cohort, making mLNR the most powerful lymph node staging systems.

A Comparison of the Currently Used Nodal Stage Classification with the Number of Metastatic Lymph Nodes and the Number of Metastatic Lymph Node Stations for Non-Small Cell Lung Cancer; Which of These Is the Best Prognostic Factor?

We aimed to compare the currently used nodal staging system (pN) with the number of metastatic lymph node (LN) stations (sN) and the number of metastatic LNs (nN) on survival in patients with NSCLC. Between 2010 and 2017, 1038 patients resected for NSCLC were analyzed. We performed three-different stratifications of LN status assessment: pN-category (pN0, pN1 and pN2); sN-category (sN0, sN1; one station metastasis, sN2; two-three stations metastases, and sN3; ≥ 4 stations metastasis); nN-category (nN0, nN1; one-three LNs metastasis, nN2; four-six Lns metastasis, and nN3; ≥ 7 LNs metastasis). Five-year survival rate was 70.1% for N0 in all classifications. It was 54.3% for pN1, and 26.4% for pN2 (p < 0.0001). Five-year survival rates for N1, N2, and N3 categories were 54.1%, 42.4% and 16.1% according to sN, and 51.4%, 36.1%, and 7.9% according to nN, respectively (p < 0.0001). In multivariate analysis, sN and nN were independent risk factors such as pN (p < 0.0001). Hazard ratios versus N0 for N1, N2, and N3 were more significant for sN and nN than pN (1.597, 2.176, and, 3.883 for sN, 1.645, 2.658, and, 4.118 for nN, and 1.576, 3.222 for pN, respectively). When the subcategories of sN and nN were divided into pN1 and pN2 subgroups, the anatomic location of the LN involvement lost importance as tumor burden and tumor spreading increased. The number of metastatic LN stations and the number of metastatic LNs are better prognostic factors than currently used nodal classification in NSCLC.

ASO Author Reflections: A Novel Station-Based Nodal Staging System for Esophageal Squamous Cell Carcinoma.

ASO Author Reflections: A Novel Station-Based Nodal Staging System for Esophageal Squamous Cell Carcinoma.

WS05.04 Particularities of Lymphadenectomy in Malignant Pleural Mesothelioma

WS05.04 Particularities of Lymphadenectomy in Malignant Pleural Mesothelioma

Hybrid Topographic Lymph Node Staging System Shows Prognostic Superiority to Numeric Pathologic Lymph Node Classification in Gastric Cancer

Capolupo, Gabriella T. MD, PhD; Lauricella, Sara MD; Mascianà, Gianluca MD; Mazzotta, Erica MD; Carannante, Filippo MD; Caputo, Damiano MD, FACS; Pagnoni, Chiara MD; Ciccozzi, Massimo PhD; Caricato, Marco MD, FACS; Coppola, Roberto MD, FACS Author Information

Stage-Specific Survival Rate of Breast Cancer Patients in Northern Thailand in Accordance with Two Different Staging Systems.

Objective:This study was attempted to investigate overall survival by stage at diagnosis in female breast cancer patients in Northern Thailand by using 2 different staging systems; namely, American Joint Committee on Cancer (AJCC) Tumor (T), Nodal (N) and Metastatic (M) staging system and Surveillance Epidemiology and End Results (SEER) summary staging system. Methods:We studies female breast cancer patients whose data were registered in Chiang Mai cancer registries between January 2006 and December 2015. Data were recorded in SEER summary staging system. The TNM AJCC staging was searched in the medical records. Results:A total of 3,873 female breast cancer patients were diagnosed from 2006-2015. All data sets were recorded in SEER summary stage 2000. Early stage was the most prevalent stage at the time of diagnosis (58%), followed by loco-regional advanced stage (32%), and metastatic breast cancer (10%). The 5-year overall survival rate of early, loco-regional advanced, and metastatic stages were 85.3%, 66.4%, and 26.2%, respectively. After examining the medical records, we excluded patients who had no data on T, N, and M in their records. Finally, only 3,251 patients were analyzed for AJCC stage-specific survival. The 5-year overall survival rate in stages I, II, III, and IV were 94.4%, 85.0%, 56.6%, and 28.3%, respectively. Conclusion:Comparing to more stable economic countries, the 5-year overall survival rate for a specific stage of breast cancer in Northern Thailand was slightly lower in early stage and stage I-II in accordance with AJCC, but much lower in loco-regional stage and stage III with respect to AJCC. Nevertheless, it was similar in metastatic stage and stage IV according to AJCC.

Lymph node staging systems in oral squamous cell carcinoma: A comparative analysis

ObjectivesThe 8th edition of the AJCC has introduced a new nodal staging system for head and neck cancers. Alternate nodal staging systems exist, however they have not been compared to the current AJCC staging system. Materials and methodsA retrospective analysis of 643 patients with oral squamous cell carcinoma (OSCC) treated with surgery ± adjuvant therapy in a single institution between 2004 and 2014 was undertaken. Nodal staging was performed using AJCC 8th edition (AJCC8), number of positive lymph nodes (PN), log odds of positive lymph nodes (LODDS) and lymph node ratio (LNR). Survival analyses for disease free survival (DFS) and overall survival (OS) were performed with the different staging systems and they were compared on the basis of hazard consistency, hazard discrimination, explained variation and likelihood difference. ResultsOverall, PN and LNR best predicted OS and DFS in our cohort of patients. AJCC8 had poor discrimination between sub-stages of pN2. ConclusionPN and LNR provided the most accurate prediction of OS and DFS for patients with OSCC.

Validation of the prognostic performance in various nodal staging systems for gallbladder cancer: results of a multicenter study.

Although the current nodal staging system for gallbladder cancer (GBC) was changed based on the number of positive lymph nodes (PLN), it needs to be evaluated in various situations. We reviewed the clinical data for 398 patients with resected GBC and compared nodal staging systems based on the number of PLNs, the positive/retrieved LN ratio (LNR), and the log odds of positive LN (LODDS). Prognostic performance was evaluated using the C-index. Subgroups were formed on the basis of an restricted cubic spline plot as follows: PLN 3 (PLN = 0, 1-2, ≥ 3); PLN 4 (PLN = 0, 1-3, ≥ 4); LNR (LNR = 0, 0-0.269, ≥ 0.27); and LODDS (LODDS < - 0.8, - 0.8-0, ≥ 0). The oncological outcome differed significantly between subgroups in each system. In all patients with GBC, PLN 4 (C-index 0.730) and PLN 3 (C-index 0.734) were the best prognostic discriminators of survival and recurrence, respectively. However, for retrieved LN (RLN) ≥ 6, LODDS was the best discriminator for survival (C-index 0.852). The nodal staging system based on PLN was the optimal prognostic discriminator in patients with RLN < 6, whereas the LODDS system is adequate for RLN ≥ 6. The following nodal staging system considers applying different systems according to the RLN.

Colon Neuroendocrine Tumors: A New Lymph Node Staging Classification.

The American Joint Commission on Cancer, the European Neuroendocrine Tumor Society, and the North American Neuroendocrine Tumor Society all classify colon neuroendocrine tumor (NET) nodal metastasis as N0 or N1. This binary classification does not allow for further prognostication by the total number of positive lymph nodes. This study aimed to evaluate whether the total number of positive lymph nodes affects the overall survival for patients with colon NET. The National Cancer Database was used to identify patients with colon NET. Nearest-neighborhood grouping was performed to classify patients by survival to create a new nodal staging system. The Surveillance, Epidemiology, and End Results database was used to validate the new nodal staging classification. Colon NETs were identified in 2472 patients. Distinct 5-year survival rates were estimated for the patients with N0 (no positive lymph nodes; 69.8%; 95% confidence interval [CI], 66.7-72.7%), N1a (1 positive lymph node; 63.9%; 95% CI, 59.6-68.0%), N1b (2-9 positive lymph nodes; 38.9%; 95% CI, 35.4-42.3%), and N2 (≥ 10 positive lymph nodes; 15.7%; 95% CI, 11.9-20.0%; p < 0.001) nodal classifications. The validation population showed distinct 5-year survival rates with the new nodal staging. In multivariable Cox regression, the new nodal stage was a significant independent predictor of overall survival. The number of positive locoregional lymph nodes in colon NETs is an independent prognostic factor. For patients with colon NETs, N0, N1a, N1b, and N2 classifications for nodal metastasis more accurately predict survival than current staging systems.

Pathological complete response after neoadjuvant/induction treatment: where is its place in the lung cancer staging system?†.

Prognosis for patients with non-small-cell lung cancer (NSCLC) who, after neoadjuvant/induction and surgery, have a pathological complete response (pCR) is expected to be improved. However, the place of the pCR patients in the context of the tumour, lymph node and metastasis (TNM) staging system is still not defined. The aim of this study is to investigate the long-term survival of NSCLC patients with pCR and to find their appropriate staging category within the TNM staging system. We retrospectively reviewed the prospectively recorded data of 1076 patients undergoing surgery (segmentectomy or more) for NSCLC between 1996 and 2016. Patients were divided into 2 groups. Group 1: clinical early-stage patients who underwent direct surgical resection (n = 660); group 2: patients who received neoadjuvant/induction treatment before surgical resection for locally advanced NSCLC (n = 416). Morbidity, mortality, survival rates and prognostic factors were analysed and compared. Postoperative histopathological evaluation revealed pCR in 72 (17%) patients in group 2. Overall 5-year survival was 58.7% (group 1 = 62.3%, group 2 = 52.8%, P = 0.001). Of note, 5-year survival was 72.2% for pCRs. In addition, 5-year survival for stage 1a disease was 82.6% in group 1 and 63.2% in group 2 (P = 0.008); 70.3% in group 1 and 60.5% in group 2 for stage 1b (P = 0.08). Patients with stage II had a 5-year survival of 53.9% in group 1 and 51.1% in group 2 (P = 0.36). This study shows that patients with locally advanced NSCLC developing a pCR after neoadjuvant/induction treatment have the best long-term survival and survival similar that of to stage Ib patients.

Comparison of three lymph node staging schemes for predicting the outcome in patients with small bowel adenocarcinoma: A population-based cohort and international multicentre cohort study.

BackgroundThe prognostic roles of three common lymph node staging schemes, number of positive lymph nodes (pN), lymph node ratio (LNR) and log odds of positive lymph nodes (LODDS) in small bowel adenocarcinoma (SBA) are unclear. We assessed their prognostic ability in SBA.MethodsA total of 2128 patients diagnosed with SBA between 1988 and 2010 from the Surveillance, Epidemiology, and End Results (SEER) database and 186 patients from 15 hospitals in France and China were identified. We evaluated the prognostic ability of the schemes in both continuous and stratified patterns using R2, Harrell's C, and time-dependent receiver operating characteristic curve analyses.FindingsFor continuous pattern, the LODDS had a better capacity of discrimination and higher accuracy of prognosis than pN and LNR. Similarly, the stratified LODDS classification had a better performance of discrimination and higher accuracy of prognosis than the pN and LNR classification. The multivariable model using the LODDS classification also showed superiorly predictive accuracy and discriminatory capacity to those of the 7th and, 8th TNM node and LNR classification. These results were fully validated in an independent international multicentre cohort.InterpretationThe LODDS scheme showed a better prognostic performance than the LNR or pN schemes in patients with SBA regardless of continuous or stratified pattern. The LODDS scheme could serve as an auxiliary to lymph node staging systems in future revisions of the American Joint Committee on Cancer (AJCC) manual.FundThis work was funded by the Zhejiang Province Natural Science Fund of China.

Abstract P2-08-36: Comparing prognostic performance of different lymph node staging systems among patients with breast cancer

Abstract Background: Metastatic regional lymph nodes (LN) is a strong predictor of worse long-term outcome after resection of breast cancer. This study aimed to compare the prognostic performance of American Joint Committee on Cancer (AJCC) N stage relative to lymph node ratio (LNR), log odds of metastatic lymph nodes (LODDS), number of removed lymph nodes (NRLNs), and number of negative lymph nodes (NNLNs) in breast cancer patients. Methods: All of the breast cancer patients who underwent surgery between 2004 and 2012 were identified from the Surveillance, Epidemiology, and End Results database. Restricted cubic spline functions were used to characterize the association between continuous variables and the risk of death and determine the optimal cut-off points. The Cox proportional hazards models were constructed, and the relative discriminative abilities of the different LN staging systems were assessed using the Akaike's Information Criterion (AIC) and the Harrell's concordance index (C-index). Results: A total of 264,096 breast cancer patients were enrolled, and 177,598 (67.2%) had no lymph node metastasis, whereas 86,498 (32.8%) had lymph node metastasis. 187,785 (71.1%) patients had a limited number of LNs harvested (NRLN &amp;lt;10). The median follow-up time was 73 months, and the 8-year overall survival (OS) and breast cancer-specific survival (BCSS) were 82.6% and 90.4%, respectively. LNR, LODDS, NRLNs, and NNLNs were all nonlinearly associated with OS and BCSS. Patients with metastatic LN had an increased risk of OS (hazards ratio: 2.32, 95% confidence interval: 2.27–2.37; P &amp;lt; 0.001) and BCSS (hazards ratio: 4.53, 95% confidence interval: 4.40–4.66; P &amp;lt; 0.001). When LNR was equal to 0 or 1, there was a heterogeneity of outcomes, and LODDS still yielded informative values compared to LNR. Among the entire cohort, LNR modeled as a continuous variable had a somewhat better prognostic performance (AIC: 923231.4 and C-index: 0.722 for OS; AIC: 482962.3 and C-index: 0.817 for BCSS) than any of other LN staging systems. However, a model with AJCC N stage showed the best fit in patients with a limited number of LNs harvested (AIC: 501321.8 and C-index: 0.699 for OS; AIC: 212605.6 and C-index: 0.809 for BCSS). When assessed among patients with metastatic LN, LODDS outperformed other staging systems including AJCC N stage, LNR, NRLNs and NNLNs, whenever assessed using continuous (AIC: 428626.2 and C index: 0.728 for OS; AIC: 296886.8 and C index: 0.770 for BCSS) or categorical (AIC: 429527.5 and C index: 0.722 for OS; AIC: 297796.6 and C index: 0.762 for BCSS) cutoff values. Conclusions: Although LNR assessed as a continuous variable was the most potent method to stratify patients regardless of LN status, the prognostic superiority of LNR is confounded by a limited LN harvest. LODDS was a better and more powerful predictor of survival when patients were LN positive, especially among those patients with either very low or high LNR. Citation Format: Gong Y, Ji P, Jiang Y-Z, Hu X, Shao Z-M. Comparing prognostic performance of different lymph node staging systems among patients with breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-36.

Development and Validation of an Improved Pathological Nodal Staging System for Urothelial Carcinoma of the Bladder

BackgroundCurrent pathological nodal staging for bladder cancer is based on lymph node (LN) location but not on the number of positive LNs. ObjectiveWe sought to improve prognostic classification by creating a novel staging system incorporating positive LN burden. Design, setting, and participantsWe sampled 12515 patients with muscle-invasive bladder cancer (MIBC) from the National Cancer Database (NCDB) and 5928 MIBC patients from the Surveillance, Epidemiology, and End Results (SEER) database for our development and validation cohorts, respectively. Outcome measurements and statistical analysisMultivariable Cox proportional hazards analysis with restricted cubic splines was used to assess the association between the number of metastatic LNs and overall mortality (OM). A novel staging system was derived by recursive partitioning analysis (RPA) in NCDB and was validated in SEER by assessing discrimination (Harrel's c-index) and calibration (mean absolute prediction error). Results and limitationsMortality risk increased continuously with more metastatic LNs; the effect was most pronounced up to four LNs (hazard ratio [HR] 1.17, 95% confidence interval [CI] 1.12–1.22) and attenuated beyond four nodes (HR 1.03, 95% CI 1.02–1.05). RPA generated a novel staging system predicting mortality by metastatic nodal number with cutpoints at zero (reference), one (HR 1.57, 95% CI 1.46–1.69), two to three (HR 2.03, 95% CI 1.88–2.19), four to seven (HR 2.46, 95% CI 2.25–2.70), and more than seven (HR 3.83, 95% CI 3.38–4.33) positive LNs. Location of LN involvement was not a significant predictor of OM. In external validation, the novel staging system showed good risk discrimination (optimism corrected c-index 0.677, 95% CI 0.672–0.682) and calibration (mean absolute prediction error 0.011 for 5-yr OM). Results are limited by development and validation using secondary data. ConclusionsThe number of metastatic LNs predicts mortality better than LN location and may improve pathological nodal staging in MIBC. Patient summaryThis retrospective study found that the number of metastatic lymph nodes more accurately predicts survival than the location of metastatic lymph nodes in patients with muscle-invasive bladder cancer. This finding argues for change to the current bladder cancer staging system.

Prognostic role of different lymph node staging systems in gastric cancer

Background: The Union for International Cancer Control (UICC) Node (N) classification is the most common used staging method for the prognosis of gastric cancer. It demands adequate, at least 16 lymph nodes to be dissected; therefore different staging systems were invented.

ASO Author Reflections: It is Essential to Explore More Accurate Nodal Staging System for Esophageal Cancer.

ASO Author Reflections: It is Essential to Explore More Accurate Nodal Staging System for Esophageal Cancer.

Comparison of Different Lymph Node Staging Systems in Patients With Resectable Colorectal Cancer.

Background and Objectives: Currently, the United States Joint Commission on Cancer (AJCC) N staging, lymph node positive rate (LNR), and log odds of positive lymph nodes (LODDS) are the main lymph node (LN) staging systems. However, the type of LN staging system that is more accurate in terms of prognostic performance remains controversial. We compared the prognostic accuracy of the three staging systems in patients with CRC and determine the best choice for clinical applications.Methods: From the Surveillance, Epidemiology, and End Results (SEER) database, 56,747 patients were identified who were diagnosed with CRC between 2004 and 2013. Akaike's Information Criterion (AIC) and Harrell's Consistency Index (c-index) were used to assess the relative discriminative abilities of different LN staging systems.Results: In 56,747 patients, when using classification cut-off values for evaluation, the LNR of Rosenberg et al. showed significantly better predictive power, especially when the number of dissected lymph nodes (NDLN) were insufficient. When analyzed as a continuous variable, the LODDS staging system performed the best and was not affected by the NDLN.Conclusions: We suggest that the LNR of Rosenberg et al. should be introduced into the AJCC system as a supplement when the NDLN is insufficient until the optimal LODDS cut-off values are calculated.

New lymph node staging for rectal neuroendocrine tumors.

Current guidelines of the American Joint Commission on Cancer (AJCC) for rectal neuroendocrine tumors (NETs) classify tumor nodal status as N0/N1. This staging does not take into consideration the number of positive lymph nodes. The goal of this study is to determine how the number of positive lymph nodes affects the prognosis for patients with rectal NETs. The National Cancer Database was used to identify patients with rectal NETs who underwent rectal resection. Nearest-neighborhood grouping was used to classify patients by survival to create a new nodal staging system. There were 687 patients with rectal NETs. There were distinct 5-year survival estimates for patients with N0 [81.8% (95%CI:77.1%-85.6%)], N1 (1-4 positive lymph nodes) [57.8% (95% confidence interval (CI: 51.2%-63.9%)] and N2 (≥5 positive lymph nodes) [32.6% (95%CI:25.1%-40.3%)] patients, P < 0.0001. Distinct 5-year survival estimates using the new nodal staging system was apparent for patients in the external validation set. After adjusting for predictors of survival in multivariable analysis, the new nodal stage remained an independent predictor of overall survival. The number of positive locoregional lymph nodes is an independent prognostic factor in rectal NETs. The next AJCC edition should consider classifying patients with rectal NETs as N0, N1, and N2 to provide better estimates of survival for patients.