Evaluation of the New American Joint Committee on Cancer/International Union against cancer classification of lymph node metastasis from gastric carcinoma in comparison with the Japanese classification

Refining gastric cancer staging: examining the interplay between number and anatomical location of metastatic lymph nodes - a retrospective multi-institutional study

BACKGROUND

The current gastric cancer staging system relies on the number of metastatic lymph nodes (MLNs) for nodal stage determination. However, incorporating additional information such as topographic status may help address uncertainties. This study evaluated the appropriateness of the current staging system and relative significance of MLNs based on their anatomical location.

METHODS

Patients who underwent curative gastrectomy for gastric cancer between 2000 and 2019 at six Catholic Medical Center-affiliated hospitals were included. Lymph node-positive patients were classified into the perigastric (stations 1-6, group P) or extragastric (stations 7-12) groups. The extragastric group was further subdivided into the near-extragastric (stations 7-9, group NE) and far-extragastric (stations 10-12, group FE) groups.

RESULTS

We analyzed the data of 3,591 patients with positive lymph node metastases. No significant survival differences were found between group P and the extragastric group in each N stage. However, in N1 and N2, group FE showed significantly worse survival than the other groups (p = 0.013 for N1, p < 0.001 for N2), but not in N3. In the subgroup analysis, group FE had a significantly lower overall survival in N2, regardless of the cancer location.

CONCLUSIONS

Our large-scale multi-institutional big data analysis confirmed the superiority of the current numerical nodal staging system for gastric cancer. Nonetheless, in N1 and N2 in which there is an upper limit on metastatic nodes, attention should be paid to the potential significance of topographic information for specific nodal stations.

Prognostic Value of the Anatomic Region of Metastatic Lymph Nodes in the Current TNM Staging of Gastric Cancer

Purpose

The numeric N stage has replaced the topographic N stage in the current tumor node metastasis (TNM) staging in gastric carcinoma. However, the usefulness of the topographic N stage in the current TNM staging system is uncertain. We aimed to investigate the prognostic value of the topographic N stage in the current TNM staging system.

Materials and Methods

We reviewed the data of 3350 patients with gastric cancer who underwent curative gastrectomy. The anatomic regions of the metastatic lymph nodes (MLNs) were classified into 2 groups: perigastric and extra-perigastric. The prognostic value of the anatomic region was analyzed using a multivariate prognostic model with adjustments for the TNM stage.

Results

In patients with lymph node metastasis, extra-perigastric metastasis demonstrated significantly worse survival than perigastric metastasis alone (5-year survival rate, 39.6% vs. 73.1%, respectively, P<0.001). Extra-perigastric metastasis demonstrated significantly worse survival within the same pN stage; the multivariate analysis indicated that extra-perigastric metastasis was an independent poor prognostic factor (hazard ratio=1.33; 95% confidence interval=1.01–1.75). The anatomic region of the MLNs improved the goodness-of-fit (likelihood ratio statistics, 4.57; P=0.033) of the prognostic model using the TNM stage.

Conclusions

The anatomic region of MLNs has an independent prognostic value in the numeric N stage in the current TNM staging of gastric carcinoma.

Critical number of lymph node involvement in esophageal and gastric cancer and its impact on long-term survival-A single-center 8-year study

BACKGROUND

Nodal disease in esophageal and gastric cancer is associated with poor survival.

OBJECTIVES

To determine the critical level of lymph node involvement where survival becomes significantly compromised.

METHODS

Survival analyses using multivariable Cox regression and receiver operator characteristics (ROC) were undertaken to determine what number of positive lymph nodes were most sensitive and specific in predicting survival.

RESULTS

A total of 317 patients underwent esophagectomy (n = 190, 59.9%) and gastrectomy (n = 127, 40.1%) for adenocarcinoma. At multivariable analyses, four nodes positivity (irrespective of T-category) was associated with nearly a fivefold increased risk of mortality when compared to node-negative patients (hazard ratio [HR], 4.9; interquartile range 2.0-11.5; P < .001). A positive ratio of up to 50.0% was not associated with worse survival than having four nodes positive (HR, 4.6; 95% confidence interval, 2.6-8.1; P < .001). ROC analysis demonstrated four lymph nodes positive to have a sensitivity of 80.5%, a specificity of 60.1%, and an accuracy of 77.8 (P < .001).

CONCLUSION

The absolute number of nodes positive for cancer is more important than the proportion of positive nodes in predicting survival in esophageal/gastric cancer. Four positive lymph nodes are associated with a fivefold increase in mortality. Beyond this, increasing numbers of positive lymph nodes make no appreciable difference to survival.

What is the Role of Nodal Ratio as a Prognostic Factor for Gastric Cancer Nowadays? Comparison with New TNM Staging System and Analysis According to the Number of Resected Nodes

Nodal ratio (NR) has been demonstrated to be an important prognostic factor in patients with gastric cancer. The aim of this study is to evaluate the prognostic role of nodal ratio comparing it with the new TNM (2010) classification. One hundred forty-two patients were submitted to potentially curative gastrectomy for cancer. Patients with low performance status underwent D1.5 lymphadenectomy, whereas the other patients underwent D2–D2.5 lymphadenectomy. Nodal staging was classified according to 2010 International Union Against Cancer/American Joint Committee on Cancer classification. Kaplan-Meier method was used to evaluate survival, stratified for nodal classes and nodal status. Total gastrectomy was performed in 39 per cent of cases and distal gastrectomy in 61 per cent. Mean number of resected nodes was 25.5. Whereas N status was strictly related to the number of resected nodes, the NR was independent from the extension of the lymphadenectomy. Overall five-year survival was 81 per cent for N0 patients, 72 per cent for N1, and 26 and 23 per cent for N2 and N3, respectively. Patients with NR0 had 81 per cent five-year survival, whereas NR1 67 per cent, NR2 51 per cent, and NR3 22 per cent. NR seems to be a simple method to predict the prognosis of patients with gastric cancer; unlike N status, it is independent from the number of resected nodes, and therefore it is particularly useful in case of inadequate lymphadenectomy.

Topographic lymph node staging system shows prognostic superiority compared to the 8th edition of AJCC TNM in gastric cancer. A western monocentric experience

INTRODUCTION

The current Tumor Node Metastasis staging system (TNM) for gastric cancer classifies the extent of lymph node metastasis based upon the number of lymph nodes involved. Choi et al. have recently proposed a new anatomical classification based upon the regionality of the involved nodes. This new classification seems to have a better predictive prognostic value than the traditional one. We investigated the prognostic role of the new anatomical based classification, reviewing our institutional gastric cancer database.

METHODS

We performed a retrospective chart review of 329 patients who underwent gastrectomy at our Institution from 2003 to 2017. We excluded from data analysis any patient with distant metastases at the time of first diagnosis and or surgery, pathology other than adenocarcinoma, lymphadenectomy less than D2, impossibility to identify location of lymph nodes (LNs) on pathological report and neoadjuvant chemotherapy. The extent of D2 lymphadenectomy was defined according to Japanese Gastric Cancer Association criteria. LN metastasis were reclassified into three topographic groups (lesser, greater curvature, and extraperigastric nodes) and staged according to Choi. The new N stage was combined with the current pT according to the 8th edition of TNM and a new hybrid TNM stage was established. All patients were followed up until June 2019. The prognostic performance of the new stage and of the current anatomical numeric based system (TNM) was analyzed and assessed by the C-index, AIC and likelihood ratio χ² value.

RESULTS

In predicting both Overall Survival (OS) and Disease free Survival (DFS) the new N stage and the new TNM staging system had the highest C-index and likelihood ratio χ2 value and the lowest Akaike Information Criterion (AIC), showing a better accuracy and displaying a better prognostic performance.

CONCLUSIONS

Our study is the first from the Western world to compare the new hybrid classification, based on the anatomical location of metastatic nodes, to the 8th of American Joint Committee on Cancer (AJCC) TNM staging system. Our findings on a small, monocentric sample suggest that hybrid topographic lymph node staging system is more accurate than TNM.

Negative lymph node count as an independent prognostic factor in stage III patients after curative gastrectomy: A retrospective cohort study based on a multicenter database

OBJECTIVE

To examine the prognostic value of negative lymph node (NLN) count in stage III gastric cancer (GC) patients after curative gastrectomy.

METHODS

The clinicopathological data of 2942 stage III patients who underwent curative gastrectomy between 2001 and 2011 were analyzed. Only patients with ≥16 examined lymph nodes (ELNs) were included. After cut-point survival analysis, the 2942 patients were divided into three subgroups with NLN counts of 0, 1-9, and ≥10. Survival differences among the subgroups were analyzed to assess the effects of NLN count on stage migration and overall survival (OS) in stage III GC patients. Spearman's correlation coefficient was used to assess the relationships between the ELN count and the positive lymph node (PLN) count, the ELN count and the NLN count, and the NLN count and the PLN count.

RESULTS

Survival analyses revealed that the NLN count was significantly associated with OS (P = 0.001) and was an independent predictor (P < 0.01) of prognosis in stage III GC patients. Subgroup analysis showed that the prognostic evaluation accuracy was highest when the NLN count was ≥10 for stage III patients. Stage migrations were mainly detected in the following pathological tumor-node (pTN) subgroups: pT2N3a with 1-9 NLNs and pT2N3b with ≥10 NLNs, and pT3N3a with 1-9 NLNs and pT3N3b with ≥10 NLNs. NLN count was positively correlated with the ELN and the PLN counts for pT2N3 and pT3N3 stage GC patients (r = 0.694 and r = 0.881 for pT2N3 patients; r = 0.685 and r = 0.902 for pT3N3 patients, respectively; P < 0.001). These findings indicate that the NLN count may be a useful prognostic predictor in stage III GC patients.

CONCLUSIONS

The NLN count may improve the prognostic prediction efficiency of the tumor-node-metastasis (TNM) classification for GC, especially for stage III patients, and should be recommended for clinical applications.

A modified subclassification to evaluate the survival of patients with N3 gastric cancer: an international database study

BACKGROUND

The eighth TNM classification for gastric cancer categorizes N3 as N3a and N3b in the final pathologic stage. The cutoff for N3a/N3b is defined as 15 metastatic lymph nodes, but the rationale for this cutoff remains unclear. This study aimed to determine the optimal N3a/N3b cutoff and evaluate its prognostic significance.

METHODS

An international database was constructed by combining data from patients with N3 gastric cancer and complete five-year follow-up data from the Surveillance, Epidemiology, and End Results program database (n = 1833) and the Fujian Medical University Union Hospital database (n = 920) (total n = 2753). A log-rank test was performed to determine the optimal N3a/N3b cutoff, and its prognostic significance was confirmed in a two-step multivariate analysis and compared to that of the eighth TNM.

RESULTS

A cut-point analysis performed at each metastatic lymph node number identified the greatest survival difference between N3a and N3b at 13 metastatic lymph nodes (χ² = 157.671, P = 3.65 × 10^- 36). In patients with 14-15 metastatic lymph nodes, prognoses were significantly worse than those in patients with 7-13 metastatic lymph nodes (P < 0.001) but similar to those in patients with > 15 metastatic lymph nodes (P = 0.078). Therefore, patients with 14-15 metastatic lymph nodes were incorporated into a modified N3b classification. In the two-step multivariate analysis, the eighth N3 classification fell out of the model, while the modified N3 classification remained intact (HR 1.51, P < 0.001). Further analyses demonstrated that the modified TNM classification had superior homogeneity, discriminatory ability, and gradient monotonicity compared to the eighth TNM classification.

CONCLUSIONS

For improved prognostic stratification, we recommend adjusting the cutoff for subclassification of N3 gastric cancer to 13 metastatic lymph nodes.

Gastric Cancer: Extent of Lymph Node Dissection and Requirements for a Correct Staging

Aims and Background

Lymphatic spread is an important prognostic factor in gastric cancer. The TNM classification requires at least 15 lymph nodes to stage and identify three prognostic groups according to the number of metastatic lymph nodes: N1 (1-6), N2 (7-15), N3 (>15). The aim of this study was to investigate which type of lymph node dissection allows an accurate staging.

Methods

From 1996 to 2001, we treated 140 gastric cancer patients, 27 with D1 and 113 with D2 dissection. We evaluated lymph node count, status and ratio between metastatic and total number of excised lymph nodes, keeping 20% as the cutoff value.

Results

The mean number of lymph nodes was 18 and 33 respectively for D1 and D2 (P <0.001), 41% of patients in D1 and 5% in D2 had less than 15 lymph nodes (P <0.001). 59% in D1 and 73% in D2 (P = 0.145) had lymph node metastases, but this incidence decreased to 36% (P = 0.045) and 16% (P <0.001) respectively for D, and D2 when less than 15 lymph nodes were available. Considering the ratio between metastatic and total number of lymph nodes, 45% of D1 versus 3% of D2 (P <0.001) in the N1 group exceeded 20%.

Conclusions

D2 lymph node dissection is better than D1 in providing at least 15 lymph nodes required for a correct staging. We confirm the risk of a downstage when less than 15 lymph nodes are available.

Lymphovascular invasion as a predictor for lymph node metastasis and a prognostic factor in gastric cancer patients under 70 years of age: A retrospective analysis

BACKGROUND

Accumulating evidence has confirmed the potential prognostic value of LVI in patients with cancers. This aim of the current study was to clarify the potential relationship between LVI and lymph node metastasis, establish predictive clinicopathologic prognostic factors for LVI and lymph node metastasis, and determine the prognostic significance of LVI for patients younger than 70 years with resected gastric cancer.

METHODS

Overall survival rates were calculated using Kaplan-Meier analysis. Differences in proportions of patients were tested with the χ² test. Univariate and multivariate analyses were applied to identify independent prognostic factors. Logistic regression analysis was employed to identify the risk factors predicting the presence of LVI and LN metastasis.

RESULTS

Univariate analysis led to the identification of tumor size, LVI and pN stage as factors significantly correlated with prognosis. Multivariate analysis demonstrated that tumor size, LVI, pN stage, and number of LNs retrieved are independent prognostic factors for the entire population. Logistic regression analysis proved that LVI and pT stage were significantly associated with LN metastasis.

CONCLUSION

LVI is an independent prognostic factor predicting LN metastasis and a strongly independent predictor of survival for patients with resected gastric cancer. We recommend that LVI should be taken into account as an important adjuvant prognostic factor, specially for pN0 cases with inadequate LNs retrieved. And the maximum number of LNs possible should be retrieved for optimal staging, especially for patients with higher cT stage.

FOXR2 Promotes the Proliferation, Invasion, and Epithelial-Mesenchymal Transition in Human Colorectal Cancer Cells

Forkhead box R2 (FOXR2), a member of the FOX gene family, has not been very well investigated for its role in cancer. A recent study has shown that FOXR2 is highly expressed in breast cancer samples and is associated with poor prognosis. In addition, FOXR2 was identified as an oncogene in medulloblastoma. Nevertheless, whether FOXR2 plays a role in colorectal cancer (CRC) remains unclear. In the present study, we conducted several in vitro and in vivo studies to investigate the expression and effect of FOXR2 in CRC. The study results demonstrated that FOXR2 was upregulated in CRC tissues and cells. Downregulation of FOXR2 inhibited CRC cell proliferation, invasion, and the epithelial-mesenchymal transition (EMT) phenotype in vitro and also suppressed CRC cell growth and metastasis in vivo. Furthermore, downregulation of FOXR2 remarkably reduced the protein expression of Shh, Gli1, and Ptch1 in SW480 cells. Taken together, our data suggested that FOXR2 significantly promoted proliferation, invasion, and EMT of CRC cells. All these findings provided evidence for the role of FOXR2 as an oncogene in CRC development.

Left Gastric Artery Lymph Nodes Should Be Included in D1 Lymph Node Dissection in Gastric Cancer

BACKGROUND

The Japanese Classification of Gastric Carcinoma includes the left gastric artery (#7) lymph nodes (LNs) in the recommended extent of D1 LN dissection, but this recommendation has not been validated in western institutions.

METHODS

We reviewed data from a prospectively maintained database of gastric cancer patients who underwent resection at our academic cancer center and had a separate pathologic assessment of #7 LN in 2005-2016. Risk factors for #7 LN metastases and overall survival were examined by uni- and multivariable analyses.

RESULTS

We identified 173 patients; 114 (66%) were treated with preoperative therapy, most commonly with chemoradiation therapy (47%, 81/173). We identified 22 patients (13%) who had #7 LN metastases, which accounted for 35% (22/63) of node-positive patients. No preoperative factors were associated with #7 LN metastases by univariable analyses. Patients with #7 metastases were not associated with shorter overall survival after adjustment by nodal stage (hazard ratio 1.49, 95% confidence interval 0.67-3.32; p = 0.33).

CONCLUSION

Metastasis to #7 LN station was common in gastric cancer, but the survival impact was not significant after adjustment by nodal stage. We conclude that #7 LNs should be routinely dissected in gastric cancer patients, and this station should be included within the extent of D1 LN dissection.

Down-regulated miRs specifically correlate with non-cardial gastric cancers and Lauren's classification system

BACKGROUND AND OBJECTIVES

Gastric cancers are usually characterized using Lauren's classification into intestinal and diffuse types. We previously documented the down-modulation of miR31, miR148a, miR204, and miR375 in gastric cancers. We aimed this manuscript to investigate these miRs with the end-points of diagnosis, Lauren's classification and prognosis.

METHODS

A total of 117 resected non-cardial adenocarcinomas were evaluated for miRs' expressions. The performance of miRs' expressions for cancer diagnosis was tested using ROC curves. Logistic regression was conducted with the end-point of Lauren's classification. Kaplan-Meier and Cox analyses were performed for OS, DFS, and DSS. miRs' targets were reviewed using PRISMA method and BCL-2 was further investigated in cell lines.

RESULTS

ROC curves documented that miRs' down-modulation was significant in differentiating cancer versus normal tissues. Diffuse type cancers were associated with female sex, young age, and miR375 higher expression. We confirmed BCL-2 as a miR204 target. However, survival analyses confirmed the pathologic criteria (advanced stages, LNR, and low LNH) as the significant variables correlated to worse prognosis.

CONCLUSIONS

The down-modulation of miR31, miR148a, miR204, and miR375 is significantly associated with non-cardial gastric cancers and miR375 is specifically linked to Lauren's classification. Nevertheless, standard pathological features display as the independent variables associated with worse prognosis.

Comparison of the current AJCC-TNM numeric-based with a new anatomical location-based lymph node staging system for gastric cancer: A western experience

Background

In gastric cancer, the current AJCC numeric-based lymph node staging does not provide information on the anatomical extent of the disease and lymphadenectomy. A new anatomical location-based node staging, proposed by Choi, has shown better prognostic performance, thus soliciting Western world validation.

Study design

Data from 284 gastric cancers undergoing radical surgery at the Second University of Naples from 2000 to 2014 were reviewed. The lymph nodes were reclassified into three groups (lesser and greater curvature, and extraperigastric nodes); presence of any metastatic lymph node in a given group was considered positive, prompting a new N and TNM stage classification. Receiver-operating-characteristic (ROC) curves for censored survival data and bootstrap methods were used to compare the capability of the two models to predict tumor recurrence.

Results

More than one third of node positive patients were reclassified into different N and TNM stages by the new system. Compared to the current staging system, the new classification significantly correlated with tumor recurrence rates and displayed improved indices of prognostic performance, such as the Bayesian information criterion and the Harrell C-index. Higher values at survival ROC analysis demonstrated a significantly better stratification of patients by the new system, mostly in the early phase of the follow-up, with a worse prognosis in more advanced new N stages, despite the same current N stage.

Conclusions

This study suggests that the anatomical location-based classification of lymph node metastasis may be an important tool for gastric cancer prognosis and should be considered for future revision of the TNM staging system.

Lymph node ratio as a prognostic factor in patients with pathological N2 non-small cell lung cancer

BACKGROUND

The aim of this study was to investigate whether the lymph node ratio (LNR) was associated with the prognosis of patients, who underwent surgery for pathological N2 non-small cell lung cancer (NSCLC).

METHODS

A total of 182 patients were diagnosed with pathological N2 disease and underwent complete resection surgeries with systematic lymphadenectomies. We counted the number of positives and removed lymph nodes to calculate a ratio between them (LNR). We also investigated the association between skip mediastinal lymph node metastasis and survival.

RESULTS

Univariate analysis of survival in patients with N2 NSCLC showed that the T factor, clinical N factor, and LNR were significant prognostic factors. Multivariate analyses showed that the clinical N stage and LNR were significant independent prognostic factors for patients with pathological N2 NSCLC. Patients with a clinical lymph node status of 0 (cN0) and LNR ≤0.22 showed a significantly higher survival rate than patients with a cN1-2 and LNR ≥0.22 and 5-year survival rates were 47.1 and 10.3%, respectively (p < 0.0001).

CONCLUSIONS

LNR is an important prognostic factor for poor outcome following surgery in patients with N2 disease. The combination of the LNR and cN status provides a valuable prognostic tool.

Applicability of the Proposed Japanese Model for the Classification of Gastric Cancer Location: The "PROTRADIST" Retrospective Study

BACKGROUND

The extension of lymphadenectomy for surgical treatment of gastric cancer remains discordant among European and Japanese surgeons. Kinami et al. (Kinami S, Fujimura T, Ojima E, et al. PTD classification: proposal for a new classification of gastric cancer location based on physiological lymphatic flow. Int. J. Clin. Oncol. 2008;13:320-329) proposed a new experimental classification, the "Proximal zone, Transitional zone, Distal zone" (PTD) classification, based on the physiological lymphatic flow of gastric cancer site. The aim of the present retrospective study is to assess the applicability of PTD Japanese model in gastric cancer patients of our Western surgical department.

METHODS

Two groups of patients with histologically documented adenocarcinoma of the stomach were retrospectively obtained: In the first group were categorized 89 patients with T1a-T1b tumor invasion; and in the second group were 157 patients with T2-T3 category. The data collected were then categorized according to the PTD classification.

RESULTS

In the T1a-T1b group there were no lymph node metastases within the r-GA or r-GEA compartments for tumors located in the P portion, and similarly there were no lymphatic metastases within the l-GEA or p-GA compartments for tumors located in the D portion. On the contrary, in the T2-T3 group the lymph node metastases presented a diffused spreading with no statistical significance between the two classification models.

CONCLUSIONS

Our results show that the PTD classification based on physiological lymphatic flow of the gastric cancer site is a more physiological and clinical version than the Upper, Medium And Lower classification. It represents a valuable and applicable model of cancer location that could be a guide to a tailored surgical approach in Italian patients with neoplasm confined to submucosa. Nevertheless, in order to confirm our findings, larger and prospective studies are needed.

A Lymph Node Staging System for Gastric Cancer: A Hybrid Type Based on Topographic and Numeric Systems

Although changing a lymph node staging system from an anatomically based system to a numerically based system in gastric cancer offers better prognostic performance, several problems can arise: it does not offer information on the anatomical extent of disease and cannot represent the extent of lymph node dissection. The purpose of this study was to discover an alternative lymph node staging system for gastric cancer. Data from 6025 patients who underwent gastrectomy for primary gastric cancer between January 2000 and December 2010 were reviewed. The lymph node groups were reclassified into lesser-curvature, greater-curvature, and extra-perigastric groups. Presence of any metastatic lymph node in one group was considered positive. Lymph node groups were further stratified into four (new N0–new N3) according to the number of positive lymph node groups. Survival outcomes with this new N staging were compared with those of the current TNM system. For validation, two centers in Japan (large center, n = 3443; medium center, n = 560) were invited. Even among the same pN stages, the more advanced new N stage showed worse prognosis, indicating that the anatomical extent of metastatic lymph nodes is important. The prognostic performance of the new staging system was as good as that of the current TNM system for overall advanced gastric cancer as well as lymph node—positive gastric cancer (Harrell C-index was 0.799, 0.726, and 0.703 in current TNM and 0.799, 0.727, and 0.703 in new TNM stage). Validation sets supported these outcomes. The new N staging system demonstrated prognostic performance equal to that of the current TNM system and could thus be used as an alternative.

Hematopoietic pre-B cell leukemia transcription factor interacting protein is overexpressed in gastric cancer and promotes gastric cancer cell proliferation, migration, and invasion

Hematopoietic pre-B cell leukemia transcription factor interacting protein (HPIP) has been shown to play an important role in the development and progression of some cancers. However, the role of HPIP in gastric cancer (GC) is unclear. Here, we show that HPIP is upregulated in most GC patients and promotes GC cell proliferation, migration, and invasion. In GC patients, HPIP positively associates with tumor size and nodal metastasis, and negatively associates with tumor differentiation. Hematopoietic pre-B cell leukemia transcription factor interacting protein increases GC cell proliferation through activation of G1 /S and G2 /M cell cycle transitions, accompanied by a marked increase of the positive cell cycle regulators, including cyclin D1, cyclin A, and cyclin B1. Hematopoietic pre-B cell leukemia transcription factor interacting protein enhances GC cell migration and invasion, and modulates epithelial-mesenchymal transition, which plays a key role in cancer cell migration and invasion. These data underscore the critical role of HPIP in GC cell proliferation and progression and suggest that HPIP inhibition may be a useful therapeutic strategy for GC treatment.

Comparison of the 6th and 7th editions of the AJCC/UICC TNM staging system for gastric cancer focusing on the "N" parameter-related survival: the monoinstitutional NodUs Italian study

Background

A large number of Asian population studies examined the difference between the 6th and the 7th tumor, node, metastasis (TNM) while it is still poorly validated among Caucasian populations. This is a retrospective study aimed at investigating the efficacy of the 7th edition American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system for gastric cancer focusing on the “N” parameter-related survival for prognostic assessment in gastric cancer patients of a single Western high-volume institution.

Methods

From January 2002 to December 2009, the data of 274 patients with gastric cancer who underwent gastric surgery at the 8th General and Gastrointestinal Surgical Centre of the Second University of Naples were analyzed retrospectively. We collected data for patient demographics, tumor characteristics, surgical characteristics, and TNM stage. Particularly, the nodal status, with the number of dissected nodes and metastatic nodes, was reviewed from the pathology records. The same patient dataset was used to stage patients according to both the 6th and 7th edition criteria.

Results

Age at surgery, tumor location, histological grade, Lauren’s classification subtypes, and 6th and 7th AJCC/UICC N categories were found to have statistically significant associations with overall survival on univariate analysis. In the 6th edition staging system, the Kaplan–Meier plot did not show significant overlapped survival curves: significant differences were found between N0 and N1, P < .001; N1 and N2, P = .04; and N2 and N3, P < .001. On the contrary, in the 7th edition, among all five substages, there were similar survival curves between N categories 2 and 3a (P = .98) with a statistically significant discriminatory ability only between N1 versus N3b and N2 versus N3b (P = .02 and .04, respectively).

Conclusions

Based on analysis, we found that several clinicopathological variables, especially histological grade and Lauren’s classification, were significant prognostic factors in our database. The 6th and 7th AJCC/UICC N classifications represent significantly independent prognostic factors, and the 6th AJCC/UICC N classification seems to be superior to the 7th AJCC/UICC N classification in terms of uniformity, differentiation, and monotonicity of gradients.

Factors associated with endoscopic full-thickness resection of gastric submucosal tumors

Objective

To identify factors that impact the procedure and treatment outcomes for endoscopic full-thickness resection (EFTR) of gastric submucosal tumors (SMTs).

Methods

Medical records were collected for all patients with gastric SMTs who underwent EFTR procedures in Shengjing Hospital between June 2012 and April 2014. The data from each patient were reviewed, including gender, age, maximum tumor size on endoscopic ultrasound (EUS), tumor location in stomach, length of EFTR procedure, pneumoperitoneum during EFTR, cost to close defects, length of hospital stay after the procedure, and procedure-related complications.

Results

Endoscopic full-thickness resection of gastric SMTs was successfully performed in all 41 patients. Maximum size on EUS [parameter estimate (PE) = 4.443, 95 % confidence interval (CI) 2.191–6.695; p = 0.000] and tumor location in the greater curvature (PE = 44.441, 95 % CI 5.539–83.343; p = 0.026) were significantly associated with the length of the procedure. A pneumoperitoneum was more likely to occur during EFTR in tumors with a larger EUS size [odds ratio (OR) = 1.415, 95 % CI 1.034–1.936; p = 0.03], and less likely to occur during EFTR for tumors located in the posterior wall (OR = 0.003, 95 % CI 0–0.351; p = 0.017). The use of the over-the-scope clip (OTSC) system was significantly associated with shorter hospital stays (PE = −1.006, 95 % CI −1.998 to −0.014; p = 0.047) and a higher cost of closing defects (PE = 854.742, 95 % CI 358.377–1351.107; p = 0.001).

Conclusions

Endoscopic full-thickness resection is an effective and safe method for removing gastric SMTs. Tumor size on EUS and location of the tumor were associated with the duration of EFTR and the occurrence of a pneumoperitoneum during the procedure. The use of an OTSC system was significantly associated with shorter hospital stays and a higher cost of closing defects.

A new pN staging system based on both the number and anatomic location of metastatic lymph nodes in gastric cancer

BACKGROUND

Our aim was to establish a new pN staging system for gastric cancer based on the number and location of metastatic lymph nodes (MLNs) and to compare it with other systems.

METHODS

We retrospectively analyzed the prognostic data of 521 gastric cancer patients who underwent curative resection. Survival analyses were used to establish a pN staging system that considers both the number and location of MLNs and to compare discriminatory ability and monotonicity of gradients (linear trend χ (2) score), homogeneity ability (likelihood ratio test), and prognostic stratification ability (Akaike information criterion) between Japanese Gastric Cancer Association (JGCA) and Union for International Cancer Control (UICC) systems.

RESULTS

Cut-point survival analysis divided pN(+) patients into two groups: Nxn1~6 and Nxn≥7. N0, N1, N2, and N3 (the previous classifications) were replaced by N0, N1n1~6, N2n1~6, and N1n≥7 + N2n≥7 + N3n1~6 + N3n≥7, respectively. Compared with two widely used staging systems, the new system had the highest likelihood ratio test [106.06 (new) vs 95.09 (JGCA) vs 94.33 (UICC)] and linear trend χ (2) scores [102.30 (new) vs 89.12 (JGCA) vs 86.97(UICC)] and the lowest Akaike information criterion (AIC) score [2,283.88 (new) vs 2,285.31 (JGCA) vs 2,299.88 (UICC)].

CONCLUSION

A new pN staging system based on the number and location of MLNs is an efficient prognostic indicator of the survival of patients with gastric cancer following radical surgery.

Detection of Her-2/neu expression in gastric cancer: Quantitative PCR versus immunohistochemistry

The aim of this study was to compare quantitative polymerase chain reaction (qPCR) with immunohistochemistry (IHC) for the detection of Her-2 in gastric cancer, and to investigate the correlation between the expression levels of human epidermal growth factor receptor 2 (Her-2) and clinical features. Clinical data from 426 cases of gastric cancer were collected. Her-2 expression levels in cancerous tissue were detected using IHC, and the Her-2/neu gene expression levels were determined by qPCR. The correlation between the expression level of Her-2 and clinical features was investigated. The positive expression rate of Her-2 in cancerous tissue detected using qPCR and IHC was 11.17% (46/412) and 13.38% (57/426), respectively. The positive expression of the Her-2 protein/gene was significantly correlated with the depth of invasion and lymphatic metastasis, as well as the TNM stage (P<0.05). No significant correlation was identified between positive expression of the Her-2 protein/gene and tumor location, age, gender, differentiation degree and Lauren classification (P>0.05). The diagnostic consistency was good between the two methods (κ=0.828). The results indicate that the expression of Her-2/neu is closely associated with the development of gastric cancer. qPCR is a convenient, objective and efficient method, which may be used as an alternative to IHC or fluorescence in situ hybridization for the detection of Her-2/neu gene.

The rationality of N3 classification in the 7th edition of the International Union Against Cancer TNM staging system for gastric adenocarcinomas: a case-control study

BACKGROUND

The 7th edition of the International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) tumor-node-metastasis (TNM) classification system for gastric cancer is more detailed than the 6th edition with respect to tumor depth and lymph node metastasis. The purpose of this study was to evaluate the rationality of the 7th UICC/AJCC TNM classification system, focusing on N3 gastric cancers.

METHODS

A total of 338 patients with N3 gastric cancer who underwent curative resection with ≥ 16 retrieved lymph nodes at two institutions between January 1997 and December 2007 were included in this study. Patients were divided into the N3a (n = 210) and N3b (n = 128) groups. Clinicopathologic characteristics and survival rates were compared between groups.

RESULTS

No difference in clinicopathologic characteristics, including age (p = 0.989), sex (p = 0.382), tumor location (p = 0.124), surgery type (p = 0.909), depth of invasion (p = 0.313), histologic type (p = 0.111), and Lauren classification (p = 0.491), was observed between patients with N3a and N3b gastric cancer. However, overall survival (OS) rates of patients with N3a gastric cancer were greater than that of patients with N3b gastric cancer (5-year OS, 46% vs. 28%; 10-year OS, 33% vs. 19%; both p < 0.001). Five-year survival rates differed significantly between patients with T3N3a and T3N3b (p = 0.006) sub-stages and between those with T4aN3a and T4aN3b (p = 0.004) sub-stages.

CONCLUSIONS

The results of this study support N3 sub-classification for gastric cancers, which warrant differential consideration according to TNM stage.

Validity and necessity of sub-classification of N3 in the 7th UICC TNM stage of gastric cancer

BACKGROUND

The 7th TNM staging is the first authoritative standard for evaluation of effectiveness of treatment of gastric cancer worldwide. However, revision of pN classification within TNM needs to be discussed. In particular, the N3 sub-stage is becoming more conspicuous.

METHODS

Clinical data of 302 pN3M0 stage gastric cancer patients who received radical gastrectomy in Tianjin Medical University Cancer Institute and Hospital from January 2001 to May 2006 were retrospectively analyzed.

RESULTS

Location of tumor, depth of invasion, extranodal metastasis, gastric resection, combined organs resection, lymph node metastasis, rate of lymph node metastasis, negative lymph nodes count were important prognostic factors of pN3M0 stage gastric cancers. TNM stage was also associated with prognosis. Patients at T2N3M0 stage had a better prognosis than other sub-classification. T3N3M0 and T4aN3aM0 patients had equal prognosis which followed the T2N3M0. T4aN3bM0 and T4bN3aM0 had lower survival rate than the formers. T4bN3bM0 had worst prognosis. In multivariate analysis, TNM stage group and rate of lymph node metastasis were independent prognostic factors.

CONCLUSIONS

The sub-stage of N3 may be useful for more accurate prediction of prognosis; it should therefore be applied in the TNM stage system.

DNA damage response-related proteins in gastric cancer: ATM, Chk2 and p53 expression and their prognostic value

OBJECTIVES

The aims of this study were to assess expressions of the DNA damage response (DDR)-related proteins and to investigate their clinical significances in gastric carcinoma.

METHODS

Two independent cohorts, a training set (n=524) and validation set (n=394), of gastric cancer patients were enrolled. Ataxia telangiectasia mutated (ATM), checkpoint kinase 2 (Chk2), and p53 expressions were examined by immunohistochemistry using tissue microarray.

RESULTS

ATM loss, Chk2 loss, and p53 positivity were observed in 21.8, 14.1, and 36.1% of the training set, and in 17.3, 12.2, and 35.8% of the validation set, respectively. In the training set, the aberrant expressions of ATM, Chk2, or p53 were significantly associated with an advanced TNM stage and poor disease-specific survival. This association was verified in the validation set. Chk2 positivity and p53 negativity were significantly related to a prolonged disease-specific survival. Also, patients with nonaberrant expressional levels of all 3 DDR-related proteins had a more favorable outcome than others. Multivariate analyses showed that Chk2 loss and at least 1 aberrant DDR-related protein remained as independent prognostic factors of poor disease-specific survival.

CONCLUSIONS

This study elucidated the prognostic implications of DDR-related proteins, and suggests that their aberrant expressions play critical roles in the development and progression of gastric cancer.

Gastric cancer staging with radiologic imaging modalities and UICC staging system

There are two major stage classification systems for gastric cancer: the tumor-node-metastasis (TNM) stages by the International Union against Cancer (UICC) and the Japanese Classification of Gastric Carcinoma by the Japanese Gastric Cancer Association (JGCA). Preoperative stage classification using either of these systems is essential for deciding on the treatment strategy in the era of various multimodal therapeutic options. Evolution of multidetector computerized tomography with isotropic volumetric imaging and various 3D images has increased the accuracy of T and N staging in patients with gastric cancer, although detection of peritoneal deposits and nodal metastasis in the absence of lymphadenopathy remain problematic with the imaging tools currently available. The TNM and JGCA classifications have undergone revisions independent of each other, and the discrepancies were not helpful when international comparisons and cooperation were needed. More recently, the JGCA and TNM classifications were merged to have identical T and N categories, in addition to the more straightforward M categories that indicate the presence of distant metastasis. The result of these efforts is that researchers in Japan and the rest of the world are now looking at a similar disease when they discuss cancer that belongs to the same stage. A nomogram that incorporates other established prognostic determinants in addition to the TNM component may be a future direction for a more sophisticated means of predicting outcome. The increasing incidence of junctional (esophagogastric junction) cancer in the Far East has spurred researchers from this region to adequately stage the disease and to consider suitable treatment modalities for this disease entity, whereas Western researchers are more inclined to treat this disease as esophageal cancer. This could be an area for future international debate. For the next more accurate staging, we suggest the collaboration between Eastern and Western high-volume centers in gastric cancer because the inconsistency of surgical approaches, especially with respect to nodal resection, remains a barrier to mutual understanding.

A comparison between the seventh and sixth editions of the American Joint Committee on Cancer/International Union Against classification of gastric cancer

OBJECTIVE

To evaluate the prognostic significance of the seventh edition TNM staging classification for gastric cancer.

BACKGROUND

The seventh edition TNM staging system for gastric cancer was adopted by the American Joint Committee on Cancer/International Union Against Cancer on January 1, 2010, and included major revisions.

METHODS

The authors analyzed data retrospectively collected on patients with gastric cancer who underwent surgery at the Affiliated Hospital of Qingdao University Medical College between 2000 and 2008. A total of 964 patients with gastric cancer who underwent R0 surgical resection were included.

RESULTS

The relative risk (RR) for the seventh edition T classification was found to increase steadily and reasonably compared with the sixth edition. However, the RR for the sixth edition N classification was found to increase steadily and reasonably compared with the seventh edition classification. Cox regression multivariate analysis showed that the sixth edition N classification was superior to the seventh edition N classification as an independent prognostic factor. In survival analysis, the seventh edition TNM classification provided a more detailed classification; however, some subgroups of the seventh edition TNM classification did not demonstrate significantly different survival rates. The combination of the seventh edition T classification and the sixth edition N classification, with ideal RR results, showed significantly different survival rates except for IA and IB.

CONCLUSIONS

The combination of the seventh edition T classification and the sixth edition N classification seems to provide the optimal prognosis.

Close association of metastasis-associated protein 1 overexpression with increased angiogenesis and poor survival in patients with histologically node-negative gastric cancer

BACKGROUND

Although metastasis-associated protein 1 (MTA1) has been recently demonstrated as a potent angiogenesis-promoting factor in various malignant tumors, its angiogenic property in gastric cancer (GC) remains unclear. This study has detected the expression of MTA1 protein in surgically resected tissues of pathologic N0 (pN0) GC and further investigated its relation with other clinicopathologic factors and tumor angiogenesis and prognosis.

METHODS

MTA1 protein expression was detected immunohistochemically in 111 pN0 GC specimens. Its correlations with clinicopathologic factors and tumor prognosis were evaluated. The intratumoral microvessel density (MVD) was assessed based on CD105 antigen immunoreactivity and analyzed for correlation with MTA1 protein expression.

RESULTS

Overexpression of MTA1 was detected in 36.04 % of patients and exhibited a significant association with tumor size and MVD. Survival analysis demonstrated that both overall (OS) and disease-free (DFS) survivals in patients overexpressing MTA1 were significantly poorer than those without MTA1 overexpression 5 years after the operation (both p < 0.001). Multivariate survival analysis demonstrated that MTA1 overexpression was an independent prognosticator for unfavorable OS and DFS (p < 0.001, respectively).

CONCLUSIONS

MTA1 overexpression is frequently observed in pN0 GC patients and is significantly associated with increased angiogenesis and poor prognosis. Detection of MTA1 protein expression may help predict the relapse and prognosis of pN0 GC. Also, MTA1 protein may form a novel target for antiangiogenic therapy.

Gastric cancer: imaging and staging with MDCT based on the 7th AJCC guidelines

Gastric cancer is a common deadly cancer worldwide. The tumor-node-metastasis (TNM) staging system is one of the most commonly used staging systems, and is accepted and maintained by the International Union against Cancer (UICC) and the American Joint Committee on Cancer (AJCC). The TNM system is well known to effectively predict the prognosis of gastric cancer patients. The latest revision of TNM staging was presented in the 7th edition of the AJCC in 2009. Multi-detector row CT (MDCT) is a powerful test for non-invasive evaluation and can assess metastatic and locoregional staging simultaneously. Current MDCT with isotropic imaging and 3D images has increased the accuracy of T and N staging in patients with gastric cancer. Multi-planar reformatted images permit the radiologist to select the optimal imaging plane to accurately evaluate tumor invasion depth of the gastric wall and perigastric infiltration to identify a fat plane between a tumor and adjacent organs, to avoid partial volume averaging effects, and to differentiate lymph nodes from small perigastric vessels. Thus, MDCT provides a useful all-in-one diagnostic method for the pre-operative evaluation of patients with known, or strongly suspected, gastric cancer according to the 7th AJCC TNM staging system.

How many lymph nodes should be assessed in patients with gastric cancer? A systematic review

BACKGROUND

Nodal status is one of the most important prognostic factors in gastric adenocarcinoma (GC). As such, it is important to assess an appropriate number of lymph nodes (LNs) in order to accurately stage patients. However, the number of LNs assessed in each GC case varies, and in many cases the number examined per gastric specimen is less than current recommendations.

PURPOSE

We aimed to identify and synthesize findings from all articles evaluating the association of clinicopathological features and long-term outcomes with the number of LNs assessed among GC patients.

METHODS

Systematic electronic literature searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from 1998 to 2009.

RESULTS

Twenty-five articles were included in this review. Extensive resection, increased tumor size, and greater TNM staging were all associated with a greater number of LNs assessed. The disease-free survival was longer and recurrence rate was lower in patients with more LNs assessed. Overall survival, as well as survival by TNM and clinical stage, was improved among patients with an increased number of LNs assessed, but much of this appears to be due to stage migration, with the effect more pronounced in more advanced disease.

CONCLUSION

More LNs assessed resulted in less stage migration and possibly better long-term outcomes. Although current guidelines suggest 16 LNs to be assessed, especially in advanced GC, a higher number of LNs should be assessed.

Ratio between negative and positive lymph nodes is suitable for evaluation the prognosis of gastric cancer patients with positive node metastasis

Objective

To date, there is no consensus to evaluate the most appropriate category of the nodal metastasis for precise predication the prognosis of gastric cancer patients with positive node metastasis after curative surgery.

Methods

We retrospectively analyzed the clinicopathologic characteristics and overall survival (OS) of 299 gastric cancer patients with positive node metastasis after curative surgery for evaluation the optimal category of the nodal metastasis.

Results

With the univariate and multivariate survival analyses, the depth of primary tumor invasion was identified as the independent predicators with the OS of 299 gastric cancer patients with nodal metastasis postoperatively, as were the number of positive lymph nodes (PLNs), the number of negative lymph nodes (NLNs), and the ratio between negative and positive lymph nodes (RNPL). The RNPL was identified to be more suitable for predication the OS of gastric cancer patients with positive node metastasis than the ratio between positive and dissected lymph nodes (RPDL) by using the stratum procedure of survival analysis. Besides, we found both PLNs and NLNs were independently correlated with OS of gastric cancer patients with nodal metastasis when RNPL, instead of RPDL, was controlled in the partial correlation model.

Conclusions

RNPL, a new category of the nodal metastasis, was suitable for predication the OS of gastric cancer patients with nodal metastasis after curative resection, as were the PLNs, and NLNs.

Value of the metastatic lymph node ratio for predicting the prognosis of non-small-cell lung cancer patients

BACKGROUND

The aim of this study was to investigate the relation between the metastatic lymph node ratio (LNR) and the prognosis of non-small-cell lung cancer (NSCLC).

METHODS

A total of 301 patients with N1 or N2 NSCLC who underwent complete pulmonary resection were analyzed retrospectively. The correlations between the LNR and clinical and pathologic data were analyzed using χ(2) test analysis. The prognostic value of the LNR was calculated by univariate Kaplan-Meier survival analysis and multivariate Cox proportional hazard model analysis. The risk groups were classified by a combination of the LNR and pN stage.

RESULTS

The LNR was correlated with age, smoking status, pathologic type, subcarinal lymph node, clinical staging, N stage (P < 0.05), and the number of positive lymph nodes and positive lymph node stations (P < 0.0001). In the univariate analysis, the LNR played an important role in predicting overall survival (OS) (P < 0.0001) and disease-free survival (P < 0.0001) by Kaplan-Meier survival analysis. In the multivariate analysis, high LNR (>18%) was an independent poor prognostic factor for OS [hazard ratio (HR) 2.5034, 95% confidence interval (CI) 1.6096-3.8933, P < 0.0001] and DFS (HR 1.9023, 95% CI 1.2465-2.9031, P = 0.0031). Stratification into high-, medium-, and low-risk groups-based on high-risk factors (LNR > 18%, N2) intermediate-risk factors (LNR > 18%, N1 or LNR < 18%, N2), and low-risk factors (LNR < 18%, N1)-could efficiently predicted outcomes (P < 0.0001) of patients with lymph node-positive NSCLC.

CONCLUSIONS

The combination of the LNR and pN status provides a valuable help with prognosis. However, these results must be evaluated further in a large prospective randomized clinical trial.

The tumor-log odds of positive lymph nodes-metastasis staging system, a promising new staging system for gastric cancer after D2 resection in China

Background

In this study, we established a hypothetical tumor-lodds-metastasis (TLM) and tumor-ratio-metastasis (TRM) staging system. Moreover, we compared them with the 7^th edition of American Joint Committee on Cancer tumor-nodes-metastasis (AJCC TNM) staging system in gastric cancer patients after D2 resection.

Methods

A total of 1000 gastric carcinoma patients receiving treatment in our center were selected for the analysis. Finally, 730 patients who received D2 resection were retrospectively studied. Patients were staged using the TLM, TRM and the 7^th edition AJCC TNM system. Survival analysis was performed with a Cox regression model. We used two parameters to compare the TNM, TRM and TLM staging system, the −2log likelihood and the hazard ratio.

Results

The cut points of lymph node ratio (LNR) were set as 0, 0–0.3, 0.3–0.6, 0.6–1.0. And for the log odds of positive lymph nodes (LODDS), the cut points were established as≤−0.5, −0.5-0, 0-0.5, >0.5. There were significant differences in survival among patients in different LODDS classifications for each pN or LNR groups. When stratified by the LODDS classifications, the prognosis was highly homologous between those in the according pN or LNR classifications. Multivariate analysis showed that TLM staging system was better than the TRM or TNM system for the prognostic evaluation.

Conclusions

The TLM system was superior to the TRM or TNM system for prognostic assessment of gastric adenocarcinoma patients after D2 resection.

Validation of the updated 7th edition AJCC TNM staging criteria for gastric adenocarcinoma

INTRODUCTION

The recently published 7th edition of the American Joint Committee on Cancer (AJCC) TNM staging criteria for gastric adenocarcinoma contains important revisions to T and N classifications, as well as overall stage grouping. Our goal was to validate the new staging system using a cancer registry.

METHODS

Retrospective review of gastric cancer patients from Surveillance, Epidemiology, and End Results (SEER) registry data (2004-2007). Patients were staged according to both 6th and 7th edition criteria, and 3-year disease-specific survival was compared.

RESULTS

Thirteen thousand five hundred forty-seven patients with gastric adenocarcinoma were identified with complete staging information. When using 7th edition criteria, there was an increase in the number of patients classified as stage III (23% vs. 13%), and a decrease in patients classified as stage IV (47% vs. 53%). Statistically significant differences in 3-year disease-specific survival were observed for all T and N categories and re-staging the same population according to the 7th edition criteria improved survival discrimination. Multivariate analysis revealed statistically significant differences in survival and linear progression of hazard ratios for each stage grouping.

CONCLUSIONS

The 7th edition AJCC staging criteria for gastric adenocarcinoma demonstrate better survival discrimination and risk stratification than previous criteria.

Do patients with pN0 gastric cancer benefit from prophylactic extended lymphadenectomy?

PURPOSE

To investigate the impact of prophylactic extended lymphadenectomy on survival for patients with node-negative (pN0) advanced gastric cancer according to the extent of lymph node dissection.

METHODS

This study retrospectively investigated the clinicopathological characteristics and prognostic outcomes of 458 patients who had pN0 advanced gastric cancer between 1995 and 2001. Postoperative survival was compared in patients who underwent different extents of prophylactic lymphadenectomy.

RESULTS

The overall 5-year and 10-year survival rates were 62.01% (284/458) and 40.83% (187/458), respectively. The survival rates differed significantly in patients who underwent a different extent of prophylactic lymphadenectomy (≤D1+ versus D2 versus D3 versus ≥D3) (X(2) = 8.59, P = 0.035). Survival in patients who received less than D1+ dissection, however, were not significantly better than patients who received D2 dissection (X(2) = 0.907, P = 0.341). Survival in patients who received D2 dissection was significantly better than survival in patients who received D3 dissection (X(2) = 5.685, P = 0.017). No differences in postoperative survival rates were observed between patients who received D3 dissection and those received more than D3 dissection (X(2) = 2.468, P = 0.116). Patients who were older than 60 years and receive more than D2 dissection experienced significantly worse postoperative survival than those who received less than D2 dissection (X(2) = 14.885, P = 0.001). The extent of prophylactic lymphadenectomy did not significantly affect local tumor recurrence in patients with node-negative advanced gastric cancer (X(2) = 0.458, P = 0.928).

CONCLUSIONS

D2 prophylactic lymphadenectomy is appropriate for pN0 patients who were less than 60 years old, and less than D2 dissection was suitable for the older cases.

Differential Expression of SPARC in Intestinal-type Gastric Cancer Correlates with Tumor Progression and Nodal Spread

AIMS

Nodal spread is the single most important prognostic factor of survival in gastric cancer patients. In this study, genes that were upregulated in the lymph node metastases of gastric cancer were identified and may serve as putative novel therapeutic target.

METHODS

Complementary DNA (cDNA) microarray analysis and quantitative real-time polymerase chain reaction of primary gastric carcinomas and matched lymph node metastasis were carried out. Immunohistochemistry with anti-SPARC antibodies was performed on large tissue sections of 40 cases with primary gastric carcinoma (20 diffuse, 20 intestinal) and the corresponding lymph node metastases, as well as on tissue microarrays of 152 gastric cancer cases.

RESULTS

A cDNA microarray identified SPARC as being upregulated in primary gastric carcinoma tissue and the corresponding lymph node metastasis compared with the nonneoplastic mucosa. SPARC was expressed in fibroblasts and, occasionally, in tumor cells. However, the level of immunoreactivity was particularly strong in stromal cells surrounding the tumor. The level of expression of SPARC, determined by immunohistochemistry, correlated in intestinal-type gastric cancer with the local tumor growth, nodal spread, and tumor stage according to the International Union Against Cancer.

CONCLUSIONS

Our study provides transcriptional and translational evidence for the differential expression of SPARC in gastric cancer tissue. On the basis of our observations and those made by others, we hypothesize that SPARC is a promising novel target for the treatment of gastric cancer.

Differential Expression of SPARC in Intestinal-type Gastric Cancer Correlates with Tumor Progression and Nodal Spread

AIMS

Nodal spread is the single most important prognostic factor of survival in gastric cancer patients. In this study, genes that were upregulated in the lymph node metastases of gastric cancer were identified and may serve as putative novel therapeutic target.

METHODS

Complementary DNA (cDNA) microarray analysis and quantitative real-time polymerase chain reaction of primary gastric carcinomas and matched lymph node metastasis were carried out. Immunohistochemistry with anti-SPARC antibodies was performed on large tissue sections of 40 cases with primary gastric carcinoma (20 diffuse, 20 intestinal) and the corresponding lymph node metastases, as well as on tissue microarrays of 152 gastric cancer cases.

RESULTS

A cDNA microarray identified SPARC as being upregulated in primary gastric carcinoma tissue and the corresponding lymph node metastasis compared with the nonneoplastic mucosa. SPARC was expressed in fibroblasts and, occasionally, in tumor cells. However, the level of immunoreactivity was particularly strong in stromal cells surrounding the tumor. The level of expression of SPARC, determined by immunohistochemistry, correlated in intestinal-type gastric cancer with the local tumor growth, nodal spread, and tumor stage according to the International Union Against Cancer.

CONCLUSIONS

Our study provides transcriptional and translational evidence for the differential expression of SPARC in gastric cancer tissue. On the basis of our observations and those made by others, we hypothesize that SPARC is a promising novel target for the treatment of gastric cancer.

Evaluation of the 7th AJCC TNM Staging System in Point of Lymph Node Classification

PURPOSE

The 7th AJCC tumor node metastasis (TNM) staging system modified the classification of the lymph node metastasis widely compared to the 6th edition. To evaluate the prognostic predictability of the new TNM staging system, we analyzed the survival rate of the gastric cancer patients assessed by the 7th staging system.

MATERIALS AND METHODS

Among 2,083 patients who underwent resection for gastric cancer at the department of surgery, Hanyang Medical Center from July 1992 to December 2009, This study retrospectively reviewed 5-year survival rate (5YSR) of 624 patients (TanyN3M0: 464 patients, TanyNanyM1: 160 patients) focusing on the number of metastatic lymph node and distant metastasis. We evaluated the applicability of the new staging system.

RESULTS

There were no significant differences in 5YSR between stage IIIC with more than 29 metastatic lymph nodes and stage IV (P=0.053). No significant differences were observed between stage IIIB with more than 28 metastatic lymph nodes and stage IV (P=0.093). Distinct survival differences were present between patients who were categorized as TanyN3M0 with 7 to 32 metastatic lymph nodes and stage IV. But patients with more than 33 metastatic lymph nodes did not show any significant differences compared to stage IV (P=0.055). Among patients with TanyN3M0, statistical significances were seen between patients with 7 to 30 metastatic lymph nodes and those with more than 31 metastatic lymph nodes.

CONCLUSIONS

In the new staging system, modifications of N classification is mandatory to improve prognostic prediction. Further study involving a greater number of cases is required to demonstrate the most appropriate cutoffs for N classification.

The effectiveness of the new (7th) UICC N classification in the prognosis evaluation of gastric cancer patients: a comparative study between the 5th/6th and 7th UICC N classification

BACKGROUND

The most important prognostic factor after curative surgery for gastric carcinoma is the presence of lymph node metastases. According to the 7th edition of the UICC TNM staging system for gastric cancer, N classification was categorized as N0 (no regional lymph node metastasis), N1 (1-2 regional lymph node metastases), N2 (3-6 regional lymph node metastases), and N3 (7 or more regional lymph node metastases). The purpose of this study was to evaluate the rationality of the new UICC/AJCC N classification in comparison with the 6th UICC classification.

METHODS

From August 2002 to July 2006, 295 patients with gastric cancer underwent curative resection with D2 lymph node dissection by a single surgeon. We analyzed retrospectively the significant prognostic factors and identified the suitability of the 7th UICC N staging system.

RESULTS

According to the 7th UICC N classification, the 5-year cumulative survival rates (5-YSR) of N0, N1, N2, N3a, and N3b were 89.7, 73.6, 54.9, 23.1, and 5.4%, respectively (P < 0.0001). Using univariate analysis, the N classification of the 7th and 6th UICC/AJCC TNM staging system, T classification of the 7th UICC TNM staging system, size and location of tumor, and histology were associated with the overall survival of gastric cancer after curative surgery. However, Cox regression multivariate analysis showed the 7th UICC N classification was an independent prognostic factor instead of the 6th UICC N classification (P < 0.0001).

CONCLUSION

The 7th UICC classification for lymph node metastasis is thought to be a more reliable prognostic factor for gastric cancer than the 6th classification.

Effect of negative lymph node count on survival for gastric cancer after curative distal gastrectomy

AIMS

The aim of this study is to evaluate the long-term effect of negative lymph node (LN) counts on the prognosis after curative distal gastrectomy among gastric cancer patients.

METHODS

The study enrolled 634 patients with gastric cancer, who had undergone curative resection (R0) with distal gastrectomy from 1995 to 2004. Long-term surgical outcomes and relationships between the negative LN count and the 5-year survival rate were investigated.

RESULTS

The 5-year survival rate of the entire cohort was 57.6%. The number of metastasis negative LN was positively associated with the retrieved node according to the Pearson's correlation test (P < 0.001). Cox regression analysis showed the negative LN count was an independent predictor of survival (P < 0.05). Based on the statistical assumption the best fitting linear, linear regression showed a significant survival improvement based on increasing negative LN count for patients with stages I (P = 0.014), II (P = 0.011) and III (P = 0.003). The greatest survival differences were observed at cutoff value 10 negative LN counts for stage I, and 15 for stages II, III and IV.

CONCLUSION

Negative LN counts can reflect the extent of lymphadenectomy for gastric cancer after curative distal gastrectomy. The higher the negative LN count, the better the survival would be; the best long-term survival outcome was observed on the negative LN count more than 10 (stage I) or 15 (stages II, III, and IV).

Comparison of 6th and 7th AJCC TNM staging classification for carcinoma of the stomach in China

BACKGROUND

The 7th edition of American Joint Committee on Cancer tumor-node-metastasis (AJCC TNM) staging system was put into use recently. The study aimed to evaluate its predictive ability on survival and compare the difference between the 6th and 7th editions of AJCC TNM system in gastric carcinoma.

MATERIALS AND METHODS

A total of 1000 gastric carcinoma patients receiving treatment in our center were selected for the analysis. Patients were staged using both the 6th and 7th editions AJCC TNM staging system. Survival analysis was performed with a Cox regression model.

RESULTS

Of previous stage IV patients, 39.9% (112 of 281) migrated to a lower tier in the 7th edition. By setting the cutoff of positive lymph nodes as 0, 2, 6, and 15, the 7th edition strengthens the role of positive lymph nodes. Multivariable regression analysis showed that both 6th and 7th TNM stage systems were independent factors for overall survival. For lymph nodes negative patients, the 5-year overall survival for patients with fewer than 15 resected lymph nodes was significantly lower than those with more than 15.

CONCLUSIONS

AJCC 7th is not superior to AJCC 6th in predicting the 5-year overall survival rates of gastric adenocarcinoma patients. The definition of stage IV and the selection of cutoffs for MLNC in the AJCC 7th system is much more reasonable compared with the AJCC 6th system.

Validation of the seventh edition of the American Joint Committee on Cancer TNM staging system for gastric cancer

BACKGROUND

The seventh edition of the American Joint Committee on Cancer (AJCC) TNM classification for gastric cancer was published in 2010 and included major revisions. The aim of the current study was to evaluate the validity of the seventh edition TNM classification for gastric cancer based on an Asian population.

METHODS

A total of 2916 gastric cancer patients who underwent R0 surgical resection from 1989 through 2008 in a single institute were included, and were analyzed according to the seventh edition of the TNM classification for validation.

RESULTS

When adjusted using the seventh edition of the TNM classification, upstaging was observed in 771 patients (26.4%) and downstaging was observed in 178 patients (6.1%) compared with the sixth edition of the TNM classification. The relative risk (RR) of seventh edition pT classification was found to be increased with regular intensity compared with the sixth edition pT classification. The RR of seventh edition pN classification was found to be increased with irregular intensity compared with the sixth edition pN classification. In survival analysis, there were significant differences noted for each stage of disease, but only a marginal difference was demonstrated between stage IA and stage IB (P = .049). In the hybrid TNM classification, which combines the seventh edition pT classification and the sixth edition pN classification, both pT and pN classifications demonstrated a more ideal distribution of the RR, and 5-year survival rates also showed a significant difference for each stage (P <.01).

CONCLUSIONS

The seventh edition of the TNM classification was considered valid based on the results of the current study. However, the hybrid TNM classification, comprised of a combination of the seventh edition pT classification and sixth edition pN classification, should be considered for the next edition.

Prognostic significance of the metastatic lymph node ratio in gastric cancer patients

BACKGROUND

Lymph node metastasis is considered one of the most important prognostic factors in gastric cancer. However, the optimal system for accurate staging of lymph node metastasis for patients with gastric cancer remains controversial. This study was designed to investigate the prognostic significance of the metastatic lymph node ratio (MLR), which is calculated by dividing the number of metastatic lymph nodes by the total number of nodes harvested from patients with gastric cancer.

METHODS

We retrospectively analyzed the clinical data of 186 consecutive patients diagnosed with gastric cancer who underwent curative gastrectomy at our hospital. The lymph node status was classified according to three systems:the International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) system; the Japanese Gastric Cancer Association (JGCA) system; and an MLR-based system (MLR0: 0, MLR1: 0.01-0.19, MLR2: >or=0.2). The influence of the MLR on patient survival was determined using univariate Kaplan-Meier survival analysis, the generalized Wilcoxon test, and analysis with the multivariate Cox proportional hazards model.

RESULTS

The 5-year survival rate of the patients with MLR0, MLR1, and MLR2 was 88.6%, 59.4%, and 13.4%, respectively. In addition to the MLR, the UICC/AJCC N category,JGCA n category, tumor stage (pT category), and tumor diameter significantly influenced the 5-year survival rate, as determined by univariate analysis. Multivariate analyses revealed that of the three factors used to stage lymph node involvement, MLR was the most significant prognostic factor.

CONCLUSIONS

The MLR is an important and easy-to-assess prognostic factor that should be considered for staging lymph node metastasis in patients with gastric cancer.

The interaction between N-category and N-ratio as a new tool to improve lymph node metastasis staging in gastric cancer: results of a single cancer center in Brazil

BACKGROUND

Depth of tumor invasion (T-category) and the number of metastatic lymph nodes (N-category) are the most important prognostic factors in patients with gastric cancer. Recently, the ratio between metastatic and dissected lymph nodes (N-ratio) has been established as one. The aim of this study is to evaluate the impact of N-ratio and its interaction with N-category as a prognostic factor in gastric cancer.

METHODS

This was a retrospective study in which we reviewed clinical and pathological data of 165 patients who had undergone curative surgery at our institution through a 9-year period. The exclusion criteria included metastases, gastric stump tumors and gastrectomy with less than 15 lymph nodes dissected.

RESULTS

The median age of the patients was 63 years and most of them were male. Total gastrectomy was the most common procedure and 92.1% of the patients had a D2-lymphadenectomy. Their 5-year overall survival was 57.7%. T-category, N-category, extended gastrectomy, and N-ratio were prognostic factors in overall and disease-free survival in accordance with univariate analysis. In accordance with TNM staging, N1 patients who have had NR1 had 5-year survival in 75.5% whereas in the NR2 group only 33% of the cases had 5-year survival. In the multivariate analysis, the interaction between N-category and N-ratio was an independent prognostic factor.

CONCLUSION

Our findings confirmed the role of N-ratio as prognostic factor of survival in patients with gastric cancer surgically treated with at least 15 lymph nodes dissected. The relationship between N-category and N-ratio is a better predictor than lymph node metastasis staging.

Evaluation of the seventh American Joint Committee on Cancer/International Union Against Cancer Classification of gastric adenocarcinoma in comparison with the sixth classification

BACKGROUND

The seventh TNM staging system for gastric cancer of the American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) had a more detailed classification than the sixth TNM staging system for both the tumor (T) and lymph nodes (N). The authors compared survival rates assessed by the seventh staging system with those by the sixth system.

METHODS

The authors analyzed the prospectively collected database on patients with gastric cancer who underwent surgery at Seoul National University Hospital between 1986 and 2006, and calculated the survival rates of 9998 cases with primary cancer, R0 resection, and >14 retrieved lymph nodes.

RESULTS

The 5-year cumulative survival rates (5YSR) according to the seventh edition T or N classifications were significantly different. The 5YSR according to seventh edition of the TNM staging system were 95.1% (stage IA), 88.4% (stage IB), 84.0% (stage IIA), 71.7% (stage IIB), 58.4% (stage IIIA), 41.3% (stage IIIB), and 26.1% (stage IIIC), which were significantly different from each other. The 5YSR of the seventh edition T2 and T3 classifications had significant differences in patients with every N classification, and the 5YSR of seventh edition N1 and N2 classifications had significant differences in T2 patients, T3 patients, and T4 patients. Each stage in the sixth edition was divided into the seventh edition stage with different survival rates. In addition, the number of homogenous groupings in seventh edition TNM stages was increased from 1 to 2.

CONCLUSIONS

The seventh system provided a more detailed classification of prognosis than the sixth system, especially between T2 and T3 tumors and N1 and N2 tumors, although further studies were found to be needed for the N3a and N3b classification.

Size of the largest lymph node visualized on multi-detector-row computed tomography (MDCT) is useful in predicting metastatic lymph node status of gastric cancer

This study was designed to investigate whether the size of the largest lymph node (long-axis diameter [LAD] and short-axis diameter [SAD]) visualized using multi-detector-row computed tomography (MDCT) was useful for predicting the metastatic lymph node (MLN) status of gastric cancer. A retrospective analysis of 305 gastric cancer patients who underwent pre-operative MDCT was performed, followed by a prospective study in 61 gastric cancer patients to determine the diagnostic effectiveness of LAD and SAD. In the retrospective study, the accuracy of LAD and SAD for predicting the MLN status of gastric cancer was 51.1% and 45.9%, respectively. In the prospective study, the accuracy of LAD and SAD measurement and the traditional MDCT method of counting MLNs was 52.5%, 49.2% and 57.4%, respectively; the differences were not significant. In conclusion, the size of the largest lymph node in terms of LAD and SAD visualized on MDCT was useful for predicting the MLN status of gastric cancer, with accuracy comparable to the traditional MDCT method of counting the total number of MLNs detected.