Prognostic significance of lymph node metastasis in advanced carcinoma of the stomach

Prognostic Performance of Three Lymph-Node Staging Systems on Gastric Signet-Ring-Cell Carcinoma

BACKGROUND

The lymph-node staging system can predict the prognosis of gastric signet-ring-cell carcinoma (SRCC). However, there are significant differences in lymph-node status between early SRCC and advanced SRCC. Additionally, the optimal system for early and advanced SRCC remains unknown.

METHODS

This study retrospectively analyzed 693 SRCC patients who underwent radical resection in the Department of Gastrointestinal Surgery, Harbin Medical University Cancer Hospital. The predicted performance of three lymph-node staging systems, including pN staging, lymph-node metastasis rate (LNR), and log odds of positive lymph nodes (LODDS), was compared using the receiver characteristic operating curve (ROC) and c-index. The Kaplan-Meier method and the log-rank test analyzed the overall survival of patients. The Cox risk regression model identified independent risk factors associated with patient outcomes. The nomogram was made by R studio.

RESULTS

The 693 SRCC included 165 early SRCC and 528 advanced SRCC. ROC showed that LODDS had better predictive performance than pN and LNR in predicting prognosis regardless of early or advanced SRCC. LODDS can be used to predict the prognosis of early and advanced SRCC and was an independent risk factor associated with patient outcomes (p = 0.002, p < 0.001). Furthermore, the nomogram constructed by LODDS and clinicopathological features had good predictive performance.

CONCLUSIONS

LODDS showed clear prognostic superiority over both pN and LNR in early and advanced SRCC.

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.

Deep-UV excitation fluorescence microscopy for detection of lymph node metastasis using deep neural network. Sci Rep. 2019;9:16912. [PMID: 31729459 PMCID: PMC6858352 DOI: 10.1038/s41598-019-53405-w]

Deep-UV (DUV) excitation fluorescence microscopy has potential to provide rapid diagnosis with simple technique comparing to conventional histopathology based on hematoxylin and eosin (H&E) staining. We established a fluorescent staining protocol for DUV excitation fluorescence imaging that has enabled clear discrimination of nucleoplasm, nucleolus, and cytoplasm. Fluorescence images of metastasis-positive/-negative lymph nodes of gastric cancer patients were used for patch-based training with a deep neural network (DNN) based on Inception-v3 architecture. The performance on small patches of the fluorescence images was comparable with that of H&E images. Gradient-weighted class activation mapping analysis revealed the areas where the trained model identified metastatic lesions in the images containing cancer cells. We extended the method to large-size image analysis enabling accurate detection of metastatic lesions. We discuss usefulness of DUV excitation fluorescence imaging with the aid of DNN analysis, which is promising for assisting pathologists in assessment of lymph node metastasis.

[Micrometastasis in Gastric Cancer]

Although the incidence and mortality rate of gastric cancer have been steadily declining, gastric cancer is still the fourth most common cancer in the world and more than 50% of cases occur in Eastern Asia. In Korea, gastric cancer is the second most common cancer and third cause of cancer related death. The standard surgical procedure for resectable advanced gastric cancer is D2 lymphadenectomy with radical gastrectomy. Even though R0 resection was completed, recurrence is relatively common, and contributes to the limited survival of the patients in gastric cancer. As a clinically relevant factor for detection of the recurrence, the presence of isolating tumor cells has been introduced and it is so called as 'micrometastasis'. Numerous immunohistochemistry and molecular studies have shown that micrometastasis can be demonstrated not only in lymph nodes but also in such body compartments as the bone marrow, peritoneal cavity and blood. Herein, we review the current knowledge and evidence of the prognostic significance of micrometastasis in peritoneal, lymph node, bone marrow. Also, we discuss the current state of research on the circulating tumor cell in peripheral blood.

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

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

Novel surgical approach based on the sentinel node concept in patients with early gastric cancer

Recent prospective multicenter trials have demonstrated the clinical safety and efficacy of sentinel node navigation surgery (SNNS) in patients with early gastric cancer. Further, development of an intraoperative imaging system and an indocyanine green fluorescence imaging approach has been attracting attention as a novel tool for detection of the sentinel node (SN). The greatest advantage of an in vivo imaging system is that it visualizes SN and afferent lymphatic vessels from the primary tumor site more clearly than the conventional dye approach. Besides visualization of the SN, it is also essential to accurately assess the presence or absence of lymph node metastasis in the intraoperative management of SNNS. However, the clinical significance of lymph node micrometastasis (LNM) in patients with gastric cancer remains controversial. Reverse transcription‐polymerase chain reaction (RT‐PCR) is one of the representative assays used to identify LNM. A rapid RT‐PCR assay that completes the detection of LNM within approximately 40 minutes has recently been produced and applied in the clinical management of SNNS. From the viewpoint of surgical methods, modified laparoscopic and endoscopic cooperative surgery with non‐exposed approaches has recently been highlighted as a promising technique to prevent tumor dissemination caused by surgical procedures, and is likely to be clinically applied to SNNS in the future. When carrying out SNNS as a minimally invasive surgery, it is important to consider the balance between post‐surgical quality of life and curability. Future prospective studies on SNNS will greatly contribute to furthering its establishment as a beneficial procedure for patients with early gastric cancer.

Alternative staging of regional lymph nodes in gastric cancer

The TNM pN stage based on the number of metastatic lymph nodes is an independent prognostic factor in gastric cancer. Many studies have highlighted the phenomenon of stage migration and problems in comparing groups of patients with different numbers of total lymph nodes harvested within TNM staging. The current version of UICC/AJCC and JGCA TNM classifications postulates a minimal number of 16 lymph nodes as the base for N stage determination. Alternative systems such as lymph node ratio (LNR), positive to negative lymph node ratio (PNLNR), and LOGODDS (or LODDS), were implemented to increase the quality of LN assessment. These methods have reached the background in the literature, but to date no standard approach according to the cut-offs for the stages has been implemented. LOGODDS is the method that most reflects the number of harvested lymph nodes. The rationale for alternative staging methods, their correlations, and limitations are presented.

The clinical usefulness of the intraoperative detection of sentinel lymph node metastases by a rapid RT-PCR system in patients with gastric cancer

BACKGROUND

The incidence of pathological lymph node metastases in patients with gastric cancer is 5% to 10%, which means that approximately 90% of patients with gastric cancer may undergo unnecessary lymphadenectomy. The precise intraoperative diagnosis of sentinel lymph node (SN) metastases is essential. The purpose of the current study was to verify the usefulness of a rapid reverse transcriptase-polymerase chain reaction (RT-PCR) system compared with hematoxylin and eosin staining for such diagnoses.

METHODS

A total of 113 patients with clinical T1-T2 (cT1-T2) gastric cancer, including 73 patients with cT1cN0 disease with a tumor diameter <4 cm, were enrolled in the current study. SNs were identified by a radioisotope method. Carcinoembryonic antigen and cytokeratin 19 were used as markers for RT-PCR and the cutoff values were set using 1701 lymph nodes harvested from 157 patients with gastric cancer.

RESULTS

SNs were detected in all 113 patients. Sensitivity and accuracy for detection by paraffin section were both 100% in patients with cT1 disease and were 60% and 90%, respectively, in patients with cT2 disease. The sensitivity of RT-PCR for the detection of pathological SN metastases was 92.3%. Furthermore, 11 patients had SN metastases detected only by RT-PCR, and these patients had frequent lymphatic invasion. Hematoxylin and eosin staining detected SN metastases in 6 of 73 patients with cT1cN0 gastric cancer; RT-PCR and frozen section detected SN metastases in 6 and 4 of these patients, respectively. Accordingly, the sensitivity of RT-PCR and frozen section for the detection of those pathological SN metastases were 100% and 66.6%, respectively.

CONCLUSIONS

The rapid RT-PCR system appears to have clinical usefulness for the intraoperative detection of SN metastases in patients with gastric cancer.

Current status and scope of lymph node micrometastasis in gastric cancer

Recently, lymph node micrometastasis has been evaluated for its prognostic value in gastric cancer. Lymph node micrometastasis cannot be detected via a usual pathologic examination, but it can be detected by using some other techniques including immunohistochemistry and reverse transcription-polymerase chain reaction assay. With the development of such diagnostic techniques, the detection rate of lymph node micrometastasis is constantly increasing. Although the prognostic value of lymph node micrometastasis remains debatable, its clinical impact is apparently remarkable in both early and advanced gastric cancer. At present, studies on the prognostic value of lymph node micrometastasis are evolving to overcome its current limitations and extend the scope of its application.

Resection of distal gastric tube cancer with sentinel node biopsy: a case report and review of the literature

Background

The frequency of gastric tube cancershas increased with advances in surgical techniques and improvement of survival rates in patients with esophageal cancer. However, a standard surgical treatment has not yet been established. Total resection of the gastric tube with lymphadenectomy has been considered a radical treatment, while repeat surgery with both laparotomy and thoracotomy has been associated with severe complications, including anastomotic leakage, recurrent nerve paralysis, bronchotracheal injury, and damage to other organs.

Case presentation

We present a successful case of a gastric tube cancer that was treated with surgical resection in combination with sentinel node biopsy. The tumor was diagnosed as a type 0-IIc lesion with ulceration, and was located proximal to the pyloric ring. Endoscopic submucosal dissection was not indicated because the primary lesion was submucosally invasive, and undifferentiated. By the dye-guided method, sentinel nodes were detected along the right gastroepiploic artery and vein. Intraoperative pathological examination revealed no metastasis of the sentinel nodes. Resection of the distal gastric tube was safely performed with a Roux-en-Y reconstruction, preserving the right gastroepiploic artery and vein and the perfusion of the proximal gastric tube.

Conclusion

We suggest distal resection of the gastric tube with sentinel node biopsy as a novel surgical method for a cT1N0 gastric tube cancer located in the abdomen.

Should lymph node micrometastasis be considered in node staging for gastric cancer?: the significance of lymph node micrometastasis in gastric cancer

BACKGROUND

In TNM staging system, lymph node staging is based on the number of metastatic lymph nodes in gastric cancer and micrometastasis is not considered. Several reports proposed the importance of lymph node micrometastasis as the causative factor for recurrence and poor survival, but it remains controversial among researchers.

METHODS

A total of 482 gastric cancer patients who underwent curative resection from 2004 to 2010 at Korea University Medical Center Ansan Hospital, South Korea were prospectively enrolled. For detecting lymph node micrometastasis, immunohistochemical staining with anti-cytokeratin antibody (CAM 5.2) was performed on negative lymph nodes by hematoxylin-eosin (H-E) staining. Survival differences were compared between conventional node staging and new node staging that took micrometastasis into consideration. Also, the prognostic value of lymph node micrometastasis was investigated in multivariate analysis.

RESULTS

A total of 156 patients (32.4%) showed lymph node micrometastasis. Overall, the micrometastatic group had more advanced tumor and lymph node stage, lymphovascular cancer cell invasion, a higher rate of recurrence, and poor survival. Furthermore, when the cumulative numbers of macro- and micrometastatic lymph nodes were calculated together, the discriminative power of survival difference between each node stage became more stratified. Also, multivariate analysis using Cox's proportional hazards model demonstrated perineural invasion, pathologic T stage, dissected lymph nodes, macro- and micrometastatic lymph nodes are independent prognostic factors.

CONCLUSIONS

Lymph node micrometastasis was clinically significant as a risk factor for recurrent gastric cancer. Lymph node micrometastasis should be considered when estimating TNM stage for determining prognosis and the best treatment strategy.

Robotic gastrectomy versus laparoscopic gastrectomy for gastric cancer: comparison of surgical performance and short-term outcomes

PURPOSE

This study was designed to compare robot-assisted gastrectomy with laparoscopy-assisted gastrectomy in surgical performance and short-term clinical outcomes for gastric cancer and evaluate the safety and feasibility of robotic surgery.

METHODS

A retrospective database of patients who underwent robotic or laparoscopic gastrectomy for gastric cancer between March 2010 and May 2013 was examined. After screening, 514 patients who underwent gastrectomy for gastric cancer were enrolled in this study: 120 robotic and 394 laparoscopic surgery. Patient demographics, surgical performance, and short-term clinical outcomes were examined.

RESULTS

All operations were performed successfully. The clinicopathologic characteristics were similar between the two groups. Compared with the laparoscopic group, the robotic group had less intraoperative blood loss (118.3 ± 55.8 vs. 137.6 ± 61.6 ml, P < 0.001), more lymph nodes dissection (34.6 ± 10.9 vs. 32.7 ± 11.2, P = 0.013), and longer operation time (234.8 ± 42.4 vs. 221.3 ± 44.8 min, P = 0.003). The survival rates were 90.2% at 1 year, 78.1% at 2 years, and 67.8% at 3 years in the RAG group compared with 87.3% at 1 year, 77.1% at 2 years, and 69.9% at 3 years in the LAG group. The difference in overall survival rate between the two groups was not statistically significant (P = 0.812). In view of lymph node involvement, the 3-year survival rates for patients with negative nodal metastasis were 84.4% in the RAG group versus 82.6% in the LAG group (P = 0.972) and 57.5% in the RAG group versus 60.3% in the LADG group (P = 0.653) for those with positive nodal metastasis.

CONCLUSIONS

Comparing well with laparoscopic gastrectomy, robot-assisted gastrectomy is a feasible and safe surgical procedure with clear operation field, precise dissection, minimal trauma, and fast recovery. Longer follow-up time and randomized, clinical trials are needed to evaluate the clinical benefits and long-term oncological outcomes of this new technology.

The prognostic impact of occult lymph node metastasis in node-negative gastric cancer: a systematic review and meta-analysis

PURPOSE

To conduct a meta-analysis to clarify whether occult lymph node metastasis (OLNM), which is identified by molecular detection techniques but is not detected by routine histological examination within regional lymph nodes, represents a prognostic factor for patients with node-negative gastric cancer.

METHODS

PubMed, Embase, and the Cochrane Library were searched from their inception to November 2012. The published studies that investigated the association between OLNM and the prognosis of patients with node-negative gastric cancer were included. We extracted hazard ratios (HRs) and associated standard errors from the identified studies and performed random-effects model meta-analyses on overall survival and disease-specific survival. Subgroup analyses were also conducted.

RESULTS

A total of 14 eligible studies that included 1,478 patients were identified. Meta-analyses revealed that OLNM was associated with poor overall survival [HR 2.72; 95% confidence interval (CI) 1.61-4.60], and disease-specific survival (HR 2.91; 95% CI 1.25-6.79). Subgroup analyses suggested that OLNM was associated with poor survival in early gastric cancer (HR 3.57; 95% CI 1.23-10.33). However, subgroup analyses of studies that exclusively enrolled patients with D2 lymph node dissection demonstrated that OLNM did not have an influence on the prognosis (HR 1.97; 95% CI 0.82-4.70).

CONCLUSIONS

OLNM correlates with poor prognosis for patients with node-negative gastric cancer, and D2 lymph node dissection could eliminate this correlation. For OLNM-positive patients with node-negative gastric cancer, D2 lymph node dissection is necessary.

Detection of metastatic lymph nodes using 5-aminolevulinic acid in patients with gastric cancer

BACKGROUND

Precise diagnosis of lymph node metastases is essential to select therapeutic strategy for patients with gastric cancer, and rapid intraoperative diagnosis is useful for performing less invasive surgery. In this study, we focused on a known photosensitizer, 5-aminolevulinic acid (5-ALA), and examined the feasibility of 5-ALA-induced protoporphyrin IX (PpIX) fluorescence to detect metastatic foci in excised lymph nodes of patients with gastric cancer.

METHODS

A total of 144 lymph nodes obtained from 14 gastric cancer patients were examined. The patients were administered 5-ALA orally before surgery. Excised lymph nodes were cut in half and observed by fluorescence microscopy. The diagnostic results were compared to those of the routine histopathological examination.

RESULTS

Observed red fluorescence of PpIX was identical to the metastatic focus, with 84 % accuracy. Twelve non-metastatic lymph nodes showed unexpected PpIX accumulation to lymphoid follicles, but these could be discriminated based on their characteristic fluorescence patterns. With incorporation of this morphological consideration, this method demonstrated good diagnostic power with 92.4 % accuracy. On the quantitative analysis using the signal intensity ratio of red to the sum of red, green, and blue (R/(R + G + B) ratio) as an index corresponding to red fluorescence of PpIX, metastatic lymph nodes showed significantly higher value than non-metastatic lymph nodes (p < 0.0001). The area under the curve was calculated as 0.832 throughout Receiver operating characteristic analysis.

CONCLUSIONS

Our results demonstrated that 5-ALA-induced fluorescence diagnosis is a simple and safe method and is a potential candidate for a novel rapid intraoperative diagnostic method applicable to clinical practice.

Clinical significance of integrin αvβ6 expression effects on gastric carcinoma invasiveness and progression via cancer-associated fibroblasts

Over-expression of integrin αvβ6 and increased numbers of cancer-associated fibroblasts (CAFs) play an important role in the development and progression of cancers. The aim of this study is to investigate the expression level of integrin αvβ6 and CAF numbers, their correlation with clinicopathologic features and their role in the prognosis of human gastric cancers. The expression levels of integrin αvβ6 and α-SMA in CAFs were analyzed by immunohistochemistry. Their correlation with clinicopathologic features, the relationships and the survival time of patients were also analyzed. The integrin αvβ6 expression levels were analyzed mainly in gastric cancers. The α-SMA expression levels were analyzed mainly in gastric cancers and paraneoplastic tissues. Patients with positive integrin β6 and α-SMA expression have a significantly lower overall survival rate than those with negative integrin β6 and α-SMA expression (P < 0.05). A multivariate analysis using a log-rank test indicated that patients with positive integrin β6 and α-SMA expression and/or a diffuse type of gastric cancer had a significantly poorer overall survival rate than did those with negative integrin β6 expression (P < 0.05). Integrin β6 expression correlated significantly with CAF numbers and served as a valuable prognostic indicator for human gastric cancers.

Comparison of three lymph node staging schemes for predicting outcome in patients with gastric cancer

BACKGROUND

Several node staging schemes have been proposed for gastric cancer. The optimal system remains controversial.

METHODS

Patients with gastric cancer were identified from the Surveillance, Epidemiology, and End Results (SEER) database, and a Chinese patient cohort was used for independent validation. The prognostic performance of three node staging schemes was compared, involving a number-based scheme (pN), ratio-based scheme (rN) and log odds of positive lymph nodes scheme (LODDS).

RESULTS

There were 12 443 patients in the SEER database and 866 in the Chinese cohort. LODDS provided better discriminatory capacity and higher predictive accuracy than either pN or rN, for patients with gastric cancer in both the SEER database and the Chinese cohort. The multivariable model using the LODDS classification was significantly more predictive than the pN classification. LODDS suffered much less from stage migration and was able efficiently to discriminate the heterogeneity for patients with no nodes involved or all nodes involved, whereas the pN and rN schemes could not.

CONCLUSION

LODDS showed a clear prognostic superiority over both pN and rN schemes. It could serve as an important reference for the tumour node metastasis (TNM) node classification.

Correlation of vascular endothelial growth factor expression with tumor recurrence and poor prognosis in patients with pN0 gastric cancer

BACKGROUND

Vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)-9 play important roles in tumor angiogenesis, development, and progression. This study investigates the expression of VEGF combined with MMP-9, their correlation with clinical characteristics, and their effect on the prognosis for patients with pN0 gastric cancer after curative surgery.

METHODS

A total of 55 patients were enrolled in the study. They were analyzed by immunohistochemistry, and their correlation with clinical characteristics was then investigated. Their relations and the survival time of patients were retrospectively analyzed.

RESULTS

VEGF and MMP-9 were positively expressed in 24 (43.6%) and 16 (29.1%) patients, respectively, and had a positive correlation (r = 0.324, p = 0.016) in the Spearman rank correlation analysis. Univariate analysis showed that VEGF, MMP-9 expression, vascular invasion, T stage, and tumor size were associated with tumor recurrence as well as the disease-specific (DSS) and overall (OS) survival rates. Patients with positive VEGF expression showed significantly higher recurrence and poorer DSS and OS rates compared with those with negative VEGF expression. Multivariate analysis showed that VEGF expression, vascular invasion, T stage (serosal invasion), and tumor size were significant independent prognostic factors for tumor recurrence, DSS, and OS in patients with pN0 gastric cancer with the exception that T stage was not for DSS.

CONCLUSIONS

VEGF expression, vascular invasion, T stage (serosal invasion), and tumor size can be used as valuable prognosticators in predicting tumor recurrence and prognosis for patients with pN0 gastric cancer after curative surgery. VEGF may have a synergistic effect with MMP-9 during tumor angiogenesis, development, and progression.

Clinical significance of lymph node micrometastasis in gastric cancer

Recently, the existence of lymph node micrometastasis (LNM), including isolated tumor cells, has been focused on during the development of molecular diagnostic tools for lymph node metastasis in various malignant neoplasms. In particular, immunohistochemistry and reverse transcription-polymerase chain reaction have been reported to be available for the detection of LNM in gastric cancer. However, at present, the clinical significance of LNM remains unclear in patients with gastric cancer. Therefore, we cannot strategically make light of this issue in clinical management. Currently, minimally invasive treatments, such as endoscopic submucosal dissection and laparoscopic surgery with personalized lymphadenectomy, are widely performed in consideration of postsurgical quality of life (QOL). However, it is important to maintain the balance between QOL and curability when selecting surgical treatments for patients with gastric cancer. If minimally invasive surgery based on LNM status was established for patients with early gastric cancer, it could be performed safely. We reviewed the clinical significance of LNM as an important strategic target in patients with gastric cancer.

Effect of negative lymph node count on survival for gastric cancer after curative distal gastrectomy. Eur J Surg Oncol. 2011;37:481-487. [PMID: 21371852 DOI: 10.1016/j.ejso.2011.01.012]

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).

Expression of B7-H4 in blood of patients with gastric cancer predicts tumor progression and prognosis

BACKGROUND AND OBJECTIVES

B7-H4 is a novel molecular B7 ligand that plays an important role as a negative regulator of the T cell-mediated immune response. However, the clinical significance of B7-H4 expression in gastric cancer remains uncertain. Here, we assessed B7-H4 expression in blood of patients with gastric cancer to determine whether or not it can predict tumor progression and prognosis.

METHODS

We measured B7-H4 mRNA expression by quantitative RT-PCR in five gastric cell lines as well as in blood specimens from 94 patients with gastric cancer and from 22 healthy volunteers.

RESULTS

Significantly more B7-H4 mRNA copies were found in gastric cell lines and in blood from patients with gastric cancer than in blood from healthy volunteers (P < 0.0001 and P < 0.0001, respectively). B7-H4 expressed in 71 (75.5%) of 94 patients with gastric cancer significantly correlated with depth of tumor invasion, lymph node metastasis, and overall stage (P = 0.006, P = 0.001, and P < 0.001, respectively). The 5-year survival rate was significantly lower in patients with than without B7-H4 expression (P = 0.04).

CONCLUSIONS

The evaluation of B7-H4 expression in blood is a useful tool for predicting the progression of gastric cancer and prognosis.

Impact of metastatic lymph node ratio in node-positive colorectal cancer

Colorectal cancer (CRC) is one of the most common malignant diseases in the world. Presently, the most widely used staging system for CRC is the tumor nodes metastasis classification system, which classifies patients into prognostic groups according to the depth of the primary tumor, presence of regional lymph node (LN) metastases, and evidence of distant metastatic spread. The number of LNs with confirmed metastasis is related to the severity of the disease, but this number depends on the number of LNs retrieved, which varies depending on patient age, tumor grade, surgical extent, and tumor site. Numerous studies and a recent structured review have demonstrated associated improvements in the survival of CRC patients with increasing numbers of LNs retrieved for examination. Hence, the impact of lymph node ratio (LNR), defined as the number of metastatic LNs divided by the number of LNs retrieved, has been investigated in various malignancies, including CRC. In this editorial, we review the literature demonstrating the clinicopathological significance of LNR in CRC patients. Some reports have indicated the advantage of considering the LNR compared to the number of LNs retrieved and/or LN status. When the LNR is taken into consideration for survival analysis, the number of LNs retrieved and/or the LN status is not always found to be a prognostic factor. The cut-off points for LNRs were proposed in numerous studies. However, optimal thresholds for LNRs have not yet received consensus. It is still unclear whether the LNR has more prognostic validity than N stage. For all these reasons, the potential advantages of LNRs in the staging system should be investigated in large prospective data sets.

Risk factors for lymph node metastasis from gastric cancers with submucosal invasion

BACKGROUND

Accurate prediction of the metastatic status of lymph nodes (LNs) is clinically important for selecting treatment strategies in patients with gastric cancer with submucosal invasion (GCSM). In this study, we determined the risk factors for lymph node metastasis (LNM), including micrometastasis, in patients with GCSM.

MATERIALS AND METHODS

A total of 5610 LNs dissected from 189 patients with GCSM who had undergone a standard gastrectomy were immunostained with CAM 5.2 monoclonal antibody to detect LN micrometastasis. Clinicopathological risk factors for lymph node metastasis (LNM), including micrometastasis, were determined.

RESULTS

LNM was detected in 216 LNs (107 macroscopic metastases, 72 micrometastases, and 37 isolated tumor cells) in 55 (29.1%) of the 189 patients with GCSM. A multivariate analysis revealed that a tumor size of more than 20 mm, a mixed- or undifferentiated-type histology, a vertical tumor invasion depth in the submucosal layer (VTIDSM) of more than 0.5 mm, and the presence of lymphatic vessel invasion (LVI) were independent risk factors for LNM. The incidences of LNM in patients with 0, 1, 2, 3, and 4 risk factors were 0, 4.5, 11.4, 36.1, and 52.9%, respectively. Among the patients with only 1 or 2 risk factors, all the metastatic lesions were located only in the first tier. On the other hand, LNM in the second tier was also detected in 24.5% of the patients with more than 3 risk factors.

CONCLUSIONS

Tumor size, histologic type, VTIDSM, and LVI are important risk factors for predicting the presence and extent of LNM in patients with GCSM.

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.

Ratio of metastatic to resected lymph nodes for prediction of survival in patients with inadequately staged gastric cancer

Background

Staging is inadequate in up to 70 per cent of patients with gastric cancer in Western countries owing to the small number of lymph nodes dissected during surgery. The aim was to determine whether using the ratio of metastatic to resected lymph nodes (LNR) might improve accuracy.

Methods

Data were analysed from patients with gastric cancer who had gastrectomy in several centres between 1986 and 1998, with dissection of 15 or fewer lymph nodes. LNRs and other prognostic factors were evaluated.

Results

From a total of 738 patients, the median number of resected nodes was 8 (range 1–15) and median LNR was 42·8 per cent. The number of metastatic nodes significantly affected survival only in univariable analysis. In a Cox proportional hazards model, patient age, depth of tumour infiltration, tumour location, and LNR were identified as independent prognostic factors. Compared with node-negative patients, the hazard ratio for an LNR of 0·1–40·0 per cent was 1·85 (P &lt; 0·001), increasing to 2·93 (P &lt; 0·001) when the LNR exceeded 40·0 per cent.

Conclusion

The LNR cannot be used as a substitute for staging with adequate lymphadenectomy. It may help to stratify patients in terms of prognosis when the number of resected lymph nodes is limited.

Vascular endothelial growth factor-C and -D expression correlates with lymph node micrometastasis in pN0 early gastric cancer

BACKGROUND AND OBJECTIVES

Vascular endothelial growth factors (VEGF)-C and -D play an important role in lymphangiogenesis, and the expressions of these factors are related to lymphatic invasion and lymph node metastasis in various malignant neoplasms. The present study investigates the expression of VEGF-C and -D in early gastric cancer and analyzes its relationship to lymph node micrometastasis determined by reverse transcription-polymerase chain reaction (RT-PCR).

METHODS

We examined 1,828 lymph nodes obtained from 80 patients with node-negative early gastric cancer. All dissected lymph nodes were examined by RT-PCR for CEA mRNA in addition to hematoxylin-eosin staining. The resected primary specimens were immunostained using anti-VEGF-C and -D polyclonal antibodies.

RESULTS

The incidence of lymph node micrometastasis determined by RT-PCR was 23.8% (19/80). The high expression of VEGF-C and -D was found in 27.5% (22/80) and in 21.3% (17/80), respectively. The expression of VEGF-C and -D was closely related to lymph node micrometastasis (P = 0.0390 and 0.0213, respectively).

CONCLUSIONS

We demonstrated a close relationship between micrometastasis and VEGF-C and -D expression of the primary tumor. Thus, levels of VEGF-C and -D expression might be useful for predicting micrometastasis in patients with early gastric cancer.

The significances of lymph node micrometastasis and its correlation with E-cadherin expression in pT1-T3N0 gastric adenocarcinoma

BACKGROUND

Recently, micrometastasis (MM) in the lymph node in gastric cancer has been detected by cytokeratin immunostaining. However, clinical significance of MM and its relationship with reduced expression of E-cadherin in primary lesion have not been well studied.

METHODS

The 4,990 lymph nodes from 184 pT1~T3N0 patients from 1995 to 2000 at Korea University Hospital were immunostained with the anticytokeratin AE1/3 antibody for detection of micometastasis. The primary lesions were also immunostained for E-cadherin expression.

RESULTS

MM in the lymph node of gastric cancer was found in 131 (2.6%) of total dissected nodes, and 31 of 184 patients (16.8%) were shown to have MM. The MM was significantly correlated with the depth of invasion, tumor size, operation method, Lauren classification, lymphovascular invasion and loss of E-cadherin expression in primary tumor. On multivariate analysis, the independent risk factors for MM were the depth of invasion and loss of E-cadherin expression. The patients with MM had significantly lower 5-year overall and disease free survival rate than those without MM.

CONCLUSION

Lymph node MM in histologically node-negative gastric cancer was significantly correlated with poor 5-year survival rate. The determination of E-cadherin expression in primary gastric tumor may be useful in prediction of the MM.

Clinical significance of the metastatic lymph-node ratio in early gastric cancer

The metastatic lymph-node ratio has important prognostic value in gastric cancer; this study focused on its significance in early gastric cancer. In total, 1,472 patients with early gastric cancer underwent curative gastrectomy between 1992 and 2001. Of these, 166 (11.3%) had histologically proven lymph-node metastasis. Prognostic factors were identified by univariate and multivariate analyses. Metastasis was evaluated using the Japanese Classification of Gastric Carcinoma (JGC) and the Union Internationale Contre le Cancer/Tumor, Node, Metastasis (UICC/TNM) Classification. The metastatic lymph-node ratio was calculated using the hazard ratio. The cut-off values for the metastatic lymph-node ratio were set at 0, <0.15, >or=0.15 to <0.30, and >or=0.30. The numbers of dissected and metastatic lymph nodes were correlated, but the number of dissected lymph nodes and the metastatic lymph-node ratio was not related. The JGC and UICC/TNM classification demonstrated stage migration and heterogeneous stratification for disease-specific survival. The metastatic lymph-node ratio showed less stage migration and homogenous stratification. The metastatic lymph-node ratio may be a superior method of classification, which provides also accurate prognostic stratification for early gastric cancer patients.

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.

Evaluation of sentinel node concept in gastric cancer based on lymph node micrometastasis determined by reverse transcription-polymerase chain reaction

OBJECTIVE

To determine the adequacy of sentinel node (SN) concept based on micrometastasis using immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR) in gastric cancer.

SUMMARY BACKGROUND DATA

The SN concept has recently been introduced in gastrointestinal tract cancers. The precise detection of lymph node metastasis including micrometastasis is important for SN navigation surgery.

METHODS

Sixty-one patients with gastric cancer who were preoperatively diagnosed with T1-T2 (cT1-T2) and N0 (cN0) were enrolled. They underwent standard radical gastrectomy with lymph node dissection. One day before surgery, 4 mCi of (99m)Technetium-tin colloid was endoscopically injected into the submucosa around the tumor. During surgery, radioisotope uptake in the lymph node was measured using Navigator GPS. All dissected lymph nodes were examined by RT-PCR in addition to hematoxylin and eosin staining and IHC.

RESULTS

Sentinel nodes were identified in all patients (100%). The incidences of metastasis determined by hematoxylin and eosin and IHC were 8.2% (5 of 61) and 13.1% (8 of 61), respectively. Micrometastases undetectable by IHC were identified in 14 patients (23.0%) by RT-PCR. Only 1 patient had micrometastasis detectable by RT-PCR in lymph nodes other than SN, but this patient had a cT2 tumor. In patients with cT1 and cN0 tumors, the false negative and accuracy rates were 0% and 100%, respectively.

CONCLUSIONS

Although the incidence of micrometastasis detected by RT-PCR was quite high, SN navigation identified such metastasis in all patients except one. Thus, the SN concept was applicable to patients with cT1 and cN0 gastric cancer, even when micrometastasis was detectable by RT-PCR.

Lymphatic invasion using D2-40 monoclonal antibody and its relationship to lymph node micrometastasis in pN0 gastric cancer

The monoclonal antibody D2-40 is a specific lymphatic endothelial markers and D2-40 staining have been applicable to evaluate lymphatic invasion in various malignant neoplasms. In the present study, we investigated lymph node micrometastasis determined by immunohistochemistry (IHC) and reverse transcription–polymerase chain reaction (RT–PCR) in all dissected lymph nodes obtained from 80 patients with node-negative gastric cancer, and analysed the relationship between micrometastasis and clinicopathological findings including lymphatic invasion of the resected primary tumour using D2-40 immunohistochemical staining. The incidence of micrometastasis determined by IHC and RT–PCR was 11.3% (nine out of 80) and 31.3% (25 out of 80), respectively. Although haematoxylin–eosin (HE) staining revealed lymphatic invasion in 11.3% (nine out of 80) of patients, D2-40 staining uncovered new invasion in 23.8% (19 out of 80) of patients. In the diagnosis of HE and D2-40 staining, the incidence of micrometastasis was significantly higher in patients with lymphatic invasion than in those without lymphatic invasion (P=0.0150 and P<0.0001, respectively). Micrometastasis correlated more closely with D2-40 than with HE staining. We demonstrated a high incidence of micrometastasis and lymphatic invasion and a correlation between them even in pN0 gastric cancer. When planning less invasive treatment, the presence of such occult cancer cells should be considered.

Metastatic lymph node ratio as a prognostic factor in gastric cancer

BACKGROUND

There is an association between the number of resected lymph node and the number of metastatic lymph nodes in gastric cancer, suggesting that pN category could be influenced by the extension of the lymphadenectomy. This study evaluates this association and proposes a comprehensive use of the ratio as prognostic factor.

METHOD

Review of 183 consecutive patients with gastric adenocarcinoma. The association between the number of resected lymph nodes and the number of metastatic lymph nodes was analysed and evaluated with other prognostic factors.

RESULTS

The number of lymph node metastases increased with the number of resected lymph nodes. The lymph node ratio was a better prognostic factor than the number of metastatic lymph nodes.

CONCLUSIONS

The metastatic lymph node ratio seems to be a good prognostic factor, but needs further evaluation.

Predictors of long-term survival in pN3 gastric cancer patients

BACKGROUND AND OBJECTIVES

Patients with pN3 gastric cancer are classified as having a stage IV disease just by virtue of having more than 15 metastatic lymph nodes according to the 5th UICC cancer staging criteria. We tried to verify whether the pN3 gastric cancer patients truly constitute a homogeneous group with the same poor prognosis by looking for predictors of long-term survival within the group.

METHODS

Medical records of 347 patients who had gastrectomy with D2/D3 lymph node dissection for gastric cancer and diagnosed with pN3 disease by pathology, between January 1987 and December 1997 were reviewed. Clinicopathologic prognostic variables were evaluated as predictors of long-term survival by univariate and multivariate analysis.

RESULTS

The overall 5-year survival rate was 13.0% (95% CI, 9.3-16.6%). The extent of gastric resection and metastatic lymph node ratio were significant independent predictors of long-term survival on multivariate analysis. The 5-year survival rates for the subtotal and total gastrectomy groups were 18.2 and 8.8%, respectively. The 5-year survival rate according to the metastatic lymph node ratio was 20.2, 8.9, and 1.9% when the ratio was <0.33, 0.33-0.67, and > 0.67, respectively.

CONCLUSIONS

Patients with pN3 gastric cancer appear to be a heterogeneous group with clinicopathologic predictors that identify subgroups with significantly different long-term prognoses. The metastatic lymph node ratio may serve as a valuable tool to predict the long-term prognosis of these patients.

Association of VCAM-1 overexpression with oncogenesis, tumor angiogenesis and metastasis of gastric carcinoma

AIM: To investigate the relationship between the expression of vascular cell adhesion molecule-1 (VCAM-1) and oncogenesis, tumor angiogenesis and metastasis in gastric carcinoma, and to evaluate the clinical significance of serum VCAM-1 levels in gastric cancer.

METHODS: Specimens from 41 patients with gastric cancer, 8 patients with benign gastric ulcer, and 10 healthy subjects were detected for the expression of VCAM-1 by immunohistochemistry. Microvessel density (MVD) was measured by counting the endothelial cells immunostained with the monoclonal antibody CD34 at × 200 magnification. Serum VCAM-1 concentrations were measured by an enzyme linked immunosorbent assay in the 41 gastric cancer patients before surgery, and at 7 d after surgery as well as in 25 healthy controls. The association between preoperative serum VCAM-1 levels and clinicopathological features, and their changes following surgery was evaluated. In addition, serum carcinoembryonic antigen (CEA) was also examined.

RESULTS: Of the 41 gastric cancer tissues, 31 (75.6%) were VCAM-1 positive. The VCAM-1 positive gastric cancers were more invasive and classified in the more advanced stage than the VCAM-1 negative ones. The VCAM-1 positive cancers were associated with more lymph node metastases than VCAM-1-negative ones (P < 0.05). The expression of VCAM-1 was detected in tissues of two of the eight patients with gastric ulcer and two of the 10 healthy controls. The expression of VCAM-1 in gastric cancer patients was significantly more frequent than that in the healthy controls and ulcer group (both P < 0.05). MVD in VCAM-1 expressing tissues was higher than that in VCAM-1 negative tissues (t = 2.13, P < 0.05). Serum VCAM-1 levels in gastric cancer patients were significantly higher than those in controls (t = 3.4, P < 0.05). There was a significant association between serum VCAM-1 levels and disease stage, as well as invasion depth of the tumor and the presence of distant metastases. The concentrations of serum CEA in gastric cancer were higher than normal controls. Both serum VCAM-1 and CEA levels decreased significantly after radical resection of the primary tumor (P < 0.05). Furthermore, the serum levels of VCAM-1 were positively correlated with the expression of VCAM-1 in the tumor tissue (r = 0.85, P < 0.05).

CONCLUSION: The expression of VCAM-1 is closely related to oncogenesis, tumor angiogenesis and metastasis in gastric carcinoma. Serum VCAM-1 level in gastric cancer patients is significantly increased compared with normal controls, which decreases significantly after radical resection of the primary tumor. The serum concentration of VCAM-1 may be considered as an effective marker of tumor burden of gastric cancer. Moreover, overexpression of VCAM-1 in gastric cancer tissue is likely a major source of serum VCAM-1.

Progressive improvement of prognosis for patients with gastric cancer (dynamic stage grouping) with increasing survival interval from initial staging: how much longer can a given survivor expect to live?

BACKGROUND

The prognosis in gastric cancer is usually defined at the time of presentation. Prognosis, however, is a variable that alters with time. Once a patient has survived for 1 year, the prognosis will change. This study examines this variable in patients who have survived from 1 to 5 years after operation.

METHODS

Of 1468 patients with gastric cancer, the next 5-year survival (5YS) of patients who already survived for 1, 2, 3, 4, and 5 years after the initial operation was examined, ie, for patients who have survived 1 year, the 5YS (the 6-year survival from operation) was calculated. Similar survival was determined for patients who had survived more than 2, 3, 4, or 5 years and reported according to stage.

RESULTS

In patients who survived 2 years, the next 5YS from that time of patients in stage III a stage was similar to that in stage II, and was similar to the 5YS of patients in stage II at the time of diagnosis. In patients who survived 3, 4, or 5 years, the next 5YS from that time of patients in stage III b and stage III a was similar to that of stage II, and subsequently improved. Similarly, the relationship between stage and survival was disordered subsequently with the passage of time. Similar improvement in survival such that 5YS from the 3rd, 4th, and 5th postoperative year approximated that of the survival of patients at an earlier stage at the time of diagnosis.

CONCLUSIONS

Survival is not only stage-dependent at the time of diagnosis but dependent on the length of survival from the initial operation. Progressive improvement in subsequent 5YS appears to approximate survival of lower-stage disease with the passage of time.

Outcome of ratio of lymph node metastasis in gastric carcinoma

BACKGROUND

The purpose of this study was to clarify the outcome of the ratio of the metastatic lymph nodes (RML) in gastric cancer patients.

METHODS

The postoperative survival of 650 patients with gastric cancer who underwent D2 curative gastrectomy was analyzed with regard to the RML. The location, number, and RML in the N1 station and in all (N1 and N2) stations were analyzed. These data were compared from the viewpoints of staging accuracy and patient survival.

RESULTS

The RML was classified as follows: RML 0, no involvement; RML 1, 0 to.1; RML 2,.1 to.25; and RML 3, >or=.25. The 5-year survival rates stratified by RML were RML 0, 86%; RML 1, 68%; RML 2, 35%; and RML 3, 16%. Cox model identified all methods of classifying lymph node metastases as independent prognostic indicators in each calculation. However, a second Cox regression revealed that RML was the only independent prognostic factor among the three methods (P <.001). Stage migration was present in 35 cases (15%) when the number was considered. However, only 15 cases (7%) were underdiagnosed when RML was used.

CONCLUSIONS

RML is a useful classification of patients with gastric cancer. It may prevent the phenomenon of stage migration.

How many nodes must be examined to accurately stage gastric carcinomas? Results from a population based study

BACKGROUND

There are few population based data about lymphadenectomy practices in resections for stomach carcinoma. The aim of the current study was to describe these practices and to determine how many nodes must be examined in order to accurately stage gastric carcinoma.

METHODS

The current study included all patients (749 patients total) with TNM Stage I, II, or III resected gastric carcinoma diagnosed over a 21 year period (1976-1996) in a well-defined French population. A model of the relationship between the proportion of positive nodes and the number of examined nodes was performed. The relationship between the proportion of positive nodes and the number of nodes examined was modeled to determine the number of nodes beyond which the proportion of N+ tumors no longer changed.

RESULTS

The average number of examined lymph nodes was 8.4 per patient. More than 15 lymph nodes were examined in 17.6% of patients. Under 10 examined nodes, the proportion of N+ classified tumors significantly decreased with the number of examined nodes, whereas it remained stable beyond this value. The type of gastrectomy and patient age were the two factors independently associated with the resection of at least 10 nodes, whereas the diagnosis period was not associated. After adjustment for the type of surgical resection, three variables independently influenced the prognosis of TNM Stage I or II tumors: extension within the gastric wall (extension T3/T4 vs. T1/T2; odds ratio [OR] = 2.05, P < 0.001), age at diagnosis (age >or= 70 years vs. < 70 years; OR = 4.06, P < 0.001), and the number of examined nodes (10 resected lymph nodes vs. 0-9; OR = 0.57, P < 0.001).

CONCLUSIONS

The current study strongly suggests that staging is not reliable when fewer than 10 lymph nodes are examined. The number of examined lymph nodes should be used as a stratification criterion in clinical trials and as an adjustment variable in survival studies.

Impact of the latest TNM classification for gastric cancer: retrospective analysis on 94 D2 gastrectomies

The aim of this study was to determine whether the latest edition of tumor-node-metastasis (TNM) classification provides reliable prognostic information. The fifth edition of TNM Classification of Malignant Tumors has introduced for gastric cancer the numeric count of involved lymph nodes whereas their topographic location was considered in earlier editions. For our study, data from 94 patients who underwent D2-gastrectomy were reviewed. The N-factor was scored according to both the Japanese Research Society for Gastric Cancer (JRSGC) classification (n) and, retrospectively, the latest TNM classification (N). Actuarial survival was calculated for both groups. The two staging systems showed similar stratification of actuarial survival with relation to N-stage; in the JRSGC classification no statistical differences were observed between n1 and n2 patients (62.7% vs. 52.5%; p = NS), whereas the 5th TNM classification showed a significant difference between N1 and N2 patients (68.5% vs. 45.0%; p = 0.04), and between N1 and the new category of N3 patients (68.5% vs. 45.0%, p = 0.03). It appears, therefore, that the numeric count of involved nodes may represent a more reliable indicator for single-case prognosis. Reclassification of all node-positive patients in our series caused an overall stage modification in 32.9% (31/94); 22 of those patients were reclassified to a less favorable stage (23.4%). In addition, 11.7% of patients (6/51) who were previously designated n1 were reclassified as N2, shifting from an expected actuarial survival after 72 months of 62.7% to 33.3%.

Prognostic value of laparoscopic ultrasound in patients with gastro-esophageal cancer

Forty-four patients with gastro-esophageal tumors regarded as resectable by conventional staging underwent laparoscopic ultrasonography (LUS). Following LUS, seven were found to be irresectable and were managed by palliative therapies. Thirty-seven patients proceeded to surgical exploration and 36 were resected (R0 80%, R1 11%, and R2 9%). All patients were reviewed until death or for a minimum of 24 months. Patients undergoing resection had a 62% 1-year survival (median 17 months; confidence intervals, CI 6-28). LUS defined nodal status indicated a trend toward prolonged survival in the node-negative group, median 22 months (CI 5-39), compared with 13 months (CI 6-20) in the node-positive group. Disease-free survival was greater in LUS node-negative patients at 29 months (CI 23-35) compared with node-positive patients at 13 months (CI 5-21) P=0.0083. LUS staging allows prediction of the likelihood of recurrence of gastro-esophageal malignancies. This may prove useful for the appropriate allocation of patients to primary and adjuvant therapies.

An evaluation of the effectiveness of extended lymph node dissection in patients with gastric cancer: a retrospective study of 1403 cases at a single institution

BACKGROUND

Many investigators have reported that extended lymph node dissection (D2 dissection) is probably an effective procedure. However, the theory that D2 dissection leads to an improvement in survival has not been confirmed in randomized trials. We attempted to confirm the effectiveness of D2 dissection with gastrectomy for gastric cancer.

MATERIALS AND METHODS

Gastric cancer patients (1403) underwent curative resection by D1 (991 patients) or D2 (412 patients) dissection with gastrectomy. Survival rates calculated for all patients and subdivided for stage, depth of invasion, and lymph node metastasis were compared between the two groups. The diagnosis of lymph node metastasis was compared between macroscopic and histological findings.

RESULTS

There was no significant difference in the survival of patients overall. However, in the patients with stage II, T1 or T2, or N1 disease, the survival of the D2 group was significantly better than that of the D1 group. The false positive rates of lymph node metastasis were 53.3% in the N1 group, 26.2% in the N2 group, and 9.2% in the N3 group. In a considerable proportion of the N1 and N2 patients, histological findings proved more or fewer metastases than macroscopic diagnosis.

CONCLUSIONS

Metastatic lymph nodes should be resected as far as possible. D2 dissection with gastrectomy is recommended for T1, N1 or T2, N1 disease, particularly in younger patients.