Lymph Node Ratio Is an Independent Prognostic Factor in Gastric Cancer After Curative Resection (R0) Regardless of the Examined Number of Lymph Nodes

Lymph node ratio as a prognostic factor in gastric cancer patients following D1 resection. Comparison with the current TNM staging system

INTRODUCTION

Nodal ratio (NR) has been demonstrated to be an independent prognostic factor in patients with gastric cancer. We evaluated the prognostic role of NR comparing it with the current TNM (2010) classification in gastric cancer patients treated with curative (R0) D1 resection.

MATERIALS AND METHODS

We retrospectively reviewed 110 patients who underwent R0 resection for gastric cancer at University Hospital of Larissa between 2002 and 2011. All patients had a D1 lymphadenectomy plus the nodes along the left gastric artery. Factors affecting survival as well as correlations between the N status, NR status and resected nodes were investigated.

RESULTS

In univariate analysis the N and NR status but not the numbers of retrieved nodes were significant prognostic factors. Inside N1 and N2 categories, patients with different NR groups were present and survival of some of these subpopulations was statistically different at long-rank test. There was a correlation between the nodes retrieved and N status but not with the NR category. In multivariate analysis both N status (HR=1.45; 95% C.I. = 1.19-1.89) and NR (HR=4.53; 95% C.I. = 1.86-11.03) found to be independent prognostic factors of survival.

CONCLUSION

Prognostic significance of N status and NR status was comparable. Unlike N status, NR is independent by the number of resected nodes, and therefore it is particularly useful in case of conventional lymphadenectomy.

Clinicopathologic implication of meticulous pathologic examination of regional lymph nodes in gastric cancer patients

BACKGROUND

We aimed to investigate effect of increased number of examined lymph nodes (LNs) to pN category, and compare various N categories in gastric cancer: American Joint Committee on Cancer (AJCC) 7th edition, metastatic LN ratio (MLR), and log odds of positive LNs (LODDS).

METHODS

Four cohorts with a total of 2,309 gastric cancer patients were enrolled. For cohort 1 and 2, prognostic significance of each method by disease-specific survival was analyzed using Akaike and Bayesian information criterion (AIC and BIC).

RESULTS

The total LNs in four cohorts significantly differed [median (range), 28 (6-97) in cohort 1, 37 (8-120) in cohort 2, 48 (7-122) in cohort 3, and 54 (4-221) in cohort 4; p<0.001]. The numbers of negative LNs increased with increase of total LN (p<0.001), but the numbers of metastatic LNs did not increase from cohort 1 to 4. MLR and LODDS in four cohorts had decreasing tendency with increase of total LNs in each pT3 and pT4 category (p<0.001), while the numbers of metastatic LNs did not differ significantly in any pT category (p>0.05). The AIC and BIC varied according to different cut-off values for MLR; model by cut-offs of 0.2 and 0.5 being better for cohort 1, while cut-offs 0.1 and 0.25 was better for cohort 2.

CONCLUSION

Our study showed that the number of metastatic LNs did not increase with maximal pathologic examination of regional LNs. AJCC 7th system is suggested as the simplest method with single cut-off value, but prognostic significance of MLR may be influenced by various cut-offs.

Prognostic impact of nodal status and therapeutic implications

The prognostic impact of lymph node (LN) metastases in gastric cancer is generally accepted. In primarily resected patients the pN-category and LN ratio are independent prognostic factors. Number of involved LNs, number of resected LNs, lymphangiosis and micrometastases also influence the prognosis significantly. To guarantee a proper D2 lymphadenectomy (LAD) at least 25 LNs according to the German S3 guidelines for the treatment of gastric cancer should be removed. Also in neoadjuvantly treated patients the ypN-category and LN ratio play an important prognostic role, despite the fact that UICC staging system was development based only on primarily resected patients. The role of response of LNs in neoadjuvantly treated patients is still unclear and needs further investigation. It seems to be less important than the response of the primary tumor. Limited data exists, suggesting that preoperative treatment might reduce the number of LNs involved and improve ypN-category. Due to further development in gastric cancer like laparoscopic resection and effective perioperative treatment in locally advanced tumor the role and the prognostic impact of LAD is again in the focus of discussion.

A long non-coding RNA signature to improve prognosis prediction of gastric cancer

BACKGROUND

Increasing evidence suggests long non-coding RNAs (lncRNAs) are frequently aberrantly expressed in cancers, however, few related lncRNA signatures have been established for prediction of cancer prognosis. We aimed at developing alncRNA signature to improve prognosis prediction of gastric cancer (GC).

METHODS

Using a lncRNA-mining approach, we performed lncRNA expression profiling in large GC cohorts from Gene Expression Ominus (GEO), including GSE62254 data set (N = 300) and GSE15459 data set (N = 192). We established a set of 24-lncRNAs that were significantly associated with the disease free survival (DFS) in the test series.

RESULTS

Based on this 24-lncRNA signature, the test series patients could be classified into high-risk or low-risk subgroup with significantly different DFS (HR = 1.19, 95 % CI = 1.13-1.25, P < 0.0001). The prognostic value of this 24-lncRNA signature was confirmed in the internal validation series and another external validation series, respectively. Further analysis revealed that the prognostic value of this signature was independent of lymph node ratio (LNR) and postoperative chemotherapy. Gene set enrichment analysis (GSEA) indicated that high risk score group was associated with several cancer recurrence and metastasis associated pathways.

CONCLUSIONS

The identification of the prognostic lncRNAs indicates the potential roles of lncRNAs in GC biogenesis. Our results may provide an efficient classification tool for clinical prognosis evaluation of GC.

Lymph node ratio as a novel and simple prognostic factor in advanced gastric cancer

TNM staging is no doubt the most critical prognostic factors, representing tumor (T)/lymph node metastasis (N)/distant metastasis (M) in gastric cancer. Lymph node ratio-based N system (Nr) has been repeatedly reported to be of prognostic relevance in advanced gastric cancer independent of stage in the multivariate analysis world-wide, and proposed as more sophisticated than N with regard to predicting accurate prognosis. As a result, proposed TNrM system may predict survival more accurately than the present TNM staging system for patients undergoing limited lymph node analysis. It could adjust stage migration when the lymph node number was used as staging factor. Although correlation of the number of metastatic lymph nodes and lymph node ratio is obvious, biological characteristics other than that could also have been reflected on. It may indicate how successful the operation of lymph node dissection was, or it may be revealing the potential of the patient's lymph node immune-reaction. Recently, high lymph node ratio is closely associated with EGFR expression in advanced gastric cancer. When efficiency of applying lymph node ratio as a biomarker is verified and confirmed in an expansive research, and when cancer causing molecules are identified, as well as the competence as a treatment target is studied, the new biomarker, namely, lymph node ratio, could find itself in a limelight in gastric cancer treatment in the future.

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

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

Subtotal gastrectomy with conventional D2 lymphadenectomy for carcinoma of the distal gastric portion: A retrospective cohort study on clinical outcomes

BACKGROUND

The study was aimed to delineate the postoperative morbidity, mortality and long-term follow-up results after R0 subtotal gastrectomy with D2 lymphadenectomy for invasive non-disseminated adenocarcinoma of the distal gastric portion.

METHODS

Between January 2005 and December 2007, 228 patients with median age at hospitalisation 66.6 ± 11.4 years underwent the above mentioned surgery for histologically proven distal gastric adenocarcinoma.

RESULTS

Postoperative morbidity was documented in 92 (40.4%) of patients within 30 days. An anastomotic leakage was diagnosed in two (0.9%), peritonitis in two (0.9%), anastomositis in five (2.2%), and prolonged ileus in six (2.6%) patients. Nine patients died (3.9%). The overall 1-year survival rate was 83.8%, and the 5-year survival rate was 54.4%. Gender, age, TNM stage, pN, and N ratio were independent factors predicting a long-term prognosis for patients.

CONCLUSIONS

A R0 type distal subtotal gastrectomy with standard D2 lymphadenectomy for a histologically proven invasive adenocarcinoma of the distal gastric portion without distant metastasis offers acceptable postoperative morbidity and mortality, and considerably high overall cumulative 5-year survival rate. The probability of cumulative survival decreases five times when the ratio between metastatic and examined lymph nodes is > 0.25.

Decreased expression of BRCA1-associated protein 1 predicts unfavorable survival in gastric adenocarcinoma

BRCA1-associated protein 1 (BAP1) has been reported as a novel tumor suppressor, while in gastric adenocarcinoma, the function of this protein was still await to be uncovered. Based on a large group of patients with gastric adenocarcinoma, our study aimed to have a further understanding about the correlation of BAP1 expression and patients' clinical outcomes. We performed quantitative PCR and Western blot to examine BAP1 expression in 38 cases of gastric adenocarcinoma samples and adjacent non-cancerous tissues. Immunochemistry was used to evaluate BAP1 expression in a large cohort of 474 paraffin-embedded specimens. The clinical and prognostic significance of BAP1 expression was statistically analyzed. Postoperative survival between groups was using Kaplan-Meier analysis. BAP1 was overexpressed in paracancerous normal mucosa compared with gastric cancer. Decreased BAP1 expression was associated with higher histologic grade (P = 0.044), tumor infiltration (P < 0.001), metastasis status (P = 0.023), and TNM stage (P < 0.001). Patients with low expression of BAP1 had shorter overall survival compared with those with high expression (P < 0.001). Patients' survival in stage N0 could be stratified by the expression of BAP1. Multivariate analysis showed that in gastric adenocarcinoma, BAP1 expressing level was an independent prognostic factor (RR = 0.575, P < 0.001). Decreased expression of BAP1 suggests pessimistic prognosis for gastric adenocarcinoma patients. Further studies are warranted.

Prognostic Value of Metastatic No.8p LNs in Patients with Gastric Cancer

Background. To evaluate prognostic value of metastatic No.8p LNs in patients with gastric cancer. Methods. From August 2002 to December 2011, a total of 284 gastric cancer patients who underwent gastrectomy with No.8p LNs dissection were analyzed retrospectively in this study. Patients were divided into two groups according to the status of No.8p LNs. Clinicopathological features were collected to conduct the correlation analysis. Follow-up was carried out up to December 31st, 2014. Overall survival was analyzed. Results. Out of 284 patients, metastatic No.8p LNs were found in 24 (8.5%) patients. Compared with other 260 cases, these patients suffered morphologically larger tumor (P = 0.003), node stage (P = 0.000), and metastatic stage (P = 0.000). The 3-year overall survival rate was 26% in No.8p-positive group and 53% in No.8p-negative group. No significant difference of cumulative survival rates existed between the No.8p-positive group and No.8p-negative stage IV group (26% versus 28%, P = 0.923). Patients with other distant metastasis or not in No.8p+ group had similar cumulative survival rates (24% versus 28%, P = 0.914). Conclusions. Positive No.8p LNs were a poor but not an independent prognostic factor for patients with GC and should be recognized as distant metastasis.

The development of the TNM classification of gastric cancer

The first tumor, node, metastasis (TNM) classification for stomach tumors was published in the second edition of the TNM classification of malignant tumors in 1974 and was followed by additional editions up to the seventh edition published in 2010. In the Buffalo Meeting 2008 a harmonization between the Eastern (Japanese) and Western stomach tumor classification was achieved with only minor remaing differences. The present TNM classification of stomach tumors has been criticized but it can be considered generally accepted worldwide. For generating data based on this new TNM classification it is important to correctly use TNM and pTNM. The decions on therapy and the estimation of prognosis are based on TNM. New molecular factor studies will be correlated and based on the results of the TNM classification.

Prognostic value of metastatic lymph node ratio as an additional tool to the TNM stage system in gastric cancer

BACKGROUND

Gastric cancer is one of most common malignancies in the world. Currently the prognostic prediction is entirely based on the TNM staging system. In this study, we evaluated whether metastatic lymph node ratio (rN) at the time of surgery would improve the prognostic prediction in conjunction with the TNM staging system.

METHODS

This retrospective study includes 745 patients, who had been referred for surgery due to gastric cancer between 1995 and 2007 and had at least 15 lymph nodes examined at the time of surgery without preoperative treatment. Clinicopathologic features and overall survival were analyzed using univariate and multivariate modes to identify the risk factors for overall survival.

RESULTS

Median overall survival of all patients analyzed is 57.8 months and 5-year overall survival is 49.5%. Tumor site, macroscopic type, pTNM stage, and rN stage are identified as independent prognostic factors. Increased positive lymph node ratio correlates with shorter survival in all patients and in each T and N stage. In stage III gastric cancer patients, rN stage shows additional prognostic value on overall survival (p < 0.001).

CONCLUSIONS

rN stage is a simple and promising prognostic factor of gastric cancer after surgery in addition to the TNM stage system especially in stage III patients. But the independent prognostic value of rN stage in stage I, II and IV gastric cancer is yet to be determined.

Metastatic lymph node ratio successfully predicts prognosis in western gastric cancer patients

BACKGROUND

Lymph node positivity is a strong prognostic indicator in many cancers including gastric cancer. The extent of surgical resection directly influences the number of lymph nodes available for staging, with the lesser D1 resection that is standard practice in non-Asian countries typically providing fewer nodes for analysis. The widely used AJCC TNM staging system has been criticized for under-staging and stage migration where fewer than 15 nodes are resected, which is often the case in these populations. The ratio of positive to total nodes harvested--Lymph Node Ration (LNR)--has been proposed as an improved and more widely applicable prognostic indicator.

HYPOTHESIS

The LNR is a reliable and accurate prognostic indicator of survival in a Western gastric cancer population.

METHODS

9357 patients were acquired via a SEER case listing session with 2004-2011 gastric adenocarcinoma diagnoses. AJCC 7th edition nodal staging (N0: 0, N1:1-2, N2:3-6, N3:≥7 positive lymph nodes) and LNR positive nodal staging (PN0: 0%, PN1: 1-20%, PN2: 21-50%, PN3: 51-100% of examined nodes positive) were compared as respects seven year survivorship.

RESULTS

Adjusted survival time ratios for AJCC nodal curves were less evenly distributed than were the percent positive nodal curves. Results of multiple regression reflected that survival time ratios of the percent positive nodal schema being more evenly spaced than those of the AJCC schema. Because BIC for AJCC, 41071.48, was larger than that for percent positive nodes, 41024.25, the LNR nodal system better explained survival than the AJCC nodal classification system.

CONCLUSION

LNR produced reliable and internally consistent survival curves for this population. LNR is an effective tool to predict survival in a western gastric cancer patient population, where the majority of the patients have limited lymph node dissection.

BMI and lymph node ratio may predict clinical outcomes of gastric cancer

AIM

BMI and the lymph node (LN) ratio can affect short- and long-term outcomes of patients with gastric cancer.

PATIENTS & METHODS

This study includes 104 consecutive patients with gastric adenocarcinoma who underwent curative gastrectomy divided in two groups: overweight group (group A) and normal weight group (group B).

RESULTS

We found that 53.4% of our patients were overweight (group A). The overall rate of postoperative complications was 16.3%, while mortality was 1%. Statistical analyses revealed that postoperative morbidity was significantly higher in group A (p < 0.05). Long-term survival was significantly higher in group B. Cox regression showed a statistically significant correlation between higher BMI and poor long-term survival after curative gastrectomy. Multivariate analysis has identified age and the LN ratios as independent prognostic factors of survival.

CONCLUSION

In this retrospective analysis, BMI and LN ratio were independently associated with survival in patients with gastric cancer. Further studies are needed to confirm our findings.

Log odds of positive lymph nodes (LODDS): what are their role in the prognostic assessment of gastric adenocarcinoma?

BACKGROUND

Nodal status is an important prognostic factor for patients with gastric cancer. Log odds of positive nodes (LODDS) (log of the ratio between the number of positive nodes and the number of negative nodes) are a new effective indicator of prognosis. The aim of the study is to evaluate if LODDS are superior to N stage and lymph nodal ratio (LNR).

METHODS

Prognostic efficacy of pN, nodal ratio, and LODDS was analyzed and compared in a group of 177 patients with gastric adenocarcinoma who underwent curative gastrectomy.

RESULTS

pT, pN, LNR, and LODDS were all significantly correlated with 5-year survival. Multivariate analyses showed significant values as prognostic factor for pN, LNR, and LODDS. A Pearson test demonstrated no significant correlation between LODDS and retrieved nodes. In patients with less than 15 examined nodes, LODDS classification and pN were significantly correlated with survival, whereas LNR classification was not significantly related.

CONCLUSIONS

LODDS are not correlated with the extension of the lymphadenectomy and are able to predict survival even if less than 15 nodes are examined. They permit an effective prognostic stratification of patients with a nodal ratio approaching 0 and 1. Further studies are needed to clarify their role and if they are capable of guaranteeing some advantages over pN and LNR.

The prognostic value of lymph nodes dissection number on survival of patients with lymph node-negative gastric cancer

Objective. The study was designed to explore the prognostic value of examined lymph node (LN) number on survival of gastric cancer patients without LN metastasis. Methods. Between August 1995 and January 2011, 300 patients who underwent gastrectomy with D2 lymphadenectomy for LN-negative gastric cancer were reviewed. Patients were assigned to various groups according to LN dissection number or tumor invasion depth. Some clinical outcomes, such as overall survival, operation time, length of stay, and postoperative complications, were compared among all groups. Results. The overall survival time of LN-negative GC patients was 50.2 ± 30.5 months. Multivariate analysis indicated that LN dissection number (P < 0.001) and tumor invasion depth (P < 0.001) were independent prognostic factors of survival. The number of examined LNs was positively correlated with survival time (P < 0.05) in patients with same tumor invasion depth but not correlated with T1 stage or examined LNs >30. Besides, it was not correlated with operation time, transfusion volume, length of postoperative stay, or postoperative complication incidence (P > 0.05). Conclusions. The number of examined lymph nodes is an independent prognostic factor of survival for patients with lymph node-negative gastric cancer. Sufficient dissection of lymph nodes is recommended during surgery for such population.

Profiling the prognosis of gastric cancer patients: is it worth correlating the survival with the clinical/pathological and molecular features of gastric cancers?

BACKGROUND

The prognosis of gastric cancer patients still remains poor. The aim of this study was investigating the prognostic value of several clinical/pathological/molecular features in a consecutive series of gastric cancers.

METHODS

150 R0 gastrectomies plus 77 gastric cancer patients evaluated for the HER2 overexpression were selected. Survival was calculated and patients stratified according to the stage, the T-stage, the LNRs, the LNH, and the HER2 scoring system. ROC curves were calculated in order to compare the performance of the LRN and LNH systems.

RESULTS

Prognosis correlated with the stage and with the T-stage. We documented a statistical correlation between the LNRs and the survival. Conversely, a LNH > 15 did not correlate with the outcomes. The ROC curves documented a significant performance of the LRN system, whereas a statistical correlation was documented for the LNH exclusively with the endpoint of disease-free survival. We documented a trend of worse prognosis for patients with an HER2 overexpression, even though it was not of statistical value.

CONCLUSION

The LNR and the evaluation of the HER2 overexpression might be useful since they correlate with survival, might identify patients with a higher risk of recurrence, and might select patients for a tailored medical treatment.

Prognostic impact of lymph node retrieval and ratio in gastric cancer: a U.S. single center experience

INTRODUCTION

Increased lymph node (LN) retrieval for gastric cancer has been associated with improved overall survival (OS). This study examines the impact of number of examined LN (eLN) and lymph node ratio.

METHODS

Patients referred for surgical care of gastric cancer were stratified by number of eLN, positive LNs (LN+), and lymph node ratio (LN+/eLN). Clinicopathologic factors were compared; OS and disease-free survival (DFS) were the primary endpoints.

RESULTS

From 1997 to 2012, 222 patients, median age 67 (range, 17-92) years, were analyzed. Of 220 (99 %) explored, 164 (74 %) underwent resection. Median OS was 22 (range, 0.3-140) months. Perineural and lymphovascular invasion and poor differentiation adversely affected OS, p < 0.05. A median 14 eLN (range, 0-45), with median 1 LN+ (range, 0-31), was observed. There were no OS or DFS differences when comparing the eLN groups. Both OS and DFS were impacted by LN+. Lymph node ratio demonstrated worse median OS with increasing ratio: 49 months (0) to 37 months (0.01-0.2), 27 months (0.21-0.5), and 12 months (>0.5), p < 0.0001. DFS was similar: 35 months (0), decreasing to 22 months (0.01-0.2), 13 months (0.21-0.5), and 7 months (>0.5), p < 0.0001.

CONCLUSION

Number of eLN did not impact survival, while LN+ adversely affected survival. Lymph node ratio may predict prognosis better than number of eLN or LN+ in gastric cancer.

Improved survival after adding dissection of the superior mesenteric vein lymph node (14v) to standard D2 gastrectomy for advanced distal gastric cancer

BACKGROUND

Extended lymph node dissection in gastric cancer (D3) was proven to have no survival benefit compared with a D2 dissection, but whether adding the superior mesenteric nodes (No. 14v) to the dissection provides survival benefit for gastric cancer patients remains controversial.

METHODS

From April 2001 to June 2007, 1,661 patients underwent curative resection for middle or lower third gastric cancer. Patients were grouped according to No. 14v lymphadenectomy (14vD+/14vD-). Clinicopathologic characteristics and treatment-related factors were compared between the groups. Overall survival according to the clinical stage (Union for International Cancer Control tumor-node-metastasis staging 6th edition) was analyzed using the Cox proportional hazard model.

RESULTS

The incidence of No. 14v lymph node metastasis was 5.0%. There was no difference in morbidity or mortality between the 14vD+ and the 14vD- groups. The proportion of locoregional recurrence was greater in 14vD- group (P = .018). In clinical stages I and II, 14v lymph node dissection did not affect overall survival; in contrast, 14v lymph node dissection was an independent prognostic factor in patients with clinical stage III/IV gastric cancer (hazard ratio, 0.58; 95% confidence interval, 0.38-0.88; P = .01).

CONCLUSION

Extended D2 gastrectomy including No. 14v lymph node dissection seems to be associated with improved overall survival of patients with clinical stage III/IV gastric cancer in the middle or lower third of the stomach.

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

BACKGROUND

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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