Metastatic lymph node ratio as a prognostic factor in gastric cancer

Prognostic performance of different lymph node classification systems in young gastric cancer

Background

Accurate staging plays a pivotal role in cancer care. The lymph node (LN) ratio (LNR) and the log odds of positive LNs (LODDS) have been suggested as alternatives to the N staging since the TNM system has the risk of stage migration. The prognostic significance of LNR and LODDS in young patients with gastric cancer (GC) has not been reported. This study aims to investigate the correlations between LNR and LODDS and survival of young patients with GC, and compare the predictive performance of these LN staging methods.

Methods

GC patients before the age of 40 from 2004 to 2016 in the Surveillance, Epidemiology and End Results database were enrolled. The prognostic evaluation of the N factor, LNR and LODDS was compared using the time-dependent receiver operating characteristic (ROC) analysis, area under the curve (AUC), C-index and Akaike information criterion (AIC).

Results

Multivariate survival analysis identified that the LNR and LODDS were significantly independent prognostic indicators for overall survival (OS) in young patients with GC and in the subgroups comprised of patients with ≤15 LNs examined. The time-dependent ROC curves of the LNR and LODDS were continuously superior to that of the N factor in predicting OS during the observation period. And the AUCs revealed that the predictive accuracy of the LNR and LODDS was remarkably superior to the N factor at 1 and 3 years (P<0.05). The model incorporating LNR or LODDS had higher C-index and lower AIC when comparing to the model incorporating the N factor.

Conclusions

The LNR and LODDS improve accuracy of survival risk prediction in young patients with GC when comparing to the N factor. These two novel LN classification methods should be considered as alternatives to the N staging for the prognostic prediction of young patients with GC.

Benchmarks for nodal yield and ratio for node-positive gastric cancer

BACKGROUND

We aimed to elucidate prognostic markers of node-positive gastric cancers with a focus on examined lymph nodes and lymph node ratio.

METHODS

Patients treated with curative-intent gastrectomy at The University of Texas MD Anderson Cancer Center from 1995-2019 were evaluated. Patients with non-metastatic, node-positive gastric cancers were considered for analysis.

RESULTS

Of 775 patients, 281 met the inclusion criteria. The mean age was 58 years, 61% were male, 51% were White, 65% received preoperative therapy, and 71% of tumors were located in the gastric body. The median overall survival was 3.6 years, and 1-, 5-, and 10-year overall survival rates were 91%, 41%, and 29%, respectively. pN3 category was associated with worse overall survival (hazard ratio 1.79, P = .001) and recurrence-free survival (hazard ratio 1.92, P = .004). Nodal burden was associated with aggressive biologic traits in primary tumors, including higher rates of lymphovascular and perineural invasion and lower preoperative therapy response rates. By receiver-operative characteristic analysis, threshold values of ≥30 examined lymph nodes and <30% lymph node ratio were most discriminant for overall survival. On adjusted analysis, positive margins, additional organ resection, <30 examined lymph nodes, and ≥30% lymph node ratio were associated with worse recurrence-free survival and overall survival. Among patients with high node burden (pN3), <30 examined lymph nodes remained significant on adjusted survival analysis.

CONCLUSION

Greater than or equal to 30 examined lymph nodes and <30% lymph node ratio were significantly associated with longer recurrence-free survival and overall survival, independent of lymphadenectomy type. These prognostic benchmarks should be considered in the surgical management of gastric cancer in the United States.

Predictive Value of Lymph Node Ratio in Patients with Pancreatic Cancer Treated with Pancreatoduodenectomy

Background: Recently, the predictive value of lymph node ratio (LNR, the ratio of metastatic lymph nodes to total examined lymph nodes) has been evaluated in patients with gastrointestinal malignancies, including pancreatic cancer. However, there is not enough evidence about the prognostic value of this factor. Objectives: We aimed at determining the value of LNR in predicting the survival of patients who have undergone the Whipple procedure. Methods: This cohort study was performed on 96 patients with pancreatic cancer undergoing the Whipple procedure during 2014 - 2019. Demographic, clinical, and pathological data of the patients were extracted from their records and patients' survival status was determined through follow-up. LNR and its effect on survival was calculated using the Cox model. Results: Of the 96 eligible patients, 51 (53.13%) were men. The mean age of the patients was 57.1 ± 14.1 (range: 19 - 82) years. The median total lymph nodes examined was 7 (range: 1 - 27), and no metastatic lymph nodes were found in 57 (59.37%) patients. The median involved lymph nodes and LNR were 2 and 0.17, respectively. Patients with LNR > 0.20 had the lowest 1 and 3-year survival rates. Age (P = 0.04), surgical radial margin (P = 0.001), lymph node status (N0, N1) (P = 0.01), and LNR (P = 0.01) were the most important prognostic factors for survival. Conclusions: LNR is a valuable indicator that can be used in patients with lymph node involvement as a prognostic factor for poor survival after the Whipple procedure. The lowest 1, 3, and 5-year survival rates were seen in patients with LNR > 0.20.

Recurrence outcome of lymph node ratio in gastric cancer after underwent curative resection: A retrospective cohort study

Introduction

D2 dissection has been regarded as the standard procedure for locally advanced gastric cancer (GC). Number of lymph nodes (LN) harvested is an important factor for accurate staging. The number of LN retrieved and the metastasis LN status are also important factors to determine the prognosis. This study aims to evaluate whether lymph node ratio (LNR) could be a prognostic indicator of GC patients following curative resection.

Patients and methods

Single center retrospective cohort study of GC patients underwent curative resection from January 1995 to December 2016 was conducted. The patients were categorized into 3 groups based on LNR (0.00-0.35, >0.35-0.75, and >0.75-1.00) and 2 groups based on number of LN retrieved (<15 and ≥ 15). Kaplan-Meier method was used to estimate recurrence-free survival. Cox-regression were used to determine the association between LNR/other factors and the disease recurrence.

Results

One-hundred fifty-three patients were included in analysis. Univariate analysis showed that LNR >0.35, pathologic LN stages (pN) 2-3, higher number of LN metastasis, and TNM stage III were significantly recurrence risk factors. After adjusting for several covariates, LNR >0.35 still was significant predictor (adjusted HR [95%CI], 8.53 [1.97, 36.86]; p = 0.004) while number of LN retrieved or number of metastasis LN were not.

Conclusion

LNR could be a strong indicator for the recurrence of GC after curative resection while the number of LN retrieved or metastasis did not predict the recurrence. Future studies, such as prospective studies, are needed to confirm and identify the optimum LNR cut-off.

Prognostic Implication of pN Stage Subdivision Using Metastatic Lymph Node Ratio in Resected Pancreatic Ductal Adenocarcinoma

In this meta-analysis, we aimed to evaluate the prognostic implication of the metastatic lymph node ratio (mLNR) and its optimal criterion in pancreatic ductal adenocarcinoma (PDAC) with lymph node metastasis (LNM). The present study included 3735 patients with PDAC who had LNM, from 11 eligible studies. We carried out a meta-analysis to determine the correlation between a high mLNR and PDAC prognosis. The estimated mean numbers of examined and metastatic lymph nodes were 22.396 (95% confidence interval [CI] = 19.681-25.111) and 6.496 (95% CI = 4.646-8.345), respectively. A high mLNR was significantly correlated with worse overall survival (hazard ratio = 1.344, 95% CI = 1.276-1.416). In 3 subgroups based on high mLNR criteria (>0 and <0.2, ≥0.2 and <0.4, and ≥0.4), there were significant correlations between a high mLNR and worse survival. A cutoff of 0.200 showed the highest hazard ratio (1.391, 95% CI = 1.268-1.525), which was statistically significant. Our results showed that mLNR is a useful prognostic factor for PDAC with LNM. Although the optimal criterion of high mLNR may be 0.200, further cumulative studies are required before this can be applied in daily practice.

Prognostic Implication of Metastatic Lymph Node Ratio in Colorectal Cancers: Comparison Depending on Tumor Location

Background: The proportion of the number of involved lymph nodes (LNs) to the number of examined LNs—defined as metastatic LN ratio (mLNR)—has been considered as a prognostic parameter. This study aims to elucidate the prognostic implication of the mLNR in colorectal cancer (CRC) according to the tumor location. Methods: We evaluated the correlation between prognoses and the involved and examined LNs as well as mLNR according to the tumor location in 266 surgically resected human CRCs. Besides, to evaluate the optimal cutoff for high and low mLNRs, we investigated the correlation between mLNR and survival according to the various cutoffs. Results: LN metastasis was found in 146 cases (54.9%), and colon and rectal cancers were found in 116 (79.5%) and 30 (20.5%) of the cases, respectively. The mean mLNRs were significantly higher in rectal cancer than in colon cancer (0.38 ± 0.28 vs. 0.21 ± 0.24, P = 0.003). Besides this, the number of involved LNs in rectal cancer was significantly high compared to colon cancer (11.83 ± 10.92 vs. 6.37 ± 7.78, P = 0.014). However, there was no significant difference in the examined LNs between the rectal and colon cancers (31.90 ± 12.28 vs. 36.60 ± 18.11, P = 0.181). In colon cancer, a high mLNR was significantly correlated with worse survival for all cutoffs (0.1, 0.2, 0.3, and 0.4). However, rectal cancer only showed a significant correlation between high mLNR and worse survival in the subgroup with a cutoff of 0.2. Conclusions: Our results showed that high mLNR was significantly correlated with worse survival. The number of involved LNs and mLNRs were significantly higher in rectal cancer than in colon cancer. The cutoff of 0.2 can be useful for the differentiation of prognostic groups, regardless of tumor location.

Metastatic Lymph Node Ratio (mLNR) is a Useful Parameter in the Prognosis of Colorectal Cancer; A Meta-Analysis for the Prognostic Role of mLNR

Background and objectives: The presenting study aimed to elucidate the prognostic role of the metastatic lymph node ratio (mLNR) in patients with colorectal cancer (CRC), using a meta-analysis. Materials and Methods: Using data from 90,274 patients from 14 eligible studies, we performed a meta-analysis for the correlation between mLNR and survival rate. Besides, subgroup analyses were performed, based on tumor stage, tumor location, and mLNR. Results: A high mLNR showed significant correlation with worse overall survival and disease-free survival rates in CRC patients (hazard ratio (HR), 1.617, 95% confidence interval (CI) 1.393-1.877, and HR 2.345, 95% CI 1.879-2.926, respectively). In patients with stage III, who had regional LN metastasis, the HRs were 1.730 (95% CI 1.266-2.362) and 2.451 (95% CI 1.719-3.494) for overall and disease-free survival, respectively. According to tumor location, rectal cancer showed a worse survival rate when compared to colon cancer. In the analysis for overall survival, when mLNR was 0.2, HR was the highest across the different subgroups (HR 5.040, 95% CI 1.780-14.270). However, in the analysis for disease-free survival, the subgroup with an mLNR < 0.2 had a higher HR than the other subgroups (HR 2.878, 95% CI 1.401-5.912). Conclusions: The mLNR may be a useful prognostic factor for patients with CRC, regardless of the tumor stage or tumor location. Further studies are necessary for the detailed criteria of mLNR before its application in daily practice.

Prognostic Role of Metastatic Lymph Node Ratio in Papillary Thyroid Carcinoma

Background

The aim of this study is to elucidate the clinicopathological significances, including the prognostic role, of metastatic lymph node ratio (mLNR) and tumor deposit diameter in papillary thyroid carcinoma (PTC) through a retrospective review and meta-analysis.

Methods

We categorized the cases into high (≥ 0.44) and low mLNR (< 0.44) and investigated the correlations with clinicopathological parameters in 64 PTCs with neck level VI lymph node (LN) metastasis. In addition, meta-analysis of seven eligible studies was used to investigate the correlation between mLNR and survival.

Results

Among 64 PTCs with neck level VI LN metastasis, high mLNR was found in 34 PTCs (53.1%). High mLNR was significantly correlated with macrometastasis (tumor deposit diameter ≥ 0.2 cm), extracapsular spread, and number of metastatic LNs. Based on linear regression test, mLNR was significantly increased by the largest LN size but not the largest metastatic LN (mLN) size. High mLNR was not correlated with nuclear factor κB or cyclin D1 immunohistochemical expression, Ki-67 labeling index, or other pathological parameters of primary tumor. Based on meta-analysis, high mLNR significantly correlated with worse disease-free survival at the 5-year and 10-year follow-up (hazard ratio [HR], 4.866; 95% confidence interval [CI], 3.527 to 6.714 and HR, 5.769; 95% CI, 2.951 to 11.275, respectively).

Conclusions

Our data showed that high mLNR significantly correlated with worse survival, macrometastasis, and extracapsular spread of mLNs. Further cumulative studies for more detailed criteria of mLNR are needed before application in daily practice.

Lymph Node Ratio-based Staging System Outperforms the Seventh AJCC System for Gastric Cancer: Validation Analysis With National Taiwan University Hospital Cancer Registry

BACKGROUND

On the basis of SEER data, in which most gastric cancer patients had limited lymph node dissection, node ratio-based staging system (TNrM) has been shown to have better accuracy than the AJCC TNM system. This study is to validate the result with patients from Taiwan, where D2 lymphadenectomy is routinely performed.

PATIENT AND METHOD

A total of 1405 consecutive gastric cancer patients treated at National Taiwan University Hospital between 1998 and 2010 were included. To evaluate the performance of the AJCC system, each TNM stage was stratified by TNrM stages. The homogeneity of patients' survival across TNrM strata was evaluated using the log-rank test. The performance of the TNrM system was evaluated with the same approach.

RESULTS

Five of the 7 evaluable AJCC stages (IA, IIA, IIIA, IIIB, and IIIC) contained TNrM subgroups with statistically heterogenous survival (P=0.003, 0.04, 0.002, 0.04, and <0.001, respectively). Thirty-six percent of patients (506/1405) were misclassified by the AJCC TNM system. However, of the assessable 6 TNrM stages, none of the AJCC subgroups showed significantly heterogenous survivals (P>0.05). About 19% of patients (264/1405) were misclassified by using the TNrM system.

CONCLUSIONS

Lymph node ratio significantly decreases the stage migration caused by inadequate examined lymph nodes. The advantage of TNrM was validated with a patient cohort from the Eastern medical center.

Prognostic value of diffuse versus intestinal histotype in patients with gastric cancer: a systematic review and meta-analysis

BACKGROUND

There are two distinct types of gastric carcinoma (GC), intestinal, more frequently sporadic and linked to environmental factors, and diffuse (undifferentiated) that is highly metastatic and characterized by rapid disease progression and a poor prognosis. However, there are many conflicting data in the literature concerning the association between histology and prognosis in GC. This meta-analysis was performed to provide demonstration if histology according to Lauren classification is associated with different prognosis in patients with GC.

METHODS

We searched PubMed, the Cochrane Library, SCOPUS, Web of Science, CINAHL, and EMBASE for all eligible studies. The combined hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) in terms of overall survival (OS) were evaluated.

RESULTS

A total of 73 published studies including 61,468 patients with GC were included in this meta-analysis. Our analysis indicates that GC patients with diffuse-type histology have a worst prognosis than those with intestinal subgroup in all studies (HR 1.23; 95% CI, 1.17-1.29; P<0.0001), in both loco-regional confined (HR 1.21; 95% CI, 1.12-1.30; P<0.0001) and advanced disease (HR 1.25; 95% CI, 1.046-1.50; P=0.014), in Asiatic (HR 1.2; 95% CI, 1.14-1.27; P<0.0001) and Western patients (HR 1.3; 95% CI, 1.19-1.41; P<0.0001), and in those not exposed (HR 1.15; 95% CI, 1.07-1.24; P<0.0001) or exposed (HR 1.27; 95% CI, 1.17-1.37; P<0.0001) to (neo)adjuvant therapy.

CONCLUSIONS

Our results indicated that histology might be a useful prognostic marker for both early and advanced GC patients, with intestinal-type associated with a better outcome. This information could be used for stratification purpose in future clinical trials.

Positive Lymph Node Ratio as an Indicator of Prognosis and Local Tumor Clearance in N3 Gastric Cancer

BACKGROUND

Nodal metastasis is an important clinical issue in gastric cancer patients. This study was designed to investigate the clinical usefulness of the positive lymph node ratio (PLNR), which reflects both metastatic and retrieved lymph node numbers, in patients with pN3 gastric cancer.

METHODS

We retrospectively analyzed the records of 138 consecutive pN3 patients who underwent curative gastrectomy with lymphadenectomy from 2000 to 2012.

RESULTS

A PLNR of 0.4 was proved to be the best cutoff value to stratify the prognosis of patients with pN3 gastric cancer (P < 0.001). Univariate and multivariate analyses revealed that older age, larger tumor size (≥10 cm), and PLNR ≥ 0.4 [P < 0.001, HR 3.1 (95 % CI 1.7-5.4)] were independent prognostic factors in pN3 gastric cancer. Regarding the recurrence, patients with PLNR <0.4 had a significantly lower rate of lymph node recurrence than those with PLNR ≥0.4 (P = 0.020). There was no significant difference in the lymph node recurrence rate between N3a and N3b patients in the PLNR <0.4 group [P = 0.546, 11.6 % (7/60) vs. 12.5 (1/8)], indicating a better local control regardless of pN3 subgroups.

CONCLUSIONS

PLNR is useful to stratify the prognosis and evaluate the extent of local tumor clearance in pN3 gastric cancer.

Evaluation of prognostic value and stage migration effect using positive lymph node ratio in gastric cancer

AIMS

To detect the best cut-off value of the positive lymph node ratio (PLNR) for stratifying the prognosis and analyzing its value with regard to stage migration effect using PLNR in gastric cancer.

METHODS

We retrospectively analyzed 1069 consecutive gastric cancer patients, who underwent curative gastrectomy with radical lymphadenectomy from 1997 through 2009.

RESULTS

1) The mean number of dissected lymph nodes was 42.6 in pStage I, 32.4 in pStage II and 37.1 in pStage III. The PLNR of 0.2 was proved to be the best cut-off value to stratify the prognosis of patients into two groups (P < 0.0001; PLNR <0.2 vs. PLNR ≥0.2), and patients were correctly classified into four groups: PLNR 0, PLNR 0-<0.2, PLNR 0.2-<0.4 and PLNR ≥0.4 by the Kaplan-Meier method. 2) Compared patients with the PLNR <0.2, those with the PLNR ≥0.2 had a significantly higher incidence of pT3 or greater, pN2 or greater, lymphatic invasion, vascular invasion and undifferentiated cancer. Multivariate analysis showed that the PLNR ≥0.2 was an independent prognostic factor [P < 0.0001, HR 2.77 (95% CI: 1.87-4.09)]. 2) The PLNR cut-off value of 0.2 could discriminate a stage migration effect in pN2-N3 and pStage II-III, which patients with PLNR ≥0.2 might be potentially diagnosed as a lower stage after gastrectomy.

CONCLUSION

The PLNR contributes to evaluating prognosis and stage migration effect even in a single institute and enable to identify those who need meticulous treatments and follow-up in patients with gastric cancer.

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.

Ratio and log odds of positive lymph nodes in breast cancer patients with mastectomy

PURPOSE

This study aimed to investigate the predictive role of lymph nodes (LNs) and assess the prognostic significance of the ratio of positive LNs (LNR) and log odds of positive LNs (LODDS) in breast cancer patients who have undergone a mastectomy.

PATIENTS AND METHODS

All of the breast cancer patients in the Taiwan Cancer Database during 2002-2006 were considered. We excluded patients who had inflammatory breast cancer, stage 0 and IV disease, breast conservative surgery or survival <1 month. The primary end point was overall survival (OS). A Cox hazards model was constructed and compared via Nagelkerke R(2) (R(2)N) and receiver operating characteristics (ROC).

RESULTS

A total of 11,349 (6042 node-negative, 5307 node-positive) patients were enrolled, and 10.5% patients had a limited number of LNs harvested. In a multivariate Cox model, LNR and LODDS demonstrated prognostic significance (<0.001). For node-positive patients, a model with LNR showed the best fit (P < 0.001; R(2)N = 18.2%) when sufficient LNs were examined. However, a model with LODDS showed the best fit in patients with a limited number of LNs harvested (P < 0.001; R(2)N = 21.1%), even in node-negative patients (P = 0.004; R(2)N = 13.5%). The area under the ROC curve (AUC) was highest for LODDS (AUC: 0.761), followed by LNR (AUC: 0.757). A limited LN harvest induced an AUC value for an approximate 3.6% loss (LNR) or 3.1% loss (LODDS).

CONCLUSION

The prognostic superiority of LNR is confounded by a limited LN harvest, thus making LODDS the most powerful and unified prognostic classifier in breast cancer patients who have had a mastectomy.

Usefulness of the log odds of positive lymph nodes to predict and discriminate prognosis in gastric carcinomas

BACKGROUND

The lymph node ratio (LNR) and log odds of positive lymph nodes (LODDS) have been proposed to minimize the stage migration phenomenon. The value of the LODDS and LNR staging systems to predict and discriminate prognosis was assessed and compared to the International Union Against Cancer (UICC) TNM classification (pN).

METHODS

Three hundred and twenty-six patients with gastric carcinoma were retrospectively studied. Disease-specific survival rates were calculated for every pN, LNR, and LODDS category.

RESULTS

Four LNR categories (0, 1-25, 26-75, and >76 %) and four LODDS categories (-5 to -3, > -3 to -1, > -1 to 3, and >3 to 5) were established. In the multivariate analysis, only the stage pT3-4 versus pT1-2 (HR 1.88, 95 % CI 1.11-3.20, p=0.02) and LODDS as continuous variable (HR 1.40, 95 % CI 1.21-1.61, p<0.001) remained as independent prognostic factors. In patients with <16 lymph nodes retrieved, only the LODDS system could discriminate different disease-specific survival curves for every category. LODDS categories were able to discriminate subgroups with different prognoses in pN stages and LNR categories.

CONCLUSIONS

The LODDS staging system was superior to the pN classification and LNR system to discriminate risk prognosis especially in patients with an insufficient number of retrieved lymph nodes.

Angiogenic factor thymidine phosphorylase associates with angiogenesis and lymphangiogenesis in the intestinal-type gastric cancer

As an angiogenic factor, thymidine phosphorylase (TP) expression in primary tumours has been thought to be a risk factor for lymph node (LN) and hepatic metastasis in patients with gastric adenocarcinoma. However, the molecular basis for the induction of metastasis by TP is largely unknown. We aim to elucidate the role of TP expression in gastric cancer neovascularisation and LN metastasis.The angiogenic and lymphangiogenic activity (CD31, D2-40, Ki-67, VEGFC, VEGFR3) and expression status of TP were detected in 103 resected human gastric carcinoma samples by immunohistochemistry. The influence of TP expression on neovascularisation and cancer cell invasion was further comparatively investigated in two groups of nude mice intraperitoneally injected with TP overexpressing MKN-45 cells (MKN-45/TP) and control cells (MKN-45/CV). In gastric cancer tissues, we found that high TP expression and various angiogenic and lymphangiogenic activities were significantly associated with poor prognostic outcomes. In addition, TP expression was also found to be associated with neovascularisation activity of gastric cancer tissues. In vivo, the MKN-45/TP group exhibited significantly increased infiltrating tumour nodules and neovascularisation activity compared to the MKN-45/CV group. TP could strongly influence gastric cancer progression via the dual activities of angiogenesis and lymphangiogenesis.

Importance of metastatic lymph node ratio in non-metastatic, lymph node-invaded colon cancer: a clinical trial

Background

The aim of this study was to evaluate the prognostic importance of the metastatic lymph node ratio for stage III colon cancer patients and to find a cut-off value at which the overall survival and disease-free survival change.

Material/Methods

Patients with pathological stage III colon cancer were retrospectively evaluated for: age; preoperative values of Crp, Cea, Ca 19-9, and Afp; pathologic situation of vascular, perineural, lymphatic, and serosal involvement; and metastatic lymph node ratio values were calculated.

Results

The study included 58 stage III colon cancer patients: 20 (34.5%) females and 38 (65.5%) males were involved in the study. Multivariate analysis was applied to the following variables to evaluate significance for overall survival and disease-free survival: age, Crp, Cea, perineural invasion, and metastatic lymph node ratio. The metastatic lymph node ratio (<0.25 or ≥0.25) is the only independent variable significant for overall and disease-free survival.

Conclusions

Metastatic lymph node ratio is an ideal prognostic marker for stage III colon cancer patients, and 0.25 is the cut-off value for prognosis.

The impact of the lymph node ratio is greater than traditional lymph node status in stage III colorectal cancer patients

BACKGROUND

The prognostic value of nodal status in colorectal cancer (CRC) patients may be influenced by the total number of lymph nodes (LNs) harvested. This study evaluates the impact of LN ratio (LNR) on CRC patients' outcome.

METHODS

A total of 612 stage III CRC patients who underwent curative-intent surgery between 2004 and 2008 were enrolled. The measured end point was postoperative disease-free survival (DFS) and overall survival (OS).

RESULTS

The metastatic LN numbers were significantly higher in patients with more than 12 LN harvested (4.6 ± 5.81 vs. 2.7 ± 1.97, P < 0.001). The mean LNR was 22.9 ± 20 % (range = 2-100 %, median = 16.7 %). As the cutoff value of LNR was set above 17 %, the impact of the LNR on 5-year DFS became statistically significant. In univariate analysis, the 5-year DFS and OS for patients with high-LNR tumors was 54.4 and 57.3 %, respectively, significantly lower than those for patients with low-LNR tumors (72.8 and 76.4 %; P < 0.001). In multivariate analysis, the independent factors affecting the 5-year DFS and OS were tumor depth, carcinoembryonic antigen level, and LNR.

CONCLUSION

The LNR, set at the median value or 17 %, could be an independent prognostic factor for stage III CRC patients.

The impact of the lymph node ratio is greater than traditional lymph node status in stage III colorectal cancer patients

BACKGROUND

The prognostic value of nodal status in colorectal cancer (CRC) patients may be influenced by the total number of lymph nodes (LNs) harvested. This study evaluates the impact of LN ratio (LNR) on CRC patients' outcome.

METHODS

A total of 612 stage III CRC patients who underwent curative-intent surgery between 2004 and 2008 were enrolled. The measured end point was postoperative disease-free survival (DFS) and overall survival (OS).

RESULTS

The metastatic LN numbers were significantly higher in patients with more than 12 LN harvested (4.6 ± 5.81 vs. 2.7 ± 1.97, P < 0.001). The mean LNR was 22.9 ± 20 % (range = 2-100 %, median = 16.7 %). As the cutoff value of LNR was set above 17 %, the impact of the LNR on 5-year DFS became statistically significant. In univariate analysis, the 5-year DFS and OS for patients with high-LNR tumors was 54.4 and 57.3 %, respectively, significantly lower than those for patients with low-LNR tumors (72.8 and 76.4 %; P < 0.001). In multivariate analysis, the independent factors affecting the 5-year DFS and OS were tumor depth, carcinoembryonic antigen level, and LNR.

CONCLUSION

The LNR, set at the median value or 17 %, could be an independent prognostic factor for stage III CRC patients.

Evaluation of the prognostic value of the metastatic lymph node ratio for gastric cancer

BACKGROUND

The aim of this study was to investigate the prognostic value of metastatic lymph node (LN) ratio (LNR) compared with pathologic node (pN) category.

METHODS

Three hundred ninety-nine patients with gastric cancer with R0 resection were reviewed. LNR, pN, and the number of retrieved LNs were evaluated in node-positive groups with ≥15 or <15 LNs resected and a node-negative group, respectively, by univariate and multivariate analyses. Associations of pN and LNR with the number of retrieved LNs were determined using Spearman's rank correlation test.

RESULTS

LNR and pN were correlated with overall survival. For the node-positive group with ≥15 LNs retrieved, pN and LNR were independent prognostic factors, with the hazard ratio higher for LNR; neither was correlated with the number of retrieved LNs. For the group with <15 LNs retrieved, LNR but not pN was an independent prognostic factor, with LNR uncorrelated with the number of LNs retrieved. For the node-negative group, the number of LNs retrieved retained an independent prognostic factor.

CONCLUSIONS

LNR is an independent prognostic factor in node-positive patients with gastric cancer with R0 resection, and it is uninfluenced by the number of LNs retrieved. It may be superior to pN.

Prognosis for gastric carcinomas with an insufficient number of examined negative lymph nodes

BACKGROUND

The optimal system for lymph node (LN) staging in gastric cancer is still a subject of debate. The aim of our study was to analyse the probability of error in negative LN (pN0) gastric carcinomas when a low number of LNs were harvested using a probabilistic model.

METHODS

Patients with gastric carcinoma who underwent R0 resection at three university hospitals between 2004 and 2009 were retrospectively included. A Bayesian model was used to analyse the probability of error for negative LNs (pN0) gastric carcinomas. Kaplan-Meier survival curves and the log-rank test were used to compare the overall and specific mortality of prognosis groups.

RESULTS

Of the 291 patients included, 123 were classified as pN0 (42%). A significant correlation was found between the extent of the LN dissection performed and the number of the LNs retrieved. According to the Bayesian model the carcinomas with 9 or fewer negative lymph nodes were considered to have a high risk (HR) of misclassification, whereas patients with 10-25 LNs analysed and those with more than 26 negative lymph nodes were considered to have a moderate risk (MR) and low risk (LR), respectively. The log-rank test showed a significant improvement in the disease-specific survival for the MR pN0 (p < 0.001) and LR pN0 (p < 0.04) but not for the HR pN0 patients compared to pN1 patients.

CONCLUSIONS

The proposed probabilistic model is clinically useful for differentiating the prognosis in pN0 gastric carcinomas when an insufficient number of negative lymph nodes are retrieved.

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

OBJECTIVE

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of a lymph node ratio-based staging system with the 7th AJCC system for gastric cancer: analysis of 18,043 patients from the SEER database

OBJECTIVES

The American Joint Committee on Cancer (AJCC) staging system for gastric cancer bases N status on absolute number of metastatic nodes, regardless of the number of examined nodes. We examined a modified staging system utilizing node ratio (Nr), the ratio of metastatic to examined nodes.

METHODS

A total of 18,043 gastric cancer patients who underwent gastrectomy were identified from the US Surveillance, Epidemiology, and End Results (SEER) database. A training set was divided into 5 Nr groups, and a TNrM staging system was constructed. Median survival and overall survival, based on 7th edition AJCC and TNrM staging systems, were compared, and the analysis was repeated in a validation set.

RESULTS

Median examined nodes were 10 to 11. For the training set, overall survival for all 5 AJCC N categories was significantly different when subgrouped into 15 or fewer versus more than 15 examined nodes, but overall survival was similar regardless of the number of examined nodes in 4 of 5 Nr categories. Seven AJCC stages had statistically different overall survival between subgroups, whereas only 1 TNrM stage had statistically different overall survival between subgroups. When misclassification was defined as any subgroup in which median survival fell outside the 95% confidence interval of the group's overall median survival, AJCC staging misclassified 57% of patients and TNrM staging misclassified only 12%. Similar results were found in the validation set.

CONCLUSIONS

The AJCC system classifies SEER gastric cancer patients into stages in which subgroups often have wide variations in survival. For patients undergoing limited lymph node analysis, the proposed TNrM system may predict survival more accurately.

Metastatic lymph node ratio versus number of metastatic lymph nodes as a prognostic factor in gastric cancer

OBJECTIVE

Knowledge of prognostic factors in gastric cancer is essential to decide on single patient management. We aim to establish the value of lymph node ratio compared to lymph node involvement in the prediction of gastric cancer survival and treatment approach.

METHODS

Charts of ninety-six consecutive patients undergoing gastrectomy for resectable gastric cancer were reviewed between January 1996 and December 2005. Receiver operating characteristic (ROC) curves were plotted to verify the accuracy of metastatic lymph node ratio (MLNR) and number of metastatic lymph node (NMLN) cut-off values for survival prediction. Patients were divided into two groups according to ROC curve cut-offs and accuracy in prognosis was reviewed.

RESULTS

ROC curves showed that 5 metastatic nodes and a node ratio value of 20% had the best survival prognostic correlation. The median survival of patients with MLNR and NMLN were similar according to cut-off determinations (≤ 5/> 5 metastatic nodes and ≤20/>20% lymph node ratio). Five-year survival rates were 70.9% vs 17.1% and 72.4% vs 15.6%, respectively (p < 0.001). Positive correlation coefficient was found between the number of excised nodes and the number of metastatic nodes.

CONCLUSION

Number of metastatic lymph nodes showed greater accuracy than lymph node ratio for survival prediction in gastric cancer.

Stage migration effect on survival in gastric cancer surgery with extended lymphadenectomy: the reappraisal of positive lymph node ratio as a proper N-staging

OBJECTIVE

The purpose of this study is to analyze the relationship between the number of examined lymph nodes (NexLN) and survival in gastric cancer and to determine whether the metastatic/examined lymph node ratio (LN ratio) system can compensate for the shortcomings of the UICC/AJCC staging.

METHODS

Prospective data of 8949 primary T1-T4a gastric cancer patients who underwent curative surgery were reviewed. The patients were stratified by T-stage and grouped according to NexLN; 1 to 14 exLN denoted the first group and every subsequent 10 LNs thereafter. Numbers of LN and 5-year survival rates were analyzed according to NexLN. "The NR-staging system" was generated using 0.2 and 0.5 as the cut-off values of LN ratio and then compared with UICC/AJCC stages.

RESULTS

The proportion of advanced N-stage increased with NexLN. Survival and the LN ratio were constant regardless of NexLN when combining all N0-N3b patients, however, T2/3 and T4a patients showed an increasing tendency toward survival in N1/2 and N3a as NexLN increased, mainly due to a stage migration effect. The LN ratio system showed better patterns of distribution of the LN stage and survival graph. The power of the differential staging of the LN ratio system was fortified with higher NexLN.

CONCLUSION

The relationship between NexLN and survival is probably affected by stage migration in a high-volume gastric cancer center. The LN ratio system could be a better option to compensate for this effect, and the value of the prognosis prediction in this system increases with a higher NexLN.

[TNM-7th edition 2009 (UICC/AJCC) and Japanese Classification 2010 in Gastric Cancer. Towards simplicity and standardisation in the management of gastric cancer]

The 7th edition of the UICC/AJCC TNM, and a new revision of the Japanese Classification for Gastric Cancer and Treatment Guidelines (Japanese Gastric Cancer Association) have been available since the beginning of 2010. One of the most important changes consists on the redefining and simplification of type D1/D2 lymphadenectomy depending on the type of gastrectomy performed (previously it depended on the location of the primary tumour), and the adoption of numeric criteria of TNM-7th Edition to evaluate the level of lymph node involvement (before, according to the anatomical location of the groups as regards the primary tumour). These changes attempt to make therapeutic management easier and a more uniform comparison of results between countries. The importance of these modifications in both systems justifies this exhaustive analysis and update of the new concepts for a correct management of gastric cancer.

Comparison of four staging systems of lymph node metastasis in gastric cancer

BACKGROUND

The classification of lymph node metastasis in patients with gastric cancer is still controversial. Our aim was to evaluate the relative merits of four staging systems of lymph node metastasis.

METHODS

In our study, the nodal status was classified according to the 5th edition of the tumor node metastasis (TNM) system, the Japanese Classification of Gastric Carcinoma (JCGC), the ratio of metastatic lymph nodes, and the size of the largest metastatic lymph node. Each staging system was scored as good (+2), fair (+1), or poor (0) with respect to the theoretical value (extent of the anatomical lymphatic tumor spread), convenience (simplicity), surgical applicability (extent of lymph node dissection), and prognostic value (ability to predict survival rate).

RESULTS

In the multivariate analysis including the four staging systems and other potential prognostic factors, stepwise Cox regression revealed that the ratio of metastatic lymph nodes was the most independent prognostic factor. The TNM, ratio, and size systems were convenient because they had no consideration for the location of the tumor and lymph node. Although the JCGC system had advantages in theoretical value and surgical application, it was most optional due to the complexity of the system.

CONCLUSIONS

Although all different staging systems are comparable, the metastatic lymph node ratio system is convenient, reproducible, and has the highest ability to predict survival.

Ratio between metastatic and examined lymph nodes (N ratio) may have low clinical utility in gastric cancer patients treated by limited lymphadenectomy: results from a single-center experience of 526 patients

BACKGROUND

The aim of this study was to evaluate the prognostic value of the ratio of metastatic to examined lymph nodes (N ratio) in gastric cancer patients who underwent limited lymphadenectomy and had a small number (< or =15) of analyzed nodes.

METHODS

The prognostic value of the actual AJCC/UICC pN staging system and the N ratio (0%, 1-25%, > 25%) were analyzed by means of univariate and multivariate analyses for 526 patients who underwent R0 resection for gastric adenocarcinoma at the Latvia Oncology Center.

RESULTS

The mean (SD) number of analyzed nodes was 5.6 (2.8). The number of positive nodes significantly increased with the number of analyzed nodes (p < 0.001). No significant differences in survival (p = 0.508) and risk of death (p = 0.224) were observed between pN1 and pN2 subsets. When the N ratio (1-25% vs. > 25%) was taken into account, a significant difference was demonstrated between pNR1 and pNR2 with respect to survival (p = 0.017) and risk of death (p = 0.012). Nonetheless, the joint allocation of the two classifications demonstrated that only a minority of patients (28 cases) belonged to the pNR1 subset and none of these belonged to the AJCC/UICC pN2 subset.

CONCLUSIONS

When a small number of lymph nodes are analyzed, the N ratio can discriminate patients better than TNM classification. However, because a small number of retrieved nodes produced only a small number of pNR1 patients, the N ratio classification cannot be justified for clinical use.

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.

New metastatic lymph node ratio system reduces stage migration in patients undergoing D1 lymphadenectomy for gastric adenocarcinoma

BACKGROUND

The American Joint Committee on Cancer (AJCC)/International Union Against Cancer (UICC) staging system for gastric cancer incorporates the absolute number of metastatic lymph nodes (N status) and is optimally used when >or=15 nodes are examined. The ratio of metastatic to examined nodes (N ratio) is an effective prognostic tool, but has not been examined in Western patients undergoing primarily D1 lymphadenectomy.

METHODS

Two hundred and fifty seven patients with gastric adenocarcinoma who underwent gastric resection between 1995 and 2005 at our institution were examined. Novel N ratio intervals were determined using the best cutoff approach (Nr0: N ratio = 0 and >or=15 nodes examined; Nr1: 0 <or= N ratio <or= 0.3; Nr2: 0.3 < N ratio <or= 0.7; and Nr3: N ratio > 0.7). Overall survival was examined according to N status and N ratio.

RESULTS

83% of patients underwent D1 lymphadenectomy with a median of 14 lymph nodes examined. Overall survival stratified by N status was significantly different in patients with <15 nodes examined compared with those with >or=15 nodes examined. When we stratified by N ratio intervals, there was no significant difference in overall survival in patients with <15 versus >or= 15 nodes examined. On multivariate analysis, N ratio but not N status was retained as an independent prognostic factor.

CONCLUSIONS

The use of N status for staging patients undergoing primarily D1 lymphadenectomy results in significant stage migration due to varying numbers of nodes examined. Use of N ratio reduces stage migration and may be a more reliable method of staging these patients.

Prognostic Factors of Patients With Transmural Advanced Gastric Carcinoma

Background

The purpose of this study is to evaluate perioperative morbidity, mortality and the prognostic factors that influence survival of the patients with transmural advanced gastric carcinoma after curative surgical therapy.

Methods

Fifty patients with transmural advanced gastric adenocarcinoma underwent curative resection in our clinic. The records of the patients were reviewed and the prognostic factors such as age, gender, location and size of the tumor, type of surgery, blood transfusion, depth of tumor invasion, lymph node metastases, stage of the disease, grading, vascular invasion, lymph vessel invasion, characteristics of the tumor according to Lauren’s classification, and lymph node ratio were evaluated by using statistical methods.

Results

In a total of 12 patients (24%) major morbidities developed, and five patients (10%) died. The overall survival rate was 48% at 1 year, 31% at 3 years, and 19% at 5 years. Lymph node metastases (P = 0.03), lymph vessel invasion (P = 0.001), blood transfusion (P = 0.021), and lymph node ratio (P = 0.006) were the prognostic features identified by univariate analysis. Among the multiple significant prognostic factors in the univariate analysis only one factor, lymph node ratio, proved to be independently significant in the multivariate analysis (RR: 4.47).

Conclusions

Our data showed that we can expect a good survival for patients with a lymph node ratio less than 0.2.

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.

Metastatic lymph node ratio is a more precise predictor of prognosis than number of lymph node metastases in stage III colon cancer

OBJECTIVE

The objective of this study is to assess the value of metastatic lymph node ratio (LNR) in predicting disease-free survival (DFS) in patients with stage III adenocarcinoma of the colon.

MATERIALS AND METHODS

From 1995 to 2003 inclusively, a total of 624 patients featuring stage III adenocarcinoma of the colon underwent curative resection. Of the 624 patients, an adequate number of lymph nodes (n > or = 12) had been harvested in 490 patients. These patients were stratified into LNR groups 1 (LNR < or = 0.4), 2 (0.4 < LNR < or = 0.7), and 3 (LNR > 0.7). Kaplan-Meier survival curve and log-rank test were used to evaluate the prognostic value of LNR. A Cox regression model was used for multivariate analyses.

RESULTS

The 5-year DFS rate was 66.7% for patients with LNR1, 35.1% for those with LNR2, and 0% for patients with LNR3 (p < 0.0001). In T3/4LNR1 patients (n = 411), there was no difference in survival between those with N1 stage and those with N2 stage. Cox proportional hazards regression analysis revealed that N stage (number of positive lymph nodes) was not a significant factor when LNR was taken into consideration.

CONCLUSIONS

LNR is a more precise predictor of 5-year DFS than number of positive lymph nodes (N stage) in patients with stage III colon cancer.

Nodal stage of stage III colon cancer: the impact of metastatic lymph node ratio

PURPOSE

We assessed which classification of lymph node metastasis better predicted outcomes in patients with colorectal carcinoma.

METHODS

We identified 318 patients (176 men) with stage III colon cancer who underwent curative resection. The number of LNs dissected, LNR, and disease-free survival time, were analyzed. Lymph node disease was stratified by the American Joint Committee on Cancer staging and LNR, with the latter categorized into groups with LNR <0.059 (n = 67), 0.059-0.23 (n = 171), and >0.23 (n = 80). Median follow-up time was 37 (range, 1-122) months.

RESULTS

LNR significantly increased with the number of metastatic LNs (P < 0.0001). Three-year disease-free survival (DFS) rates differed significantly in the three LNR groups. Within each TNM stage, 3-year DFS rates differed according to LNR, but, within each LNR subgroup, 3-year DFS did not differ according to TNM stage. When both TNM stage and LNR subgroup were considered, 3-year DFS was stratified into four groups, which differed significantly (P < 0.0001). Considering number of retrieved lymph nodes, this stratification was not found when <12 lymph nodes retrieved.

CONCLUSIONS

Re-stratified lymph node staging, reflecting both LNR and TNM stage, can predict survival in patients with LN-positive colon cancer, especially when more than 12 lymph nodes harvested.

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.

A novel subclassification of pT2 gastric cancers according to the depth of muscularis propria invasion: superficial muscularis propria versus deep muscularis propria/subserosa

PURPOSE

To propose a novel subclassification of pT2 gastric cancers according to the depth of muscularis propria (MP) invasion (superficial MP vs. deep MP/subserosa [SS]) and to investigate its impact in prognostic assessment.

SUMMARY BACKGROUND DATA

The major change in the sixth edition of the International Union Against Cancer (UICC)/American Joint Committee on Cancer (AJCC) TNM classification concerned the pT (primary tumor) category. Specifically, pT2 lesions were divided into pT2a (invading the MP) and pT2b (invading the SS) to discriminate these intramural locations. However, the value of the modification is still debated.

METHODS

One thousand two hundred fifty-six patients with pT2 cancers classified according to the UICC/AJCC pT staging system were reviewed. Among them, 214 (17.0%) were classified as invasion of the superficial MP (sMP) or inner circular muscle, 163 (13.0%) as invasion of the deep MP (dMP) or outer longitudinal muscle, and 879 (70.0%) as invasion of SS. Clinicopathologic features were compared between patients with sMP, dMP, and SS invasion. Overall survival rates were compared between the pT2a and pT2b stage cancers, according to the UICC/AJCC and the novel pT2 system. Two-step multivariate analysis was performed to identify the significantly important prognostic factors.

RESULTS

There was significant difference in most of the clinicopathologic features between sMP and SS cancers. Although, only 5 factors (tumor location, tumor size, Borrmann type, metastasis number, and metastasis ratio) were significantly different between dMP and SS cancers. In step 1 of the multivariate analysis, the UICC/AJCC pT2 system was an independent factor that correlated with prognosis, but was substituted by the novel pT2 system in step 2 of the multivariate analysis. With a certain metastasis ratio of lymph nodes, the novel pT2 system discriminated 2 subsets of patients with significantly different prognoses, whereas the UICC/AJCC pT2 system did not.

CONCLUSIONS

The novel pT2 staging system, which was subclassified as sMP and dMP/SS cancers, had more potential to identify the different prognoses for patients with pT2 gastric cancers.

Adjustment of N stages of gastric cancer by the ratio between the metastatic and examined lymph nodes

BACKGROUND

The present study attempted to determine whether N stage could be adjusted for the differences in survival rates based on the ratio between the examined and metastatic lymph nodes (LN ratio).

METHODS

Five hundred and twenty-nine patients with both >15 lymph nodes examined and >or= N1 after R0 resection were enrolled in the present study. To determine the cutoff LN ratio, the ratios at each N stage were compared at intervals of 10% with the log-rank test of Kaplan-Meier estimates of the survival curves.

RESULTS

The 5-year survival rate of patients with N1 was 71.7%. Those of N2 patients with LN ratio of <60% (n = 116) and >or=60% (n = 3) were 37.0% and 0%, respectively. Those of N3 patients with LN ratio of <30% (n = 32), between 30% and 60% (n = 67), and >or=60% (n = 26) were 31.0%, 16.3%, and 0%, respectively. Thus, adjusted N2 was obtained from the sum of N2 < 60% and N3 < 30%. N3 with an LN ratio between 30% and 60% was regarded as adjusted N3. N2 and N3 patients with an LN ratio of >or=60% were regarded as adjusted T4. The 5-year survival rate in patients with adjusted N2, N3, and N4 were 35.7%, 16.3%, and 0%, respectively. Multivariate analysis showed adjusted N stage and tumor depth were significant independent prognostic factors.

CONCLUSIONS

The results of this study suggest that, since stage migration can be induced in the N staging system, such stage migration can be adjusted by the LN ratio based on the survival rate.

Does lymph node ratio impact survival in resected periampullary malignancies?

BACKGROUND

Lymph node ratio (LNR) has been associated with long-term survival in patients with pancreatic adenocarcinoma; however, this has not been demonstrated in other periampullary malignancies. The purpose of this study was to determine if LNR is associated with survival in other periampullary malignancies.

METHODS

A retrospective review of a prospective database of 522 pancreaticoduodenectomies (PDs) performed between 1988 and 2007 was undertaken. Clinicopathologic data were collected, and LNR was calculated. Patients with positive lymph node (LN) status were placed into the following groups: (1) LNR = 0; (2) LNR < or =0.2; (3) LNR < or =0.4; and (4) LNR >0.4.

RESULTS

Of the 364 malignancies identified, there were 219 (60%) pancreatic adenocarcinomas, 36 (10%) duodenal adenocarcinomas, 75 (21%) ampullary adenocarcinomas, and 35 (10%) cholangiocarcinomas. Positive LN status affected patient survival in all malignancies studied. Increasing LNR is associated with decreased survival in PA (P = .03) and AA (P = .04).

CONCLUSIONS

Positive LN status in all patients with periampullary malignancies is associated with worse survival rates than in those with no evidence of disease. LNR is inversely associated with survival rates in pancreatic and ampullary adenocarcinoma patients.

Does lymph node ratio impact survival in resected periampullary malignancies?

BACKGROUND

Lymph node ratio (LNR) has been associated with long-term survival in patients with pancreatic adenocarcinoma; however, this has not been demonstrated in other periampullary malignancies. The purpose of this study was to determine if LNR is associated with survival in other periampullary malignancies.

METHODS

A retrospective review of a prospective database of 522 pancreaticoduodenectomies (PDs) performed between 1988 and 2007 was undertaken. Clinicopathologic data were collected, and LNR was calculated. Patients with positive lymph node (LN) status were placed into the following groups: (1) LNR = 0; (2) LNR < or =0.2; (3) LNR < or =0.4; and (4) LNR >0.4.

RESULTS

Of the 364 malignancies identified, there were 219 (60%) pancreatic adenocarcinomas, 36 (10%) duodenal adenocarcinomas, 75 (21%) ampullary adenocarcinomas, and 35 (10%) cholangiocarcinomas. Positive LN status affected patient survival in all malignancies studied. Increasing LNR is associated with decreased survival in PA (P = .03) and AA (P = .04).

CONCLUSIONS

Positive LN status in all patients with periampullary malignancies is associated with worse survival rates than in those with no evidence of disease. LNR is inversely associated with survival rates in pancreatic and ampullary adenocarcinoma patients.