Effect of lymph node micrometastases on prognosis of gastric carcinoma

TUMOR MARKERS EXPRESSION LEVELS IN GASTRIC CANCER PATIENT'S PERIPHERAL BLOOD BY RT-PCR ASSESSMENT

BACKGROUND

Hematological recurrence is the second most frequent cause of failure in the treatment of gastric cancer. The detection of circulating tumor markers in peripheral blood by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) method may be a useful tool to predict recurrence and determine the patient's prognosis. However, no consensus has been reached regarding the association between the tumor markers level in peripheral blood and its impact on patient survival.

AIMS

To evaluate the expression of the circulating tumor markers CK20 and MUC1 in peripheral blood samples from patients with gastric cancer by qRT-PCR, and to verify the association of their expression levels with clinicopathological characteristics and survival.

METHODS

A total of 31 patients with gastric adenocarcinoma were prospectively included in this study. CK20 and MUC1 expression levels were analyzed from peripheral blood by the qRT-PCR technique.

RESULTS

There was no statistically significant (p>0.05) association between CK20 expression levels and clinical, pathological, and surgical features. Higher MUC1 expression levels were associated with female patients (p=0.01). There was a correlation between both gene levels (R=0.81, p<0.001), and CK20 level and tumor size (R=0.39, p=0.034).

CONCLUSIONS

CK20 and MUC1 expression levels could be assessed by qRT-PCR from total peripheral blood samples of patients with gastric cancer. CK20 levels were correlated to MUC1 levels as well as to tumor size. There was no difference in disease-free survival and overall survival regarding both genetic markers expression in this series.

Impact of Removal of Lymph Nodes on Survival in Stage I-III Gastric Signet-Ring Cell Cancer: The More, the Better?

BACKGROUND

There is an ongoing debate over the prognostic value of the number of examined lymph nodes (ELNs) in cases of gastric signet-ring cell cancer (GSRCC). In this study, we sought to evaluate the correlation between the number of ELNs and the prognosis of GSRCC and identify the optimal number of ELNs.

METHODS

A total of 1020 patients diagnosed with GSRCC between 2011 and 2018 in the National Cancer Center database were identified. Clinicopathological characteristics were retrospectively collected, and optimal cutoff values of ELNs were calculated by using X-tile. The impact of different ELNs on overall survival (OS) was compared by using Kaplan-Meier curves. We used univariate and multivariate Cox and subgroup analyses to explore the relationship between ELNs and OS. Furthermore, nonlinear correlations were investigated by using restricted cubic splines (RCSs).

RESULTS

X-tile showed that the optimal cutoff value of ELNs was 22. The 5-year OS was higher for patients with ELNs > 22 (vs. ELNs ≤ 22, 66.9% vs. 74.9%, P = 0.026). Multivariate Cox analyses showed that high ELNs were associated with superior OS (hazard ratio = 0.56, 95% confidence interval 0.43-0.74, P < 0.001). In subgroup analyses, the significant association between tumor size > 4 cm, and TNM III stage was still observed. The RCS regression model showed a U-shaped dose-response nonlinear relationship between ELNs and OS; the inflection point, as well as the lowest risk points, corresponded to 44-52 ELNs.

CONCLUSIONS

A U-shaped, nonlinear correlation with inflection points of 44-52 ELNs between ELNs and prognosis in GSRCC was identified.

Deep learning trained on lymph node status predicts outcome from gastric cancer histopathology: a retrospective multicentric study

AIM

Gastric cancer (GC) is a tumour entity with highly variant outcomes. Lymph node metastasis is a prognostically adverse biomarker. We hypothesised that GC primary tissue contains information that is predictive of lymph node status and patient prognosis and that this information can be extracted using deep learning (DL).

METHODS

Using three patient cohorts comprising 1146 patients, we trained and validated a DL system to predict lymph node status directly from haematoxylin and eosin-stained GC tissue sections. We investigated the concordance between the DL-based prediction from the primary tumour slides (aiN score) and the histopathological lymph node status (pN). Furthermore, we assessed the prognostic value of the aiN score alone and when combined with the pN status.

RESULTS

The aiN score predicted the pN status reaching area under the receiver operating characteristic curves of 0.71 in the training cohort and 0.69 and 0.65 in the two test cohorts. In a multivariate Cox analysis, the aiN score was an independent predictor of patient survival with hazard ratios of 1.5 in the training cohort and of 1.3 and 2.2 in the two test cohorts. A combination of the aiN score and the pN status prognostically stratified patients by survival with p-values <0.05 in logrank tests.

CONCLUSION

GC primary tumour tissue contains additional prognostic information that is accessible using the aiN score. In combination with the pN status, this can be used for personalised management of GC patients after prospective validation.

Feasibility of Preserving No. 5 and No. 6 Lymph Nodes in Gastrectomy of Proximal Gastric Adenocarcinoma: A Retrospective Analysis of 395 Patients

Objective

The extent of regional lymphadenectomy for proximal gastric cancer (PGC) has remained a controversy and a matter of considerable debate for a long time. We retrospectively analyzed the clinicopathological features to investigate the predictive factors for No. 5 and/or No. 6 lymph node metastases (LNMs) and evaluate the feasibility of performing proximal gastrectomy (PG) with preservation of No. 5 and/or No. 6 lymph nodes for these patients.

Method

Patients who had undergone total gastrectomy plus D2 lymphadenectomy in the Department of Gastrointestinal Surgery, Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, from January 2008 to December 2017 were retrospectively collected and analyzed.

Results

Among the 395 eligible patients in our study, 34 patients (8.61%) had No. 5 and No. 6 LNM. The degree of differentiation, Borrmann classification, vascular or perineural invasion, tumor diameter, depth of invasion, and other perigastric LNM were associated with No. 5 and/or No. 6 LNM. Multivariate analyses showed that tumor diameter ≥4 cm, No. 4 LNM positive, and No. 7, No. 8, No. 9 LNM positive were independent risk factors of No. 5 and/or No. 6 LNM. No. 5 and/or No. 6 LNM was not observed in the 105 patients who were staged from T1 to T3 and were found to be without independent risk factors.

Conclusion

The metastatic rate of No. 5 and/or No. 6 lymph node of the proximal gastric adenocarcinoma was closely associated with the diameter of the tumor and other perigastric LNMs. It is feasible to preserve No. 5 and No. 6 lymph nodes with PG for the T1-T3 patients with lower risk of No. 5 and/or No. 6 LNM.

Clinical Application of Indocyanine Green Fluorescence Technology in Laparoscopic Radical Gastrectomy

Background

This study aimed to observe the application and evaluate the feasibility and safety of indocyanine green (ICG) fluorescence technology in laparoscopic radical gastrectomy (LRG).

Methods

Patients who underwent LRG & D2 lymphadenectomy at Qilu Hospital of Shandong University were included between January 2018 and August 2019. According to whether endoscopic injection of ICG was performed, patients were assigned to the ICG group (n=107) and the control group (n=88). The clinicopathologic features, retrieved lymph nodes, postoperative recovery, and follow-up data were compared between the two groups.

Results

Baseline characteristics are comparable. The ICG group had a significantly larger number of lymph nodes retrieved (49.55 ± 12.72 vs. 44.44 ± 10.20, P<0.05), shorter total operation time (min) (198.22 ± 13.14 vs. 202.50 ± 9.91, P<0.05), shorter dissection time (min) (90.90 ± 5.34 vs. 93.74 ± 5.35, P<0.05) and less blood loss (ml) (27.51 ± 12.83 vs. 32.02 ± 17.99, P<0.05). The median follow-up time was 29.0 months (range 1.5-43.8 months), and there was no significant difference between the ICG group and the control group in 2-year OS (87.8% vs. 82.9%, P>0.05) or DFS (86.0% vs. 80.7%, P>0.05).

Conclusions

ICG fluorescence technology in laparoscopic radical gastrectomy has advantages in LN dissection, operation time, and intraoperative blood loss. The 2-year OS and 2-year DFS rates between the two groups were comparable. In conclusion, ICG fluorescence technology is feasible and safe.

The Poor Prognosis of Patients with Stage III Gastric Cancer after D2 Dissection Is Mainly due to Lymphatic Metastasis, Especially the Metastasis of No.12a LN: A Nested Case-Control Study

BACKGROUND

The prognosis of stage III gastric cancer (GC) patients based on the 8th edition TNM staging system after D2 dissection was still heterogeneous. We aimed to explore clinicopathological reasons that led to the poor prognosis of these patients, especially from a surgical aspect.

METHODS

We divided 320 stage III GC patients who underwent distal or total gastrectomy with D2 lymphadenectomy into group 1 and group 2, according to the disease-free survival (DFS), and compared the clinicopathological features between these 2 groups. Then, we divided group 1 into group 1D and group 1T and group 2 into group 2D and group 2T, according to distal or total gastrectomy. Finally, we compared the status of lymph node (LN) metastasis in each group of perigastric LN between the subgroups, respectively.

RESULTS

Univariate analyses revealed that patients' LN metastasis was the only significant difference between group 1 and group 2 (p < 0.05). Compared with group 1D, the percentage of patients who had metastatic LN in all groups of the perigastric LN (included No.1, 3, 4sb, 4d, 5, 6, 7, 8a, 9, 11p and 12a) increased in group 2D. A similar tendency was found in group 2T (included No.1, 2, 3, 4sa, 4sb, 4d, 5, 6, 7, 8a, 9, 10, 11p, 11d and 12a) compared with group 1T. Further multivariate regression analyses revealed that the increases of group No.12a and 5 LN were significant (p < 0.05) in group 2D, the increases of group No.12a, 8a and 6 LN were significant (p < 0.05) in group 2T, respectively. Among these, the increases of group No.12a LNs were the most significant (p < 0.01).

CONCLUSIONS

The poor prognosis of patients with stage III GC after D2 dissection is mainly due to lymphatic metastasis. The status of LN metastasis in the prognostic value of GC needs to be further enhanced in present staging systems. Maybe the metastasis of No.12a LN is the most significant poor prognostic factor of these patients. It points out that the dissection of No.12a LN should be carefully performed in radical gastrectomy.

Aberrant Cytokeratin 20 mRNA Expression in Peripheral Blood and Lymph Nodes Indicates Micrometastasis and Poor Prognosis in Patients With Gastric Carcinoma

Several studies suggest that peripheral blood and lymph node micrometastases may be a causative factor for gastric cancer recurrence. Cytokeratin 20 shows enriched expression in intestinal epithelial cells. This study aimed to evaluate the clinical utility of monitoring cytokeratin 20 levels in peripheral blood and lymph nodes of patients with gastric cancer for detecting micrometastasis and predicting prognosis. We detected messenger RNA levels of cytokeratin 20 in gastric cancer cell lines and in the peripheral blood of 125 patients (85 patients with gastric cancer and 40 patients with benign neoplasm) by fluorescence quantitative real-time polymerase chain reaction both before and after radical resection. In all, 1586 lymph node samples from 85 patients with gastric cancer were evaluated for cytokeratin 20 expression using real-time polymerase chain reaction, as well as by immunohistochemistry staining with anti-pan-keratin and anti-cytokeratin 20 antibodies. All patients underwent follow-up until cancer-related death or for more than 3 years after tumor resection. We found that elevated cytokeratin 20 expression in peripheral blood as detected by quantitative real-time polymerase chain reaction closely correlates with poor clinicopathological characteristics. Detecting cytokeratin 20 messenger RNA in the lymph nodes by quantitative real-time polymerase chain reaction enabled more accurate determination of the clinicopathological staging of gastric cancer, best treatment approach, and prognosis. Our findings show that patients with increased cytokeratin 20 messenger RNA expression in the peripheral blood or lymph nodes have a shorter time to recurrence and poorer overall survival.

Effect of total number of harvested lymph nodes on survival outcomes after curative resection for gastric adenocarcinoma: findings from an eastern high-volume gastric cancer center

BACKGROUND

Greater lymph node retrieval in gastric cancer improves staging accuracy and may improve survival from increased clearance of nodal micrometastasis. This retrospective cohort study investigated if more lymph nodes removed in gastric cancer increases survival and if such effect is stage-specific due to differential risks of nodal micrometastasis and systemic disease.

METHODS

The prospectively collected database of curatively resected gastric cancer patients in National Cancer Center, South Korea between 2000 and 2009 was reviewed. Disease-free survival (DFS) and overall survival (OS) for all patients and for each stage according to number of lymph nodes examined (1-30, 31-45, > 45) were analyzed.

RESULTS

Of 4049 patients, 96.6% and 98.4% underwent D2 (perigastric and extragastric) lymphadenectomy and had ≥ 15 lymph nodes examined. Mean number of nodes examined was 43. Five-year OS & DFS rates were 83.3% and 80.7%. Patients with > 45 nodes examined had significantly lower DFS (p = 0.002) and OS (p = 0.007) compared to those with 1-30 and 31-45 nodes. However, proportion of patients with > 45 nodes examined increased with stage (p = 0.0005). Per stage, there was no significant difference in DFS and OS according to number of nodes examined except for stage IIIA favoring more nodes (p = 0.018 and p = 0.044, respectively). Similar trend was seen in stage IIB. Number of examined nodes positively correlated with number of pathologic nodes for all patients (r = 0.144, p < .001) but not for stage IIB and IIIA. Number of nodes examined was a significant survival predictor in stage IIIA.

CONCLUSION

Greater lymph node harvest showed improved survival in intermediate-stage gastric cancer.

Carnoy's solution increases the number of examined lymph nodes following gastrectomy for adenocarcinoma: a randomized trial

BACKGROUND

Pathological examination of a minimum of 16 lymph nodes is recommended following surgery for gastric adenocarcinoma, despite this a longer survival is expected when 30 or more lymph nodes are examined. Small lymph nodes are difficult to identify, and fat-clearing solutions have been proposed to improve this, but there is no evidence of their clinical benefit.

METHODS

Fifty D2 subtotal gastrectomy specimens were randomized for fixation in Carnoy's solution (CS) or 10% neutral buffered formalin (NBF), with subsequent fat dissection. After dissection, the residual fat from the NBF group, instead of being discarded, was immersed in CS and dissected again. Data from 25 D2 subtotal gastrectomies performed before the study were also analyzed.

RESULTS

The mean number of examined lymph nodes was 50.4 and 34.8 for CS and NBF, respectively (p < 0.001). Missing lymph nodes were found in all cases from the residual fat group (mean of 16.9), and in eight of them (32%) metastatic lymph nodes were present; this allowed the upstaging of two patients. Lymph nodes in the CS group were smaller than those in the NBF group (p = 0.01). The number of retrieved lymph nodes was similar among the NBF and Retrospective groups (p = 0.802).

CONCLUSIONS

Compared with NBF, CS increases lymph node detection following gastrectomy and allows a more accurate pathological staging. No influence of the research protocol on the number of examined lymph nodes was observed.

Risk factors associated with splenic hilar lymph node metastasis in patients with advanced gastric cancer in northwest China

There are plenty of risk factors associated with splenic hilar lymph node metastasis (SHLNM) in patients with advanced gastric cancer (AGC). Whereas, their main influencing factors have not reached a consensus yet. The aim of the study is to investigate the related clinicopathological factors influencing SHLNM in AGC. A retrospective study was performed to investigate 150 patients who underwent D2 curative partial or total gastrectomy for gastric carcinoma from January 2007 to November 2012. Clinicopathological factors were analyzed by univariate and multivariate analysis. A total of 10.7% (16/150) of the patients had SHLNM. The overall ratio of metastatic lymph node (positive lymph nodes/lymph nodes harvested) in the splenic hilum was 17.5% (38/217). Univariate analysis results showed SHLNM was related with depth of invasion, tumor grade, tumor size, tumor location and Bormann type, with significant difference (P<0.05); Multivariate analysis demonstrated that SHLNM was related with depth of invasion and tumor size, with significant difference (P<0.05). Consequently, depth of invasion, tumor grade, tumor size, tumor location and Bormann type were associated with SHLNM in AGC, meanwhile depth of invasion and tumor size are independent risk factors. Preoperative predicting risk factors of SHLNM greatly benefits making more rational surgical scheme of treating AGC.

Occult Tumor Cells in Lymph Nodes of Patients with Gastric Cancer: A Systematic Review on Their Prevalence and Predictive Role

BACKGROUND AND AIMS

The presence of lymph node (LN) metastasis is a key prognostic factor for gastric adenocarcinoma. However, even among patients without LN metastasis (N0), recurrence may occur. In some of these cases, occult tumor cells (OTC) are thought to play an important role. We aimed to determine the prevalence of OTC and its clinical relevance.

METHODS

We conducted a systematic review of studies in English published until September 2013 that addressed OTC prevalence and/or its clinical relevance. The studies were retrieved from the MEDLINE database.

RESULTS

We included 42 studies. The most frequently used methods for detecting OTC were immunohistochemical examination (IHC) and/or polymerase chain reaction (PCR) with a wide range of markers. Using IHC for OTC detection, in patients and in LN, the prevalence varied from 9 to 88% and 0.4 to 42%, respectively. With PCR, it ranged from 17 to 46% in patients, and from 3 to 33% in LN. In the studies assessing the predictive role of OTC in gastric cancer recurrence (n=24), 8 studies found no statistical association, while 18 concluded that OTC presence was associated with poorer prognosis. However, only 6 studies presented a significantly different 5-year survival rate between patients with and without LN micrometastasis.

CONCLUSIONS

OTC seems to occur in gastric cancer patients with a variable prevalence, depending on the definition, methods and setting. The majority of the retrieved studies (75%) evaluating the predictive role of OTC conclude that its presence is associated with a worse prognosis.

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.

Comparison of five staging systems of lymph node metastasis in the gastric carcinoma

BACKGROUND

The presence of metastatic lymph nodes is the most important prognostic factor for gastric carcinoma; however, the optimal system for the accurate staging of lymph node metastasis for patients with gastric cancer remains controversial. This study was designed to compare five systems in relation to the N classification of gastric carcinoma.

MATERIALS AND METHODS

This multicentric historical cohort study was conducted on 148 patients with M0 gastric adenocarcinoma who underwent gastrectomy in, five referral hospitals in Iran. Lymph nodes were sectioned, stained with hematoxyl in and eosin. The lymph node status was classified according to the five systems which are: The number of involved lymph nodes (TNM staging), metastatic lymph node ratio (N ratio), and the largest involved lymph node size, largest metastatic nest size and largest metastatic nest to lymph node size ratio.

RESULTS

Patients were classified into significant prognostic groups by the five N classification method including the TNM method, N ratio (0, ≤0.15, 0.15-0.4, >0.4), largest involved lymph node size (0, ≤5, 5-11, >11 mm), Largest metastatic nest size (≤1, 1-7.5, >7.5 mm) and largest metastatic nest to lymph node size ratio (≤0.3, 0.3-0.9, >0.9). All of the above systems remained as independently significant prognostic factors in terms of overall and disease free survival time.

CONCLUSION

Among the N staging systems we recommend the metastatic lymph node ratio and largest metastatic nest to lymph node size systems, since they are reproducible, simple, have good survival applicability, have prognostic value and include less stage migration especially in patients whom fewer than 15 lymph nodes are dissected.

Lymph node micrometastasis in gastrointestinal tract cancer--a clinical aspect

Lymph node micrometastasis (LNM) can now be detected thanks to the development of various biological methods such as immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR). Although several reports have examined LNM in various carcinomas, including gastrointestinal (GI) cancer, the clinical significance of LNM remains controversial. Clinically, the presence of LNM is particularly important in patients without nodal metastasis on routine histological examination (pN0), because patients with pN0 but with LNM already in fact have metastatic potential. However, at present, several technical obstacles are impeding the detection of LNM using methods such as IHC or RT-PCR. Accurate evaluation should be carried out using the same antibody or primer and the same technique in a large number of patients. The clinical importance of the difference between LNM and isolated tumor cells (≤0.2 mm in diameter) will also be gradually clarified. It is important that the results of basic studies on LNM are prospectively introduced into the clinical field. Rapid diagnosis of LNM using IHC and RT-PCR during surgery would be clinically useful. Currently, minimally invasive treatments such as endoscopic submucosal dissection and laparoscopic surgery with individualized lymphadenectomy are increasingly being performed. Accurate diagnosis of LNM would clarify issues of curability and safety when performing such treatments. In the near future, individualized lymphadenectomy will develop based on the establishment of rapid, accurate diagnosis of LNM.

Detection and clinical significance of lymph node micrometastasis in gastric cardia adenocarcinoma

OBJECTIVES

Lymph node micro metastasis was investigated in gastric cardia adenocarcinoma (GCA) patients without lymph node metastasis on routine pathological examination. The relationship between micrometastasis and clinicopathological features was also evaluated.

METHODS

A total of 349 lymph nodes were obtained from 45 patients with GCA. Micrometastases were detected by immunohistochemical staining for the markers cytokeratin 19 (CK19) and CD44 variant 6 (CD44v6).

RESULTS

A total of 33 lymph nodes (9.5%) from 15 patients (33.3%) were positive for CK19. Of these, 27 lymph nodes (7.7%) from 12 patients (26.7%) were also positive for CD44v6. Micrometastasis was significantly related to depth of tumour invasion and Lauren classification (intestinal or diffuse). The recurrence rate was significantly higher and 2-year survival rate significantly lower in patients with than in those without lymph node micrometastasis, showing the necessity of detecting micrometastasis in GCA patients who test negative for lymph node metastasis on routine examination.

CONCLUSION

CK19 and CD44v6 were shown to be good markers for micrometastasis detection.

Effect of lymph node number on survival of patients with lymph node-negative gastric cancer according to the 7th edition UICC TNM system

BACKGROUND

For the patients with node-negative gastric cancer, the 7th edition classification does not define the minimum number of lymph nodes necessary. We aimed to explore the prognostic significance of examined lymph nodes and determine how many nodes must be examined.

METHODOLOGY/PRINCIPAL FINDINGS

435 patients underwent D2 gastrectomy with node-negative gastric cancer between December 1992 and December 2006 were obtained. Patients were classified into 4 groups by the number of negative LNs examined during surgery (1-6LNs, 7-10 LNs, 11-15 LNs, and > = 16 LNs). Stratified and Cox regression analyses were used to evaluate the association between survival and the number of negative LNs. Survival was significantly better in the > = 16 LNs, compared with the 1-5 LNs, 6-10 LNs and 11-15 LNs group in T2-4 patients; Multivariate analysis demonstrated tumor size, depth of invasion, 7th UICC stage and the number of examined nodes are strongly independent predictors of survival.

CONCLUSIONS

This study first demonstrates that patients with lymph node-negative gastric cancer underwent D2 dissection should have at least 16 LNs examined, especially in advanced gastric cancer. These results are a reasonable supplement to our previous tumor-ratio-metastasis staging system and a stratification criterion in clinical practice.

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.

The clinical importance of micrometastases within the lymphatic system in patients after total gastrectomy

BACKGROUND

In spite of radical gastrectomy with resection of the lymphatic system, where no metastases are found during histopathological examination, about 30% of patients have relapse of the neoplastic process. This situation may be caused by micrometastases or isolated neoplastic cells in the lymphatic system which were not identified during a standard histopathological examination.

AIM

The aim of the study was to evaluate the clinical importance of micrometastases within the lymphatic system in patients with gastric cancer.

MATERIALS AND METHODS

A group of 20 patients treated for gastric cancer were subjected to retrospective analysis. Of all the patients who underwent surgery, a group with tumours classified as T1 or T2 was selected. No metastases within the lymphatic system were found in the standard evaluation - N0 mark. Paraffin-embedded blocks of lymph nodes were cut and new specimens were made, which were then stained again by means of immunohistochemistry. Antibodies against cytokeratin AE1/AE3 were used.

RESULTS

A total of 319 lymph nodes were assessed in 20 patients in an H + E examination. After the immunohistochemical examination, micrometastases within the lymphatic system were found in 4 (20%) patients and isolated neoplastic cells in other 4 (20%) patients.

CONCLUSION

On the basis of numerous publications and our own material, we think that the presence of micrometastases may be related to a worse prognosis. The clinical importance of micrometastases within the lymphatic system in patients after total gastrectomy.

Impact of the number of dissected lymph nodes on survival for gastric cancer after distal subtotal gastrectomy

Objectives. To investigate the prognostic impact of the number of dissected lymph nodes (LNs) in gastric cancer after curative distal gastrectomy. Methods. The survival of 634 patients who underwent curative distal gastrectomy from 1995 to 2004 was retrieved. Long-term surgical outcomes and associations between the number of dissected LNs and the 5-year survival rate were investigated. Results. The number of dissected LNs was one of the most important prognostic indicators. Among patients with comparable T category, the larger the number of dissected LNs was, the better the survival would be (P < 0.05). The linear regression showed that a significant survival improvement based on increasing retrieved LNs for stage II, III and IV (P < 0.05). A cut-point analysis yields the greatest variance of survival rate difference at the levels of 15 LNs (stage I), 25 LNs (stage II) and 30 LNs (stage III). Conclusion. The number of dissected LNs is an independent prognostic factor for gastric cancer. To improve the long-term survival of patients with gastric cancer, removing at least 15 LNs for stage I, 25 LNs for stage II, and 30 LNs for stage III patients during curative distal gastrectomy is recommended.

Prognostic factors in patients with node-negative gastric cancer: an Indian experience

Background

The status of the regional nodes is the most important prognostic factor in gastric cancer. There are subgroups of patients with different prognosis even in node-negative patients of gastric cancer. The aim of this study is to analyze the factors influencing the prognosis in Indian patients with node-negative gastric cancer.

Methods

This was a retrospective analysis of patients who underwent radical gastrectomy in a tertiary cancer centre in India between1991 and 2007. The study group included only patients with histologically node-negative disease. Various clinical, pathological and treatment related factors in this group of patients were analyzed to determine their prognostic ability by univariate and multivariate analyses.

Results

Among the 417 patients who underwent gastrectomy during this period, 122 patients had node-negative disease. A major proportion of the patients had advanced gastric cancer. The 5-year overall survival and disease-free survival in all node-negative gastric cancer patients was 68.2% and 67.5% respectively. The overall recurrence rate in this group was 27.3%. On univariate analysis, the factors found to significantly influence the disease-free survival were the size, location and presence or absence of serosal invasion of the primary tumor. However, on multivariate analysis, only tumor size more than 3 cm and serosal invasion were found to be independently associated with an inferior survival.

Conclusion

Serosal invasion and primary tumor size more than 3 cm independently predict a poor outcome in patients with node-negative gastric cancer.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prognostic factors for patients after curative resection for proximal gastric cancer

The factors influencing the long-term survival of patients with proximal gastric cancer (PGC) after curative resection were investigated. Data from 171 patients who underwent curative resection for PGC were retrospectively analyzed. The patients were grouped according to the clinicopathological factors and operative procedures. The tumor depth (T stage) and lymph node metastasis (pN stage) were graded according to the fifth edition of TNM Staging System published by UICC in 1997. The metastatic lymph node ratio (MLR) was divided into four levels: 0%, <10%, 10%-30% and >30%. The data of survival rate were analyzed by Kaplan-Meier method (log-rank test) and Cox regression model. The 5-year overall survival rate of 171 patients was 37.32%. The univariate analysis demonstrated that the survival time of the postoperative patients with PGC was related to tumor size (chi2=4.57, P=0.0325), gross type (chi2=21.38, P<0.001), T stage (chi2=27.91, P<0.001), pN stage (chi2=44.72, P<0.001), MLR (chi2=61.12, P<0.001), TNM stage (chi2=44.91, P<0.001), and range of gastrectomy (chi2=4.36, P=0.0368). Multivariate analysis showed that MLR (chi2=10.972, P=0.001), pN stage (chi2=6.640, P=0.010), TNM stage (chi2=7.081, P=0.007), T stage (chi2=7.687, P=0.006) and gross type (chi2=6.252, P=0.012) were the independent prognostic factors. In addition, the prognosis of patients who underwent total gastrectomy (TG) was superior to that of patients who underwent proximal gastrectomy (PG) for the cases of tumor>or=5 cm (chi2=6.31, P=0.0120), Borrmann III/IV (chi2=7.96, P=0.0050), T4 (chi2=4.57, P=0.0325), pN2 (chi2=5.52, P=0.0188), MLR 10%-30% (chi2=4.46, P=0.0347), MLR>30% (chi2=13.34, P=0.0003), TNM III (chi2=14.05, P=0.0002) or TNM IV stage (chi2=4.37, P=0.0366); and combining splenectomy was beneficial to the cases of T3 (chi2=5.68, P=0.0171) or MLR>30% (chi2=6.11, P=0.0134). It was concluded that MLR, pN stage, TNM stage, T stage, and gross type had advantages in providing a precise prognostic evaluation for patients undergoing curative resection for PGC, in which MLR was the most valuable index. TG and combining splenectomy were useful to improve the prognosis to patients with PGC of TNM III/IV stage, serosa invasion, or extensive regional lymph node metastasis.

Prognostic impact of metastatic lymph node ratio on gastric cancer after curative distal gastrectomy

AIM: To investigate the prognostic impact of metastatic lymph node ratio (rN) on gastric cancer after curative distal gastrectomy.

METHODS: A total of 634 gastric cancer patients who underwent curative resection (R0) of lymph nodes at distal gastrectomy in 1995-2004. Correlations between positive nodes and retrieved nodes, between rN and retrieved nodes, and between rN and negative lymph node (LN) count were analyzed respectively. Prognostic factors were identified by univariate and multivariate analyses. Staging accuracy of the pN category (5th UICC/TNM system) and the rN category was compared according to the survival rates of patients. A linear regression model was used to identify the relation between rN and 5-year survival rate of the patients.

RESULTS: The number of dissected LNs was related with metastatic LNs but not related with rN. Cox regression analysis showed that depth of invasion, pN and rN category were the independent predictors of survival (P < 0.05). There was a significant difference in survival between LN stages classified by the rN category or by the pN category (P < 0.05). However, no significant difference was found in survival rate between LN stages classified by the pN category or by the rN category (P > 0.05). Linear regression model showed a significant linear correlation between rN and the 5-year survival rate of gastric cancer patients (β = 0.862, P < 0.001). Pearson’s correlation test revealed that negative LN count was negatively correlated with rN (P < 0.001).

CONCLUSION: rN category is a better prognostic tool than the 5th UICC pN category for gastric cancer patients after curative distal gastrectomy. Increased negative LN count can reduce rN and improve the survival rate of gastric cancer patients.

Prognostic impact of dissected lymph node count on patients with node-negative gastric cancer

AIM: To investigate the long-term effect of the number of resected lymph nodes (LNs) on the prognosis of patients with node-negative gastric cancer.

METHODS: Clinical data of 211 patients with gastric cancer, without nodal involvement, were analyzed retrospectively after D2 radical operation. We analyzed the relationship between the number of resected LNs with the 5-year survival, the recurrence rate and the post-operative complication rate.

RESULTS: The 5-year survival of the entire cohort was 82.2%. The total number of dissected LNs was one of the independent prognostic factors. Among patients with comparable depth of invasion, the larger the number of resected LNs, the better the survival (P < 0.05). A cut-point analysis provided the possibility to detect a significant survival difference among subgroups. Patients had a better long-term survival outcomes with LN counts ≥ 15 for pT1-2, ≥ 20 for pT3-4, and ≥ 15 for the entire cohort. The overall recurrence rate was 29.4% within 5 years after surgery. There was a statistically significant, negative correlation between the number of resected LNs and the recurrence rate (P < 0.01). The post-operative complication rate was 10.9% and was not significantly correlated with the number of dissected LNs (P > 0.05).

CONCLUSION: For node-negative gastric cancer, sufficient number of dissected LNs is recommended during D2 lymphadenectomy, to improve the long-term survival and reduce the recurrence. Suitable increments of the dissected LN count would not increase the post-operative complication rate.

Lymph nodes and gastric cancer

Worldwide, gastric cancer is one of the top three leading causes of cancer mortality, but incidence and presentation vary geographically. Currently, surgery is the only possible cure. Nodal status is an important prognostic indicator for gastric cancer, and despite results of randomized controlled trials, debate continues over the importance of aggressive lymphadenectomy.

Outcome in relation to numbers of nodes harvested in lymph node-positive gastric cancer

AIMS

We conducted a retrospective case-control study to compare the prognostic differences of lymph node-positive gastric cancer patients between dissected lymph nodes (DLNs) <15 group and DLNs > or =15 group.

METHODS

A retrospective study of 323 lymph node-positive gastric patients who underwent potentially curative resection for gastric cancer was analyzed to identify the prognostic differences between DLNs <15 group and DLNs > or =15 group. Of these patients, 49 patients with <15 DLNs were matched with 147 patients with > or =15 DLNs according to gender, age, location of primary tumor, and type of gastrectomy.

RESULTS

Patients with n1 lymph node metastasis (according to JCGC), serosal involvement, ratio of positive lymph nodes less than 25%, or without adjuvant chemotherapy in > or =15 DLN group had comparatively longer median survival than patients with homologous clinicopathologic variables in <15 DLN group, respectively. Patients with n1 stage lymph node metastasis, serosal involvement, non-intestinal Lauren classification, or without adjuvant chemotherapy in <15 DLN group had higher recurrence rate than patients with homologous clinicopathologic variables in > or =15 DLN group, respectively. In addition, we demonstrated that patients with more than n1 stage lymph node metastasis in <15 DLN group had higher rate of peritoneal dissemination than those with more than n1 lymph node metastasis in > or =15 DLN group.

CONCLUSIONS

DNL > or =15 was an important factor to improve the prognosis of lymph node-positive gastric cancer patients after potential curative resection.

Prognostic impact of metastatic lymph node ratio in advanced gastric cancer from cardia and fundus

AIM: To investigate the prognostic impact of the metastatic lymph node ratio (MLR) in advanced gastric cancer from the cardia and fundus.

METHODS: Two hundred and thirty-six patients with gastric cancer from the cardia and fundus who underwent D2 curative resection were analyzed retrospectively. The correlations between MLR and the total lymph nodes, positive nodes and the total lymph nodes were analyzed respectively. The influence of MLR on the survival time of patients was determined with univariate Kaplan-Meier survival analysis and multivariate Cox proportional hazard model analysis. And the multiple linear regression was used to identify the relation between MLR and the 5-year survival rate of the patients.

RESULTS: The MLR did not correlate with the total lymph nodes resected (r = -0.093, P = 0.057). The 5-year overall survival rate of the whole cohort was 37.5%. Kaplan-Meier survival analysis identified that the following eight factors influenced the survival time of the patients postoperatively: gender (χ² = 4.26, P = 0.0389), tumor size (χ² = 18.48, P < 0.001), Borrmann type (χ² = 7.41, P = 0.0065), histological grade (χ² = 5.07, P = 0.0243), pT category (χ² = 49.42, P < 0.001), pN category (χ² = 87.7, P < 0.001), total number of retrieved lymph nodes (χ² = 8.22, P = 0.0042) and MLR (χ² = 34.3, P < 0.001). Cox proportional hazard model showed that tumor size (χ² = 7.985, P = 0.018), pT category (χ² = 30.82, P < 0.001) and MLR (χ² = 69.39, P < 0.001) independently influenced the prognosis. A linear correlation between MLR and the 5-year survival was statistically significant based on the multiple linear regression (β = -0.63, P < 0.001). Hypothetically, the 5-year survival would surpass 50% when MLR was lower than 10%.

CONCLUSION: The MLR is an independent prognostic factor for patients with advanced gastric cancer from the cardia and fundus. The decrease of MLR due to adequate number of total resected lymph nodes can improve the survival.

Effect of lymphadenectomy extent on advanced gastric cancer located in the cardia and fundus

AIM: To analyze the prognostic impact of lymphade-nectomy extent in advanced gastric cancer located in the cardia and fundus.

METHODS: Two hundred and thirty-six patients with advanced gastric cancer located in the cardia and fundus who underwent D2 curative resection were analyzed retrospectively. Relationships between the numbers of lymph nodes (LNs) dissected and survival was analyzed among different clinical stage subgroups.

RESULTS: The 5-year overall survival rate of the entire cohort was 37.5%. Multivariate prognostic variables were total LNs dissected (P < 0.0001; or number of negative LNs examined, P < 0.0001), number of positive LNs (P < 0.0001), T category (P < 0.0001) and tumor size (P = 0.015). The greatest survival differences were observed at cutoff values of 20 LNs resected for stage II (P = 0.0136), 25 for stage III(P < 0.0001), 30 for stage IV (P = 0.0002), and 15 for all patients (P = 0.0024). Based on the statistically assumed linearity as best fit, linear regression showed a significant survival enhancement based on increasing negative LNs for patients of stages III (P = 0.013) and IV (P = 0.035).

CONCLUSION: To improve the long-term survival of patients with advanced gastric cancer located in the cardia and fundus, removing at least 20 LNs for stage II, 25 LNs for stage III, and 30 LNs for stage IVpatients during D2 radical dissection is recommended.

A clinicopathological study on the expression of cadherin-17 and caudal-related homeobox transcription factor (CDX2) in human gastric carcinoma

AIMS

To analyse the clinicopathological characteristics of the expression of cadherin-17 (CDH17) and caudal-related homeobox transcription factor (CDX2) in human gastric carcinoma, and to evaluate the clinical significance of these two markers in the histological classification and prognosis of gastric carcinoma.

MATERIALS AND METHODS

CDH17, CDX2 protein expression in paraffin-embedded specimens gathered from 166 patients with gastric carcinoma were detected by immunohistochemistry. The association of CDH17, CDX2 protein expression with the clinicopathological characteristics, and with the prognosis of gastric carcinoma were subsequently assessed.

RESULTS

CDH17, nucleus and cytoplasm CDX2 expression were positively expressed in 101/166 (60.8%), 59/166 (35.5%) and 57/166 (34.3%) gastric carcinoma patients, respectively. The expression of both CDH17 and CDX2 is associated with the intestinal-type gastric carcinoma (P<0.01). Positive expression of CDH17 was significantly associated with the depth of gastric wall invasion (P=0.04), lymph node metastasis (P<0.01) and stages of gastric carcinoma (P=0.01). Positive expression of CDX2 in the nucleus was mainly found in male patients (P=0.02), in early stage (P=0.01) and medullary-type gastric carcinoma (P=0.02). There was a negative association between nuclear CDX2 expression and lymph node metastasis of gastric carcinoma (P<0.01). The combined expression of CDH17 and CDX2 was significantly lower in diffuse-type carcinoma than intestinal- or mixed-type carcinoma (P<0.01 and P=0.01, respectively). The patients with CDH17 expression associated with poor prognosis of gastric carcinoma (P<0.01), as opposed to patients with CDX2 expression (P<0.01). The survival rate of patients with CDH17+/CDX2- expression was the lowest (P<0.01), and conjoined expressions of CDH17+/CDX2- and CDH17+/CDX2+ were independent prognostic indicators of gastric carcinoma (both P<0.01).

CONCLUSION

The results suggest that the expression of CDH17 or CDX2 may be an important feature of gastric carcinoma. A combined detection of CDH17/CDX2 co-expression may benefit us in predicting the prognosis of gastric carcinoma.