Comparative study of the 7th and 8th AJCC editions for gastric cancer patients after curative surgery

Normalization weighted combination scores re-evaluate TNM staging of gastric cancer: a retrospective cohort study based on a multicenter database

BACKGROUND

The pathological depth of tumor invasion (pT) and lymph node metastasis (pN) are critical independent prognostic factors for patients with gastric cancer (GC), representing effective methods for evaluating prognosis. In this study, the authors employed a normalization weight combination score to calculate the weight ratio of the pT stage and pN stage. Subsequently, the authors established a novel weighted TN (wTN) staging model based on these T and N weights, evaluating its prognostic capacity.

METHODS

This study utilized a training cohort from A Medical University Cancer Hospital and a validation cohort from the SEER database. Least absolute shrinkage and selection operator (LASSO) and Cox regression were employed to screen clinical characteristics. Multivariate linear regression and cluster analysis calculated the weight ratio of T stage and N stage in the training and validation cohorts, respectively, followed by re-staging. Prognostic value was evaluated using C-index, likelihood ratio, Wald, and Score tests for wTN stage and tumor-node-metastasis (TNM) stage. A nomogram model was developed, and accuracy was assessed using receiver operating characteristic curve (ROC), decision curve analysis (DCA), and restricted cubic spline (RCS) analyses.

RESULTS

LASSO was used for initial screening, selecting eight potential features for Cox analysis. Age, tumor size, metastasis lymph nodes (MLNs), and tumor location were confirmed as independent prognostic factors. wTN was calculated in the training and validation cohorts, and nomograms were established with the independent factors. N stage had a higher weight proportion than T stage in both cohorts (0.625/0.375 in training cohort, 0.556/0.444 in validation cohort). wTN outperformed the 8th TNM stage in C-index, likelihood ratio, Wald, and Score tests in the training cohort, with successful validation in the validation cohort. Stratified analysis of distinct pathological types further demonstrates that wTN staging exhibits superior prognostic performance.

CONCLUSION

The wTN staging model based on T stage and N stage weights has a good prognostic value for GC patients. The same conclusion was obtained in different pathological stratification.

Nomogram-Based Prognostic Evaluation of Gastric Cancer Patients with Low Counts of Examined Lymph Nodes Outperforms the Predictive Ability of the 7th and 8th Editions of the American Joint Committee on Cancer Staging System

BACKGROUND

The American Joint Committee on Cancer (AJCC) staging system has limited accuracy in predicting survival of gastric cancer patients with inadequate counts of evaluated lymph nodes (LNs). We therefore aimed to develop a prognostic nomogram suitable for clinical applications in such cases.

METHODS

A total of 1511 noncardia gastric cancer patients treated between 1990 and 2010 in the academic surgical center were reviewed to compare the 7^th and 8^th editions of the AJCC staging system. A nomogram was developed for the prediction of 5-year survival in patients with less than 16 LNs evaluated (n = 546). External validation was performed using datasets derived from the Polish Gastric Cancer Study Group (n = 668) and the SEER database (n = 11,225).

RESULTS

The 8th edition of AJCC staging showed better overall discriminatory power compared to the previous version, but no improvement was found for patients with < 16 evaluated LNs. The developed nomogram had better concordance index (0.695) than the former (0.682) or latest (0.680) staging editions, including patients subject to neoadjuvant treatment, and calibration curves showed excellent agreement between the nomogram-predicted and actual survival. High discriminatory power was also demonstrated for both validation cohorts. Subsequently, the nomogram showed the best accuracy for the prediction of 5-year survival through the time-dependent ROC curve analysis in the training and validation cohorts.

CONCLUSIONS

A clinically relevant nomogram was built for the prediction of 5-year survival in patients with inadequate numbers of LNs evaluated in surgical specimens. The predictive accuracy of the nomogram was validated in two Western populations.

Identification of a Biomarker Combination for Survival Stratification in pStage II/III Gastric Cancer after Curative Resection

Simple Summary

Gastric cancer (GC) is the fifth most common cancer worldwide and the fourth most common cause of cancer-related deaths, with a high frequency of recurrence and metastasis, and a poor prognosis. This study presents a novel combination of four proteins (PDGFRB, INHBA, MMP11, and galectin-10) in GC tissues that have been identified as useful survival stratification markers in patients with pStage II/III GC after curative resection by quantitative polymerase chain reaction (qPCR), proteomic analysis, and immunohistochemistry (IHC).

Abstract

Background: We sought to identify an optimal combination of survival risk stratification markers in patients with pathological (p) stage II/III gastric cancer (GC) after curative resection. Methods: We measured the expression levels of 127 genes in pStage II/III GC tissues of two patient cohorts by quantitative polymerase chain reaction (qPCR) and the expression of 1756 proteins between two prognosis (good and poor) groups by proteomic analysis to identify candidate survival stratification markers. Further, immunohistochemistry (IHC) using tumor microarrays (TMAs) in another cohort of patients was performed to identify an optimal biomarker combination for survival stratification in GC patients. Results: secreted protein acidic and rich in cysteine (SPARC), erb-b2 receptor tyrosine kinase 2 (ERBB2), inhibin subunit beta A (INHBA), matrix metallopeptidase-11 (MMP11), tumor protein p53 (TP53), and platelet-derived growth factor receptor-beta (PDGFRB) were identified as candidate biomarkers from qPCR analysis, and SPARC and galectin-10 were obtained from the proteomic analysis. The combination of PDGFRB, INHBA, MMP11, and galectin-10 was identified as the optimal combination of survival risk stratification markers. Conclusions: A combination of four proteins in GC tissues may serve as useful survival risk stratification markers in patients with pStage II/III GC following curative resection. Our results may facilitate future multicenter prospective clinical trials.

Gastric adenocarcinoma: 1-year overall survival, disability-adjusted life years, years of life lost, and prognostic factors-a single-institution experience

Objective

To analyze factors affecting 1-year overall survival and burden of gastric adenocarcinoma in a single-institution cohort.

Methods

A prospective cohort study of gastric adenocarcinoma patients from a cancer center in São Paulo, Brazil, was conducted between February 2016 and July 2019. Overall survival was analyzed at 12 months post-diagnosis using the Kaplan-Meier method. A log-rank test was applied to compare curves. Sociodemographic and clinicopathological features were assessed to detect prognostic factors using univariate and multivariable Cox regression analyses to calculate hazard ratio (HR) and its confidence intervals (CIs). Disability-adjusted life years (DALY) constituted the sum of years of life lost (YLL) plus years lived with disability (YLD). YLL represented the sum of years lost before the age of 76.6 years. YLD was calculated as the number of cases multiplied by the duration and burden of the disease. YLL per death was calculated as the mean YLL for each individual.

Results

Overall survival at 1-year follow-up was 80.8%. The multivariable model adjusted for age and sex identified cerebrovascular disease (HR 8.5, 95% CI 3.3-21.8), stage III/IV (HR 5.7, 95% CI 2.3-13.7), diabetes (HR 3.2, 95% CI 1.5-6.6), and<9 years of education (HR 2.9, 95% CI 1.5-5.8) as prognostic factors. Out of the 214 treated cases, there was 700.72 DALY during the first year, of which 90.55% corresponded to YLL and 9.45% to YLD. The average YLL per death was 15.48 and was higher among women (19.24 YLL per death).

Conclusion

At a single cancer center, 1-year overall survival probability was approximately 80% in patients with gastric adenocarcinoma. Patients with a higher risk of death had cerebrovascular disease, advanced clinical staging, diabetes, and/or lower educational level. Approximately 700 years of DALY was documented, with women having the highest YLL per death. Because this study was conducted at a single cancer center, the results might not be representative of a general population. To the best of our knowledge, this study was the first to assess gastric adenocarcinoma DALY, YLL, and YLL per death in the first year of follow-up in a hospital cohort in Brazil.

Revisiting the 8th AJCC system for gastric cancer: A review on validations, nomograms, lymph nodes impact, and proposed modifications

Gastric cancer is the fifth most frequently diagnosed cancer worldwide, behind breast, lung, colorectal, and prostate cancers. In gastric cancer, multimodality treatment shows prospective benefits and also improves survival. Surgery, however, is the mainstay of curative treatment. The staging of gastric cancer patients is critical for harmonization of care. Accurate stages assure that informed clinical decisions are timely made. The American Joint Committee on Cancer (AJCC) staging system is the most widely applied system in to determine the disease's prognosis and survival prediction. The recently adopted 8th AJCC TNM staging system has been revised to enhance its survival predictive power. Subsequent studies have established the validity of the current edition, demonstrating improved stage stratification, discriminatory power, and survival prediction. However, other studies have cast doubt on the superiority of the new edition. Innovations aimed at further improving its prognosis have resulted in developing of novel models. Advances in our understanding of the tumor microenvironment and molecular categorization of cancer have resulted in proposals for their inclusion in TNM staging as potential complementary factors that enhance survival prediction and prognostic assessment ability. The purpose of this study is to conduct a review of the published literature regarding the validity of the 8th AJCC TNM staging system, proposed modifications, and nomograms.

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The 8th AJCC is valid in prognostic stratification of gastric cancer, however, revisions are still required.

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The yPT staging requires some modifications and inclusion of stages that currently don't exist in the 8th AJCC.

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High lymph nodes count and anatomical localization improve the prediction ability of the current AJCC.

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Nomograms comprising of individual prognostic factors are crucial to the current AJCC.

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Molecular markers positively influence survival prediction of gastric cancer.

ARE THERE DIFFERENCES IN LAPAROSCOPIC GASTRECTOMY MORBIDITY AND MORTALITY BETWEEN YOUNG AND OLDER?

Background:

Due to the longer life expectancy and consequently an increase in the elderly population, a higher incidence of gastric cancer is expected in this population in the coming decades.

Aim:

To compare the results of laparoscopic GC surgical treatment between individuals aged<65 years (group I) and ≥ 65 years (group II), according to clinical, surgical, and histopathological characteristics.

Methods:

A observational retrospective study was performed by analyzing medical charts of patients with gastric cancer undergoing total or subtotal laparoscopic gastrectomy for curative purposes by a single oncologic surgery team.

Results:

Thirty-six patients were included in each group. Regarding the ASA classification, 31% of the patients in group I was ASA 1, compared to 3.1% in group II. The mean number of concomitant medications in group II was statistically superior to group I (5±4.21 x 1.42±3.08, p<0.001). Subtotal gastrectomy was the most performed procedure in both groups (69.4% and 63.9% in groups I and II, respectively) due to the high prevalence of distal tumors in both groups, 54.4% group I and 52.9% group II. According to Lauren's classification, group I presented a predominance of diffuse tumors (50%) and group II the intestinal type (61.8%). There was no difference between the two groups regarding the number of resected lymph nodes and lymph node metastases and the days of hospitalization and mortality.

Conclusion:

Laparoscopic gastrectomy showed to be a safe procedure, without a statistical difference in morbidity, mortality, and hospitalization time between both groups.

Association of serum pepsinogen with degree of gastric mucosal atrophy in an asymptomatic population

BACKGROUND

Atrophic gastritis is a precancerous lesion of the stomach. It has been reported that pepsinogen (PG) can reflect the morphology and function of the gastric mucosa, and it is therefore used as a marker for the early diagnosis of atrophic gastritis.

AIM

To evaluate the diagnostic value of serum PG for degree of gastric mucosal atrophy in asymptomatic Chinese upon physical examination.

METHODS

Medical data were collected from subjects who underwent transnasal gastroscopy between October 2016 and October 2018. For each study subject, serum PG levels and presence of Helicobacter pylori (H. pylori) infection were investigated. Pathology was evaluated using the Operative Link for Gastritis Assessment (OLGA) classification and Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) systems. All statistical analyses were carried out using SPSS statistical software.

RESULTS

A total of 2256 subjects were enrolled and 1922 cases were finally included in the study. Based on the OLGA grading system, the levels of PGI were slightly decreased, while those of PGII were slightly increased. The PGI/PGII ratio (PGR) was reduced with increasing atrophy. The association between PG and OLGA grading was higher compared with that between PG and the OLGIM grading system. Compared with the OLGA-0 group, a statistically significant difference was observed in the mean age of OLGA-I, III, and IV groups (P < 0.05). In the H. pylori-positive subjects, the PGR levels were notably lower in the OLGA-I, II, and III groups compared with the OLGA-0 group (P < 0.05). H. pylori-positive subjects exhibited significantly higher PGI and PGII serum levels and a significantly lower PGR compared with H. pylori-negative patients in different OLGA groups (P < 0.05).

CONCLUSION

Serum PG levels may represent a non-invasive screening marker for gastric mucosal atrophy in asymptomatic subjects.

Comparison of the sixth, seventh, and eighth editions of the American Joint Committee on Cancer Tumor-Node-Metastasis staging system for gastric cancer: A single institution experience

In 2018, the eighth edition of the American Joint Committee on Cancer Tumor-Node-Metastasis classification and staging system was implemented. Few reports were made comparing the performance of different editions of the American Joint Committee on Cancer (AJCC) system. Therefore, this study aimed to examine the prognostic predictability from the sixth to the eighth editions of the AJCC staging system for gastric cancer.A total of 414 patients with gastric cancer who underwent surgery at Changhua Christian Hospital from January 2007 to December 2017 were enrolled in the study. To identify the prognostic factors for gastric cancer death, univariate and multivariate analyses were performed. The homogeneity and discrimination abilities of the sixth to eighth editions of the staging system were compared using the likelihood ratio chi-square test, linear trend chi-square test, and Akaike information criterion.The sixth edition of the staging system had the lowest Akaike information criterion value, suggesting a better prognostic stratification than other editions. From the result of the likelihood ratio chi-square test, the T and N staging systems of the seventh and eighth editions had better homogeneity and discriminatory ability than the sixth edition. The eighth edition had better prognostic performance in patients at stage III compared with the seventh edition.The AJCC seventh and eighth editions had improved prognostic predictability of the T and N factors compared with the sixth edition. However, the overall staging performance of the eighth edition is not superior compared to the sixth edition. Further studies with larger sample size should be conducted to compare the performance of different editions of the AJCC staging system for different ethnic populations.

Clinical Utility of ypTNM Stage Grouping in the 8th Edition of the American Joint Committee on Cancer TNM Staging System for Esophageal Squamous Cell Carcinoma

BACKGROUND

The 8th edition of the American Joint Committee on Cancer (AJCC) TNM staging system provided a specific 'ypTNM' stage grouping for patients with esophageal cancer.

OBJECTIVE

This study aimed to evaluate the clinical utility of the AJCC 8th edition ypTNM stage grouping for patients with esophageal squamous cell carcinoma (ESCC).

METHODS

We enrolled 152 patients with ESCC who underwent surgery after neoadjuvant cisplatin plus 5-fluorouracil (CF) therapy between June 2005 and December 2011. ypStage was evaluated according to the AJCC 7th and 8th editions. Predictive performance for disease-specific survival (DSS) and overall survival (OS) was compared between both editions. The prognostic significance of ypTNM stage grouping was evaluated using univariate and multivariate analyses.

RESULTS

Revision of the AJCC 7th edition to the 8th edition was associated with a change in ypStage in 96 patients (63.2%). The AJCC 8th edition revealed a better predictive performance than the 7th edition in terms of DSS (Akaike's information criterion [AIC] 499 vs. 513; Bayesian information criterion [BIC] 505 versus 519; concordance index [C-index] 0.725 versus 0.679) and OS (AIC 662 vs. 674; BIC 669 vs. 681; C-index 0.662 vs. 0.622). On univariate and multivariate analyses, ypStage in the 8th edition was an independent prognostic factor for both DSS and OS.

CONCLUSIONS

ypTNM stage grouping in the AJCC 8th edition provided a better predictive performance for DSS and OS than that in the 7th edition. ypStage in the 8th edition was the most reliable prognostic factor for ESCC patients who underwent surgery after neoadjuvant CF therapy.

ADAM10 expression in gastric adenocarcinoma: Results of a curative gastrectomy cohort

Objective:

Gastric cancer is among the most common human cancers with high mortality rates. ADAM10, a member of the ADAM (a disintegrin and metalloproteinase) family has also been found to be associated with gastric carcinoma and has been suggested as a potential therapeutic target. Here, we investigated the association of ADAM10 expression with prognosis in gastric adenocarcinoma patients that underwent gastric resection with D2 lymph node dissection.

Methods:

Total 86 consecutive patients that underwent resection for gastric adenocarcinoma were included. Immunohistochemical ADAM10 expression and its association with clinicopathological parameters were analyzed. Univariate and multivariate analyses and survival analyses were performed using SPSS ver.22.

Results:

High grade tumors, advanced stage tumors and diffuse type tumors showed significantly worse prognosis. A statistically significant association between ADAM10 expression and overall survival (OS) was observed in the univariate analysis, however, this association did not maintain its significance in the multivariate analysis. No statistically significant association was found ADAM-10 expression and clinicopathological parameters.

Conclusion:

Immunohistochemical ADAM10 expression may be used as a prognostic marker in gastric adenocarcinoma, however, introduction of a standardized immunohistochemical scoring system seems to be necessary for evaluation of ADAM10 staining.

Proposed Modification of the 8th Edition of the AJCC Staging System for Gastric Cancer

Background: The American Joint Committee on Cancer (AJCC) staging system has been the standardized staging system for malignancies since the first edition in 1987. The 8th edition of gastric cancer was released in 2016, and is expected to be used in clinical practice in 2018. The aim of this study was to improve this new gastric cancer staging system. Methods: We conducted median overall survival analyses in a cohort of 8359 gastric cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database (2004-2014) via Kaplan-Meier curves and log-rank tests, and proposed a modified staging system based on median OS. The concordance index (C-index) was conducted to evaluate the predictive accuracy. Results: Using the 8th AJCC staging system, the median OS of patients at the same stage varied widely between the different substages, especially in stage III. Despite the definitions of T, N, and M, substages in the modified staging system were regrouped based on median OS. The C-index of stage III patients with the modified staging system [0.579, 95% confidence interval (CI) 0.564-0.593] was higher than the 8th AJCC staging system (0.567, 95% CI 0.552-0.581). Moreover, we divided these patients into two groups according to their examined lymph node counts (≥15 or 1-14), and studied the effectiveness of the modified staging system in the two groups. Conclusions: The modified 8th AJCC staging system for gastric cancer proposed in this study generates better prognostic stratifications and may be evaluated for further update. Abbreviations:AJCCAmerican Joint Committee on CancerOSOverall SurvivalSEERSurveillance, Epidemiology, and End Results.

Prognostic implications of the eighth edition of the union for international cancer control - classification for gastric cancer patients from specialized treatment centers in Germany and Korea: A STOBE-Compliant large-scale cohort study

The validity of the 8th edition of the Union for International Cancer Control (UICC) staging system for gastric cancer has been evaluated only in Asian cohorts and not in European cohorts. The aim of this study was to evaluate the prognostic performance of the 8th edition of the UICC staging system in German and Korean cohorts independently and compare it with that of the 7th edition.A total of 6121 patients (526 from Germany and 5595 from Korea) who underwent upfront surgery for gastric cancer were retrospectively reclassified according to the 8th edition. Survival according to the UICC stages was estimated by the Kaplan-Meier method and compared by log-rank tests. A Cox proportional hazards model was fitted after adjusting for clinicopathological factors, and receiver operating characteristics analysis was conducted.The 8th edition showed significant differences in survival between each adjacent stage in the Korean cohort but not in the German cohort. Multivariate analyses revealed that the 8th edition staging was an independent prognostic factor, and its C-statistics were >0.76 in both German and Korean patients. The results were comparable to those observed with the UICC seventh edition (C-statistics was 0.768 vs 0.767 in the German cohort and 0.789 vs 0.785 in the Korean cohort for the 7th vs the 8th edition).The 8th edition showed prognostic value in predicting the survival of gastric cancer patients in both German and Korean cohorts. However, the predictive ability of the 8th and 7th edition was similar.

Proposal of a novel stage grouping of the Eighth Edition of American Joint Committee on Cancer TNM Staging System for Gastric Cancer: results from a retrospective study of 30 years clinical data from a single institute in China

Objectives: To improve the prognostic accuracy of 8th edition of American Joint Committee on Cancer TNM staging system for gastric cancer by reclassifying N3a category.Methods: 1446 patients who underwent R0 surgery for histologically proven gastric cancers with ≥16 lymph nodes retrieved were selected.Results: Significant prognostic difference was observed among patients in N3a category ('7-10' group vs '11-15' group; P = 0.029). We proposed a revised pN category in which patients with '7-10' metastatic lymph nodes were categorized as r-N3a, '11-15' as r-N3b, and '>15' as r-N3c. Prognosis for patients in T2r-N3aM0 was similar to that of patients in T4aN0M0/T3N1M0/T2N2M0/T1r-N3bM0 (P = 0.584), but significantly better than that of patients in T4bN0M0/T4aN1-2M0/T3N2M0/T2r-N3bM0 (P = 0.031). Similarly, prognoses for patients in T3r-N3aM0 and T4ar-N3aM0 were similar to that of patients in T4bN0M0/T4aN1-2M0/T3N2M0/T2r-N3bM0 (P = 0.136; P = 0.193), but significantly better than that of patients in T4bN1-2M0/T4ar-N3bM0/T3r-N3bM0/T1-2r-N3cM0 (P = 0.011; P = 0.017). A revised TNM system was also proposed, in which T2r-N3aM0 was incorporated into stage IIB, T3r-N3aM0 and T4ar-N3aM0 into stage IIIA. The revised TNM system had better homogeneity, discriminatory ability, and monotonicity of gradients than the 8th edition system.Conclusion: Patients with 7-10 metastatic lymph nodes in T2-T4a categories should be considered lower stage in the final TNM stage.

A novel TNM staging system for gastric cancer based on the metro-ticket paradigm: a comparative study with the AJCC-TNM staging system

BACKGROUND

The metro-ticket prognostic tool for hepatocellular carcinoma has been proven to predict outcome, but a similar concept has not been investigated for GC. The objective of the current study was to apply the principles of the metro-ticket paradigm to develop a novel TNM staging system (nTNM) for gastric cancer (GC).

METHODS

The nTNM considered the distance from the origin on a Cartesian plane incorporating the pN (x-axis) and pT (y-axis) stages. GC patients undergoing radical resection at Fujian Medical University Union Hospital (FMUUH) (n = 4267) were included. The nTNM was validated using 2 external cohorts from the Sun Yat-sen University Cancer Center (SYSUCC) (n = 1800) and Surveillance, Epidemiology, and End Results (SEER) (n = 3227) databases.

RESULTS

nTNM classes with the same distance from the origin have same stage; the stage increases with this distance. Among all patients, 48.0% (n = 2049) were restaged in the nTNM compared with the 7th edition of the AJCC-TNM classification; 26.2% (n = 1116) were downstaged in the nTNM compared with the 8th edition. The nTNM provides significant survival differences between stages (all P < 0.001). The survival difference between stages IB and IIA was especially large for the nTNM (P < 0.001) compared to the 7th and 8th editions (P = 0.073). The concordance index and hazard ratio increased successively with the nTNM stage. Similar findings were observed in both external cohorts.

CONCLUSION

Compared with the AJCC-TNM classification, the nTNM for GC is easier to remember and provides some improvements; therefore, the nTNM may be considered for adoption in future editions of the AJCC-TNM classification.

Development and validation of a new staging system for node-negative gastric cancer based on recursive partitioning analysis: An international multi-institutional study

BACKGROUND

Whether the tumor-node-metastasis (TNM) staging system is appropriate for patients with node-negative gastric cancer (GC) is still inconclusive. The modified staging system developed by recursive partitioning analysis (RPA) showed good prognostic performance in a variety of cancers. The application of RPA has not been reported in the prognostic prediction of GC.

METHODS

Node-negative GC patients who underwent radical resection at Fujian Medical University Union Hospital (n = 862) and Sun Yat-sen University Cancer Center (n = 311) with at least 5 years of follow-up were selected as the training set. RPA was used to develop a modified staging system. Patients from the Surveillance, Epidemiology, and End Results database (n = 1415) were selected as the validation set.

RESULTS

The 5-year overall survival (OS) rates of patients with 8th AJCC-TNM stage IA-IIIA in the training set were IA 95.2%, IB 87.1%, IIA 78.3%, IIB 75.8%, and IIIA 72.6%. Multivariate analysis (MVA) showed that larger tumor size, elder age, and deeper depth of invasion were independent predictors for OS in patients with node-negative GC (all P < 0.05). Patients were reclassified into RPA I, RPA II, RPA III, and RPA IV stages based on RPA; the 5-year OS rates were 96.1%, 87.2%, 81.0%, and 64.3%, respectively, with significant difference (P < 0.05). Two-step MVA showed that the RPA staging system was an independent predictor of OS (P < 0.05). Compared with the 8th AJCC-TNM staging system, the RPA staging system had a smaller AIC value (2544.9 vs 2576.2), higher χ2 score (104.2 vs 69.6) and higher Harrell's C-index (0.697 vs 0.669, P = 0.007). The similar results were found in the validation set.

CONCLUSIONS

A new prognostic predictive system based on RPA was successfully developed and validated, which may be suggested for staging node-negative GC in future.

Evaluation of the Eighth Edition of the American Joint Committee on Cancer TNM Staging System for Gastric Cancer: An Analysis of 7371 Patients in the SEER Database

OBJECTIVE

To investigate the validity of the 8th edition of the American Joint Committee on Cancer (AJCC) TNM staging system for gastric cancer.

METHODS

The clinicopathologic data of 7371 patients who were diagnosed with gastric cancer and had 16 or more involved lymph nodes (LNs) were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database and retrospectively reviewed.

RESULTS

Stage migration occurred primarily during stage III between the 7th and 8th edition TNM staging systems. Stages IIIB and IIIC in the 7th edition staging system were divided in the 8th edition and had obvious differences in survival rates (both P < 0.001). The 8th edition TNM stages IIIC and IV showed similar survival rates (P = 0.101). The prognosis of patients with T4aN3bM0 was not different from that of patients with TxNxM1 (P = 0.433), while the prognosis of patients with T4bN3bM0 was significantly poorer than that of patients with TxNxM1 (P = 0.008). A revised TNM system with both T4aN3bM0 and T4bN3bM0 incorporated into stage IV was proposed. Multivariable regression analysis showed that the revised TNM system, but not the 7th and 8th editions, was an independent factor for disease-specific survival (DSS) in the third step of the analysis. Further analyses revealed that the revised TNM system had superior discriminatory ability to the 8th edition staging system, which was also an improvement over the 7th edition staging system.

CONCLUSION

The 8th edition of the AJCC TNM staging system is superior to the 7th edition for predicting the DSS rates of gastric cancer patients. However, for better prognostic stratification, it might be more suitable for T4aN3bM0/T4bN3bM0 to be incorporated into stage IV in the 8th edition TNM staging system.

Superiority of the 8th edition of the TNM staging system for predicting overall survival in gastric cancer: Comparative analysis of the 7th and 8th editions in a monoinstitutional cohort

The present study was performed to evaluate the predictive capacity of the 8th edition vs. the 7th edition of the American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) staging system for overall survival (OS) of patients with gastric cancer. Data of eligible patients with gastric cancer in our institution between June 2004 and June 2014 were retrospectively reviewed. A total of 1,506 patients were followed up to July 2016, among whom 1,484 patients with complete stage information were included in the TNM staging analysis. A total of 339 (22.8%) patients presented stage migration, including 325 (21.9%) migrating to a lower tier and 14 (0.9%) to a higher tier. All patients with stage migration to a lower tier were in stage III, including 177 (54.5%) patients migrating from stage IIIB to IIIA, and 148 (45.5%) from stage IIIC to IIIB. Patients migrating from IIIB to IIIA yielded a median OS time and 5-year OS rate closer to those remaining in stage IIIA. Similarly, patients migrating from IIIC to IIIB yielded a median OS time and 5-year OS rate closer to those remaining in stage IIIB. The 7th edition of the staging system exhibited prognostic discrepancy in discriminating stage IIIA from IIIB on survival curves, which was improved in the 8th edition. The 8th edition had a better predictive capability of survival, as evidenced by a smaller value of -2log likelihood in the Cox proportional regression model (7th edition 4738.859 vs. 8th edition 4736.683). Therefore, the present study demonstrated that the 8th edition of the AJCC TNM staging system is superior to the 7th edition in predicting the OS of patients with gastric cancer.