Minimum number of lymph nodes that should be examined for the International Union Against Cancer/American Joint Committee on Cancer TNM classification of gastric carcinoma

Abstract The classification of lymph node metastasis based on the number of positive nodes has been adopted in the International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) TNM classification of gastric carcinoma. However, the N classification (for condition of the regional lymph nodes) would be underestimated when the number of examined nodes were too small. To determine the minimum number of lymph nodes to examine for a correct classification, we analyzed 926 patients undergoing curative resection for gastric carcinoma. The number of metastatic lymph nodes correlated significantly with the number of examined lymph nodes. The pN0 patients with 10 to 14 examined nodes showed a significantly higher survival rate than did those with 5 to 9 examined nodes, and they had as good a prognosis as those with 15 or more examined nodes. In the pN1 and pN2 categories, patients with 29 or fewer examined nodes tended toward lower survival rates than did patients with 30 or more examined nodes. Among the patients who were classified as stage IA, the survival rate for those with 5 to 9 examined nodes was significantly lower than that for patients with 30 or more examined nodes. Among the patients classified as stage III, those with 10 to 19 examined nodes and those with 20 to 29 examined nodes had lower survival rates than did patients with 30 or more examined nodes. In conclusion, the minimum number of lymph nodes examined for a correct pN0 classification can be reduced from 15 to 10. For pN1–3 classifications, 20 or more nodes should be examined, and examining 30 or more lymph nodes may be desirable. Electronic Publication     

第8版国际抗癌联盟和美国癌症联合委员会胃癌TNM分期系统简介及解读

目前胃癌的TNM分期已经成为临床胃癌诊疗的首选参考依据。在国际抗癌联盟(UICC)、国际胃癌协会(IGCA)和美国癌症联合委员会(AJCC)的共同协作推动下,通过对全世界范围内胃癌大数据的收集与分析,于2016年10月颁布了第8版胃癌TNM分期系统。第8版TNM分期系统对食管-胃结合部及贲门癌分期标准的选择做出了明确的定义;同时还在单一分期系统的基础上新增了临床TNM分期(cTNM)和新辅助治疗后分期(ypTNM)。此外,新版的分期系统将N3的两个亚组N3a和N3b作为独立组别纳入到分期系统,还对组织学分级进行了一些调整。总的来说,相比第7版胃癌TNM分期系统,新版的分期系统可以指导临床医生更加合理地制定治疗方案,更加科学地评价治疗效果,更加准确地评估预后。然而,随着临床广泛应用和进一步验证,以及新的预测因子的发现,必将会有新的分期系统替代和完善旧的分期系统。     

Appraisal of compliance with the UICC/AJCC staging system in the staging of gastric cancer. Union Internacional Contra la Cancrum/American Joint Committee on Cancer

BACKGROUND: In the surgical management of gastric carcinoma, regional lymphatic spread is of prognostic importance. The fifth edition of the Union Internacional Contra la Cancrum classification has been shown to be reproducible, practical and of significant prognostic use. The tumour node metastasis (TNM) system requires at least 15 lymph nodes to be acquired and examined for staging to be accurate. This has raised concern over the consistency with which the requisite numbers of nodes would be acquired. This study was performed to assess how consistently surgically managed cases of gastric cancer in the West Midlands fulfilled this requirement to allow accurate staging. METHODS: Data from the West Midlands Cancer Intelligence Unit on all cases of gastric cancer registered from 1998 to 1999 were obtained and the number of lymph nodes documented for each surgically managed case was assessed. RESULTS: Overall, only 31.0 per cent of surgically resected cases could be assessed accurately according to the TNM system. The proportion staged accurately varied widely across hospitals from 10.9 to 76.0 per cent. CONCLUSION: These results reflect the need for improved N staging across the region to aid the appropriate multimodal treatment of patients.     

The New American Joint Committee on Cancer/International Union Against Cancer Staging System for Adenocarcinoma of the Stomach: Increased Complexity without Clear Improvement in Predictive Accuracy

Purpose

To evaluate the changes in the 7th edition American Joint Committee on Cancer (AJCC) staging system for stomach cancer compared to the 6th edition; to compare the predictive accuracy of the two staging systems.

Methods

In a combined database containing 2,196 patients who underwent an R0 resection for gastric adenocarcinoma, differences between the two staging systems were evaluated and stage-specific survival estimates compared. Concordance probability and Brier scores were estimated for both systems to examine the predictive accuracy.

Results

Nodal status cutoff values were changed, leading to a more even distribution for the redefined N1, N2, and N3 group. AJCC 6th edition stage II reflected a highly heterogeneous population, which is now adequately subdivided in the AJCC 7th edition into stages IIA, IIB, and IIIA. The predictive accuracy of N classification improved significantly as measured by concordance. Despite increased complexity, the predictive accuracy of AJCC 7th stage grouping was significantly worse than that of the AJCC 6th edition.

Discussion

The increased complexity of the 7th edition staging system is accompanied by improvements in the predictive value of nodal staging as compared to the 6th edition, but it was no better in overall stage-specific predictive accuracy. Future refinements of the tumor, node, metastasis staging system should consider whether increased complexity is balanced by improved prognostic accuracy.     

Prognostic Evaluation of the New American Joint Committee on Cancer/International Union Against Cancer Staging System for Hepatocellular Carcinoma: Analysis of 112 Cirrhotic Patients Resected for Hepatocellular Carcinoma

Background In 2002, the American Joint Committee on Cancer and the International Union Against Cancer redefined the T-classification for hepatocellular carcinoma, shifting the cutoff value for tumor size from 2 to 5 cm and giving more emphasis to vascular invasion.Methods A retrospective cohort study was conducted on 223 consecutive patients with hepatocellular carcinoma observed between 1990 and 2002. One hundred twelve were resected and considered for retrospective analysis. Univariate and multivariate analyses were performed on several clinicopathologic variables. After classification according to each staging system, the long-term survival of different stages was compared. The prognostic value of each staging system was further evaluated by entering each stage, in turn, into the Cox regression model with other clinicopathologic variables. The median follow-up was 19 months.Results On multivariate analysis, the viral etiology of cirrhosis and the presence of multiple nodules were independent prognostic factors. When the new staging system was entered into the multivariate analysis, it was the only independent factor (P = .02). When stratified according to the old tumor-node-metastasis system, there were no significant differences in the survival between stage I and II (P = .14) or between stage IIIA and IVA (P = .33); only the survival of stage II and IIIA was different (P < .01). When stratified according to the new tumor-node-metastasis system, there were significant differences between stage I and II (71.7% vs. 54.7%; P = .02).Conclusions The new staging system is a more reliable and objective method for T classification. It is easy to use in clinical practice and is better at stratifying curatively resected patients with respect to prognosis.Published by Springer Science + Business Media, Inc. © 2005 The Society of Surgical Oncology, Inc.     

The ability of the American Joint Committee on Cancer Staging system to predict progression-free survival after radical prostatectomy

OBJECTIVE: To examine, in a retrospective analysis of outcome based on prostate-specific antigen (PSA) levels, whether the 1992 and revised 1997 staging criteria for prostate cancer can be used to predict progression-free survival for patients after radical prostatectomy for pT2 and pT3 prostate cancer. PATIENTS AND METHODS: In all, 291 patients with a PSA determination during a 6-month interval after radical prostatectomy were analysed (mean follow-up 5.2 years). In the absence of a uniform system of pathological staging, the histopathological stage was defined according to the 1992 and 1997 American Joint Cancer Committee/Union Internationale Contre le Cancer (AJCC/UICC) tumour-nodes-metastases (TNM) staging classification. Findings were correlated with the PSA value after surgery. The subgroups of pT2 and pT3 disease were compared for the time to PSA progression, using Kaplan-Meier data analysis and the log-rank test. RESULTS: The biochemical progression-free 5-year survival rates for stage pT2 were 83% (pT2a), 81% (pT2b) and 62% (pT2c); there were no significant differences in the pT2 subgroups. The recurrence-free rates for pT3 were 79% (pT3a), 65% (pT3b) and 50% (pT3c); the actuarial recurrence-free rate was significantly different for patients with 1997 AJCC pT3a vs pT3b disease (P=0.0132). There was no significant difference in the 1992 AJCC stages pT2a vs pT2b (P=0.1232) and the recurrence-free rate was not significantly different for patients with 1992 AJCC pT3a vs pT3b disease (P=0.9). There was a significant difference in the likelihood of a PSA relapse between patients with positive and negative surgical margins (P=0.131). CONCLUSION: These results support the current revised 1997 AJCC/UICC staging system for prostate cancer. There is an urgent need to develop a pathological equivalent to the AJCC/UIC TNM clinical staging system. Greater clinical input and evaluation from different institutions are essential to reach consensus on pathological staging categories that maximize the predictability of outcome after definitive therapy. Crucial issues are the definition and quantification of extraprostatic extension and definition of surgical margin categories.     

Lymph node density vs. the American Joint Committee on Cancer TNM nodal staging system in node-positive bladder cancer in patients undergoing extended or super-extended pelvic lymphadenectomy

Purpose

We compared the prognostic value of the American Joint Committee on Cancer (AJCC) TNM nodal staging system with that of lymph node (LN) density in patients with LN-positive bladder cancer who received extended or super-extended pelvic lymphadenectomy.

Evaluation of classification of pancreatic cancer by the Japan Pancreas Society and Union Internationale Contre le Cancer and proposal for a new international classification

Different classification systems of pancreatic cancer by the Japan Pancreas Society (JPS, 1996) and Union Internationale Contre le Cancer (UICC) (1997), both of which are based on the TNM system, have been hampering the exchange of data between Japan and Western countries. In the present study, both classifications were assessed using data from 67 patients with invasive ductal carcinoma of the pancreatic head who underwent resection at our clinic. We also propose a new TNM classification and stage grouping system that draws on the merits of both. The results showed that UICC stage grouping did not reflect outcome well, while the JPS system predicted outcome much better. The prognostic value of tha T category is sufficiently reliable in both classifications, but the major drawback of the JPS system is its complex structure and difficult handling. To meet the ideal standard for an international classification system, we propose a new classification: the T category is a minor modification of that of the UICC, and the N category is a modification of that of the JPS for much simpler grouping. Based on the data from our 67 resected patients cases, our new staging system reflects the outcome in the four stages well. Our new classification system may improve the staging classification and lead to the establishment of a more practical and universal staging system for ductal carcinoma of the pancreas.     

Prediction of lymphatic invasion/lymph node metastasis, recurrence, and survival in patients with gastric cancer by cDNA array-based expression profiling

BACKGROUND: We assessed the predictability of various classes of gastric carcinoma defined by clinicopathological parameters, such as invasiveness and clinical outcomes, using cDNA array data obtained from 54 cases. MATERIALS AND METHODS: We searched an optimal combination of genes to discriminate the classes defined with the clinicopathological parameters by using a feature subset selection algorithm, which was applied to a set of genes preselected on the basis of statistical difference in expression (two-sided t test, P < or = 0.05). With the selected features (gene set), we evaluated the predictability of each parameter in a leave-one-out cross-validation test. RESULTS: We successfully selected sets of genes for which the classifier predicted better versus worse overall survival (tumor-specific death) and tumor-free survival (recurrence), with respective classification rates of 94 and 92%. A contingency table analysis (chi2 test) and Cox proportional hazard model analysis revealed that lymph node metastasis is the most important factor (confounding factor) in patients' prognoses and risks of recurrence. The feature subset selection procedure successfully extracted expression patterns characteristic of lymph node metastasis and lymphatic vessel invasion, yielding 92 and 98% prediction accuracies for these respective factors. CONCLUSION: We conclude that expression profiling using feature subset selection provides a powerful means of stratification of gastric cancer patients in regard to the prognostic factors. Further studies should be warranted to apply this method to personalization of the treatment options.