Ratio between negative and positive lymph nodes is suitable for evaluation the prognosis of gastric cancer patients with positive node metastasis. PLoS One. 2012;7:e43925. [PMID: 22952812 PMCID: PMC3432045 DOI: 10.1371/journal.pone.0043925]

Impact of the extent of negative lymph nodes in gastric adenocarcinoma undergoing primary surgical resection: An institutional report

BACKGROUND

Sub-total/total gastrectomy with lymph node dissection (LND) remains an effective therapeutic strategy for resectable gastric adenocarcinomas (GACs). Despite the prognostic significance of positive lymph nodes (PLNs) defined in N-status, few have appraised the impacts of negative lymph nodes (NLNs) and the percentage of NLN (=number of NLNs/number of total lymph nodes [TLNs], %), as well as the extent of TLNs to be dissected in GACs.

METHODS

We retrospectively analyzed 62 GAC patients (mean age of 67.1 years; 41 men) undergoing primary sub-total/total gastrectomy from a single institute. Candidate variables, including the number of NLNs (≤9 and >9) and the percentage of NLN (≤37.5, 37.5-80.6 and >80.6, %), were evaluated to determine their prognostic impacts and hazard ratios (HRs).

RESULTS

Under the multivariate Cox proportional-hazards regression model, tumor length exceeding 4 cm (p = 0.017; HR = 2.828), perineural invasion (p = 0.037; HR = 3.182), and lower percentage of NLN (p = 0.016 and p = 0.060; HRs = 1.000, 0.327, and 0.333 for subgroups ≤37.5, 37.5-80.6, and >80.6, respectively) were three independent predictors with elevated HRs for poor prognosis. GAC patients with the percentage of NLN > 80.6 were highly related to those with NLNs > 9 (p < 0.001), and GAC patients with NLNs > 9 were highly related to those with TLNs > 15 (p < 0.001). For all 62 GAC or 42 N(+) GAC patients, those who underwent LND with TLNs>15 tended to have more PLNs (p = 0.018, p = 0.003) and more NLNs (p < 0.001, p = 0.029) than did those with TLNs ≤ 15. Among the 42 GAC patients with TLNs > 15, a lower percentage of NLN (p = 0.026 and p = 0.015; HRs = 1.000, 0.272, and 0.180 for subgroups ≤37.5, 37.5-80.6, and >80.6, respectively) remained an independent predictor of poor prognosis.

CONCLUSION

The percentage of NLN could predict the prognosis of GAC patients properly. However, an accurate percentage of NLN needs a minimal requirement of TLNs > 15 to detect an adequate number of PLNs and sufficient number of NLNs.

Ratio between negative and positive lymph nodes is a novel prognostic indicator for patients with esophageal cancer: A Surveillance, Epidemiology and End Results database analysis

Background

The aim of this study was to explore whether the ratio between negative and positive lymph nodes (R_NP) could predict the overall survival (OS) of esophageal cancer (EC) patients with lymph node metastasis following esophagectomy.

Methods

We utilized the Surveillance, Epidemiology and End Results (SEER) database to include the records of 2374 patients with lymph node metastases post‐surgery. All patients were randomly assigned into the training cohort (n = 1424) and validation cohort (n = 950). Multivariate Cox regression analyses were performed to identify independent prognostic factors. A novel R_NP ‐based TR_NPM staging system was proposed. The prognostic value of N, R_NP, TNM and TR_NPM staging system was evaluated using the linear trend χ² test, likelihood ratio χ² test, and Akaike information criterion (AIC) to determine the potential superiorities. We constructed nomograms to predict survival in both cohorts, and the calibration curves confirmed the predictive ability.

Results

Univariate analyses showed that N and R_NP stage significantly influenced the OS of patients. Multivariate analyses revealed that R_NP was an independent prognostic predictor in both the training and validation cohorts. For the stratification analysis in the two cohorts, we found significant differences in the prognosis of patients in different R_NP groups on the basis of the different N stages and the number of dissected lymph nodes. In addition, the lower AIC value of R_NP stage and TR_NPM staging system represented superior predictive accuracy for OS than the N stage and TNM staging system, respectively. Furthermore, the calibration curves for the probability of three‐ and five‐year survival showed good consistency between nomogram predictive abilities and actual observation.

Conclusions

We demonstrated that compared to the classical pathological lymph nodal staging system, the R_NP stage showed superior predictive accuracy for OS and can serve as a more effective prognostic guidance for lymph node positive EC patients.

Impact of examined lymph node count on staging and long-term survival of patients with node-negative stage III gastric cancer: a retrospective study using a Chinese multi-institutional registry with Surveillance, Epidemiology, and End Results (SEER) data validation

Background

Accumulating evidence has confirmed the potential prognostic value of examined lymph nodes (ELNs) in patients with gastric cancer (GC). However, there is currently no consensus on the threshold ELN number for predicting both stage migration and long-term survival, especially in patients with stage III GC. This study aimed to validate the need to increase the ELN count to improve its prognostic accuracy in node-negative patients with stage III GC after curative gastrectomy.

Methods

This retrospective, population-based study analyzed the clinical data of 84 patients with node-negative stage III GC from three high-volume institutions in China and 196 cases from the Surveillance, Epidemiology and End Results (SEER) program registry. The optimal number of ELNs was determined by receiver operating characteristic (ROC) curve analysis. Clinicopathological characteristics significantly related to survival were evaluated using the Kaplan-Meier method and Cox proportional hazards analysis. Stratified analyses were adopted to assess the prognostic predictive ability of the identified optimal number of ELNs in different populations. Survival differences among subgroups were analyzed to assess the impact of ELN count on stage migration according to overall survival (OS) among GC patients.

Results

The optimal number of ELNs was >31 according to ROC analysis of patients with node-negative stage III GC who underwent gastrectomy. Multivariate analysis identified ELNs as an independent predictor of postoperative OS in patients with node-negative stage III GC in both the Chinese cohort [hazard ratio (HR) 0.235; P<0.001] and the SEER cohort (HR 0.421; P<0.010). Stratified analysis demonstrated that >31 ELNs was a prerequisite for accurate prognostic evaluation of patients with node-negative stage III GC, regardless of sex, tumor size, and other factors. Stage migration between pT4bN0M0 and pT4bN1M0 was detected in patients with >31 ELNs. A nomogram was created to predict OS among patients with node-negative stage III GC. These results were validated using data from the SEER cohort.

Conclusions

The number of ELNs was significantly associated with prognosis in patients with stage III GC after gastrectomy with systemic lymphadenectomy in both the Chinese and SEER cohorts. The results suggest that >31 ELNs are required for an accurate prognostic evaluation in patients with GC, especially those with node-negative stage III GC.

Impact of the number of examined lymph nodes on stage migration in node-negative gastric cancer patients: a Chinese multi-institutional analysis with propensity score matching

Background

This propensity score matching (PSM) analysis assessed the influence of examined lymph nodes (ELNs) count on stage migration and survival in node-negative (pN0) gastric cancer (GC) patients.

Methods

We performed a retrospective analysis of 7,620 GC patients who underwent curative gastric resection in three Chinese medical centers. PSM was used to reduce the confounding effects between the pN0 GC patients with ELNs <16 or ≥16. Survival differences among various subgroups of GC patients were analyzed to assess the impact of the ELNs count on the stage migration in accordance with the overall survival (OS) of pN0 GC patients.

Results

After matching, the backgrounds of pN0 GC patients in the ELNs <16 (n=825) and ELNs ≥16 (n=826) groups were well-balanced. Survival analyses revealed that the ELNs count was positively correlated with the OS (P=0.001). Multiple Cox analysis indicated that the ELNs count was an independent predictor of the OS in pN0 GC patients. Stage migrations were mainly detected in subgroups of pN0 GC patients with specific pTNM stages, as follows: (I) pT2N0M0 with ELNs <16 vs. pT3N0M0 with ELNs ≥16; (II) pT3N0M0 with ELNs <16 vs. pT3N1M0 with ELNs ≥16; and (III) pT4aN0M0 with ELNs <16 vs. pT4aN1M0 with ELNs ≥16.

Conclusions

We show that stage migration can be detected in pN0 GC patients, and that it could be gradually reduced or prevented by increasing the ELNs count.

Outcomes after completion total gastrectomy for gastric remnant cancer: experience from a Canadian tertiary centre

BACKGROUND

There is controversy about the safety and outcomes of completion total gastrectomy (CTG) for gastric adenocarcinoma. We compared a cohort of patients who underwent CTG for gastric remnant cancer (GRC) after partial gastrectomy for benign disease with patients who underwent primary total gastrectomy (PTG) for sporadic gastric cancer.

METHODS

We retrospectively reviewed a single-institution, prospectively maintained clinical database of patients who had undergone gastrectomy from 2005 to 2016 for demographic, surgical, clinical and tumour pathology data, as well as postoperative, pathologic and oncologic outcomes including complications, length of stay, disease-free survival and overall survival. We used the χ² and Wilcoxon rank-sum tests to compare groups and performed the Mantel-Cox log-rank test for Kaplan-Meier survival estimates. We compared the CTG group to all patients in the PTG group and to a 5:1 propensity-matched PTG cohort.

RESULTS

We analyzed data for 64 patients (9 CTG, 55 PTG). The groups were equivalent at baseline and had similar operative, perioperative treatment and pathologic characteristics. After propensity matching, the reoperation rate for complications was higher after CTG than PTG (22% v. 0%, p = 0.03), but there was no significant difference in the overall complication rate or length of stay. At 5 years, there was no difference in disease-free survival (28% v. 58%, p = 0.4) or overall survival (33% v. 44%, p = 0.7).

CONCLUSION

Our findings suggest that CTG for gastric adenocarcinoma can be undertaken safely a priori with no additional risk of recurrence or death compared to PTG for sporadic gastric cancer.

Impact of lymph node ratio on survival in stage III ovarian high-grade serous cancer: a Turkish Gynecologic Oncology Group study

Objective

The purpose of this study was to investigate the prognostic value of lymph node ratio (LNR) in patients with stage III ovarian high-grade serous carcinoma (HGSC).

Methods

A multicenter, retrospective department database review was performed to identify patients with ovarian HGSC at 6 gynecologic oncology centers in Turkey. A total of 229 node-positive women with stage III ovarian HGSC who had undergone maximal or optimal cytoreductive surgery plus systematic lymphadenectomy followed by paclitaxel plus carboplatin combination chemotherapy were included. LNR, defined as the percentage of positive lymph nodes (LNs) to total nodes recovered, was stratified into 3 groups: LNR1 (<10%), LNR2 (10%≤LNR<50%), and LNR3 (≥50%). Kaplan-Meier method was used to generate survival data. Factors predictive of outcome were analyzed using Cox proportional hazards models.

Results

Thirty-one women (13.6%) were classified as stage IIIA1, 15 (6.6%) as stage IIIB, and 183 (79.9%) as stage IIIC. The median age at diagnosis was 56 (range, 18–87), and the median duration of follow-up was 36 months (range, 1–120 months). For the entire cohort, the 5-year overall survival (OS) was 52.8%. An increased LNR was associated with a decrease in 5-year OS from 65.1% for LNR1, 42.5% for LNR2, and 25.6% for LNR3, respectively (p<0.001). In multivariate analysis, women with LNR≥0.50 were 2.7 times more likely to die of their tumors (hazard ratio [HR]=2.7; 95% confidence interval [CI]=1.42–5.18; p<0.001).

Conclusion

LNR seems to be an independent prognostic factor for decreased OS in stage III ovarian HGSC patients.

Prognostic value of number of negative lymph node in patients with stage II and IIIa non-small cell lung cancer

Background

The definitive validation evidence of the implications of lymph node metastases regarding the survival of Non-Small Cell Lung Cancer (NSCLC) patients is lacking. We aimed to evaluate the prognostic impact of several lymph node metastases-associated risk factors including Number of Negative Lymph Node (NLN) and risk-stratify NSCLC patients into subsets with different prognosis.

Method

A total of 482 patients with N1 and N2 NSCLC were included in this study. The prognostic importance of a set of risk factors was examined by univariate and multivariate analysis. The cut-off points and 5 years survival rates were calculated to test the best grouping system to stratify the patients with difference outcome.

Results

Our analysis indicated that both Ratio of the Metastatic Lymph nodes (RML) and Number of Negative Lymph Node (NLN) were associated with overall survival (OS) and disease free survival (DFS). RML percentage 20% and 55%, and NLN counts 10 and 30 were proved as the optimal cut-off points to predict OS by classifying patients into 3 groups, respectively. RML and NLN actually are more powerful in predicting survival outcome for male patients compared to female patients. Stratified survival analyses using combined factors indicated that the 5-year survival rate (5-YSR) is high in RML I + NLN I/III subgroup (5-YSR = 57.1% and 43.3%) and low in RML III + NLN II/III subgroup (5-YSR = 0.0 % each).

Conclusions

NLN is a strong prognostic factor for OS and DFS of stage II/IIIa NSCLC patients, and provides a useful classification scheme for NSCLC patients when combined with RML.

Increasing the Number of Examined Lymph Nodes is a Prerequisite for Improvement in the Accurate Evaluation of Overall Survival of Node-Negative Gastric Cancer Patients

BACKGROUND

This study aims to elucidate whether increasing the number of examined lymph nodes (NELN) is mandatory for the accurate prognosis of node-negative gastric cancer (GC) patients after curative gastrectomy in Eastern countries (China and Japan).

METHODS

The clinicopathological data of 2455 GC patients (including 1137 node-negative cases) were included to demonstrate whether a minimum NELN is inevitable for guaranteeing the accurate prognosis of node-negative GC patients after curative gastrectomy.

RESULTS

Survival analyses revealed that the NELN significantly positively correlated with overall survival (p < 0.001) and was an independent prognostic predictor (hazard ratio 0.447; p = 0.025) of 1137 node-negative GC patients. Stratum analysis within the Kaplan-Meier method showed that sex, tumor size, and extent of lymphadenectomy did not affect the NELN in predicting the prognosis of all node-negative GC patients. Stage migration was mainly detected in the subgroup of node-negative GC Chinese patients who presented considerably lower mean NELN and more advanced staging than patients from Japan. The NELN was identified as the most intensively independent predictor of prognosis of 600 node-negative GC patients from China, with the smallest Akaike information criterion (176.964) and Bayesian information criterion values (194.552). These findings indicate that increasing the NELN is a prerequisite to guaranteeing precise TNM classification.

CONCLUSIONS

The NELN should be considered a mandatory requirement for improving the accuracy of prognostic evaluation of GC patients, especially for advanced-stage patients.

Impact on long-term survival of the number of lymph nodes resected in patients with pT1N0 gastric cancer after R0 resection: A multicenter study in China

Although studies on the association between the number of lymph nodes resected and prognosis in patients with pT2-4N0 stages of gastric cancer have reported consistent results, there is no consensus on the optimal number of lymph nodes to be examined for pT1N0 stage gastric cancer. The aim of this study was to evaluate the long-term effect of the number of lymph nodes removed on the outcomes of patients with pT1N0 stage gastric cancer after R0 resection.From December 2009 to December 2011, 227 patients undergoing R0 resection of pT1N0 stage gastric cancer at 4 Chinese centers were enrolled in this study. Patients were assigned to 2 groups according to the number of lymph nodes dissected (≤15 or > 15). Standard survival methods and restricted multivariable Cox regression models were applied.More women (P = 0.031) were in the ≤15 group than in the >15 group. The mean number of lymph nodes removed from women was greater than that from men (P = 0.007). The 5-year survival rate was significantly higher in the >15 lymph nodes resected group than the ≤15 group. The number of lymph nodes resected was identified as an independent prognostic factor and was significantly correlated with overall survival (OS).A lymphadenectomy with dissection of more than 15 lymph nodes improved the long-term survival of patients with pT1N0 gastric cancer after R0 resection. Therefore, it is necessary to consider removing more than 15 lymph nodes among such patients.

Lymph node ratio as a novel and simple prognostic factor in advanced gastric cancer

TNM staging is no doubt the most critical prognostic factors, representing tumor (T)/lymph node metastasis (N)/distant metastasis (M) in gastric cancer. Lymph node ratio-based N system (Nr) has been repeatedly reported to be of prognostic relevance in advanced gastric cancer independent of stage in the multivariate analysis world-wide, and proposed as more sophisticated than N with regard to predicting accurate prognosis. As a result, proposed TNrM system may predict survival more accurately than the present TNM staging system for patients undergoing limited lymph node analysis. It could adjust stage migration when the lymph node number was used as staging factor. Although correlation of the number of metastatic lymph nodes and lymph node ratio is obvious, biological characteristics other than that could also have been reflected on. It may indicate how successful the operation of lymph node dissection was, or it may be revealing the potential of the patient's lymph node immune-reaction. Recently, high lymph node ratio is closely associated with EGFR expression in advanced gastric cancer. When efficiency of applying lymph node ratio as a biomarker is verified and confirmed in an expansive research, and when cancer causing molecules are identified, as well as the competence as a treatment target is studied, the new biomarker, namely, lymph node ratio, could find itself in a limelight in gastric cancer treatment in the future.

Subtotal gastrectomy with conventional D2 lymphadenectomy for carcinoma of the distal gastric portion: A retrospective cohort study on clinical outcomes

BACKGROUND

The study was aimed to delineate the postoperative morbidity, mortality and long-term follow-up results after R0 subtotal gastrectomy with D2 lymphadenectomy for invasive non-disseminated adenocarcinoma of the distal gastric portion.

METHODS

Between January 2005 and December 2007, 228 patients with median age at hospitalisation 66.6 ± 11.4 years underwent the above mentioned surgery for histologically proven distal gastric adenocarcinoma.

RESULTS

Postoperative morbidity was documented in 92 (40.4%) of patients within 30 days. An anastomotic leakage was diagnosed in two (0.9%), peritonitis in two (0.9%), anastomositis in five (2.2%), and prolonged ileus in six (2.6%) patients. Nine patients died (3.9%). The overall 1-year survival rate was 83.8%, and the 5-year survival rate was 54.4%. Gender, age, TNM stage, pN, and N ratio were independent factors predicting a long-term prognosis for patients.

CONCLUSIONS

A R0 type distal subtotal gastrectomy with standard D2 lymphadenectomy for a histologically proven invasive adenocarcinoma of the distal gastric portion without distant metastasis offers acceptable postoperative morbidity and mortality, and considerably high overall cumulative 5-year survival rate. The probability of cumulative survival decreases five times when the ratio between metastatic and examined lymph nodes is > 0.25.

Prognostic value of lymph node ratio in patients with advanced epithelial ovarian cancer

OBJECTIVE

Lymph node status is an established prognostic factor in epithelial ovarian cancer (EOC). Lymph node ratio (number of positive LN/number of resected LN) reflects both qualitative and quantitative lymph node spread as well as surgical effort and extent of disease. We evaluated whether LNR is a more precise prognostic factor than conventional lymph node status in patients with EOC.

METHODS

The present retrospective study includes 809 patients with EOC, who underwent primary cytoreductive surgery between 2000-2013. Clinico-pathological parameters and survival data were extracted from a prospectively maintained tumor registry database. The optimal cut-off point for LNR was calculated by using Martingale residuals. Survival analyses were calculated using Kaplan-Meier method and Cox regression models.

RESULTS

Lymphadenectomy was performed in 693 (85.7%) out of 809 patients. Median number of removed LN was 64 (IQR 25-75%: 39-84). LNR of 0.25 was identified as the optimal prognostic cut-off value. The estimated 5-year-OS rates were 69.3% for patients with node-negative EOC compared to 33.1% for patients with any lymph node metastasis (p<0.001). The estimated 5-year-OS rates were 42.5% for patients with LNR≤0.25, and 18.0% for patients with LNR>0.25 (p<0.001). Additionally in multivariate analysis LNR>0.25 was approved to be an independent prognostic factor for overall survival (adjusted HR 1.44, 95% CI 1.04-2.00; p=0.028).

CONCLUSION

LNR more precisely predicts overall survival than conventional lymph node status in EOC patients undergoing primary debulking surgery.

Enhanced intensity on preoperative double contrast-enhanced sonography as a useful indicator of lymph node metastasis in patients with gastric cancer

OBJECTIVES

The aim of this study was to investigate the predictive value of enhanced intensity on double contrast-enhanced sonography in assessing lymph node metastasis of gastric cancer.

METHODS

A total of 357 patients with gastric cancer were enrolled in this study. Double contrast-enhanced sonography, in which an oral ultrasound contrast agent is combined with an intravenous contrast agent, was performed preoperatively, and the data were analyzed quantitatively. The predictive ability of enhanced intensity, a quantitative double contrast-enhanced sonographic measure, for lymph node metastasis was evaluated retrospectively.

RESULTS

Compared to negative lymph node metastasis cases, the presence of thicker lesions, deeper invasion, poorer differentiation, and higher enhanced intensity were found in positive cases (P< .05). An enhanced intensity cutoff value of 16.91 dB was the best point for balancing the sensitivity and specificity (71.50% and 79.30%, respectively) for prediction of lymph node metastasis, with the highest Youden index of 0.508. The area under the receiver operating characteristic curve was 0.828 (P < .001; 95% confidence interval, 0.786-0.870). In cases in which the lesions were hyperenhanced (enhanced intensity >16.91 dB), the lesions were significantly thicker and had deeper invasion, poorer differentiation, and more positive metastasis findings compared to non-hyperenhanced cases (enhanced intensity ≤16.91 dB; P < .05). On logistic regression analysis, the enhanced intensity of primary tumors and the invasion depth were significantly associated with lymph node metastasis.

CONCLUSIONS

Double contrast-enhanced sonography with quantitative analysis may be considered a novel alternative imaging modality for noninvasive preoperative evaluation of lymph node metastasis with good reliability.

Prognostic value of number of examined lymph nodes in patients with node-negative gastric cancer

AIM: To elucidate the potential impact of examined lymph nodes (eLNs) on long-term survival of node-negative gastric cancer patients after curative surgery.

METHODS: A total of 497 node-negative gastric cancer patients who underwent curative gastrectomy between January 2000 and December 2008 in our center were enrolled in this study. Patients were divided into 4 groups according to eLNs through cut-point analysis. Clinicopathological features were compared between ≤ 15 eLNs group and > 15 eLNs group and potential prognostic factors were analyzed. The Log-rank test was used to assess statistical differences between the groups. Independent prognostic factors were identified using the Cox proportional hazards regression model. Stratified analysis was performed to investigate the impact of eLNs on patient survival in each stage. Overall survival was also compared among the four groups. Finally, we explored the recurrent sites associated with eLNs.

RESULTS: Patients with eLNs > 15 had a better survival compared with those with eLNs ≤ 15 for the entire cohort. By the multivariate survival analysis, we found that the depth of invasion and the number of eLNs were the independent predictors of overall survival (OS) of patients with node-negative gastric cancer. According to the cut-point analysis, T2-T4 patients with 11-15 eLNs had a significantly longer mean OS than those with 4-10 eLNs or 1-3 eLNs. Patients with ≤ 15 eLNs were more likely to experience locoregional and peritoneal recurrence than those with > 15eLNs.

CONCLUSION: Number of eLNs could predict the prognosis of node-negative gastric cancer, and dissection of > 15 eLNs is recommended during lymphadenectomy so as to improve the long-term survival.

Digestive cancer surgery in the era of sentinel node and epithelial-mesenchymal transition

Lymph node involvement is one of the most important prognostic indicators of carcinoma of the digestive tract. Although the therapeutic impact of lymphadenectomy has not been proven and the number of retrieved nodes cannot be considered a measure of successful cancer surgery, an adequate lymph node count should be guaranteed to accurately assess the N-stage through the number of involved nodes, lymph node ratio, number of negative nodes, ratio of negative to positive nodes, and log odds, i.e., the log of the ratio between the number of positive lymph nodes and the number of negative lymph nodes in digestive carcinomas. As lymphadenectomy is not without complications, sentinel node mapping has been used as the rational procedure to select patients with early digestive carcinoma in whom nodal dissection may be omitted or a more limited nodal dissection may be preferred. However, due to anatomical and technical issues, sentinel node mapping and nodal basin dissection are not yet the standard of care in early digestive cancer. Moreover, in light of the biological, prognostic and therapeutic impact of tumor budding and tumor deposits, two epithelial-mesenchymal transition-related phenomena that are involved in tumor progression, the role of staging and surgical procedures in digestive carcinomas could be redefined.

Evaluation of the staging systems for gastric cancer

BACKGROUND

Some staging systems for gastric cancer (GC) have been developed as alternatives to the 6th and 7th TNM staging systems, including the Hybrid, tumor-ratio-metastasis (TRM), and Kiel staging systems. This study evaluated the overall performance of these systems for GC.

METHODS

A total of 540 GC patients undergoing surgical resection were staged using these five systems. Homogeneity, discrimination power, predictive accuracy, and complexity of these systems were compared.

RESULTS

Multivariate analyses showed that all of 7th pT, pN, and pM classifications were independent factors for GC prognosis (P < 0.001 for all). Compared with the other four systems, 7th TNM system had improved stage groups homogeneity (7 of 8 stage groups homogeneous), enhanced discrimination power (4 of 5, 5 of 7, 4 of 7, 3 of 7, and 1 of 4 adjacent stage groups were differentiated by the 6th, 7th TNM, Hybrid, TRM, and Kiel systems, respectively), and better prediction value for GC patients' outcome (AUC = 0.801, P < 0.001). In addition, the 7th TNM system did not increase the staging complexity (9 groups and 21 subgroups).

CONCLUSIONS

The 7th TNM staging system represents advancement in GC staging system for better prediction of clinical outcomes.

Impact of lymph node ratio on the survival of patients with hypopharyngeal squamous cell carcinoma: a population-based analysis

Objective

To analyze the impact of the lymph node ratio (LNR, ratio of metastatic to examined nodes) on the prognosis of hypopharyngeal cancer patients.

Methods

SEER (Surveillance, Epidemiology and End Results)-registered hypopharyngeal cancer patients with lymph node metastasis were evaluated using multivariate Cox regression analysis to identify the prognostic role of the LNR. The categorical LNR was compared with the continuous LNR and pN classifications to predict cause-specific survival (CSS) and overall survival (OS) rates of hypopharyngeal cancer patients.

Results

Multivariate analysis of 916 pN+ hypopharyngeal cancer cases identified race, primary site, radiation sequence, T classification, N classification, M classification, the number of regional lymph nodes examined, the continuous LNR (Hazard ratio 2.415, 95% CI 1.707–3.416, P<0.001) and age as prognostic variables that were associated with CSS in hypopharyngeal cancer. The categorical LNR showed a higher C-index and lower Akaike information criterion (AIC) value than the continuous LNR. When patients (n = 1152) were classified into four risk groups according to LNR, R0 (LNR = 0), R1 (LNR ≤0.05), R2 (LNR 0.05–0.30) and R3 (LNR >0.30), the Cox regression model for CSS and OS using the R classification had a higher C-index value and lower AIC value than the model using the pN classification. Significant improvements in both CSS and OS were found for R2 and R3 patients with postoperative radiotherapy.

Conclusions

LNR is a significant prognostic factor for the survival of hypopharyngeal cancer patients. Using the cutoff points 0.05/0.30, the R classification was more accurate than the pN classification in predicting survival and can be used to select high risk patients for postoperative treatment.