Superiority of a new UICC-TNM staging system for gastric carcinoma

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.

Efficacy of Lymph Node Location-Number Hybrid Staging System on the Prognosis of Gastric Cancer Patients

BACKGROUND

Lymph node metastasis location and number significantly affects the prognosis of patients with gastric cancer (GC). This study was designed to examine a new lymph node hybrid staging (hN) system to increase the predictive ability for patients with GC.

METHODS

This study analyzed the gastrointestinal treatment of GC at the Harbin Medical University Cancer Hospital from January 2011 to December 2016, and selected 2598 patients from 2011 to 2015 as the training cohort (hN) and 756 patients from 2016 as the validation cohort (2016-hN). The study utilized the receiver operating characteristic curve (ROC), c-index, and decision curve analysis (DCA) to compare the prognostic performance of the hN with the 8th edition of AJCC pathological lymph node (pN) staging for GC patients.

RESULTS

The ROC verification of the training cohort and validation cohort based on each hN staging and pN staging showed that for each N staging, the hN staging had a training cohort with an AUC of 0.752 (0.733, 0.772) and a validation cohort with an AUC of 0.812 (0.780, 0.845). In the pN staging, the training cohort had an AUC of 0.728 (0.708, 0.749), and the validation cohort had an AUC of 0.784 (0.754, 0.824). c-Index and DCA also showed that hN staging had a higher prognostic ability than pN staging, which was confirmed in the training cohort and the verification cohort, respectively.

CONCLUSION

Lymph node location-number hybrid staging can significantly improve the prognosis of patients with GC.

Central lymph node metastasis is predictive of survival in advanced gastric cancer patients treated with D2 lymphadenectomy

Background

The number of positive lymph nodes, which was defined as “N stage”, is mostly used to predict the survival of D2-resected gastric cancer patients, not the location. A “central lymph node” (CnLN) was defined by Ikoma et al., included common hepatic, celiac and proximal splenic artery LNs. CnLNs located in the extraperigastric area are included in the D2 LN station for gastric cancer. We speculate that CnLNs can be regarded as a predictor of survival.

Methods

Eligible advanced gastric cancer patients who underwent curative resection and D2 lymph node dissection between 2004 and 2012 at our institution were identified. The frequency of CnLN metastases and risk factors affecting DFS were examined. Survival differences were assessed by log-rank tests and Kaplan–Meier curves.

Results

The study identified 1178 patients who underwent curative surgery or D2 or more extensive lymphadenectomy. A total of 342 patients had been proven to have CnLN metastasis. Larger tumor size (P < 0.001), more frequent lymphatic vessel invasion (P < 0.001), signet ring cell histology (P = 0.014), and more advanced pathological T stage (P = 0.013) were significantly related to CnLNs metastasis. The patients with CnLN metastasis had a poor prognosis (HR for DFS of 1.366, 95%CI = 1.138–1.640, P = 0.001). For the pN2/3 patients, CnLN metastasis was associated with shorter 5-year DFS (for pN2 patients: 25.9% vs 39.3%, P = 0.017; for pN3 patients: 11.5% vs 23.4%, P = 0.005).

Conclusion

Gastric cancer patients with CnLN metastasis who underwent D2 resection had a poor prognosis. With the same N stage, the patients with positive CnLNs had shorter survival. CnLNs metastasis could be a supplement to N stage and a predictor of survival in gastric cancer patients. Large sample, multicenter, randomized clinical trials are still needed in the future.

Efficacy of the fat-dissociation method for nodal harvesting in gastric cancer

BACKGROUND

There is an increased need for accurate staging for gastric cancer treatment. Consequently, it is necessary to carefully examine all dissected lymph nodes for precise staging. Recently, the fat-dissociation method has been developed as a quick and accurate method for harvesting dissected lymph nodes of colorectal cancer cases.

AIM

To investigate the usefulness of the fat-dissociation method for harvesting dissected lymph nodes of gastric cancer cases.

METHODS

Fifty-six resected specimens from gastric cancer patients who underwent standard curative gastrectomy and lymph node dissection at our hospital were used. Group 2 lymph nodes were separated from each specimen, and the remaining adipose tissue containing the group 1 lymph nodes was used. Some resected specimens were subjected to the fat-dissociation method. One vial of Imofully® was dissolved in 50 mL of saline and injected into the tissue. The tissue was incubated for 1 h and the dissolved fat was removed. Subsequently, the nodes were identified, picked up with scissors, and mapped. The number of nodes in each lymphatic compartment and duration of lymph node harvest and mapping were compared.

RESULTS

The fat-dissociation method was used for 24 samples, while the conventional dissection method was used for 32 samples. The total number of harvested lymph nodes was 45.9 in the fat dissociation group and 44.3 in the control group, and there was no significant difference between the two groups. There were also no significant differences in the number of lymph nodes between the two groups based on a comparison of the lymphatic compartments. However, the total median duration of the fat-dissociation method was 38.2 min, reflecting a reduced duration of approximately 60 min compared to the control group.

CONCLUSION

Based on our results, the fat-dissociation method is effective in shortening the duration of lymph node harvest in gastric cancer surgery.

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.

MicroRNA-1271 functions as a potential tumor suppressor in hepatitis B virus-associated hepatocellular carcinoma through the AMPK signaling pathway by binding to CCNA1

Hepatocellular carcinoma (HCC) is mainly associated with hepatitis B virus (HBV) infection and characterized by metastasizing and infiltrating adjacent and distant tissues. Notably, microRNA-1271 (miR-1271) is a tumor suppressor in various cancers. Therefore, we evaluate the ability of miR-1271 to influence cell proliferation, migration, invasion, and apoptosis in HBV-associated HCC through the Adenosine monophosphate-activated protein kinase (AMPK) signaling pathway via targeting CCNA1. HBV-associated HCC and adjacent normal tissues were collected to identify the expression of miR-1271 and CCNA1. To verify the relationship between miR-1271 and CCNA1, we used bioinformatics prediction and the dual-luciferase reporter gene assay. The effects of miR-1271 on HBV-associated HCC cell behaviors were investigated by treatment of the miR-1271 mimic, the miR-1271 inhibitor, or small interfering RNA against CCNA1. The HBV-DNA quantitative assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromid assay, scratch test, transwell assay, and flow cytometry were used to detect HBV-DNA replication, cell proliferation, invasion, migration, and apoptosis. MiR-1271 showed a low expression, whereas CCNA1 showed a high expression in HBV-associated HCC tissues. We identified that miR-1271 targeted and negatively regulated CCNA1. Upregulated miR-1271 and downregulated CCNA1 inhibited the HBV-associated HCC cell HBV-DNA replication, proliferation, migration, and invasion, while accelerating apoptosis by activating the AMPK signaling pathway. MiR-1271 promotes the activation of the AMPK signaling pathway by binding to CCNA1, whereby miR-1271 suppresses HBV-associated HCC progression. This study points to a potential therapeutic approach of downregulation of miR-1271 in HBV-associated HCC treatment.

Central Lymph Node Metastasis in Gastric Cancer Is Predictive of Survival After Preoperative Therapy

BACKGROUND

It is unclear how preoperative therapy for gastric cancer affects the metastasis rate of lymph nodes (LNs) and whether the location of positive LNs affects survival after preoperative therapy. Therefore, we determined the association between positive central lymph nodes (CnLNs) and disease stage and overall survival (OS).

METHODS

We reviewed a prospectively maintained database to identify patients who had undergone resection of gastric adenocarcinoma at our institution from 2005 to 2015. CnLNs were defined as common hepatic, celiac, and proximal splenic artery LNs (stations no. 8, 9, and 11p). The frequency of CnLN metastases and risk factors affecting OS were examined.

RESULTS

We identified 356 patients. Preoperative therapy was administered to 66% of patients. D2 LN dissection was performed in 80% of patients, and the median number of LNs examined was 25 (IQR, 18-34). In 243 patients (68%), CnLNs had undergone separate pathologic examination; the CnLN-positive rate was 9.1% (22 of 243; station no. 8, 4.5%; no. 9, 2.1%; and no. 11p, 4.8%). CnLN metastasis was associated with shorter 3-year OS in patients with pN2/3 disease (33 vs. 62%; p = 0.004). Among patients who had undergone preoperative therapy, ypT3-4 stage (HR 2.44; p = 0.01) and positive CnLNs (HR 5.44; p < 0.001) were negatively associated with OS by multivariate analysis.

CONCLUSIONS

CnLN metastases are uncommon in gastric cancer and have an adverse effect on OS in patients who have undergone preoperative therapy. Larger multi-institutional studies are needed to determine whether CnLN positivity requires a separate staging category after preoperative therapy.

Anatomical location of metastatic lymph nodes: an indispensable prognostic factor for gastric cancer patients who underwent curative resection

BACKGROUND

Although the numeric-based lymph node (LN) staging was widely used in the worldwide, it did not represent the anatomical location of metastatic lymph nodes (MLNs) and not reflect extent of LN dissection. Therefore, in the present study, we investigated whether the anatomical location of MLNs was still necessary to evaluate the prognosis of node-positive gastric cancer (GC) patients.

METHODS

We reviewed 1451 GC patients who underwent radical gastrectomy in our institution between January 1986 and January 2008. All patients were reclassified into several groups according to the anatomical location of MLNs and the number of MLNs. The prognostic differences between different patient groups were compared and clinicopathologic features were analyzed.

RESULTS

In the present study, both anatomical location of MLNs and the number of MLNs were identified as the independent prognostic factors (p < .01). The patients with extraperigastric LN involvement showed a poorer prognosis compared with the perigastric-only group (p < .001). For the N1-N2 stage patients, the prognostic discrepancy was still observed among them when the anatomical location of MLNs was considered (p < .05). For the N3-stage patients, although the anatomical location of MLNs had no significant effect on the prognosis of these patients, the higher number of MLNs in the extraperigastric area was correlated with the unfavorable prognosis (p < .05).

CONCLUSION

The anatomical location of MLNs was an important factor influencing the prognostic outcome of GC patients. To provide more accurate prognostic information for GC patients, the anatomical location of MLNs should not be ignored.

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.

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.

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.

Prognostic significance of distal subtotal gastrectomy with standard D2 and extended D2 lymphadenectomy for locally advanced gastric cancer

This study was conducted to investigate prognosis and survival of patients undergoing distal subtotal gastrectomy with D2 and D2+ lymphadenectomy for patients with locally advanced gastric cancer. Overall survival rates of 416 patients with locally advanced gastric cancer were compared between D2 and D2+ lymphadenectomy. Univariate analysis and multivariate analysis was used to identify significant prognostic factors correlated with LN metastasis and prognosis. Univariate analysis identified tumor size, lymphatic vessel invasion, pT stage, pN stage, TNM stage, locoregional recurrence, and distant recurrence, to significantly correlate with prognosis; Tumor size, LVI, and pT stage were identified as independent factors correlating with LN metastasis. Multivariate analysis demonstrated that tumor size, pT stage, pN stage, locoregional recurrence, and distant recurrence were independent prognostic factors; Tumor size and pT stage were independent prognostic factors predicting LN metastasis. When comparing 5-year survival rates of patients who underwent D2 and D2+ lymphadenectomy, as stratified by pT stage and pN stage, a significant difference was found in pN3 patients, but not for pT2–4 and pN0–2 patients, or the patient cohort as a whole. In conclusion, D2 lymphadenectomy for patients with locally advanced gastric cancer undergoing distal subtotal gastrectomy was recommended, especially in eastern Asia.

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.

Clinical significance of lymph node metastasis in gastric cancer

Gastric cancer, one of the most common malignancies in the world, frequently reveals lymph node, peritoneum, and liver metastases. Most of gastric cancer patients present with lymph node metastasis when they were initially diagnosed or underwent surgical resection, which results in poor prognosis. Both the depth of tumor invasion and lymph node involvement are considered as the most important prognostic predictors of gastric cancer. Although extended lymphadenectomy was not considered a survival benefit procedure and was reported to be associated with high mortality and morbidity in two randomized controlled European trials, it showed significant superiority in terms of lower locoregional recurrence and disease related deaths compared to limited lymphadenectomy in a 15-year follow-up study. Almost all clinical investigators have reached a consensus that the predictive efficiency of the number of metastatic lymph nodes is far better than the extent of lymph node metastasis for the prognosis of gastric cancer worldwide, but other nodal metastatic classifications of gastric cancer have been proposed as alternatives to the number of metastatic lymph nodes for improving the predictive efficiency for patient prognosis. It is still controversial over whether the ratio between metastatic and examined lymph nodes is superior to the number of metastatic lymph nodes in prognostic evaluation of gastric cancer. Besides, the negative lymph node count has been increasingly recognized to be an important factor significantly associated with prognosis of gastric cancer.

N stages of the seventh edition of TNM Classification are the most intensive variables for predictions of the overall survival of gastric cancer patients who underwent limited lymphadenectomy

The objective of this study was to explore the prognostic prediction rationality of the seventh edition N stage for gastric cancer (GC) patients who underwent the limited lymphadenectomy. Clinicopathological data of 769 GC patients who underwent the curative resection between 1997 and 2006 were analyzed for demonstration that the seventh edition N stage had the significant superiorities of prognostic prediction to the patients who underwent the limited lymphadenectomy. Although the extent of lymphadenectomy was associated with the overall survival (OS) of gastric cancer (GC) patients, the N stages of the seventh edition of the TNM Classification were identified as the most intensively independent predictors of GC prognosis. Using stratum analysis, the 5-year survival rate of patients who underwent limited lymphadenectomy was observed to be significantly different from that of patients who underwent extended lymphadenectomy, regardless of the extent of lymph node metastasis. Multinomial logistic regression analysis revealed that combining the extents of lymph node metastasis and lymphadenectomy could improve the prediction accuracy of patient survival status. Case control analysis showed that regardless of the extent of lymphadenectomy, the seventh edition N stages featured significant superiority for OS evaluation of GC patients. The seventh edition N stage had the prediction rationality for the OS of GC patients who underwent the limited lymphadenectomy.

The lymph node ratio as a prognostic factor for gastric cancer

To predict prognosis of gastric cancer, an adequate assessment of the stage of gastric cancer is important. The UICC/AJCC TNM classification is the most commonly used classification system. For adequate N staging at least 15 lymph nodes should be retrieved. In some countries, this amount of lymph nodes is not met, which can lead to understaging. Therefore, the lymph node ratio (LNR) is proposed as an alternative N staging modality. The purpose of this study was to compare the different staging modalities. Patients and methods. We included all patients who underwent surgery for gastric cancer, newly diagnosed between 2000 and 2009 and staged patient by UICC/AJCC TNM 5th/6th or 7th and by LNR. We conducted crude survival analysis, univariate and multivariate analyses according to the different staging systems. Results. The five-year overall survival rates ranged from 58% for N0 disease to 18% in case of more than 15 metastatic lymph nodes. The distribution of overall five-year survival according to LNR was 58% for LNR0 and 10% for LNR3. Univariate analysis showed that all the UICC/AJCC TNM classification systems as well as the LNR were strong prognostic factors for overall survival. The LNR correlated less with the number of nodes examined. Conclusion. LNR is a good prognostic tool for overall survival, it is an independent prognostic factor with a more homogenous spread of hazard ratios and five-year survival rates than UICC/AJCC systems. Furthermore, the LNR has a lower correlation with the number of nodes examined, making it less vulnerable for stage migration.

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.

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

BACKGROUND

In gastric cancer, the classification of lymph node status is still a controversial prognostic factor. Recent studies have proposed a new prognostic factor (metastatic lymph node ratio: MLR) for gastric cancer patients who undergo curative resection. The present study tested the hypothesis that MLR was better than the current pN staging system by analyzing the correlation between MLR and the International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) staging system, by analyzing the correlation between MLR and 5-year overall survival (OS), by comparing area under the curve (AUC), and by performing univariate and multivariate analyses for OS.

METHODS

Of 409 patients who were diagnosed with gastric adenocarcinoma between January 2003 and December 2006, 370 patients underwent curative resection and were included in this study. The prognostic significance of the number of metastatic lymph nodes and the metastatic lymph node ratio were compared in AUC and univariate and multivariate Cox regression analyses.

RESULTS

MLR was significantly correlated with the depth of invasion and the number of lymph node metastases (p < 0.001). Increasing MLR also was statistically correlated with a lower 5-year OS rate (p < 0.001). The AUC of MLR and the number of lymph node metastases were not significantly different (p = 0.825). MLR was an independent prognostic factor on multivariate analysis, but the number of metastatic lymph nodes was not.

CONCLUSIONS

MLR can be a prognostic factor in patients who undergo radical resection for gastric cancer and can overcome the limitations of existing prognostic factors.

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.

Diagnostic and prognostic value of metastasis inducer S100A4 transcripts in plasma of colon, rectal, and gastric cancer patients

Early detection of tumors and metastases is critical for improving treatment strategies and patient outcomes. The development of molecular markers and simple tests that are clinically applicable for detection, prognostication, and therapy monitoring is strongly needed. The gene S100A4 has long been known to act as a metastasis inducer. High S100A4 levels in the primary tumor are prognostic for metachronous metastasis and correlate with reduced patient survival. We provide, for the first time, a plasma-based assay for transcript quantification of S100A4 in gastrointestinal patients' plasma. We conducted a study to define the diagnostic and prognostic power of S100A4 transcripts using 466 plasma samples from colon, rectal, and gastric cancer patients. Plasma was separated, RNA was isolated, and S100A4 mRNA was determined by quantitative RT-PCR. S100A4 transcripts were increased in cancer patients of each entity (P < 0.0001) and all disease stages (P < 0.05), compared with tumor-free volunteers (sensitivities of 96%, 74%, and 90% and specificities of 59%, 82%, and 71%, for colon, rectal, and gastric cancer patients, respectively). Prospectively analyzed follow-up patients who later experienced metastasis showed higher S100A4 levels than follow-up patients without metastasis. Disease-free survival was decreased in high S100A4-expressing follow-up colorectal cancer patients (P = 0.013). In summary, we developed a method for quantitative S100A4 transcript determination in plasma that allows clinical application routinely. We demonstrated the diagnostic and prognostic potential of this method for early defining cancer staging and patients' risk for metastasis.

Gastric cardiac carcinomas involving the esophagus are more adequately staged as gastric cancers by the 7th edition of the American Joint Commission on Cancer Staging System

The aim of this study was to compare the 7th with the 6th edition of the American Joint Commission on Cancer Staging System for prognostic stratification of gastric cardiac carcinomas involving the esophagus. We retrospectively compared differences in pathological stages with patient survival between the 7th and the 6th staging systems in 142 consecutive resection cases of this cancer. Patient median age was 65 years. The male-female ratio was 3.3. The epicenter of all tumors was within 5 cm below the gastroesophageal junction. The median tumor size was 5.0 cm. Most tumors (79%) were typical adenocarcinomas and the rest showed uncommon histology types. Using the guidelines for gastric cancer, this group of cancer was better stratified by the 7th than the 6th edition of the staging system, especially for pathological nodal (pN) and overall stage pIIIC. Patients with celiac axis nodal disease had the 5-year survival rate worse than those staged at pN3A and pIIIA. Patients staged at pT3 and pN3B had the 5-year survival rate worse than those at pM1 and pIV. We showed that the overall stage of gastric cardiac carcinomas was better stratified by gastric than by esophageal cancer grouping. We conclude that these tumors are better stratified with the 7th than the 6th edition of the gastric staging system, especially for pIII cancers, and better staged by the new gastric than esophageal cancer staging system. We propose that the staging of these tumors be reverted to gastric grouping and combine pT3 and pN3B into the overall stage pIV.

Evaluation of UICC-TNM and JSBS staging systems for surgical patients with extrahepatic cholangiocarcinoma

AIM

Two staging systems exist to classify extrahepatic cholangiocarcinoma (EHC), the TNM staging of the International Union Against Cancer (UICC) and the classification system of the Japanese Society of Biliary Surgery (JSBS). This study sought to evaluate the utility of these two staging systems.

METHOD

One hundred and twenty eight consecutive patients who underwent surgical resection were retrospectively classified into the appropriate stages using the UICC-TNM and JSBS systems. We also compared the distribution and survival curves of respective stages.

RESULTS

Although the UICC-TNM staging system divided patients into seven categories, 106 of 128 patients (82.8%) fell into three stages (stages IA, IIA, or IIB). In contrast, patients were relatively evenly divided across the five categories in JSBS staging. The survival curve of UICC-TNM stage IIB was more similar to stage IV than stages IIA or III; survival rates for stages IIB and IV were significantly lower than the other stages. According to the JSBS staging system, there were significant differences between stages I and III, IVA and IVB, and II and IVA/IVB, and III and IVA/IVB.

CONCLUSIONS

Patients who underwent surgical resection were not evenly divided across UICC-TNM staging categories in comparison to JSBS staging. Stratification of survival ability was better when using the JSBS staging in comparison to the UICC-TNM system. The better understanding about distribution of patient classified by stage and stratification ability of survival of these two staging system may help surgeons assess the patients with EHC.

Prognostic value of preoperative clinical staging assessed by computed tomography in resectable gastric cancer patients: a viewpoint in the era of preoperative treatment

BACKGROUND

In the era of pre- or perioperative therapy for gastric cancer, clinical staging before treatment appears to be increasingly important for prognosis, yet there are no data on the subject for resectable gastric cancer patients.

OBJECTIVES

To evaluate the prognostic role of preoperative locoregional staging in gastric cancer patients undergoing curative resection.

METHODS

We reviewed 1964 gastric cancer patients who underwent curative resection without preoperative therapy from 2001 to 2005. We performed computed tomography and clinical staging according to both the International Union Against Cancer (UICC)/American Joint Committee on Cancer (AJCC) (sixth edition) classification system, which bases N stage on the number of involved nodes, and the Japanese Classification of Gastric Carcinoma (JCGC) system, which bases N stage on node location.

RESULTS

The 5-year survival rates for patients with clinical T1, T2, T3, and T4 disease were 94.5%, 83.6%, 57.7%, and 35.5%, respectively (P < 0.001). The 5-year survival rates were 89.4% and 68.3%, respectively, for patients with clinical UICC/AJCC N0 and N1 disease (P < 0.001) and 89.4%, 72.4%, 61.0%, and 41.9%, respectively, for patients with clinical JCGC n0, n1, n2, and n3 disease (P < 0.001). When the JCGC system was applied within the UICC/AJCC N1 category, the 5-year survival rates significantly decreased, going from n1 (72.4%) to n2 (61.0%) to n3 (38.2%) (P < 0.001). In multivariate analysis, clinical T and N stage remained significant prognostic factors for overall survival.

CONCLUSIONS

Clinical stage is an independent predictor of long-term survival in the preoperative setting. It should be incorporated as a stratification factor in a randomized clinical trial of preoperative therapy for gastric cancer patients.

Enhancement the prediction of postoperative survival in gastric cancer by combining the negative lymph node count with ratio between positive and examined lymph nodes

BACKGROUND

The purpose of this study was to evaluate the impact of the negative lymph node (NLN) count on the prognostic prediction of the ratio between positive and examined lymph nodes (RML) in gastric cancer after curative resection.

METHODS

The positive and negative node counts were determined for 456 patients who underwent curative resection for gastric cancer. Overall survival was examined according to clinicopathologic variables. The correlation between the NLN count and the aforementioned best variable for prediction the disease-specific overall survival was examined.

RESULTS

The NLN count cutoffs were designed as 0-9, 10-14, and > or =15, with the 5-year survival rate 4.1, 30.7, and 74.8%, respectively. RML of 98 patients who had an NLN count of nine or fewer was > or =40%. The median survival of these patients was 12 months. Of 88 patients who had 10 to 14 NLN count, 7 had 74-month median survival with 0.1-10% RML, 52 had 47-month median survival with 10.1-40% RML, and 29 had 22-month median survival with >40% RML. Of 270 patients who had > or =15 NLN count, 157 had 114-month median survival without positive nodes, 62 had 98-month median survival with 0.1-10% RML, 45 had 40-month median survival with 10.1-40% RML, and 6 had 14-month median survival with >40% RML.

CONCLUSIONS

The NLN count is a key factor for improvement of survival prediction of RML in gastric cancer.

Determining of metastatic lymph node ratio in patients who underwent D2 dissection for gastric cancer

The purpose of this study was to determine outcome of the ratio of metastatic lymph nodes to the total number of dissected lymph nodes (MLR) in patients with gastric cancer. We retrospectively analyzed 111 patients who underwent D(2) lymph node dissection. The prognostic factors including UICC/AJCC TNM classification and MLR were evaluated by univariate and multivariate analysis. The MLR was significantly higher in patients with a larger tumor, lymphatic vessel invasion, blood vessel invasion and perineural invasion, and advanced stage. Moreover, the MLR was significantly associated with the depth of invasion and the number of lymph node metastasis. The univariate analysis revealed for overall survival (OS) that stage of disease, lymphatic vessel invasion, blood vessel invasion, perineural invasion, lymph node metastasis (UICC/AJCC pN stage) and MLR were relevant prognostic indicators. Furthermore, both UICC/AJCC pN stage and MLR were detected as prognostic factor by multivariate analysis, as was perineural invasion. Our results indicated that MLR and UICC/AJCC pN staging system were important prognostic factors for OS of patients with D(2) lymph node dissection in gastric cancer in a multivariate analysis. MLR may be useful for evaluating the status of lymph node metastasis in gastric cancer.

Clinical Significance of Telomerase Activity in Gastric Carcinoma and Peritoneal Dissemination

Telomerase activity is responsible for telomere maintenance and is believed to be crucial in most cancer cells, but its significance in gastric cancer remains unknown. This observational study investigated whether there is a relationship between telomerase activity and the development of gastric cancer, and between telomerase activity and peritoneal dissemination. Telomerase activity was measured in primary gastric cancers and in peritoneal washings from the same patients, and findings were compared with those of conventional cytology and an immunoassay for cancer antigen 125 (CA125). Positive cytological examination and telomerase activity in peritoneal washings both correlated with the histological grade, depth of tumour invasion, area of serosal invasion and peritoneal metastasis. The detection of free cancer cells in peritoneal washings by the telomeric repeat amplification protocol/enzyme-linked immunosorbent assay (TRAP–ELISA) was significantly more sensitive than cytology or the CA125 immunoassay, suggesting that this could be used to diagnose early peritoneal dissemination.

Ultrathin endoscopy versus high-resolution endoscopy for diagnosing superficial gastric neoplasia

BACKGROUND

Ultrathin endoscopy (UTE) is an acceptable and cost-effective alternative to EGD with the patient under sedation, although the diagnostic accuracy of UTE is not well established.

OBJECTIVE

To compare the diagnostic accuracy of UTE and high-resolution endoscopy (HRE) for superficial gastric neoplasia.

DESIGN

Prospective comparative study.

SETTING

Academic center.

PATIENTS AND INTERVENTIONS

Patients with or without superficial gastric neoplasia underwent peroral UTE and HRE, back-to-back in a random order while under standard sedation. The procedures were performed by 2 endoscopists who were blinded to the clinical information.

MAIN OUTCOME MEASUREMENTS

The rate of missed lesions and misdiagnosis, sensitivity, and specificity for the diagnosis of gastric neoplasia when using pathology as the reference standard.

RESULTS

In total, 126 lesions (41 superficial gastric neoplasias, 85 nonneoplastic lesions) were recorded in 57 enrolled patients. For the diagnosis of gastric neoplasia, the sensitivity of UTE (58.5%) was significantly (P = .021) lower than that of HRE (78%), and the specificity of UTE (91.8%) was significantly (P = .014) lower than that of HRE (100%). The rate of missed lesions and misdiagnosis of gastric neoplasias when using UTE (41.5%) was significantly (P > .001) higher than that of HRE (22.0%). The corresponding rate of neoplasias at the proximal portion (fornix and corpus) when using UTE (29%) was significantly (P = .002) higher than that of HRE (7.2%), although the rates of neoplasias at the distal portion (angulus and antrum) were comparable for UTE and HRE.

LIMITATION

Small sample numbers in an enriched population.

CONCLUSIONS

The diagnostic accuracy of UTE is significantly lower than that of HRE for superficial gastric neoplasia, and this difference is particularly striking for neoplasias in the proximal stomach. For UTE to be used as an alternative modality, improvements in optical quality and the incorporation of additional procedures, including close-range observations and chromoendoscopy, are required to enhance visualization.

The impact of N-ratio in minimizing stage migration phenomenon in gastric cancer patients with insufficient number or level of lymph node retrieved: results from a Chinese mono-institutional study in 2159 patients

BACKGROUND

Previous studies indicate that N-ratio has significant superiority in minimizing 'stage migration' for patients with >15 lymph nodes retrieved. Whether the result is applicable to patients with < or =15 lymph nodes retrieved is still in question.

PATIENTS AND METHODS

Overall survival rates of 2159 gastric cancer patients who underwent radical resection were compared between patients with different number and level of lymph nodes retrieved according to pN [International Union Against Cancer (Union Internationale Contre le Cancer)/AJCC N stage], n (JGCA N stage) and rN (N-ratio) staging system.

RESULTS

Patient number was significantly different between insufficient and sufficient number or level retrieved group in pN and n system, respectively, but not in rN system, while overall survival rates were not significantly different between those groups. The 5-year survival rates of patients with insufficient nodes retrieved were significantly lower than those with sufficient nodes retrieved in pN and n system, but not in rN system. The hazard risk for patients with insufficient nodes retrieved was significantly higher than that for patients with sufficient nodes retrieved in pN and n system, but not in rN system.

CONCLUSION

The rN stage has more potential advantages in minimizing stage migration phenomenon for patients with insufficient number or level of lymph nodes retrieved.

The prognostic analysis of lymph node-positive gastric cancer patients following curative resection

BACKGROUND

The purpose of this study was to evaluate the appropriate prognostic indicators of lymph node-positive gastric cancer patients following curative resection.

METHODS

A retrospective study of 196 lymph node-positive patients who underwent radical gastrectomy (R0) for gastric cancer from January 1997 to December 2000 was analyzed statistically to identify the intensive indictors of prognosis.

RESULTS

In 196 evaluable patients, 5-year survival rate was 33.2%. A total of 4048 lymph nodes were examined (median, 20.6; range, 15-49), and 1661 lymph nodes were positive (median, 8.5; range, 1-37). The median survival was 29 months. With multivariate analysis, we found number and ratio of metastatic lymph nodes were associated with overall survival (OS) of lymph node-positive patients after curative surgery. However, we ultimately identified that ratio of metastatic lymph nodes was more appropriate to evaluate OS of lymph node-positive patients than number of metastatic lymph nodes by using the case-control matched fashion. One hundred forty-four (73.5%) patients had recurrence after curative surgery. The median disease-free time was 18 month, and the median survival after recurrence was 4 month. With multivariate analysis (logistic regression model), we found number of metastatic lymph nodes was associated with recurrence after curative surgery.

CONCLUSION

Ratio and number of metastatic lymph nodes were important indicators of OS and recurrence of lymph node-positive gastric cancer patients following curative resection, respectively.

The number of lymph nodes identified in a simple pancreatoduodenectomy specimen: comparison of conventional vs orange-peeling approach in pathologic assessment

Lymph node status is one of the most important predictors of survival in resectable pancreatic ductal adenocarcinoma; therefore, thorough lymph node evaluation is a critical assessment in pancreatoduodenectomy specimens. There is considerable variability in pancreatoduodenectomy specimens processed histologically. This study compares two approaches of lymph node dissection and evaluation (standard vs orange peeling) of pancreatoduodenectomy specimens. A different approach to dissection of pancreatoduodenectomy specimens was designed to optimize lymph node harvesting: All peripancreatic soft tissues were removed in an orange-peeling manner before further dissection of the pancreatic head. This approach was applied to 52 consecutive pancreatoduodenectomy specimens performed for ductal adenocarcinoma at two institutions. Specimen dissection was otherwise performed routinely. Overall number of lymph nodes harvested, number of positive lymph nodes, and their anatomic distribution were analyzed and compared with cases that had been dissected by the conventional approach. The mean number of lymph nodes identified by the orange-peeling approach was 14.1 (by institution, 13.8 and 14.4), as opposed to 6.1 (by institution, 7 and 5.3) in cases processed by conventional approach (P=0.0001). The number of lymph node-positive cases also increased substantially from 50% (by institution, 54 and 46%) in the conventional method to 73% (by institution, 88 and 58%) in the orange-peeling method (P=0.02). The orange-peeling method of lymph node harvest in pancreatoduodenectomy specimens for ductal adenocarcinoma enhances overall and positive lymph node yield and optimizes ductal adenocarcinoma staging. Therefore, lymph node harvest by the orange-peeling method should be performed routinely before specimen sectioning in assessment of pancreatoduodenectomy for ductal adenocarcinoma.

Prognostic significance of the number of metastatic lymph nodes: is UICC/TNM node classification perfectly suitable for early gastric cancer?

Metastatic lymph node (MLN) is less frequently involved in early gastric cancer (EGC) and barely exceeds six in number. The prognostic value of the 5th edition of the UICC tumor-node-metastasis (TNM) node classification appears to be less accurate when applied to patients with EGC and needs to be further stratified. Three hundred twenty-three EGC patients were enrolled into this study. Prognoses of these patients were first assessed based on the 5th edition UICC TNM classification, followed by a reevaluation in which the prognoses of patients were further stratified according to the number of MLNs involved with an increment of one node at a time. A new node classification was proposed based on the correlation between prognoses and the number of positive nodes. According to the prognostic value, a new node classification was categorized as new N0 (0 MLN), new N1 (1-3 MLNs), new N2 (4-6 MLNs), and new N3 (>6 MLNs). While the survival of N0 and N1 groups based on the 5th edition UICC TNM classification appeared to be homogeneous (p = 0.0947), significant difference was unmasked between the new N2 and new N0/N1 groups (p < 0.001). In addition, differentiation status, vessel involvement, and new node classification were identified as independent prognostic factors by multivariate analysis for EGC. We conclude that subsets exist in patients with EGC at stage IB by UICC classification; patients with >/=4 MLNs are at higher risk of recurrence and surgical outcome in this population is relatively poor.

The most appropriate category of metastatic lymph nodes to evaluate overall survival of gastric cancer following curative resection

AIMS

The purpose of this study was to provide a nodal grouping category based on metastatic lymph nodes to evaluate overall survival in gastric cancer patients following curative resection (R0).

PATIENTS AND METHODS

We reviewed data of 308 gastric cancer patients following curative resection to evaluate significantly survival differences in different categories of the number of metastatic lymph nodes.

RESULTS

In 308 evaluable patients, 5-year survival rate (YSR) was 52.9% (median follow-up, 84 months; range, 6-144 months). A total of 6309 lymph nodes were harvested and examined from all 308 patients, and the average number of lymph nodes harvested for per patient was 20.5 (range, 15-49). The average number of metastatic lymph nodes was 5.4 (range, 0-37) per patient. The initial metastatic node cutoffs were designed as 0, 1-4, 5-8, 9-11, 12-16, and >or=17. According to this new category of the number of metastatic lymph nodes, the 5-YSR of various patient groups were 85.7%, 62.8%, 34.3%, 0%, 0%, and 3.4%, respectively. However, we found that there were not significant prognostic differences between patients with 9 metastatic lymph nodes and patients with more than 9 metastatic lymph nodes (P > 0.05). So we redesigned the later cutoffs of number of metastatic lymph nodes. They were as follows: 0, 1-4, 5-8, and >or=9 of metastatic lymph nodes. We demonstrated this new category of the number of metastatic lymph nodes was more appropriate to evaluate overall survival of gastric cancer patients following curative resection than anyone of the current metastatic lymph nodal stagings (such as N stag in UICC, location of metastatic lymph nodes in JCGC, or ratio of metastatic lymph nodes) by using the case-control matched fashion.

CONCLUSIONS

Our new category of the number of metastatic lymph nodes was an important prognostic factor of gastric cancer patients following curative resection. There were significant overall survival differences in gastric cancer patient groups with various numbers of metastatic lymph nodes following curative resection.

Validation of staging systems for gastric cancer

BACKGROUND

The two major staging systems for gastric cancer, the Japanese classification of gastric cancer (JCGC) and the International Union Against Cancer (UICC) TNM system, are periodically revised as a consequence of critical validation studies in light of newly accumulated clinical data. This study aimed to validate and improve upon the current versions for a better prognostic stratification of gastric cancer.

METHODS

One thousand and ten gastric cancer patients who underwent tumor resection were enrolled at the Kitasato University Hospital for staging validation. According to the JCGC stage, the patients consisted of stage IA (n=453), IB (n=185), II (n = 119), IIIA (n=75), IIIB (n=51), and IV (n=127).

RESULTS

Regarding consistency between the JCGC and the UICC system, the results were: for patients in stage IA (100%), IB (98%), II (84%), IIIA (51%), IIIB (24%), and IV (64%). The JCGC system was superior to the UICC system for the prognostic stratification of stage IIIA, IIIB, and IV cancers; we therefore used the JCGC system for prognostic validation according to depth of invasion in cancers of the same stage. Stage II and IIIA cancers were heterogeneous for prognosis according to depth of invasion, and the outstanding difference was found between the muscularis propria (MP) and subserosa (SS), which are both classified as pT2 in the JCGC system. MP cancer represented an earlier property of gastric cancer rather than an advanced one. A proposed novel staging system adjusted for this heterogeneity provided a clearer stratification of prognosis with a homogeneous prognostic distribution within each stage.

CONCLUSION

Our findings revealed that invasion into the MP has an earlier propensity than expected, and a novel staging system taking this into account may provide a better stratification of prognosis than the current systems.

Prognostic factors and availability of D2 lymph node dissection for the patients with stage II gastric cancer: comparative analysis of subgroups in stage II

BACKGROUND

According to the fifth edition of the UICC TNM classification, stage II gastric cancer has three subgroups: T1N2M0, T2N1M0, and T3N0M0. This study was designed to investigate the prognosis of stage II gastric cancer according to the T and N category to verify the accuracy of TNM staging for stage II and to determine the prognostic factors for patients with stage II gastric cancer by subgroup.

METHODS

Clinicopathologic data from 326 patients with stage II gastric cancer were studied. We stratified the patients into T2N1 and T3N0 groups and performed comparative analysis between the two groups as well as univariate and multivariate survival analyses for each group.

RESULTS

The five-year survival rate for patients with T2N1 disease was 75.6%, whereas for patients with T3N0 disease it was 68.3%. There was no significant difference in survival between T2N1 and T3N0 groups (p = 0.174). Univariate survival analysis showed that age, gender, histological type, and the extent of lymph node dissection were significant prognostic factors for stage II gastric cancer. However, multivariate analysis demonstrated that only gender and the extent of lymph node dissection were significant variables. Among these variables, gender was an independent prognostic factor for survival only in the T2N1 group. On the other hand, the extent of lymph node dissection was an independent prognostic factor in the T3N0 group, not in the T2N1 group.

CONCLUSIONS

There was no significant difference in survival between the T2N1 and the T3N0 groups. Thus, our data support the accuracy of the TNM staging classification for stage II gastric cancer. We found a significant survival benefit with D2 dissection for T3N0 but not T2N1. However, before recommending limited lymph node dissection for T2N1 stage disease, development of a preoperative method for prediction of depth of invasion and lymph node status is needed.

Phase III trial of adjuvant 5-fluorouracil and adriamycin versus 5-fluorouracil, adriamycin, and polyadenylic-polyuridylic acid (poly A:U) for locally advanced gastric cancer after curative surgery: final results of 15-year follow-up

BACKGROUND

This phase III trial was to compare 5-fluorouracil (5-FU), adriamycin, and polyadenylic-polyuridylic acid (poly A:U) against 5-fluorouracil plus adriamycin (FA) for operable gastric cancer.

PATIENTS AND METHODS

From 1984 to 1989, patients who had D(2-3) curative resection were randomly assigned to receive chemotherapy or chemoimmunotherapy. Chemotherapy consisted of 12 mg/kg 5-FU every week for 18 months and 40 mg/m2 adriamycin every 3 weeks for 12 cycles. Chemoimmunotherapy consisted of FA plus 100 mg of poly A:U weekly for six cycles and was followed 6 months later by six weekly 50-mg booster injections.

RESULTS

A total of 292 patients were enrolled. After excluding 12 ineligible patients, 142 and 138 patients were allocated to each treatment. Patients were balanced with prognostic variables: age, sex, tumor location, differentiation, degree of tumor invasion (T2-T4a), and lymph node status (N0-N2). During the 15-year follow-up, chemoimmunotherapy significantly prolonged overall (P = 0.013) and recurrence-free (P = 0.005) survivals compared with chemotherapy alone. The survival benefits were prominent in the subset of patients with T3/T4a, N2, or stage III. Treatments were generally well tolerated in both arms.

CONCLUSIONS

These results indicate a survival advantage of chemoimmunotherapy with a regimen of FA and poly A:U in curatively resected gastric adenocarcinoma.

Prognostic impact of positive lymph node ratio in gastric carcinoma

BACKGROUND AND OBJECTIVES

To evaluate the prognostic value of metastatic lymph node ratio in gastric carcinoma.

METHODS

One hundred and sixty four patients who underwent D(2) dissection for gastric carcinoma at Ankara Oncology Hospital were reviewed retrospectively. The prognostic factors including Japanese classification, AJCC/UICC TNM classification and metastatic lymph node ratio (1-10% and >10%) were evaluated in univariate and multivariate Cox regression analysis.

RESULTS

The multivariate analysis showed that Borrmann classification, pN-category of AJCC/UICC classification and metastatic lymph node ratio were the most significant prognostic factors and a higher hazard ratio was obtained for metastatic lymph node ratio than pN category of AJCC/UICC classification (4.5 vs. 11.4). When the metastatic ratio groups of 1-10% and >10% were subdivided into pN(1), pN(2) and pN(3) categories of the AJCC/UICC classification, there was no statistical difference between survival curves. When pN(1), pN(2) and pN(3) categories of the AJCC/UICC classification were subdivided into the ratio groups of 1-10% and >10%, the survival rate of ratio group 1-10% was better than ratio group >10%.

CONCLUSION

With its simplicity and reproducibility, metastatic lymph node ratio can be used as a reliable prognostic indicator.

Ratio of metastatic lymph nodes: impact on staging and survival of gastric cancer

AIMS

No consensus exists on the level and number of lymph nodes to be dissected and examined for accurate staging of patients with resectable gastric cancer. The aim of this study was to examine the prognostic value and staging accuracy of the metastatic lymph nodes ratio (NR).

METHODS

The postoperative survival of 247 patients with gastric cancer who underwent gastrectomy was analyzed. Lymph nodes status was assigned according to three different classifications: 6th UICC/AJCC TNM; JGCA; NR (NR0: 0%; NR1: < or =20%; NR2: >20%). Staging accuracy of the three classifications was compared according to patients survival.

RESULTS

A significant difference in survival was observed in patients with NR1 versus NR2. At multivariate analysis only NR along with pT and grading were found to be independent prognostic factors. Stage migration was present in 84 cases (51%) with JGCA classification, in 30 (19%) with 6th UICC/AJCC TNM classification and in only 18 cases (11%) when NR was applied.

CONCLUSIONS

Our data showed that NR is a simply reproducible and highly reliable staging system with a strong ability to predict patients' outcome. Compared to other nodal staging classifications, NR is less influenced from the number of the lymph nodes dissected and examined, reducing the stage migration phenomenon.

pN3M0 gastric cancer: the category that allows the sub-classification of stage-IV gastric cancer (IVa and IVb)

BACKGROUND

Since the publication of the fifth edition of the UICC TNM classification, the rate of curative surgical resection for stage-IV gastric cancer has increased. It is related to the N3 category, which was the prior pN1 or pN2 in the fourth UICC TNM staging system and now pN3 in the fifth. We performed a retrospective analysis to determine whether the prognosis of N3M0 gastric cancer is different from that of other stage-IV gastric cancer; this may support sub-division of this disease.

METHODS

We analyzed 422 patients with stage-IV gastric cancer who underwent gastric resection from 1983 to 2002 at Korea University Hospital. Clinical and pathological characteristics as well as survival of the patients were evaluated retrospectively according to the TNM categories.

RESULTS

The 5-year survival rate for those with N3M0 gastric cancer was 10.5%; this was influenced by depth of invasion (P = 0.001). According to the survival analysis in patients with stage-IV subtypes, the mean survival time was 25.6 months for T1-3N3M0, 24.7 months for T4N1-2M0, 10.0 months for T4N3M0, and 13.6 months for anyT anyNM1. Thus, the survival of patients with T4N3M0 and M1 stage disease was significantly shorter than that of patients with T1-3N3M0 and T4N1-2M0 stage disease (P = 0.000).

CONCLUSIONS

Sub-classification of stage-IV gastric cancer into IVa (T1-3N3M0, T4N1-2M0) and IVb (T4N3M0, anyT anyNM1) may be helpful to predict the outcome of patients with stage-IV gastric cancer.

Classification of Lymph Node Metastases from Gastric Cancer: Comparison between N-Site and N-Number Systems. Our Experience and Review of the Literature

The tumor, node, metastasis (TNM) system has become the principal method for assessing the extent of disease, determining prognosis in gastric cancer patients, and affecting the therapy strategies. The extent of lymph node metastasis is the most important prognostic factor. The aim of this study was to compare the N-classifications of the 4th and the 5th-6th TNM editions and to evaluate retrospectively the prognostic value of the 2002 TNM edition. We evaluated 344 patients who underwent curative total or subtotal gastrectomy. Nodal involvement was detected in 221 (64%) patients. Median follow-up period was 76 months. Thirty per cent of the old N1 patients were reclassified as pN2 (18.5%) and pN3 (11.3%). Eighty-eight per cent of the old N2 patients were reclassified as pN1 (75%) and pN3 (13.7%). In reclassifying the patients, statistically significant changes were reported between 1987 and 2002 TNM stage grouping, mainly in stage IIIB and IV. The 5-year survival rate per stage group did not statistically differ between the 4th and the 5th–6th editions, although a diminutive trend was registered in the IIIA stage. pTNM stage, nodal numerical stage, nodal topographical stage, and depth of tumor invasion resulted in significantly independent prognostic factors. Our data confirm the simplicity and easy application of the new stadiation and the better prognostic stratification of the N-stage. The pN3 group showed a worse prognosis independent of location. On the other hand, prognostic value of pN1 and pN2 stage is lower, probably depending on lymph node location. In multivariate analysis, the difference between old and new TNM staging is low. Hence, we suggest comparing lymph node location and number in larger series. In our series, in pT1 tumors, neither pN2 nor pN3 involvement was found. Hence, in our opinion, for correct N-staging, 10 lymph nodes in early gastric cancer and at least 16 in the other pT-stages seem sufficient for a real pN0 stadiation.

The ratio of metastatic/resected lymph nodes is an independent prognostic factor in patients with node-positive pancreatic head cancer

OBJECTIVES

The aim of this study was to evaluate the prognostic value of nodal involvement in resected adenocarcinoma of the pancreatic head.

METHODS

For the period between 1980 and 2002, 96 patients underwent pancreaticoduodenectomy for pancreatic cancer. Lymph nodes were numbered and classified into groups according to the Japan Pancreatic Society rules. Metastatic lymph nodes were identified based on hematoxylin and eosin staining.

RESULTS

Sixty-four (66.7%) patients had positive lymph nodes. The median number of metastatic nodes was 2 (95% confidence interval [CI], 1.0-3.0) and the median ratio of metastatic/resected nodes was 9.7% (95% CI, 7.1%-14.4%). The median survival was 14.2 months (95% CI, 10.7-17.7) and was significantly higher for node-negative than node-positive patients (27.9; 95% CI, 20.9-34.9 vs. 10.6; 95% CI, 8.7-12.5; P < 0.001). The Cox proportional hazards model, including all patients, demonstrated that nodal involvement (hazard ratio [HR], 1.461; 95% CI, 1.177-12.024), moderate or poor tumor differentiation (HR, 2.330; 95% CI, 1.181-6.949), and positive resection margins (HR, 3.838; 95% CI, 1.390-10.597) were independent negative prognostic factors. If the analysis was limited to node-positive patients, lymph node ratio of more than 20% (HR, 1.364; 95% CI, 1.116-2.599), moderate or poor tumor differentiation (HR, 3.393; 95% CI, 1.041-11.061), and positive resection margins (HR, 9.400; 95% CI, 2.235-39.536) significantly correlated with a poorer survival.

CONCLUSIONS

Lymph node ratio seems to be a new promising prognostic factor in patients with respectable node-positive pancreatic head cancer.

Diagnostic accuracy of multidetector row computed tomography in T- and N staging of gastric cancer with histopathologic correlation

PURPOSE

To evaluate the diagnostic accuracy of multidetector row computed tomography (MDCT) for the preoperative T- and N staging of gastric cancer.

MATERIALS AND METHODS

Eighty-four consecutive patients with gastric cancer underwent preoperative MDCT. Except for 15 patients who did not undergo surgery, 69 patients were included in our study. Two radiologists independently evaluated the T- and N staging on the axial CT images alone and in combination with the MPR images. For N staging, the new TNM and Japanese classifications were independently used. Differences in staging accuracy for T- and N staging were assessed using the McNemar test.

RESULTS

The overall T staging accuracy of the axial and combined axial and MPR images was as follows: 67% (47 of 70 cancers) versus 77% (54 of 70 cancers) (P=0.039). The overall N staging accuracy of the axial and combined axial and MPR images was as follows: 59% (41 of 69 cancers) versus 67% (46 of 69 cancers) (P=0.180, Japanese classification) and 54% (37 of 69 cancers) versus 59% (41 of 69 cancers) (P=0.109, TNM classification).

CONCLUSIONS

Using MPR images enables more accurate preoperative T staging of gastric cancer, but not for N staging in either classification system.

[Gastric cancer: probability assessment after lymph node-negative staging and its consequences]

OBJECTIVE

To provide an approach to calculating the probability of error after lymph node-negative staging in gastric cancer.

PATIENTS AND METHOD

Retrospective data of 75 gastric resections for cancer were used to calculate the probability of error in general, according to T staging of the TNM classification (6th edition) and according to the type of lymphadenectomy performed. A modification of a procedure based on Bayes' theorem was used.

RESULTS

For all tumors, at least 11 negative lymph nodes were required to ensure a true pN0. Two lymph nodes were required for T1 tumors, 11 for T2 tumors, and 14 for T3 tumors. A greater number of lymph nodes were required for a D2 lymphadenectomy than for a D1 lymphadenectomy. However, in D2 lymphadenectomy, pN0 stages were almost always reliable, while in D1 lymphadenectomy 24% of stagings were unreliable.

CONCLUSIONS

The present study describes a simple and reproducible mathematical model that could help surgeons to determine the accuracy of lymph node-negative stages in a substantial group of patients with gastric cancer.

Inadequacy of lymph node staging in gastric cancer patients: a population-based study

BACKGROUND

In 1997, examination of at least 15 lymph nodes was recommended for adequate gastric cancer staging. However, the proportion of patients undergoing an adequate lymph node examination (LNE) has not been studied in a population-based manner.

METHODS

We used Surveillance, Epidemiology, and End Results cancer registry data to assess LNE adequacy in adults with nonmetastatic gastric adenocarcinoma. We selected patients aged 18 through 80 years whose disease was diagnosed from 1998 through 2001 and who underwent at least partial gastrectomy. We evaluated the overall number of nodes, estimated the likelihood of adequate LNE (i.e., > or =15 nodes examined), and determined the influence of selected tumor and patient characteristics on LNE.

RESULTS

In this 4-year period, 3593 patients met our study's selection criteria. The median number of nodes examined was 10: 32% of patients underwent adequate LNE, and 9% of patients had no nodes examined. Node-positive patients were more likely to have undergone an adequate LNE than node-negative patients (42% vs. 23%; P < .0001). Younger age, female sex, and more radical surgery were associated with adequate LNE in both univariate and multivariate analysis (P < .0001). Geographical site was an important predictor; patients from one registry (Hawaii) were significantly more likely to have undergone adequate LNE than patients from all other registries (56% vs. 30%; P < .0001).

CONCLUSIONS

Our 4-year review of the Surveillance, Epidemiology, and End Results database revealed that only a third of patients with gastric cancer underwent adequate LNE, i.e., had the recommended minimum of 15 nodes examined for gastric cancer staging. Better results at one registry (Hawaii) indicate that substantial improvements could be made.

Developing an appropriate staging system for esophageal carcinoma

BACKGROUND

Development of an optimal staging system for esophageal cancer is essential to estimate prognostic factors accurately and treat them appropriately. In this study, we evaluated the surgical outcomes of esophageal cancer according to five existing staging systems and assessed their prognostic significance.

STUDY DESIGN

For 113 patients with esophageal cancer who had undergone curative resection, lymph-node metastasis was classified using the 8th and 9th editions of the Japanese classification, the 6th edition of the Union Internationale Contre le Cancer (UICC) TNM classification, and systems based on the number (0, 1 to 3, or > or = 4) or ratio (0, < 0.15, or > or = 0.15) of metastatic lymph nodes. Survival and prognostic factors of the respective stages were evaluated.

RESULTS

Univariate analysis of disease-specific survival revealed that depth of invasion and lymph-node classification notably affected prognosis. Multivariate analysis confirmed that each classification independently influenced prognosis. According to the criteria of the two Japanese classifications, there was no clear correlation between lymph-node stage and survival. The Union Internationale Contre le Cancer/TNM classification, and those based on the number or ratio of metastatic lymph nodes showed a clear correlation between lymph-node metastasis and survival. These systems had better stratification than the Japanese classifications.

CONCLUSIONS

Staging systems for esophageal cancer based on the number or ratio of metastatic lymph nodes showed better prognostic significance than those based on the anatomic distribution of metastatic lymph nodes, because of their good stratification and clinical utility. Such classifications are suitable for use throughout the world.

Adjuvant therapy in gastric cancer

Gastric cancer has a poor prognosis. The majority of patients will relapse after definitive surgery, and 5-year survival after surgery remains poor. The role of adjuvant therapy in gastric cancer has been controversial given the lack of significant survival benefit in many randomized studies so far. The results of a large North American study (Gastrointestinal Cancer Intergroup Trial INT 0116) reported that postoperative chemoradiotherapy conferred a survival advantage compared with surgery alone, which has led to the regimen being adopted as a new standard of care. However, controversies still remain regarding surgical technique, the place of more effective and less toxic chemotherapy regimens, and the use of more modern radiation planning techniques to improve treatment delivery and outcome in the adjuvant and neoadjuvant setting. This article reviews the current status of the adjuvant treatment for gastric cancer including discussion on the research directions aimed at optimizing treatment efficacy. Issues such as the identification of patients who are more likely to benefit from adjuvant therapy are also addressed. Further clinical trials are needed to move towards better consensus and standardization of care.

Status of extended lymph node dissection: Locoregional control is the only way to survive gastric cancer

There are many factors that are of influence on gastric cancer treatment. The only way to survive is complete locoregional control. More extended dissections should lead to better outcome, but increased morbidity and mortality probably offset its long-term effect in survival in randomised studies. In this article the factors of influence on outcome of gastric cancer treatment such as the extent of lymph node dissection, splenectomy, pancreatectomy, age, volume and additional treatments are discussed. A literature review of these factors in relation to the latest results of the Dutch Gastric Cancer Trials are presented. If morbidity and mortality can be reduced there might be an advantage of extended lymph node dissection. Splenectomy and pancreatectomy should be performed only in case of direct in growth from the tumour into these organs. Centralisation of gastric cancer treatment should be achieved in order to improve results and to facilitate research. By refining selection criteria in the treatment of gastric cancer further improvements are to be expected.

Detection of sentinel lymph nodes in gastric cancers based on immunohistochemical analysis of micrometastases

BACKGROUND AND OBJECTIVES

The sentinel lymph node (SN) theory has the potential to change the trend of surgery for gastric cancer that is based on wide resection of the stomach with dissection of regional lymph nodes. However, feasibility tests of SN mapping procedures in gastric cancers with analysis of micrometastasis are rare. This study aimed to estimate the clinical usefulness of SN mapping using a dual procedure with dye- and gamma probe-guided techniques for gastric cancers, based on immunohistochemical staining (IHC) analysis.

METHODS

SN mapping procedures were performed on 41 patients with T1-T2 gastric cancer, and gastrectomy with D2 lymphadenectomy followed. All SNs and non-SNs obtained from the patients were tested by IHC analysis using anti-cytokeratin antibodies.

RESULTS

Using the dual mapping procedure, SNs were detected in all patients (100%). SN was positive in all patients with lymph node metastasis except in one with non-solid type poorly differentiated adenocarcinoma with marked lymphatic permeation, thus achieving an accuracy rate of 98%.

CONCLUSIONS

The method was accurate in predicting nodal status and could be an indicator for less invasive treatment in patients with gastric cancer.

Correlation of histological heterogeneity and lymph node metastasis in gastric adenocarcinoma

AIM: To study the possible correlation between the intratumor histological heterogeneity and degree of lymph node metastasis in gastric adenocarcinoma and to explore the clinical significance of histological heterogeneity in gastric adenocarcinoma.

METHODS: Tumor specimens were collected from 138 gastric adenocarcinoma cases in which lymph nodes were also checked. All tumor specimens were consecutively cut into serial sections and examined by microscope. The intratumor histological heterogeneity was defined by finding of at least two histological subtypes. Total number of metastatic lymph nodes was counted. And staging was conducted according to the classification of UICC/AJCC standard. The N stage distributions of intratumor histological heterogeneity were examined and compared.

RESULTS: The incidence of intratumor histological heterogeneity was 58.7% in 138 specimens of gastric adenocarcinoma. It was two-subtype histological heterogeneity that were found in most positive specimens (69/81, 85%). More than half of them were of glandular plus poorly differential types (42/69, 60.9%). A total of 8568 lymph nodes were found in 138 cases (average 62.1). 33 cases of N₀, 36 N₁, 29 N₂ and 40 N₃ were identified according to the N classification of UICC/ AJCC standard. Intratumor histological heterogeneity was found in 36% of the N0 group and 80% of N₃ group. Distribution of intratumor histological heterogeneity displayed difference among the N stages, which was of high statistical significance (χ² = 14.86, P < 0.001). When classified through the currently prevailing method, however, the 138 sample cases of gastric adenocarcinoma presented no significant pertinence to lymph nodes metastasis and its magnitude (χ² = 5.24, P > 0.05).

CONCLUSION: The intratumor histological heterogeneity can be seen as a frequent event in gastric adenocarcinoma (58%). Intratumor histological heterogeneity is found evidently correlated with lymph node metastasis in gastric adenocarcinoma.

Gastric cancer: establishing predictors of biologic behavior with use of population-based data

BACKGROUND

Tumor thickness and nodal status are important predictors of survival following curative resection for gastric cancer. Lymphovascular invasion (LVI) is a potential predictor of biological behavior. The relationship between LVI and tumor thickness (T status) has not been established in population-based studies.

METHODS

Clinicopathological and survival data of 577 patients at nine centers, from between 1991 and 1997, was collected from patient records and a Provincial Cancer Registry. The primary endpoint of the study was death. A secondary analysis of a node-negative subgroup examined the significance of LVI with respect to T status.

RESULTS

The population disease-specific survival was 28%. In a multivariate analysis, T, N, M, esophageal margin, tumor morphology, and residual tumor category were independent predictors of survival. LVI was documented in 58% of resected tumors. LVI correlated with advancing T and N status but was not significant in a multivariate population model. Subgroup analysis of node-negative gastric cancer found T status and LVI to be independent predictors of survival. LVI was associated with a 5-year survival of 8%, versus 43% among patients in whom it was absent (P <.001).

CONCLUSIONS

T status and N status were the most important independent predictors of survival in a population-based study of gastric cancer. LVI correlated with advancing N and T status. Multivariate analysis of node-negative patients showed LVI and T status are independent predictors of survival.