Incorporation of extranodal metastasis of gastric carcinoma into the 7th edition UICC TNM staging system

Correlation Analysis Between Tumor Deposit and Clinicopathologic Characteristics and Prognosis of Gastric Cancer: A Multicenter Retrospective Study

BACKGROUND

The mechanism underlying the formation of gastric tumor deposits (TDs) is unclear. We aimed to explore the risk factors for the formation and prognostic value of TDs.

METHODS

This retrospective analysis included 781 locally advanced gastric cancer (LAGC) patients from four medical institutions in China, from June 2014 to June 2018. The risk factors for TD formation and prognostic value were determined through univariate and multivariate analyses.

RESULTS

Univariate analysis revealed that TD positivity was closely related to tumor diameter, Borrmann classification, differentiation degree, pT stage, pN stage, pTNM stage, and nerve and vascular invasion (p < 0.05). Multivariate logistic regression revealed that tumor diameter ≥ 5 cm (odds ratio [OR] 1.836, 95% confidence interval [CI] 1.165-2.894, p = 0.009) and vascular invasion (OR 2.152, 95% CI 1.349-3.433, p = 0.001) were independent risk factors for TD positivity. Multivariate Cox analysis revealed that TD positivity (OR 1.533, 95% CI 1.101-2.134, p = 0.011), tumor diameter ≥ 5 cm (OR 1.831, 95% CI 1.319-2.541, p < 0.001), pT4a stage (OR 1.652, 95% CI 1.144-2.386, p = 0.007), and vascular invasion (OR 1.458, 95% CI 1.059-2.008, p = 0.021) were independent risk factors for GC prognosis. The 5-year overall and disease-free survival of the TD-positive group showed significant effects among patients in the pT4a and pN3b stages (p < 0.05).

CONCLUSIONS

TDs are closely related to tumor diameter and vascular invasion in LAGC patients, and TD positivity is an independent prognostic factor for LAGC patients, especially those at pT4a and pN3b stages.

Construction and validation of a prognostic model for gastric cancer patients with tumor deposits

Background

Tumor deposits (TD) was a significant risk factor impacting the prognosis of patients diagnosed with gastric cancer (GC), yet it was not currently incorporated into TNM staging systems. The objective of this research was to develop a predictive model for assessing the prognosis of patients with TD-positive GC.

Methods

Retrospective analysis was performed on the data of 4,972 patients treated for GC with D2 radical gastrectomy at Wannan Medical College's Yijishan Hospital between January 2012 and December 2021. The patients were categorized based on the number of TD (L1: 1, L2: 2-3, L3: ≥4) and the anatomical location of TD (Q1: single area, Q2: multiple areas). In a 3:1 ratio, patients were randomly assigned to one of two groups: training or validation.

Results

The study included a total of 575 patients who were divided into the training group (n = 432) and validation group (n = 143). Survival analysis showed that the number and anatomical location of TD had a significant impact on the prognosis of patients with TD-positive GC. Univariate analysis of the training group data revealed that tumor size, T-stage, N-stage, histological grade, number and distribution of TD, neural invasion, and postoperative chemotherapy were associated with prognosis. Multivariate Cox regression analysis identified poor histological grade, T4 stage, N3 stage, number of TD, neural invasion, and postoperative chemotherapy as independent prognostic factors for GC patients with TD. A nomogram was developed using these variables, demonstrating well predictive ability for 1, 3, and 5-year overall survival (OS) in the validation set. The DCA curve shows that the constructed model shows a large positive net gain compared to the eighth edition Tumour, Node, Metastasis (TNM) staging system.

Conclusion

The prognostic model developed for patients with TD-positive GC has a higher clinical utility compared to the eighth edition of TNM staging.

Clinical significance of tumor deposits in gastric cancer after radical gastrectomy: a propensity score matching study

OBJECTIVE

The value of tumor deposits (TDs) in the prognosis and staging of gastric cancer (GC) is still under debate. This study aims to evaluate the prognostic value of TDs and the best ways to incorporate TDs in the TNM classification of GC.

METHODS

Patients (n = 3460) undergoing curative gastrectomy for GC in the West China Hospital from 2005 to 2017 were retrospectively reviewed and divided into two groups according to the TD status (positive vs. negative). Later, clinicopathological features and overall survival (OS) between the two groups were compared. Thereafter, the associations between the presence of TD and other clinicopathological factors were evaluated through logistic regression. In addition, univariate and multivariate Cox regression were conducted for determining prognostic factors. The possibility of selection bias was reduced through conducting the 1:1 propensity score matching (PSM) analysis. The modified classification systems proposed previously that incorporated TDs into the TNM staging system were assessed.

RESULTS

There were 10.5% of patients (362/3460) diagnosed with TDs. TDs were significantly related to unfavorable factors such as advanced T stage and N stage and independently associated with poor prognosis. The 5-year OS of patients with TDs was significantly lower than that of patients without TDs (31.0% vs. 60.9%, P < 0.001), whereas higher than that of patients with peritoneal metastasis (31.0% vs. 5.0%, P < 0.001). In patients receiving chemotherapy, the 5-year OS of patients with TDs was also significantly lower than that of patients without TDs (42.0% vs. 50.9%, P = 0.026). Moreover, the system incorporating TDs in the TNM classification as metastatic lymph nodes outperformed others.

CONCLUSIONS

TDs are related to the aggressive characteristics and are an independent prognostic factor for GC. Incorporating TDs in the TNM classification as the metastatic lymph nodes increases the accuracy in predicting prognosis.

Prognostic value of tumor deposits in lymph node-negative gastric cancer: A propensity score matching study

BACKGROUND

The purpose of this study was to assess the prognostic value of TD in lymph node-negative GC.

METHODS

A retrospective study was conducted to collect the clinicopathological data from 1224 patients with lymph node-negative GC. According to their TD status, patients were categorized into TD-positive and TD-negative groups. Patients in both groups underwent a 1:1 propensity score matching analysis. Survival analysis was performed by the Kaplan-Meier method, and the differences between survival curves were measured by log-rank test. The cox proportional hazards model was used for univariate and multivariate analyses.

RESULTS

The TD-negative group had higher 5-year overall survival(OS) rate than TD-positive group(69.4%VS.36.4%,P < 0.05). Further subgroup analysis indicated that patients in the TD-negative group had higher 5-year OS rates than those in the TD-positive group in the T1-2, T3, and T4 subgroups(all with P < 0.05).The OS rates were decreased with the increase of the number of TD.The univariate Cox regression analysis demonstrated that tumor location in antrum, distal gastrectomy, perineural invasion, T4-stage,lymphovascular invasion and the number of TD were all associated with prognosis in patients undergoing curative gastric resection (P < 0.05).The multivariable analysis revealed that the number of TD, perineural invasion, lymphovascular invasion and T4 stage were independently associated with OS.

CONCLUSION

In lymph node-negative GC, TD is an independent risk factor for prognosis, regardless of T-stage, and patients with ≥3 TD have a worse prognosis.

Prognostic significance of tumor deposits in radically resected gastric cancer: a retrospective study of a cohort of 1915 Chinese individuals

BACKGROUND

Tumor deposits (TDs) have been identified as an independent prognostic factor in gastric cancer (GC). However, the associated clinicopathological factors and how to simply and reasonably incorporate TD into the TNM staging system remain undetermined. The aim of the current study was therefore to assess the significance of TD among radically resected GC patients.

METHODS

We retrospectively reviewed 1915 patients undergoing radical resection between 2007 and 2012. The patients were classified into two groups according to TD status (absent vs. present), and the clinicopathologic characteristics, DFS, and OS were compared. Associations of TD presence with other clinicopathologic factors were evaluated by logistic regression analysis. Univariate and multivariate Cox regression analyses were performed to determine the prognostic factors for DFS and OS in the primary cohort. Propensity score matching (PSM) was performed to reduce the possibility of selection bias according to the presence of TD. External validation of previously proposed modified staging systems incorporating TD was conducted.

RESULTS

The detection rate of TD was 10.5% (201/1915). The presence of TD was significantly related to unfavorable clinicopathologic variables, including advanced T and N categories. According to the multivariate Cox regression analysis, the presence of TD was identified as an independent prognostic factor for DFS and OS in the primary cohort (both P < 0.001). In the after-PSM cohort, TD presence also significantly shortened DFS and OS. In the external validation, one system that incorporated TD into the pTNM stage had the best performance.

CONCLUSIONS

The presence of TD was significantly associated with poor survival in radically resected GC patients. The incorporation of TD into the TNM staging system can further improve the predictive capability. A multicenter cohort with a large sample size is needed to determine the appropriate method of incorporation.

Pathologic Lymph Node Staging of Gastric Cancer

OBJECTIVES

The TNM classification is the main tool for lymph node (LN) staging in gastric cancer (GC). However, alternative LN staging systems have been proposed, and the role of features other than the number of metastatic LNs is being investigated. Our aim is to discuss the main challenges of LN assessment in GC.

METHODS

Comprehensive review of the literature on alternative LN staging systems, examined LNs, sentinel LN (SLN) biopsy, LN micrometastases (LNMIs), extracapsular extension (ECE), and tumor deposits (TDs) in GC.

RESULTS

Many controversies exist regarding LN assessment in GC. The TNM classification shows excellent prognostic performance, but alternative prognostic methods such as the LN ratio or log odds of positive LNs have demonstrated to be better than the TNM system in terms of prognostic accuracy. The value of SLN biopsy and LNMIs in GC is still unclear, and several challenges concerning their clinical impact and pathologic analysis must be overcome before their introduction in clinical practice. Most authors have identified ECE and TDs as independent prognostic factors for survival in GC.

CONCLUSIONS

Further studies should be performed to evaluate the impact of these features on the TNM classification and patient outcomes, as well as to standardize alternative LN staging systems.

Clinicopathological factors associated with the presence of tumor deposits in resected gastric cancer patients

Purpose

The role of tumor deposits (TDs) in the staging of gastric cancer is currently debatable. TDs are defined as tumoral nodules in perigastric adipose tissue with no evidence of lymphatic, vascular, or neural structures. Clinicopathological factors related to the presence of TDs are not well defined. This study aimed to identify the clinicopathological factors associated with the presence of TDs in resected gastric cancer patients.

Materials and methods

This prospective study included patients diagnosed with gastric cancer and treated with D2 radical gastrectomy from January 2019 to January 2020. Univariate and multivariate analyses were performed to determine the factors related to the presence of TDs.

Results

A total of 111 patients were eligible and TDs were present in 31 of them (28%). In the univariate analysis, male gender (p = 0.027), tumor size ≥ 5cm (p = ≤0.001), serosa and adjacent organs invasion (pT4a and pT4b) (p = ≤0.001), ≥16 metastatic lymph nodes (pN3b) (p = ≤0.001), and TNM stage III tumors (p = ≤0.001) were significantly associated with the presence of TDs. The multivariate analysis showed that a tumors size ≥5 cm (OR = 3.69, 95% CI: 1.17-11.6), serosa and adjacent organs invasion (pT4a and pT4b) (OR = 3.78, 95% CI: 1.31-10.86) and ≥16 metastatic lymph nodes (pN3b) (OR = 3.21, 95%CI:1.06-9.7) were independent risk factors for the presence of TDs.

Conclusions

Larger tumors (tumor size ≥ 5cm), serosa and adjacent organs invasion (pT4 and pT4b), and ≥16 metastatic lymph nodes (pN3b) were independent risk factors for the presence of TDs.

Extra-nodal metastasis should be classified separately from lymph node metastasis in gastric cancer

INTRODUCTION

Extra-nodal metastasis (ENM) is defined as a tumor nodule without histological evidence of a lymph node structure. Although ENM has pathological features distinct from those of metastatic lymph nodes, both ENM and metastatic lymph nodes are considered within the same category in the pathological nodal (pN) classification. This study aimed to clarify the clinicopathological characteristics and prognostic relevance of ENM in gastric cancer patients who underwent curative gastrectomy.

MATERIALS AND METHODS

We retrospectively evaluated 1207 Japanese patients who underwent curative gastrectomy at a single center between January 2009 and December 2013. All resected specimens were fixed in 10% formalin, processed, and stained using hematoxylin and eosin, and subsequently reviewed by two pathologists. Survival times were analyzed using the Kaplan-Meier method, and independent prognostic factors were identified using a Cox proportional hazards regression model.

RESULTS

Patients who were ENM-positive had significantly poorer overall survival; multivariable analysis revealed that independent prognostic factors were older age (hazard ratio [HR]: 3.68, 95% confidence interval [CI]: 2.60-5.20), higher pathological tumor classification (HR: 2.28, 95% CI: 1.43-3.62), presence of metastatic lymph nodes (HR: 1.57, 95% CI: 1.0-2.36), and ENM-positive status (HR: 2.33, 95% CI: 1.48-3.66). ENM-positive patients had similar survival outcomes to those of ENM-negative patients with ≥16 metastatic lymph nodes.

CONCLUSIONS

Among Japanese patients with gastric cancer who underwent curative gastrectomy, ENM was an independent prognostic factor with a prognostic significance different from that of lymph node metastasis. These results suggest that ENM and lymph node metastasis should be classified separately.

Extranodal soft tissue metastasis as an independent prognostic factor in gastric cancer patients aged under 70 years after curative gastrectomy

Background

Accumulating evidence confirms the potential prognostic value of extranodal soft tissue metastasis (ESTM) in patients with solid cancers. The aim of this study was to elucidate the potential relationship between ESTM and lymph node (LN) metastasis, demonstrate clinicopathological predictive prognostic factors for ESTM and LN metastasis, and identify the prognostic value of ESTM for gastric cancer (GC) patients aged under 70 years.

Methods

A total of 580 GC patients who underwent the curative resection between 2003 and 2011 were included to identify if ESTM is essential to improve the accuracy of prognostic evaluation of the GC patients postoperatively. Overall survival rates were tested by Kaplan-Meier analysis. Univariate and multivariate analyses were applied to clarify the independent prognostic factors. Logistic regression analysis was adopted to clarify the risk factors for evaluating the presence of ESTM and LN metastasis. After cut-point survival analysis, the GC patients were divided into three subgroups based on the number of ESTM and then incorporated into the pTNM stage of gastric carcinoma to identify the possibility and necessity of incorporating ESTM into staging.

Results

ESTM was associated with advanced pT, pN and pTNM categories, large tumour size and the presence of signet-ring cell (SRC) variants. Survival analyses revealed that ESTM was associated with the OS and was an independent prognostic predictor in this GC patient cohort. Logistic regression analysis proved that ESTM and pT stage are significantly correlated with LN metastasis. Additionally, the ESTM was incorporated into the eighth edition of the pTNM classification and the prognostic evaluation of pTNME classification were calculated directly, and the results indicated that ESTM can reduce the stage migration.

Conclusions

ESTM is a significant independent predictor of survival in GC patients. To achieve R0 surgery, lymph nodes, soft tissues, fascia and adipose tissue should be resected en bloc at the same time as lymph node dissection. ESTM should be incorporated into pTNM staging according to the number retrieved from postoperative samples.

Tumour deposits are a significant prognostic factor in gastric cancer - a systematic review and meta-analysis

AIMS

Tumour deposits (TDs) are clusters of cancer cells in the soft tissue that are discontinuous from the primary tumour. In this review we are exploring their relevance for prognosis in patients with gastric cancer.

METHODS AND RESULTS

A literature search was performed to identify studies providing data on TDs and prognosis in gastric cancer patients. Eight papers were included in the meta-analysis, which was carried out in terms of risk ratios (RR) and hazard ratios (HR) with 95% confidence interval (95% CI). Of 7445 patients, 1551 had TDs (20.9%). TDs were associated with a decreased overall survival (OS) in univariate (HR = 2.82, 95% CI = 1.9-4.3) and multivariate analyses (HR = 1.65, 95% CI = 1.3-2.1). TDs were also associated with known prognostic factors such as synchronous metastatic disease (RR = 9.5), invasion depth (RR = 1.8), lymph node metastasis (RR = 1.7), lymphatic invasion (RR = 1.7), vascular invasion (RR = 2.6) and poor differentiation (RR = 1.2).

CONCLUSIONS

We found a strong indication that TDs are independent predictors of prognosis in patients with gastric cancer; hence, TDs should be included in the staging of gastric cancers.

Prognostic significance and the role in TNM stage of extranodal metastasis within regional lymph nodes station in gastric carcinoma

The role of extranodal metastasis (ENM) in TNM stage in gastric carcinoma (GC) is controversial. This study was aimed to make a detailed investigation of the prognostic significance and the role in TNM stage of ENM in GC. The patients with primary GC, who underwent gastrectomy with curative intention in West China Hospital from January 2005 to December 2011, were retrospectively enrolled. The prognosis and clinicopathological traits were compared between ENM positive (ENMP) and negative (ENMN) groups in all patients, TNM I-II, III and IV stages, respectively. The significance of the number and the role in TNM stage of ENM were also assessed. In our study, 1457 patients were enrolled, with 1324 (90.9%) in ENMN group and 133 (9.1%) in ENMP group. ENMP group had significantly more advanced GC and worse prognosis (all p<0.05) than ENMN group in all patients, TNM I-II stages and TNM III stage. ENM>2 subgroup had remarkably larger tumor size (p=0.002) and more advanced N stage (p=0.016) than ENM=1-2 subgroup. The number of ENM was an independent prognostic factor in ENMP group (p=0.029). The prognosis of ENM>2 in TNM I-III stages was significantly worse than ENMN patients in TNM III stage. The C-index of TNM stage plus the number of ENM was significantly higher than that of current TNM stage alone (p=0.005). In conclusion, the patients in ENMP subgroup had more advanced GC and worse prognosis than those in ENMN subgroup. It might be more reasonable to categorize ENM>2 into TNM IV stage.

Beyond T, N and M: The impact of tumor deposits on the staging and treatment of colorectal and gastric carcinoma

This review aims to describe the results of the most recent studies on the prognostic value of TDs and highlight the impact of TDs on the staging and treatment of colorectal and gastric carcinoma. For colorectal carcinoma TDs have an adverse prognostic effect that is at least similar to that of positive regional lymph nodes. However, support is growing in favor of including of TDs in the M category, rather than the N or T categories of the TNM classification. Moreover, TDs seem to have an adverse effect on outcomes not only in patients without lymph node involvement but also in patients with nodal involvement. Although the prognostic impact of TDs in gastric cancer appears to be undeniable, the actual prognostic determinants of TDs, particularly in relation to the number, size and histological types, remain to be established. Although the 7th and 8th Edition of the TNM classification of colorectal and gastric carcinoma includes TDs in the N category, no current procedures or methods to assess preoperative or intraoperative N-status allow TD detection. After neoadjuvant treatment for advanced rectal carcinoma, the presence of TDs may indicate incomplete eradication of the main tumor and not discontinuous tumor foci. TDs have an undeniable prognostic impact but no algorithm of staging and strategy of treatment has been conformed to this prognostic factor to overcome the classical T,N, and M prognostic categories. Staging and treatment of colorectal and gastric cancers should be reconsidered in light of the emerging prognostic value of TDs.

Node-extranodal soft tissue stage based on extranodal metastasis is associated with poor prognosis of patients with gastric cancer

BACKGROUND

The purpose of this study was to evaluate the effect of Node-Extranodal soft tissue (pNE) stage based on Extranodal Metastasis (EM) on recurrence and survival in patients with gastric cancer (GC).

MATERIALS AND METHODS

A total of 642 patients were divided into two groups according to statue of EM. Clinicopathologic features were compared among the two groups, the log-rank test was used to assess statistical differences between the groups. Independent prognostic factors were identified by the Cox proportional hazards regression model. According to the number of EMs, EM was incorporated into the pN stage of gastric carcinoma. The 5-y overall survival (OS) and disease free survival (DFS) rates were 48.1% and 17.4%, 44.5% and 14.3% between the two groups. Patients with EM had a deeper tumor invasion and more number of lymph node metastases. Peritoneal dissemination and distant metastasis were more frequent with EM. EM is an independent risk factor for distance recurrence (odds ratio = 1.605), and it is the highest risk factor for peritoneal recurrence (odds ratio = 2.448). Multivariate analysis showed that depth of tumor invasion (P = 0.025), lymph node metastasis (P <0.001), and EM (P = 0.006) were independent factors associated with OS. Furthermore, EM (P = 0.0039) was also an independent prognostic factor for DFS. The differences in prognostic prediction between the seventh edition of the pN classification and the pNE classification were directly compared. We found the pNE classification (hazard ratio = 1.730, P <0.001) was more appropriate for predicting the OS of GC patients after curative surgery, and the -2 loglikehood of the pNE staging (4533.991) is smaller than the value of pN.

CONCLUSIONS

EM was closely associated with cancer aggressiveness and the presence of EM was a significant independent predictor of reduced DFS and OS in GC patients. EM is an independent risk factor for distance recurrence, especially for peritoneal recurrence, the selection of postoperative adjuvant therapy in systemic (intravenous or intra-arterial) and regional (intraperitoneal) based on EM may be a reasonable approach. The lymph node imaging techniques such as injecting nanocarbon during surgery should be applied. As an important prognostic factor, EM should be incorporated into N stage according to its number retrieved in postoperative samples.

Tumor deposits in gastric carcinomas

We performed this study to examine the prevalence of tumor deposits (TD) in gastric adenocarcinomas (GACa), and the relevance of their presence, size and type to clinical outcome. Ninety-six patients, histopathologically diagnosed as GACa following a total/subtotal gastrectomy were included, and clinicopathologic data were recorded. Due to the statistical analysis, the majority of TD(+) cases were of intestinal type and showed vascular invasion. In these cases, the incidence of local recurrence was significantly higher. The majority of GACa of intestinal type with TD were of high grade and showed vascular invasion. Recurrence and death were more commonly encountered among them. The recurrence-free survival (RFS) was significantly shorter in patients with TDs, which was also confirmed by multivariate analysis, and there was a significant difference between both RFS and overall survival of TD(+) and TD(-) cases of intestinal type GACa. In conclusion, in this study, we demonstrate that TDs are not infrequently observed in GACa, they are more commonly associated with the intestinal type and vascular invasive gastric cancers. Our study shows the prognostic impact of TDs, especially regarding the RFS. Therefore, the documentation of TDs might be considered for prospective studies, especially for the intestinal type GACa, a shortcoming of this study.

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.

Extranodal metastasis is a powerful prognostic factor in patients with adenocarcinoma of the esophagogastric junction

BACKGROUND AND OBJECTIVES

The purpose of this study is to estimate the effect of extranodal metastasis (EM) on recurrence and survival in patients with adenocarcinoma of the esophagogastric junction (AEG) after curative resection.

METHODS

Clinical data from 284 node-positive AEG patients who underwent curative resection were reviewed. Univariate and multivariate analyses were conducted to elucidate the effect of EM on recurrence-free survival (RFS) and overall survival (OS).

RESULTS

EM was detected in 70 (24.6%) of the 284 cases. It had a significant correlation with tumor size, Lauren type, histopathological grading, depth of tumor invasion, number of metastatic nodes, lymph node ratio, and TNM stage. The 5-year RFS and OS rates were 22.2% and 24.3%, respectively. Patients with EM had a significantly decreased RFS (16 vs. 36 months, P < 0.001) and OS (23 vs. 41 months, P < 0.001) compared with those without EM. Multivariate analyses identified EM as an independent prognostic factor (P = 0.003 and 0.001, respectively).

CONCLUSION

The presence of EM increases recurrence probability and reduces OS probability of AEG patients with lymph node metastasis. EM is a powerful prognostic factor reflecting a particularly aggressive biological behavior. Better understanding of EM status can help clinicians with regard to treatment decision and prognosis evaluation.

Prognostic implications of the seventh edition of the international union against cancer classification for patients with gastric cancer: the Western experience of patients treated in a single-center European institution

PURPOSE

Validity of the seventh edition of the American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) staging systems for gastric cancer has been evaluated in several studies, mostly in Asian patient populations. Only few data are available on the prognostic implications of the new classification system on a Western population. Therefore, we investigated its prognostic ability based on a German patient cohort.

PATIENTS AND METHODS

Data from a single-center cohort of 1,767 consecutive patients surgically treated for gastric cancer were classified according to the seventh edition and were compared using the previous TNM/UICC classification. Kaplan-Meier analyses were performed for all TNM stages and UICC stages in a comparative manner. Additional survival receiver operating characteristic analyses and bootstrap-based goodness-of-fit comparisons via Bayesian information criterion (BIC) were performed to assess and compare prognostic performance of the competing classification systems.

RESULTS

We identified the UICC pT/pN stages according to the seventh edition of the AJCC/UICC guidelines as well as resection status, age, Lauren histotype, lymph-node ratio, and tumor grade as independent prognostic factors in gastric cancer, which is consistent with data from previous Asian studies. Overall survival rates according to the new edition were significantly different for each individual's pT, pN, and UICC stage. However, BIC analysis revealed that, owing to higher complexity, the new staging system might not significantly alter predictability for overall survival compared with the old system within the analyzed cohort from a statistical point of view.

CONCLUSION

The seventh edition of the AJCC/UICC classification was found to be valid with distinctive prognosis for each stage. However, the AJCC/UICC classification has become more complex without improving predictability for overall survival in a Western population. Therefore, simplification with better predictability of overall survival of patients with gastric cancer should be considered when revising the seventh edition.

Can the tumor deposits be counted as metastatic lymph nodes in the UICC TNM staging system for colorectal cancer?

OBJECTIVE

The 7th edition of AJCC staging manual implicitly states that only T1 and T2 lesions that lack regional lymph node metastasis but have tumor deposit(s) will be classified in addition as N1c, though it is not consistent in that pN1c is also an option for pT3/T4a tumors in the staging table. Nevertheless, in this TNM classification, how to classify tumor deposits (TDs) in colorectal cancer patients with lymph node metastasis (LNM) and TDs simultaneously is still not clear. The aim of this study is to investigate the possibility of counting TDs as metastatic lymph nodes in TNM classification and to identify its prognostic value for colorectal cancer patients.

METHODS AND RESULTS

In this retrospective study, 513 cases of colorectal cancer with LNM were reviewed. We proposed a novel pN (npN) category in which TDs were counted as metastatic lymph nodes in the TNM classification. Cancer-specific survival according to the npN or pN category was analyzed using Kaplan-Meier survival curves. Univariate and multivariate analyses were performed to identify significant prognostic factors. Harrell's C statistic was used to test the predictive capacity of the prognostic models. The results revealed that the TD was a significant prognostic factor in colorectal cancer. Univariate and multivariate analyses uniformly indicated that the npN category was significantly correlated with prognosis. The results of Harrell's C statistical analysis demonstrated that the npN category exhibited a superior predictive capacity compared to the pN category of the 7th edition TNM classification. Moreover, we also found no significant prognostic differences in patients with or without TD in the same npN categories.

CONCLUSIONS

The counting of TDs as metastatic lymph nodes in the TNM classification system is potentially superior to the classification in the 7th edition of the TNM staging system to assess prognosis and survival for colorectal cancer patients.