Prognostic value of extracapsular invasion and fibrotic focus in single lymph node metastasis of gastric cancer

EMT-related genes are unlikely to be involved in extracapsular growth of lymph node metastases in gastric cancer

BACKGROUND

In gastric cancer (GC), extracapsular growth (ECG) pattern of lymph node metastases is associated with decreased overall survival rates compared to intracapsular lymph node metastases (ICG). Epithelial-to-mesenchymal transition (EMT) plays a pivotal role in hematogenous metastatic spread. Aim of the present study was to analyze if EMT related genes are involved in the growth pattern of lymph node metastases in GC.

METHODS

Out of our prospective database with 529 patients who underwent surgical resection for GC between 2002 and 2014 forty lymph node positive patients were identified (20 ECG, 20 ICG). The expression of 84 EMT-associated genes were analyzed by RT2 Profiler PCR Array (n = 20). Results were validated by Real-Time PCR (n = 20).

RESULTS

GC with ECG showed differently expressed EMT related genes. GC leading to ECG showed an upregulation of three and downregulation of eleven genes. Those differences, however, could not be confirmed in PCR analysis.

CONCLUSIONS

This study demonstrates that EMT related genes are not responsible for the different growth patterns of lymph node metastases in GC. Further studies are required to evaluate the underlying mechanisms of ECG in GC as it might provide a potential therapeutic target for this subgroup of more aggressive tumors in the future.

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.

Accuracy of MRI for nodal restaging in rectal cancer: a retrospective study of 166 cases

AIM

Assessing metastatic mesorectal nodal involvement is a challenge in rectal cancer, especially in the post chemoradiation setting. We aim to assess the accuracy of MRI for nodal restaging and the validity of SAR criteria (≥ 5 mm size being metastatic).

MATERIALS AND METHODS

This was an IRB-approved retrospective study of 166 patients with locally advanced rectal cancers, operated after neoadjuvant treatment. Two dedicated oncoradiologists reviewed the 166 post-chemoradiation presurgical MRIs in consensus. Nodal size and morphology (shape, margins, and signal intensity) were noted. The most accurate cut-off for size for predicting positive pN status was determined using the Youden index.

RESULTS

MRI understaged 30/166 (18%) and overstaged 40/166 (24%) patients using the SAR criteria. The most accurate cut-off for node size was 5.5 mm, with a sensitivity of 75%, specificity of 60.2%, PPV of 40.7%, NPV of 86.9% (95% CI:78-92.5%), accuracy of 64.2%, and area under the curve (AUC) 0.657 (95% CI-0.524-0.79). Morphological characteristics were not significant to determine involvement, with positive nodes including 42% of round and 31% of oval nodes, 40% of heterogeneous and 45% of homogeneous nodes, and 31% irregularly marginated and 46% nodes with regular margins being positive on pathology. MRI was accurate in predicting pathology for mucinous nodes in 9/29 (31%) cases. Seven cases which were yN2 on MRI and yN0 on pathology demonstrated mucinous changes on MRI and had acellular mucin on histopathology.

CONCLUSIONS

MRI has good negative predictive value, poor positive predictive value and moderate accuracy in nodal restaging. The cut-off of 5.5 mm demonstrated in our study is close to the SAR cut-off of 5 mm in the post-treatment setting. MRI accuracy is lower in patients with mucinous nodes.

Impact of Extracapsular Extension of Lymph Node in Adenocarcinoma of the Stomach

BACKGROUND

Extracapsular extension (ECE) of lymph node may have important prognostic impact for patients with adenocarcinoma of the stomach, but it generally is ignored in staging systems and prognostic models. This study aimed to examine the impact that ECE of lymph node has on prognosis for patients with adenocarcinoma of the stomach.

METHODS

The study analyzed 321 consecutive patients with gastric cancer who underwent radical gastrectomy between January 2008 and December 2015. None of these patients had distant metastases. Lymph node metastases were found in 187 patients. The ECE grade was evaluated according to the previously described system used in head and neck cancers. Deposits of cancer cells in sub-serosal fat without a recognizable lymph node were classified as ECE grade 4. Survival outcomes were compared using Kaplan-Meier and Cox regression analyses. A nomogram was constructed using identified significant prognostic factors. The predictive accuracy and model performance were measured by the concordance index (C-index).

RESULTS

Patients with ECE(+) showed significantly worse 3-year overall survival (OS) and disease-free survival (DFS) than those without ECE. In the sensitivity analysis, ECE had independent prognostic value for both 3-year OS and 3-year DFS, whereas ECE grading showed little impact on mortality trend or disease progression trend. The ECE-based nomogram showed a significantly higher C-index than the pathological tumor and node staging (pTN) staging system.

CONCLUSIONS

The adverse prognostic impact of ECE was validated. Sub-serosal tumor deposits without recognizable lymph node tissue are recommended for inclusion in the ECE definition. A nomogram involving ECE could provide better individual prediction of survival for patients with lymph node-positive gastric cancer.

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.

The Prognostic Impact of Extracapsular Lymph Node Involvement in Esophageal Squamous Cell Carcinoma

BACKGROUND

The role of extracapsular lymph node involvement (ELNI) in esophageal cancer has not been fully investigated. We aim to assess its incidence and prognostic significance in patients with esophageal squamous cell carcinoma (ESCC) treated with and without neoadjuvant treatments.

METHODS

Data of patients who underwent esophagectomy for ESCC in a single medical center was retrospectively reviewed. Patients with positive lymph node involvement were classified as either with ELNI or without ELNI (intracapsular lymph node involvement, ILNI). The impact of ELNI on overall survival (OS), disease-free survival (DFS), and disease recurrence was analyzed.

RESULTS

A total of 336 patients, including 179 without (NCRT -) and 157 with (NCRT +) neoadjuvant chemoradiotherapy, were included. Seventy-two of 179 (40.2%) patients in NCRT - group were with positive lymph node, of whom 19 (26.4%) had ELNI, whereas 49 (31.2%) patients in NCRT + group had positive lymph node, of whom 25 (51.0%) had ELNI. In NCRT + group, patients with ELNI had worse outcome compared to those with ILNI in 5-year OS (10.4 vs. 13.8%, p = 0.008), and DFS (5.3 vs. 17.5%, p = 0.008). The presence of ELNI was also associated with more distant recurrence (p = 0.03). In contrast, there was no survival difference between patients with ELNI and ILNI in NCRT - group.

CONCLUSIONS

Compared with ILNI, ELNI is a significant poor prognostic factor in patients with ESCC treated with neoadjuvant treatments, but not in those with primary surgery.

Prognostic value of fibrosis ratio in metastatic lymph nodes of node-positive advanced gastric cancer

Lymph node metastasis plays a crucial role in predicting prognosis in advanced gastric cancer (AGC). In the present study, we formulated a fibrosis ratio (FR), defined as the number of metastatic lymph nodes with fibrosis divided by the total number of lymph nodes, and sought to determine whether it can be used to predict the prognosis of patients with AGC and improve on existing node staging. We retrospectively analyzed 161 patients who underwent curative resection for node-positive AGC between 2001 and 2010, evaluating the association between FR, lymph node ratio (LNR), and micrometastasis, and the relationship between FR and clinicopathologic findings, overall survival (OS) and disease-free survival (DFS). A high FR was significantly related to T stage (P < .001), N stage (P < .001), tumor stage (P < .001), lymphatic invasion (P < .001), and venous invasion (P = .007). FR was significantly correlated with an increased number of metastatic lymph nodes (P = .001, R = 0.869) and LNR (P = .001, R = 0.943), but not with total harvested lymph nodes. Patients with micrometastases had a lower FR, compared with those without micrometastases (P < .001). A survival analysis showed poor OS for patients in the entire cohort (P < .001); N1 (P = .002), N2 (P = .004), N3a (P = .010), and N3b (P = .003) stages; and groups with high LNR (P = .013) and low LNR (P = .001). DFS was also poor for the entire cohort (P < .001) and the N2 (P = .013), N3b (P = .002), high-LNR (P = .036), and low-LNR (P = .001) groups, but not the N1 or N3a group. Univariate and multivariate analyses revealed that high FR was an independent prognostic factor for OS (hazard ratio [HR], 2.780; CI, 1.655-4.670; P < .001) and DFS (HR, 2.051; CI, 1.199-3.508; P = .009) in AGC. Collectively, our findings indicate that high FR is associated with adverse clinicopathologic parameters in AGC, clearly establishing nodal fibrosis as a pathological finding with value in predicting poor prognosis of patients with AGC. Thus, combining current N stage and LNR diagnostics with FR could improve prognostic prediction in AGC.

Extranodal Extension of Nodal Metastases Is a Poor Prognostic Indicator in Gastric Cancer: a Systematic Review and Meta-analysis

INTRODUCTION

The extranodal extension (ENE) of nodal metastases (the extension of neoplastic cells through the nodal capsule into the perinodal soft tissue) is a histological feature that has been considered a prognostic factor in several cancers, but the role in gastric cancer was not yet investigated. We aimed to investigate the prognostic role of ENE in patients affected by gastric cancer through a systematic review and meta-analysis.

MATERIAL AND METHODS

Two independent authors searched major databases until 09/30/2015 to identify studies providing data on gastric cancer patients' prognostic parameters and comparing patients with ENE (ENE+) vs intra-nodal extension (ENE-). The data were summarized using risk ratios (RRs) for the number of deaths/recurrences and hazard ratios (HRs) with 95 % confidence intervals (CI), adjusted for potential confounders.

RESULTS

Nine studies followed up 3250 patients with gastric cancer (1064 ENE+ and 2186 ENE-). ENE+ was associated with a significantly higher risk of all-cause mortality (RR = 1.70; 95 % CI: 1.43-2.03, I (2) = 66 %; HR = 2.14; 95 % CI: 1.66-2.75, I (2) = 0 %), cancer-specific mortality (RR = 1.59; 95 % CI: 1.42-1.79; HR = 1.52; 95 % CI: 1.19-1.96), and disease recurrence (RR = 3.43, 95 % CI: 1.80-6.54, I (2) = 0 %).

DISCUSSION

Judging from our results, ENE in gastric cancer patients should be considered for prognostic purposes from the gross sample to the pathology report.

Extracapsular invasion of sentinel lymph nodes is not associated with disease recurrence in breast cancer

The purpose of this study was to evaluate the presence of extracapsular invasion (ECI) in positive sentinel lymph nodes (SLNs) as a predictor of disease recurrence in breast cancer. SLN biopsy was performed on 318 breasts of 316 breast cancer patients, of which 50 (15.7%) had positive SLNs. Six (12.0%) of these 50 cases had disease recurrence. The clinicopathologic features of these cases were reviewed. The ECI at SLNs was not significantly associated with disease recurrence. The recurrence-free interval by Kaplan-Meier curves did not differ significantly among patients with and without ECI at SLNs. On the other hand, metastasis at non-SLNs was observed in 12 cases (24.0%) among the 50 cases with positive SLNs, and in the non-SLN metastasis group there were 7 patients with ECI at non-SLNs. Three of 7 cases with ECI at non-SLNs had disease recurrence and none of those 5 without ECI at non-SLNs had disease recurrence. Our current study suggests that the presence of ECI at metastatic SLNs is not associated with recurrent disease in breast cancer. Our results also imply that patients with ECI at positive non-SLNs have a high risk of disease recurrence.

Prognostic value of PPM1D in 800 gastric cancer patients

Protein phosphatase magnesium‑dependent 1 delta (PPM1D) has recently been associated with tumor biology. However, the expression pattern and clinical significance of PPM1D in gastric cancer (GC) have yet to be elucidated. The present study aimed to investigate the clinical and prognostic significance of PPM1D in GC. PPM1D expression was assessed in 800 patients with GC using immunohistochemistry and tissue samples were divided into a PPM1D‑positive and ‑negative group. The correlation between PPM1D expression and clinicopathological parameters or prognosis was investigated. PPM1D expression was significantly higher in GC tissue than in adjacent normal tissue (48 versus 9.5%; P<0.001). PPM1D positivity was significantly correlated with nodal status, distant metastasis and vascular invasion. Survival analysis indicated that the five‑year survival rate in the PPM1D‑positive group was significantly lower than that in the PPM1D‑negative group (41 versus 72%; p=0.0012). Furthermore, the association between PPM1D positivity and survival rate was still significant following regulation of other prognostic markers in a multivariate analysis [hazard ratio (HR), 6.572; 95% confidence interval (CI), 3.108‑13.471; P=0.0018]. In conclusion, the present study suggested that PPM1D positivity is associated with GC invasion and metastasis, and proposed PPM1D positivity as an indicator of unfavorable prognosis in patients with GC.

Carcinoma-associated fibroblasts provide operational flexibility in metastasis

Malignant cancer cells do not act as lone wolves to achieve metastasis, as they exist within a complex ecosystem consisting of an extracellular matrix scaffold populated by carcinoma-associated fibroblasts (CAFs), endothelial cells and immune cells. We recognize local (primary tumor) and distant ecosystems (metastasis). CAFs, also termed myofibroblasts, may have other functions in the primary tumor versus the metastasis. Cellular origin and tumor heterogeneity lead to the expression of specific markers. The molecular characteristics of a CAF remain in evolution since CAFs show operational flexibility. CAFs respond dynamically to a cancer cell's fluctuating demands by shifting profitable signals necessary in metastasis. Local, tissue-resident fibroblasts and mesenchymal stem cells (MSCs) coming from reservoir sites such as bone marrow and adipose tissue are the main progenitor cells of CAFs. CAFs may induce awakening from metastatic dormancy, a major cause of cancer-specific death. Cancer management protocols influence CAF precursor recruitment and CAF activation. Since CAF signatures represent early changes in metastasis, including formation of pre-metastatic niches, we discuss whether liquid biopsies, including exosomes, may detect and monitor CAF reactions allowing optimized prognosis of cancer patients.

The rationale for targeting the LOX family in cancer

The therapeutic targeting of extracellular proteins is becoming hugely attractive in light of evidence implicating the tumour microenvironment as pivotal in all aspects of tumour initiation and progression. Members of the lysyl oxidase (LOX) family of proteins are secreted by tumours and are the subject of much effort to understand their roles in cancer. In this Review we discuss the roles of members of this family in the remodelling of the tumour microenvironment and their paradoxical roles in tumorigenesis and metastasis. We also discuss how targeting this family of proteins might lead to a new avenue of cancer therapeutics.

Evaluation of extra capsular lymph node involvement in patients with extra-hepatic bile duct cancer

Background

Lymph node metastasis is one of the most important prognostic factors for extra-hepatic bile duct carcinoma (ExHBDC). Extra capsular lymph node involvement (ExCLNI) is the extension of cancer cells through the nodal capsule into the perinodal fatty tissue. The prognostic impact of ExCLNI has been shown to be significant mainly in head and neck malignancies. Recently, the prognostic impacts of ExCLNI have evaluated in gastrointestinal malignancies. However no data is available regarding the incidence and prognostic significance of extra-capsular lymph node involvement (ExCLNI) in resectable ExHBDCs. The aim of the present study is first to evaluate the incidence of ExCLNI in surgically-treated ExHBDCs and second, to determine the prognostic impact of ExCLNI in patients with surgically-treated ExHBDCs.

Methods

A total of 228 patients (110 cases of hilar cholangiocarcinoma and 118 cases of distal cholangiocarcinoma) with surgically-treated ExHBDCs were included in this retrospective study. ExCLNI was defined as the extension of cancer cells through the nodal capsule into the perinodal fatty tissue. The existence of ExCLNI and its prognostic value were analyzed as a subgroup of lymph node metastasis.

Results

ExCLNI was detected in only 22% of patients with lymph node metastasis of surgically-treated ExHBDC. The presence of ExCLNI correlated with distal cholangiocarcinoma (p = 0.002). On univariate analysis for survival, perineural invasion, vascular invasion, histological grade, and lymph node metastasis were statistically significant factors. On multivariate analysis, only lymph node metastasis was identified as a significant independent prognostic factor in patients with resectable ExHBDC. Subgroups of lymph node metastasis including the presence of ExCLNI, location of lymph node metastasis, and the number of lymph node metastasis had no statistically significant impact on survival.

Conclusion

ExCLNI was present in only 22% of the LNM (7% of overall patients) in patients with surgical treated ExHBDCs. And ExCLNI would have no impact on the survival of patients with surgically-treated ExHBDCs.

Automating the tracking of lymph nodes in follow-up studies of thoracic CT images

The study of lymph node features over time is of great clinical significance. Tracking of the same lymph node in CT images over time is done manually in the current clinical practice, which is tedious and lack of consistency. In this paper, we propose a search scheme to automate the process. Regions of interest (ROIs) are located by mapping the center point of lymph node based on the transformation found in the rigid registration. Similarity values between ROI of the template image and ROIs of repository images are compared, the highest of which decides the best match. Our method generated a success rate of 82% in determining the corresponding image in follow-up scan with the same lymph node as in baseline. The location of the lymph node in the corresponding image is tracked and estimated by mapping the lymph node center at baseline image using the transformation obtained from both affine and free-form deformation (FFD) registration. FFD performs better than affine registration in tracking the lymph node location. All lymph nodes in our study are tracked successfully by the suggested points which fall within the boundary of the same node in the corresponding follow-up images using FFD registration.

Process of distant lymph node metastasis in colorectal carcinoma: implication of extracapsular invasion of lymph node metastasis

BACKGROUND

We previously demonstrated that extracapsular invasion (ECI) at a metastatic sentinel node was significantly associated with the presence of positive non-sentinel nodes in patients with breast cancer. However, the mechanism of metastatic spreading of tumor cells to distant lymph nodes in patients with colorectal carcinoma is not fully understood. In this study, we investigated the factors that may determine the likelihood of additional regional lymph node metastasis when metastasis is found in nodes at the N1 site in colorectal cancer, especially focusing on the presence of ECI.

METHODS

Two hundred and twenty-eight consecutive patients who underwent colorectal resection were identified for inclusion in this study, of which 37 (16.2%) had positive lymph nodes at the N1 site. Six of these 37 cases had additional metastasis in N2 site lymph nodes. We reviewed the clinicopathological features of these cases and performed statistical analysis of the data.

RESULTS

In the univariate analysis ECI at the N1 site was the only factor significantly associated with the presence of cancer cells in the N2 site. Other factors, including number of positive lymph nodes, lymphovascular invasion of the primary tumor, tumor size and tumor depth of invasion, were not associated with metastatic involvement at the N2 site.

CONCLUSIONS

Our results suggest that the presence of ECI at metastatic lymph nodes at the N1 site is correlated with further metastasis at the N2 site. These findings imply the possibility that ECI might indicate the ability of colorectal tumor cells to disseminate to distant lymph nodes.

Extracapsular invasion as a risk factor for disease recurrence in colorectal cancer

AIM: To evaluate the presence of extracapsular invasion (ECI) in positive nodes as a predictor of disease recurrence disease in colorectal cancer.

METHODS: Two hundred and twenty-eight consecutive patients who underwent colorectal resection were identified for inclusion in this study, of which 46 had positive lymph nodes. Among 46 cases with stage IIIcolorectal cancer, 16 had ECI at positive nodes and 8 had disease recurrence. The clinical and pathological features of these cases were reviewed.

RESULTS: In the univariate analysis, the number of positive lymph nodes and depth of tumor invasion were significantly associated with the presence of ECI at positive nodes. Multivariate analysis demonstrated that only ECI was a predictor of recurrence. The recurrence-free interval differed significantly among patients with ECI at positive nodes.

CONCLUSION: Our results suggest that ECI at metastatic nodes can identify which cases are at high risk of short-term disease recurrence in colorectal cancer.

Gastrointestinal cancer metastasis and lymphatic advancement

The role of angiogenesis in the growth of solid tumors is well established, but the role of lymphatic vessels and the relationship between lymphangiogenesis and tumor spread are less clear. Recently, the molecular pathway that signals lymphangiogenesis and specific markers for lymphatic endothelium have been discovered; however, the lymphatic pathway of cancer metastasis is only partly clarified. Several investigators from the mid 20th century indicated the existence of lymphatico-venous communications, and some observed the retrograde filling of lymph flow and lymphatico-venous communication in obstructive lymphopathy. In the 1960s Burn reported the importance of lymphovenous communication in his clinical and animal experimental data. Thus, the role of potential peripheral lymphatico-venous communication must be considered in the mechanism of cancer metastasis. We observed the lymphatico-venous (portal) communication, as well as lymph retention and reflux, in a rat model of mesenteric lymph vessel obstruction. Based on the phenomenon of lymphatico-venous communication and lymph flow reflux by lymphatic obstruction, we speculate that tumor cell obstruction in the lymph system will lead to the establishment of liver and/or peritoneal metastasis. Clinically, we observed extranodal cancer invasion in a model of lymphatic obstruction, and noted a strong relationship between extranodal invasion and liver or peritoneal metastasis. Thus, the existence of peritoneal and liver metastasis via a lymphatic pathway should be considered.

Extracapsular lymph node spread: a new prognostic factor in gastric cancer

BACKGROUND

Lymphatic spread is 1 of the most relevant prognostic factors for gastric carcinoma. The current International Union Against Cancer (UICC) pN staging system is based on the number of metastatic lymph nodes and does not take into consideration the characteristics of the metastatic lymph nodes itself. The aim of the current study was to examine the prognostic value of extracapsular lymph node involvement in gastric cancer and to find correlations with clinicopathological parameters.

METHODS

Tissue samples were obtained from 159 gastric cancer patients who underwent gastrectomy with D2-lymphadenectomy in 142 (89.3%) cases and subtotal gastrectomy with D2-lymphadenectomy in 17 (10.7%) cases. The number of resected lymph nodes, number of metastatic lymph nodes, and number of metastatic lymph nodes with extracapsular lymph node involvement were determined. Extracapsular spread was defined as infiltration of cancer cells beyond the capsule of the metastatic lymph node.

RESULTS

Ninety-six (60.4%) patients had lymph node metastasis. In 57 (35.8%) cases, extracapsular lymph node involvement was also detected. Extracapsular lymph node involvement was significantly associated with higher pN-category (P < .001), higher pM category (P = .048), and higher UICC stages (P = .001). According to the Kaplan-Meier log-rank statistical method, extracapsular lymph node involvement was significantly associated with poor survival (P = .001). In the multivariate analysis besides pT (P < .001) and R-category (P = .009), extracapsular lymph node involvement also remained as an independent prognostic factor (P = .003), whereas the UICC pN-category (P = .822) lost its prognostic value.

CONCLUSIONS

Extracapsular lymph node involvement is associated with higher tumor stages and is an independent negative prognostic factor in gastric cancer. In future staging systems for gastric cancer, extracapsular lymph node involvement should be considered.