Comparison of the 6th and 7th editions of the UICC TNM staging system for gastric cancer: results of a Chinese single-institution study of 1,503 patients

Impact of 18FFDG-PET/CT and Laparoscopy in Staging of Locally Advanced Gastric Cancer: A Cost Analysis in the Prospective Multicenter PLASTIC-Study

BACKGROUND

Unnecessary D2-gastrectomy and associated costs can be prevented after detecting non-curable gastric cancer, but impact of staging on treatment costs is unclear. This study determined the cost impact of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18FFDG-PET/CT) and staging laparoscopy (SL) in gastric cancer staging.

MATERIALS AND METHODS

In this cost analysis, four staging strategies were modeled in a decision tree: (1) 18FFDG-PET/CT first, then SL, (2) SL only, (3) 18FFDG-PET/CT only, and (4) neither SL nor 18FFDG-PET/CT. Costs were assessed on the basis of the prospective PLASTIC-study, which evaluated adding 18FFDG-PET/CT and SL to staging advanced gastric cancer (cT3-4 and/or cN+) in 18 Dutch hospitals. The Dutch Healthcare Authority provided 18FFDG-PET/CT unit costs. SL unit costs were calculated bottom-up. Gastrectomy-associated costs were collected with hospital claim data until 30 days postoperatively. Uncertainty was assessed in a probabilistic sensitivity analysis (1000 iterations).

RESULTS

18FFDG-PET/CT costs were €1104 including biopsy/cytology. Bottom-up calculations totaled €1537 per SL. D2-gastrectomy costs were €19,308. Total costs per patient were €18,137 for strategy 1, €17,079 for strategy 2, and €19,805 for strategy 3. If all patients undergo gastrectomy, total costs were €18,959 per patient (strategy 4). Performing SL only reduced costs by €1880 per patient. Adding 18FFDG-PET/CT to SL increased costs by €1058 per patient; IQR €870-1253 in the sensitivity analysis.

CONCLUSIONS

For advanced gastric cancer, performing SL resulted in substantial cost savings by reducing unnecessary gastrectomies. In contrast, routine 18FFDG-PET/CT increased costs without substantially reducing unnecessary gastrectomies, and is not recommended due to limited impact with major costs.

TRIAL REGISTRATION

NCT03208621. This trial was registered prospectively on 30-06-2017.

Could fertility-sparing surgery be considered for stage I ovarian sex cord-stromal tumors? A comparison of the Fine-Gray model with Cox model

Objective

To evaluate the oncologic outcomes in patients with International Federation of Gynecology and Obstetrics (FIGO) stage I ovarian sex cord-stromal tumors (SCSTs) who underwent fertility-sparing surgery (FSS) and the independent risk factors affecting overall survival (OS) and cancer-specific survival (CSS).

Methods

Data were acquired from the Surveillance, Epidemiology, and End Results (SEER) database between 1973 and 2018. A total of 240 patients diagnosed with stage I ovarian SCSTs were divided into the definitive surgery group (N=116) and FSS group (N=124). The Kaplan-Meier analysis and Cox model were used to evaluate the overall survival (OS) and cancer-specific survival (CSS) of the two groups and assess the independent risk factors respectively. The Fine-Gray model evaluated cancer-specific mortality (CSM) and the independent risk factors that affected CSM.

Results

Kaplan-Meier survival analysis showed no statistically significant differences in OS and CSS between the two groups (P>0.05). Univariate analysis of the Fine-Gray model also showed that there was no difference in the CSS between the two groups (P>0.05). However, from the 15th year postoperatively, the CSS of the FSS group decreased by 13.21% compared with that of the control group and by 17.49% in the 20th and 25th years postoperatively. The Cox proportional hazards model found that surgical methods (“defined surgery” vs “FSS”; HR=0.03259, P=0.0196) and FIGO stage (“stage IA” vs “stage IC”; HR=0.03073, P=0.0300) were independent risk factors for OS. The multivariate analysis of Fine-Gray model showed that the cancer-specific mortality of patients receiving definitive surgery was 40.1% lower than that of patients receiving FSS (“definitive surgery” vs “FSS”; HR=0.599, P=0.005), indicating that FSS might lead to higher tumor-specific mortality and lower CSS. However, age, race, laterality, history, FIGO stage, and tumor size had no significant influence on the tumor-specific mortality (P>0.05).

Conclusions

FSS is considered for patients with stage I SCSTs with reproductive needs, but the follow-up period should not be less than 15 years. For patients with stage IC disease, FSS should be selected carefully, and close follow-up is necessary. Perhaps, definitive surgery after birth is a means to improve long-term survival rates.

Adjuvant Chemotherapy in Node-Negative Advanced Gastric Cancer Patients

Currently, there is still controversy on postoperative adjuvant chemotherapy for node-negative advanced gastric cancer. Herein, we sought to evaluate the role of postoperative adjuvant chemotherapy in these patients. We retrospectively analyzed the clinical and pathological characteristics of 363 node-negative advanced gastric cancer patients in our hospital from 1996 to 2007 who underwent gastrectomy and D2 lymphadenectomy. We compared the survival rate of the surgery-only group with that of the adjuvant chemotherapy treatment group. The 5-year survival rates of patients in the surgery-only group and the chemotherapy treatment group were 70.7% and 73.8%, respectively. There was no significant difference in the survival rate between patients receiving postoperative chemotherapy and patients not receiving chemotherapy (P=0.328). However, postoperative chemotherapy treatment significantly increased the survival rate of pT4aN0M0 patients (P=0.020), although it did not exert a direct effect on the survival rate in pT2N0M0 and pT3N0M0 patients (P=0.990 and P=0.895). We also summarized and analyzed the side effects and safety of postoperative adjuvant chemotherapy. The rate of chemotherapy-related adverse events was 79.9%. Although 61 (36.1%) patients had to adjust their chemotherapy dose, no patient died from side effects. In conclusion, postoperative chemotherapy treatment is safe but did not show a direct impact on the survival rate of the node-negative advanced gastric cancer patients. However, pT4aN0M0 patients can benefit from postoperative adjuvant chemotherapy after undergoing D2 radical resections.

Lymphatic Invasion Might Be Considered as an Upstaging Factor in N0 and N1 Gastric Cancer

(Background) The aim of this study was to investigate the prognostic impact of lymphatic invasion in gastric cancer, focusing on survival differences between N stage groups. (Methods) A total of 398 consecutive patients who underwent curative gastrectomy for primary gastric adenocarcinoma from January 2006 to December 2015 were analyzed retrospectively using data from a prospectively collected registry database. We compared various clinicopathological features and survival differences between lymphatic invasion-positive and -negative groups. (Results) Of the 398 patients, 141 (35.4%) showed lymphatic invasion. The lymphatic invasion-positive subgroup had poorer prognosis than the lymphatic invasion-negative subgroup in N0 (five-year survival rate: 87.8% vs. 73.6%, p = 0.048) and N1 (87.2% vs. 50%, p = 0.007) stage patients. The odds ratio (OR) of lymphatic invasion to five-year survival rate was 2.078 (95% confidence interval (CI), 1.103-3.916; p = 0.024). The presence of lymphatic invasion had worse effect on survival than age (OR, 1.807; 95% CI, 1.024-2.242; p = 0.029) or tumor depth (OR, 1.286; 95% CI, 1.078-1.897; p = 0.013) in N0 and N1 stage patients. The overall survival of patients with lymphatic invasion was not different from that of patients at a one-higher N stage without lymphatic invasion at any N stage. (Conclusions) The presence of lymphatic invasion may be the most important independent prognostic factor in N0 and N1 gastric cancer and might be an upstaging factor of N stage at any N stage. Therefore, in addition to the number of metastasized lymph nodes, the presence of lymphatic invasion should be included in N stage determination.

Multicenter Validation Study of the American Joint Commission on Cancer (8th Edition) for Gastric Cancer: Proposal for a Simplified and Improved TNM Staging System

Objective: To evaluate the prognostic significance of the eighth edition of the American Joint Committee on Cancer (AJCC) TNM staging classification for gastric cancer.

Methods: Prospective databases were reviewed to identify patients who underwent radical gastrectomy at two specialized eastern centers. The prognostic value of the eighth edition TNM classification was estimated and compared with that of the seventh edition. Additional external validation was performed using a dataset from a Western population.

Results: Significant differences in 5-year overall survival (OS) rates were observed for each TNM stage when using the eighth edition system, and smaller Akaike information criteria (AIC) values and a higher c-statistic were observed relative to those of the seventh edition. However, the OS rates in each subgroup of stage III patients based on the eighth edition were significantly different. Patients with the same pN stage, namely, the pT4a and pT4b groups, showed similar 5-year OS (P>0.05). Based on the survival data, we propose a simplified staging system. In the improved TNM (iTNM) staging system, the subgroups of a given TNM stage do not show statistically significant differences in OS. The iTNM staging exhibits superior prognostic stratification, with lower AIC values and a higher c-statistic than the eighth edition TNM classification. Similar results were obtained with the external validation dataset from the IMIGASTRIC database.

Conclusion: The prognostic prediction of the eighth edition of the AJCC TNM classification is superior to that of the seventh edition. However, it remains associated with some stage migration. The iTNM staging system permits simplification and slightly better prognostic prediction.

Systematic assessment of complications after robotic-assisted total versus distal gastrectomy for advanced gastric cancer: A retrospective propensity score-matched study using Clavien-Dindo classification

BACKGROUND

Despite increasing evidence demonstrated robot-assisted distal gastrectomy (RADG) is safe and feasible for the treatment of advanced gastric cancer (AGC), robot-assisted total gastrectomy (RATG) remains a challenging procedure due to its technical difficulties and possible postoperative complications (POCs). This study aimed to systematically evaluate POCs following RATG.

METHODS

Between January 2017 and January 2019, 319 AGC patients with pathological stage T2-4aN0-3M0 who underwent RADG or RATG were enrolled. POCs were stratified using the Clavien-Dindo classification. One-to-one propensity score matching was performed to reduce confounding differences.

RESULTS

After matching, 266 patients met the criteria for further analysis. Ultimately, 64 patients (24.1%) who developed POCs had 126 clinical manifestation events. Overall the POCs rate was significantly greater after RATG in comparison with RADG (29.3% vs. 18.8%; P = 0.045), and more major POCs (Clavien-Dindo grade ≥ IIIa) were observed in the RATG group (14.3% vs. 5.3%; P = 0.013). The POCs were then classified into local and systemic POCs. The rates of local POCs (35.3% vs. 19.5%; P = 0.004) and systemic POCs (24.8% vs. 15.0%; P = 0.046) were significantly higher in the RATG group than the RADG group. Subgroup analysis showed that the anastomotic leakage rate was higher after RATG (5.3% vs. 0.8%; P = 0.031), whereas the remaining POCs were similar between the two groups. Patients with higher POCs significantly had longer postoperative length of stay (R = 0.895, P = 0.003). Multivariate analysis confirmed age, extent of resection, and TNM stage were risk factors for all POCs.

CONCLUSIONS

These findings demonstrated that RATG is technically feasible and safe for treatment of AGC with acceptable morbidity and mortality rates. The POCs rate of RATG was higher than RADG, especially for anastomotic leakage. More effective anastomotic techniques are needed in RATG to prevent leakage.

Postoperative dynamic survival of gastric cancer patients: A multi-institutional, international analysis of 22 265 patients

BACKGROUND

How to best evaluate the disease-specific survival (DSS) of gastric cancer (GC) survivors over time is unclear.

METHODS

Clinicopathological data from 22 265 patients who underwent curative intend resection for GC were retrospectively analyzed. Changes in the patients' 3-year conditional disease-specific survival (CS3) were analyzed. We used time-dependent Cox regression to analyze which variables had long-term effects on DSS and devised a dynamic predictive model based on the length of survival.

RESULTS

Based on 1-, 3-, and 5-year survivorships, the CS3 of the population increased gradually from 62% to 68.1%, 83.7%, and 90.6%, respectively. Subgroup analysis showed that the CS3 of patients who had poor prognostic factors initially demonstrated the greatest increase in postoperative survival time (eg, N3b: 26.6%-84.1%, Δ57.5% vs N0: 84.1%-93.3%, Δ9.2%). Time-dependent Cox regression analysis showed the following predictor variables constantly affecting DSS: age, the number of examined lymph nodes (LNs), T stage, N stage, and site (P < .05). These variables served as the basis for a dynamic prediction model.

CONCLUSIONS

The influence of prognostic factors on DSS and CS3 changed dramatically over time. We developed an effective model for predicting the DSS of patients with GC based on the length of survival time.

Prognosis of Young Survivors of Gastric Cancer in China and the U.S.: Determining Long-Term Outcomes Based on Conditional Survival

BACKGROUND

Young survivors of gastric cancer (GC) have better prognoses than elderly patients, yet their disease-specific survival (DSS) has received little attention.

PATIENTS AND METHODS

Data on young patients (aged ≤40 years) with GC undergoing resections at three Chinese institutions (n = 542) and from the SEER database (n = 533) were retrospectively analyzed. Three-year conditional disease-specific survival (CS3) was assessed. The effects of well-known prognostic factors over time were analyzed by time-dependent Cox regression.

RESULTS

Overall, young Chinese patients with GC had a better 5-year DSS than U.S. patients (62.8% vs. 54.1%; p < .05). The disease-specific mortality likelihood of the entire cohort was not constant over time, with most deaths occurring during the first 3 years after surgery but peaking at 1 and 2 years in China and the U.S., respectively. Based on 5-year survivorship, the CS3 rates of both groups were similar (90.9% [U.S.] vs. 91.5% [China]; p > .05). Cox regression showed that for Chinese patients, site, size, T stage, and N stage were independent prognostic factors at baseline (p < .05). For U.S. patients, grade, T stage. and N stage significantly affected DSS at baseline (p < .05). In both groups, only T stage continuously affected DSS within 3 years after gastrectomy. However, for both groups, the initial well-known prognostic factors lost prognostic significance after 5 years of survival (all p > .05). Although the 5-year DSS rates of young Chinese patients with T3 and T4a disease were significantly better than those of young U.S. patients, in each T stage, the CS3 of both regions trended toward consistency over time.

CONCLUSION

For young patients with GC, the factors that predict survival at baseline vary over time. Although the initial 5-year DSS is heterogeneous, insight into conditional survival will help clinicians evaluate the long-term prognoses of survivors while ignoring population differences.

IMPLICATIONS FOR PRACTICE

With the increasing number of young survivors of gastric cancer (GC), it is essential for clinicians to understand the dynamic prognosis of these patients. Based on large data sets from China and the U.S., this study found that the prognostic factors that predict survival for young patients with GC at baseline vary over time. Although the initial 5-year disease-specific survival is heterogeneous, insight into conditional survival will help clinicians evaluate the long-term prognoses of survivors while ignoring population differences. This knowledge may be more effective in helping young patients with GC to manage future uncertainties, especially when they need to make important life plans.

New metastatic lymph node classification for early gastric cancer should differ from those for advanced gastric adenocarcinoma: Results based on the SEER database

AIM

To establish an appropriate N classification system for early gastric cancer (EGC).

METHODS

Data from 10714 patients who underwent radical gastrectomy between 1988 and 2011 were retrieved from the National Cancer Institute’s Surveillance, Epidemiology, and End Result database. The overall survival (OS) based on the eighth edition and new tumor lymph node metastasis (TNM) staging systems were compared, and the analysis was repeated in an external validation set from the Fujian Medical University Union Hospital database.

RESULTS

There were no significant differences in OS between N1 and N2 cancers or between N3a and N3b cancers in cases of EGC. The X-tile program identified that the new staging system for EGC consisted of T1N0, T1N1’ [1-6 metastatic lymph nodes (LNs)], and T1N2’ ( ≥ 7 metastatic LNs). Compared with the eighth edition of the TNM staging system, the OS of patients in T1N1’ stage was similar to that of patients with stage IIA disease, whereas the OS of patients in T1N2’ stage was similar to that of patients with stage IIB disease. The new TNM staging system exhibited a slightly lower Akaike Information Criterion value and higher χ² and c-statistic compared with the eighth edition of the TNM classification system. Similar results were found in the external validation dataset from the external validation set.

CONCLUSION

We have developed an optional new TNM staging system with a better predictive ability that can be used to accurately predict the 5-year OS of patients with EGC.

Proposal and validation of a modified staging system to improve the prognosis predictive performance of the 8th AJCC/UICC pTNM staging system for gastric adenocarcinoma: a multicenter study with external validation

Background

The 8th edition of the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) pathological tumor-node-metastasis (pTNM) staging system may have increased accuracy in predicting prognosis of gastric cancer due to its important modifications from previous editions. However, the homogeneity in prognosis within each subgroup classified according to the 8th edition may still exist. This study aimed to compare and analyze the prognosis prediction abilities of the 8th and 7th editions of AJCC/UICC pTNM staging system for gastric cancer and propose a modified pTNM staging system with external validation.

Methods

In total, clinical data of 7911 patients from three high-capacity institutions in China and 10,208 cases from the Surveillance, Epidemiology, and End Results (SEER) Program Registry were analyzed. The homogeneity, discriminatory ability, and monotonicity of the gradient assessments of the 8th and 7th editions of AJCC/UICC pTNM staging system were compared using log-rank χ², linear-trend χ², likelihood-ratio χ² statistics and Akaike information criterion (AIC) calculations, on which a modified pTNM classification with external validation using the SEER database was proposed.

Results

Considerable stage migration, mainly for stage III, between the 8th and 7th editions was observed in both cohorts. The survival rates of subgroups of patients within stage IIIA, IIIB, or IIIC classified according to both editions were significantly different, demonstrating poor homogeneity for patient stratification. A modified pTNM staging system using data from the Chinese cohort was then formulated and demonstrated an improved homogeneity in these abovementioned subgroups. This staging system was further validated using data from the SEER cohort, and similar promising results were obtained. Compared with the 8th and 7th editions, the modified pTNM staging system displayed the highest log-rank χ², linear-trend χ², likelihood-ratio χ², and lowest AIC values, indicating its superior discriminatory ability, monotonicity, homogeneity and prognosis prediction ability in both populations.

Conclusions

The 8th edition of AJCC/UICC pTNM staging system is superior to the 7th edition, but still results in homogeneity in prognosis prediction. Our modified pTNM staging system demonstrated the optimal stratification and prognosis prediction ability in two large cohorts of different gastric cancer populations.

Proposal for a New TNM Stage based on the 7th and 8th American Joint Committee on Cancer pTNM Staging Classification for Gastric Cancer

Background: The 8^th edition of the American Joint Committee on Cancer (AJCC) staging system for gastric cancer incorporated several new changes. We aimed to assess the comparative prognostic values of the 7^th and 8^th AJCC pTNM staging systems in patients with gastric cancer (GC), and accordingly, to put forward a refined staging classification. Methods: The SEER database was queried to identify GC patients between 2004 and 2009. GC patients from Sun Yat-sen University Cancer Center (SYSUCC) were used as external validation data. The Kaplan-Meier method and Cox proportional hazards regression models were used to analyze cause-specific survival (CSS). The prognostic performance of different staging schemes was assessed using the concordance index (c-index), Akaike's information criterion (AIC), and likelihood ratio χ² test. Results: In the SEER cohort, stage migration occurred in 8.74% of patients. Survival analysis showed that it was better to treat T4bN0M0 + T4aN2M0 as stage IIIB and T4bN3bM0 as stage IV. Based on this, we established a new staging system which exhibited a superior c-index (0.7501) to the 7^th and 8^th AJCC staging systems (0.7498 and 0.7500, respectively). The new staging system also outperformed the 7^th and 8^th AJCC staging systems in terms of AIC and the likelihood ratio χ² test. The predictive superiority of the new staging system remained valid in the SYSUCC database. Conclusions: We demonstrated that some stage modifications in the 8^th AJCC pathologic staging were unnecessary. Therefore we established a new staging system, which was superior to the 7^th and 8^th staging systems.

Superiority of the 8th edition of the TNM staging system for predicting overall survival in gastric cancer: Comparative analysis of the 7th and 8th editions in a monoinstitutional cohort

The present study was performed to evaluate the predictive capacity of the 8th edition vs. the 7th edition of the American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) staging system for overall survival (OS) of patients with gastric cancer. Data of eligible patients with gastric cancer in our institution between June 2004 and June 2014 were retrospectively reviewed. A total of 1,506 patients were followed up to July 2016, among whom 1,484 patients with complete stage information were included in the TNM staging analysis. A total of 339 (22.8%) patients presented stage migration, including 325 (21.9%) migrating to a lower tier and 14 (0.9%) to a higher tier. All patients with stage migration to a lower tier were in stage III, including 177 (54.5%) patients migrating from stage IIIB to IIIA, and 148 (45.5%) from stage IIIC to IIIB. Patients migrating from IIIB to IIIA yielded a median OS time and 5-year OS rate closer to those remaining in stage IIIA. Similarly, patients migrating from IIIC to IIIB yielded a median OS time and 5-year OS rate closer to those remaining in stage IIIB. The 7th edition of the staging system exhibited prognostic discrepancy in discriminating stage IIIA from IIIB on survival curves, which was improved in the 8th edition. The 8th edition had a better predictive capability of survival, as evidenced by a smaller value of -2log likelihood in the Cox proportional regression model (7th edition 4738.859 vs. 8th edition 4736.683). Therefore, the present study demonstrated that the 8th edition of the AJCC TNM staging system is superior to the 7th edition in predicting the OS of patients with gastric cancer.

Which staging system better predicts 10-year survival for gastric cancer? A study using an international multicenter database

PURPOSE

Our aim was to evaluate the prognostic performance of the 8th edition AJCC staging system for gastric cancer survival after 10 years or more.

PATIENTS AND METHODS

An international multicenter database was constructed (total n = 4537) by combining gastric cancer cases from the SEER database (n = 3066) and the database (n = 1471) of the Department of Gastric Surgery, Fujian Medical University Union Hospital. The relative discriminatory abilities were assessed using the likelihood ratio chi-square test, Akaike's Information Criterion (AIC) and Harrell's concordance index (c-statistic).

RESULTS

The 10-year overall survival rate for all the patients was 32.2%. A 2-step multivariate analysis showed that the 8th edition staging system was an independent factor for long-term overall survival. It also had higher likelihood ratio chi-square score, c-statistic and smaller AIC values compared with the 7th edition. However, stages IB and IIA of the TNM staging system showed a similar prognosis (both P > 0.05). Based on the survival data, we revised the 8th edition by merging stages IB and IIA into 1 category in the training set. The modified staging system demonstrated superior prognostic stratification with a higher c-statistic, likelihood ratio chi-square score and smaller AIC values compared to the 8th edition. Similar results were observed in the external validation set.

CONCLUSION

The 8th edition AJCC TNM classification predicts the 10-year survival of gastric cancer patients more accurately than the 7th edition. However, by merging stages IB and IIA into 1 category, we propose a revised TNM stage system that provides an optimal prognosis.

A novel nomogram individually predicting disease-specific survival after D2 gastrectomy for advanced gastric cancer

BACKGROUND

Few studies have shown nomograms that may predict disease-specific survival (DSS) probability after curative D2 gastrectomy for advanced gastric cancer (AGC), particularly among Chinese patients. This study sought to develop an elaborative nomogram that predicts long-term DSS for AGC in Chinese patients.

METHODS

A retrospective study was conducted on 6753 AGC patients undergoing D2 gastrectomy between January 1, 2000 and December 31, 2012 from three large medical hospitals in China. We assigned patients from Sun Yat-sen University Cancer Center to the training set, and patients from the First Affiliated Hospital of China Medical University and Tianjin Medical University Cancer Hospital to two separate external validation sets. A multivariate survival analysis was performed using Cox proportional hazards regression model in a training set, and a nomogram was constructed. Harrell's C-index was used to evaluate discrimination and calibration plots were used to validate similarities between survival probabilities predicted by the nomogram model and actual survival rates in two validation sets.

RESULTS

The multivariate Cox regression model identified age, tumor size, location, Lauren classification, lymphatic/venous invasion, depth of invasion, and metastatic lymph node ratio as covariates associated with survival. In the training set, the nomogram exhibited superior discrimination power compared with the 8th American Joint Committee on Cancer TNM classification (Harrell's C-index, 0.82 vs. 0.74; P < 0.001). In two validation sets, the nomogram's discrimination power was also excellent relative to TNM classification (C-index, 0.83 vs. 0.75 and 0.81 vs. 0.74, respectively; P < 0.001 for both). After calibration, the nomogram produced survival predictions that corresponded closely with actual survival rate.

CONCLUSIONS

The established nomogram was able to predict 3-, 5-, and 10-year DSS probabilities for AGC patients. Validation revealed that this nomogram exhibited excellent discrimination and calibration capacity, suggesting its clinical utility.

Is the 8th Edition of the AJCC TNM Staging System Sufficiently Reasonable for All Patients with Noncardia Gastric Cancer? A 12,549-Patient International Database Study

BACKGROUND

The aim of this work is to compare the prognostic ability between the 7th and 8th editions of the American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) classification for gastric cancer (GC).

METHODS

A total of 10,194 noncardia GC patients were identified from the Surveillance, Epidemiology, and End Results database from 1988 to 2008. Concordance index (C-index), bayesian information criterion (BIC), and time-dependent receiver operating characteristic (t-ROC) analyses were used. External validation was performed using a dataset (n = 2355) derived from Fujian Medical University Union Hospital.

RESULTS

Overall survival for all five AJCC N categories differed significantly when patients were subgrouped into ≤ 15 versus >15 examined lymph nodes (eLNs). The prognostic ability of the 8th edition (C-index 0.716) was not improved over the 7th edition (C-index 0.716). Subgroup analysis showed superior performance of the 8th over the 7th edition in patients with > 15 eLNs (C-index 0.742 vs. 0.735); however, the two editions showed similar performance for patients with ≤ 15 eLNs (C-index 0.713 vs. 0.713). The BIC and t-ROC analyses were consistent. To better predict the prognosis of patients with ≤ 15 eLNs, we established a novel prognostic model based on independent prognostic factors (C-index 0.735). BIC analysis showed that this new model was better than the 7th and 8th editions. Similar results were obtained from the validation set.

CONCLUSIONS

The 8th edition of the AJCC TNM classification shows better prognostic ability than the 7th edition in noncardia GC patients with > 15 eLNs, but no improvement was found in patients with ≤ 15 eLNs; therefore, a novel prognostic model is proposed.

Validation of the American Joint Committee on Cancer (AJCC) 8th edition stage system for gastric cancer patients: a population-based analysis

BACKGROUND

Our aim was to validate the American Joint Committee on Cancer (AJCC) 8th edition stage system for gastric cancer in the Western world and to compare several modifications between the 7th and 8th edition systems.

METHODS

Eligible patients having undergone surgical resection of gastric cancer during 2004-2011 from the Surveillance, Epidemiology, and End Results (SEER) database were included in the current study. Survival differences were assessed by Kaplan-Meier curve and log-rank tests. The discriminative power of the AJCC 8th and 7th editions was compared by Harrell's concordance index (c-index).

RESULTS

Patients with pN3a and pN3b presented distinct survival outcomes, especially for cases in which more than 15 lymph nodes were examined. The overall (OS) and cancer-specific survival (CSS) c-indices for the 8th edition were largely comparable with c-indices for the 7th edition throughout the cohort. Notably, the new edition improved the power of discrimination slightly in OS and CSS (c-indices: 0.717, 0.744) compared with the 7th edition (c-indices: 0.712, 0.739) for patients for whom 15 or more lymph nodes were examined. The analysis of stage migration in the new edition revealed nonhomogeneous survival outcomes in stages IIIB and IIIC.

CONCLUSION

The AJCC 8th stage system for gastric cancer performs as well as the AJCC 7th edition in the United States (USA). Importantly, when more than 15 lymph nodes are examined, the discriminatory performance of the new edition is improved.

Comparative study of computed tomography (CT) and pathological diagnosis toward mediastinal lymph node metastasis in esophageal carcinoma

OBJECTIVE

To investigate the diagnostic criteria of mediastinal lymph node metastasis (MLNM) in esophageal carcinoma (EC) by comparing the lymph node sizes measured by computed tomography (CT) and obtained by postoperative pathological examination.

METHOD

A total of 305 EC patients were selected. MLNM location, shortest diameter and number were investigated one week before surgery, and then compared with their pathological findings.

RESULTS

The receiver operating characteristic (ROC) curve analysis revealed that the minimum diameters of MLNM in the thoracic cavity was 8 mm (area under curve [AUC] = 0.766, Youden index = 0.424), 5 mm in supraclavicular fossa (AUC = 0.785, Youden index = 0.494), 6 mm in tracheoesophageal groove (AUC = 0.755, Youden index = 0.405); the sensitivity was increased significantly, and the Youden index was increased significantly when compared with 10 mm.

CONCLUSION

The shortest diameter of diagnostic criteria of lymph nodes in EC could be less than 10 mm on CT.

Efficacy comparison of transcervical video-assisted mediastinoscopic lymphadenectomy combined with left transthoracic esophagectomy versus right transthoracic esophagectomy for esophageal cancer treatment

Background

This study aimed to propose a new surgical strategy, i.e., the transcervical video-assisted mediastinoscopic lymphadenectomy (VAMLA) with esophagectomy via the left transthoracic approach for patients with esophageal cancer (EC), and to compare the outcomes with those of esophagectomy via the right thoracic approach.

Methods

From December 2014 to March 2016, 49 cases were enrolled in this non-randomized concurrent control study. Twenty-eight patients with EC who underwent transcervical VAMLA with esophagectomy via the left transthoracic approach were assigned into the study group, while 21 EC patients undergoing esophagectomy via the right transthoracic approach during the same period were enrolled into the control group. Operative outcomes including operative time, the numbers of removed lymph nodes, intraoperative blood loss, the length of hospital stay, and postoperative complications in both groups were evaluated and compared.

Results

There were no significant differences in the baseline profiles between the two groups, and all patients in the two groups successfully underwent the surgery. There was a significant difference between transcervical VAMLA with esophagectomy via the left thoracic approach and esophagectomy via the right thoracic approach with regard to the number of all dissected lymph nodes [(29.0 ± 8.7) vs. (17.8 ± 8.1), p < 0.05], dissected superior mediastinal lymph nodes [(11.2 ± 5.0) vs. (3.7 ± 2.9), p < 0.05], and dissected in the recurrent laryngeal nerve lymph nodes [(5.6 ± 3.5) vs. (2.3 ± 2.1), p < 0.05]. No significant differences were observed in the operative time, intraoperative blood loss, length of postoperative hospital stay, number of dissected abdominal lymph nodes, postoperative pulmonary complications (pneumonia and atelectasis), anastomotic fistula, chylothorax, and vocal cord paralysis (p > 0.05).

Conclusion

Transcervical VAMLA combined with esophagectomy via the left thoracic approach appears technically feasible and safe and shows advantages in the number of dissected superior mediastinal lymph nodes, suggesting that it may serve as a new treatment option for patients with esophageal carcinoma.

Conditional survival of patients with gastric cancer who undergo curative resection: A multi-institutional analysis in China

BACKGROUND

Conditional survival estimates, which take into consideration the changing risk with increasing survival time, provide a dynamic survival probability and more accurate survival information for clinician decision making. The objective of the current study was to evaluate the conditional disease-specific survival (DSS) for patients with gastric cancer who underwent curative surgery in China.

METHODS

In total, 7658 patients with gastric cancer from a multi-institutional cohort in China were included in the analyses. Actuarial DSS was estimated using the Kaplan-Meier method. Three-year conditional DSS (CDS₃ ) of patients who had already survived for x years was estimated as CDS₃ = DSS(x + 3)/DSS(x). Cox proportional hazards regression analyses were used to identify the factors related to DSS.

RESULTS

The 1-year, 3-year, and 5-year actuarial DSS rates were 88.2%, 64.5%, and 54.6%, respectively. By using CDS estimates, the probabilities that patients would remain alive for an additional 3 years given that they had already survived for 1, 3, and 5 years were 66.6%, 80.2%, and 88.3%, respectively. Patients who had unfavorable tumor characteristics diagnosed initially at surgery had the greatest improvement in CDS and the largest survival gap between actuarial DSS and CDS.

CONCLUSIONS

The current results indicate that CDS estimates for Chinese patients with gastric cancer who underwent surgery were dynamic and increased with time elapsed. Patients who had unfavorable tumor characteristics had the greatest improvement in CDS. This valuable information could provide more a precise evaluation of long-term prognosis and may serve as an important prognostic index in clinical practice. Cancer 2018;124:916-24. © 2017 American Cancer Society.

A comprehensive analysis comparing the eighth AJCC gastric cancer pathological classification to the seventh, sixth, and fifth editions

To perform a comprehensive analysis comparing the prognostic and discriminative ability of the eighth AJCC gastric cancer (GC) pathological classification to that of the seventh, sixth and fifth editions, and secondly to assess their long‐term significance. Patients who had undergone R0 gastrectomy were identified and restaged accordingly. To evaluate and confirm any difference in prognostic ability between the competing editions, the Akaike information criterion (AIC) and Bayesian information criterion (BIC) were computed and compared since both have different analytic strengths. The area under the curve (AUC) with 95% CI based on the time‐dependent receiver‐operating characteristics analyses were also calculated to assess any change in prognostic rankings from the first to tenth postoperative year. The rankings calculated by both statistical methods showed similar results, in which the seventh edition was identified as possessing the best prognostic ability. Additionally, these ranks were found to remain consistent over the ten postoperative years, but demonstrated no clinical significance as their respective 95% CIs calculated by the AIC, BIC, and AUC were found to overlap. However, the more detailed staging classifications of the eighth edition was shown to display the best prognostic demarcation for stratifying patients with higher‐staged disease. This study thereby identified the eighth AJCC GC edition to possess similar long‐term prognostic ability as to its previous three editions but contrastingly demonstrated the best distinctive ability for stratifying overall survival and can thus be considered as being clinically more reliable.

Regulator of G-protein signaling 3 targeted by miR-126 correlates with poor prognosis in gastric cancer patients

The Wnt/β-catenin signaling pathway dominates numerous cellular processes including cell proliferation, differentiation, and epithelial-mesenchymal transition, which play a crucial role in human cancer malignancies. Regulator of G-protein signaling 3 (RGS3) is a pivotal molecule involved in the Wnt/β-catenin signaling pathway, which is worthy of intensive research as a potential target in cancer treatment. In this study, we found that RGS3 is significantly upregulated in gastric cancer (GC) tumor samples compared with normal samples from the analysis of two independent GC mRNA microarray datasets in the NCBI public database. Further immunohistochemistry assay and western-blot experiments confirmed this finding on the basis of the results of our own 102 paired GC specimens and three GC cell lines. We found that a high expression of RGS3 is associated with advanced TNM stages and more aggressive malignant behaviors. In addition, the association of overexpression of RGS3 and poor overall survival and progression-free survival outcomes suggests that RGS3 has the potential to serve as a molecular therapy target for GC. Interestingly, our pathways analysis and the follow-up dual-luciferase reporter assay showed that there is a direct 3'-untranslated region binding site between RGS3 mRNA and microRNA-126, a GC inhibitor. On the basis of all the above evidences, our findings suggest that overexpressed RGS3 regulated by microRNA-126 through the post-transcriptional modulation is associated significantly with a poor prognosis of GC patients.

Comparison of the Seventh and Eighth Editions of the American Joint Committee on Cancer/Union for International Cancer Control Tumor-Node-Metastasis Staging System for Differentiated Thyroid Cancer

OBJECTIVE

To evaluate the efficacy and prognostic validity for disease-specific survival (DSS) of the eighth edition American Joint Committee on Cancer/Union for International Cancer Control tumor-node-metastasis (TNM) staging system (TNM-8) compared to the seventh edition (TNM-7) in patients with differentiated thyroid carcinoma (DTC).

METHODS

The seventh and eighth editions of the TNM staging system were applied to 1613 DTC patients who underwent thyroid surgery between 1996 and 2003. The proportion of variation explained and Harrell's c-index were evaluated to compare the predictive capability of DSS.

RESULTS

The mean age of the patients was 44.7 years, and the median follow-up period was 11.2 years. When TNM-8 was applied, 63% of T3 and 3% of N1b DTCs were downgraded to T1/T2 and N1a, respectively. About 38% of patients were downstaged according to TNM-8. The 10-year DSS rates in TNM-7 stages I, II, III, and IV were 99.7%, 98.2%, 98.8%, and 83.2%, respectively. Those in TNM-8 stages I, II, III, and IV were 99.6%, 95.4%, 72.3%, and 48.6%, respectively. The proportion of variation explained values of TNM-7 and TNM-8 were 6.0% and 7.0%, respectively. The Harrell's c-index of TNM-7 was 0.86 and that of TNM-8 was 0.88.

CONCLUSIONS

A significant number of patients were reclassified to lower stages with the application of TNM-8 compared to TNM-7. Applying TNM-8 could improve the accuracy of the staging system for predicting DSS in patients with DTC.

Comparison of the Differences in Survival Rates between the 7th and 8th Editions of the AJCC TNM Staging System for Gastric Adenocarcinoma: a Single-Institution Study of 5,507 Patients in Korea

Purpose

The aims of this study were to compare the 7th and 8th editions of the American Joint Committee on Cancer (AJCC) staging manuals on tumor, node, and metastasis (TNM) staging systems and to evaluate whether the 8th edition represents a better refinement of the 7th staging system, when applied for the classification of gastric cancers.

Materials and Methods

A total of 5,507 gastric cancer patients, who underwent treatment from January 1989 to December 2013 at a single institute, were included. We compared patient survival rates across the disease groups classified according to the 7th and 8th editions of the AJCC TNM staging systems.

Results

Stage migration was observed in 6.4% (n=355) of the patients. Of these, 3.5% (n=192) and 2.9% (n=158) of patients showed a higher stage and lower stage, respectively. According to the 8th edition of the AJCC TNM staging criteria, the 5-year overall survival rates of the patients with stage IIIB and IIIC showed a significant difference (40.8% vs. 20.2%, P<0.001) whereas no significant differences in the 5-year overall survival rates were observed according to the 7th edition criteria (37.6% vs. 33.2%, P=0.381).

Conclusions

Restaging stage III cancers according to the 8th edition of the AJCC TNM classification criteria improved survival rate discrimination, particularly, in institutes where the stage III patients were not distinctly categorized.

Comparison of the 7th and 8th editions of the American joint committee on cancer TNM classification for patients with stage III gastric cancer

Background and Objectives

The eighth TNM edition for gastric cancer was released in 2016 and included major revisions, especially of stage III. The purpose of this study was to evaluate the prognostic value of the new AJCC TNM classification in comparison with the 7th edition for stage III gastric cancer.

Methods

Clinical and histopathological data on 1,496 patients operated on for stage III GC according to the seventh edition between 2005 and 2013 were analyzed and compared using 7th and 8th classifications. The 2 systems were compared in terms of prognostic performance.

Results

The stage shifted for 650 (43.45%) patients: from IIIA to IIIB (2 patient, 0.13%), from IIIB to IIIA (214 patients, 14.30%), from IIIB to IIIC (99 patients, 6.62%), and from IIIC to IIIB (335 patients, 22.39%). Cox regression multivariate analysis showed both the 8th and 7th TNM classification were independent prognostic factors. The 8th edition system had higher linear trend and likelihood ratio χ² scores, and smaller AIC values compared with those for the 7th edition. However, the performance of the eighth edition did not reveal significant improvement compared to the seventh edition (c-index 0.625 vs. c-index 0.616, p=0.085).

Conclusion

The eighth TNM edition may not provide significantly better accuracy in predicting the prognosis of stage III GC. However, to confirm our findings, further studies are warranted.

Comparison of the current AJCC-TNM numeric-based with a new anatomical location-based lymph node staging system for gastric cancer: A western experience

BACKGROUND

In gastric cancer, the current AJCC numeric-based lymph node staging does not provide information on the anatomical extent of the disease and lymphadenectomy. A new anatomical location-based node staging, proposed by Choi, has shown better prognostic performance, thus soliciting Western world validation.

STUDY DESIGN

Data from 284 gastric cancers undergoing radical surgery at the Second University of Naples from 2000 to 2014 were reviewed. The lymph nodes were reclassified into three groups (lesser and greater curvature, and extraperigastric nodes); presence of any metastatic lymph node in a given group was considered positive, prompting a new N and TNM stage classification. Receiver-operating-characteristic (ROC) curves for censored survival data and bootstrap methods were used to compare the capability of the two models to predict tumor recurrence.

RESULTS

More than one third of node positive patients were reclassified into different N and TNM stages by the new system. Compared to the current staging system, the new classification significantly correlated with tumor recurrence rates and displayed improved indices of prognostic performance, such as the Bayesian information criterion and the Harrell C-index. Higher values at survival ROC analysis demonstrated a significantly better stratification of patients by the new system, mostly in the early phase of the follow-up, with a worse prognosis in more advanced new N stages, despite the same current N stage.

CONCLUSIONS

This study suggests that the anatomical location-based classification of lymph node metastasis may be an important tool for gastric cancer prognosis and should be considered for future revision of the TNM staging system.

Prognostic Discrepancy of the 6th and 7th UICC N Classification for Lymph Node Staging in Gastric Cancer Patients after Curative Resection

BACKGROUND

The validity of N classification of the 7th edition of the American Joint Committee on Cancer/Union Internationale contre le Cancer (AJCC/UICC) tumor-node-metastasis (TNM) staging system is still under debate. The purpose of this study was to evaluate the prognostic efficacy of the 7th edition of the AJCC/UICC TNM staging system (focusing on N stage), in comparison with the 6th edition, at a single Eastern institution.

METHODS

We analyzed 1,435 patients with gastric cancer who underwent curative resection performed from September 1998 to August 2003 at the Memorial Jin-Pok Kim Korea Gastric Cancer Center. We analyzed the survival rate of the patients according to the AJCC/UICC 6th and 7th editions, and compared each stage, focusing on N stage.

RESULTS

Significant differences in the 5-year survival rates were observed between the 6th and the 7th AJCC/UICC staging system. In the 6th edition staging system, the Kaplan-Meier curves discriminated each N stage significantly. In contrast, there was no difference in terms of survival curves for N stage according to the 7th edition, especially between N1 and N2: the Kaplan-Meier plots of survival curves between N1 (77.0%) and N2 (78.1%) stages overlapped significantly (p < 0.05).

CONCLUSION

Although the 7th UICC staging system is a more detailed and sophisticated system in the T category, there was no prognostic significance between the pN1 and pN2 stages according to our data. Therefore, we suggest establishing a new UICC staging system taking into consideration the application of the N stage.

Comparison of different lymph node staging systems in prognosis of gastric cancer: a bi-institutional study from Hungary

Objective

The Union for International Cancer Control (UICC) Node (N) classification is the most common used staging method for the prognosis of gastric cancer. It demands adequate, at least 16 lymph nodes (LNs) to be dissected; therefore different staging systems were invented.

Methods

Between March 2005 and March 2010, 164 patients were evaluated at the Department of General Surgery in the Kenézy Gyula Hospital and at the Department of General, Thoracic and Vascular Surgery in the Kaposi Mór Hospital. The 6th, 7th and 8th UICC N-staging systems, the number of examined LNs, the number of harvested negative LNs, the metastatic lymph node ratio (MLR) and the log odds of positive LNs (LODDS) were determined to measure their 5-year survival rates and to compare them to each other.

Results

The overall 5-year survival rate for all patients was 55.5% with a median overall survival time of 102 months. The tumor stage, gender, UICC N-stages, MLR and the LODDS were significant prognostic factors for the 5-year survival with univariate analysis. The 6th UICC N-stage did not follow the adequate risk in comparing N2 vs. N0 and N3 vs. N0 with multivariate investigation. Comparison of performances of the residual N classifications proved that the LODDS system was first in the prediction of prognosis during the evaluation of all patients and in cases with less than 16 harvested LNs. The MLR gave the best prognostic prediction when adequate (more than or equal to 16) lymphadenectomy was performed.

Conclusions

We suggest the application of LODDS system routinely in western patients and the usage of MLR classification in cases with extended lymphadenectomy.

Validation of the 7th AJCC/UICC staging system for gastric cancer and a proposal for a new TNM system based on a prognostic score: a retrospective multicenter study

Purpose

We validate the 7th American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) staging system for gastric cancer and propose a new staging system that reflects the prognostic significances of each of T and N category.

Methods

Data from 5,957 patients who underwent curative gastrectomies from 2000 to 2007 at 4 university hospitals in Daegu Metropolitan city in Korea were analyzed for the validation of the 7th AJCC/UICC staging system for gastric cancer. The hazard ratios of the respective T and N categories were estimated and converted to weightings and summated to make prognostic score (P-score). Homogeneity and stage grouping were determined according to the P-scores.

Results

In the 7th AJCC/UICC staging system for gastric cancer, poor discrimination was noted between stages IIB and IIIA (P = 0.152). In addition, heterogeneity in stage IIB (P = 0.021) and a small gap in 5-year survival rates (1.7%) between stages IA and IB were noted. A new proposed staging system was generated on the basis of P-scores and demonstrated more discrimination between stages and more homogeneity within stages. The new staging system reflects the different prognostic impacts of N3a and N3b.

Conclusion

Several controversial issues of the 7th AJCC/UICC staging system for gastric cancer were reconfirmed in the present analysis. The TNM system based on P-score appears to be more scientifically accurate than the 7th AJCC/UICC staging system for gastric cancer.

SLC7A5 Functions as a Downstream Target Modulated by CRKL in Metastasis Process of Gastric Cancer SGC-7901 Cells

SLC7A5, who is also named LAT-1, has been validated as a promoter regulated by miRNA-126 in our previous research for gastric cancer cells. However, the mechanisms driving SLC7A5 to affect the bio-function of gastric cancer cells are unclear, remaining us lots of to elucidate. The aim of this study is to investigate the regulating effect of CRKL, one of the critical genes involving with gastric cancer progression, on SLC7A5 expression. By studying the gastric cancer cell lines and clinical pathological specimens, we found that the expression of SLC7A5 was significantly correlated to CRKL. By depleting CRKL in gastric cancer SGC-7901 cells, the SLC7A5 expression was impaired, and the invasion and migration of SGC-7901 cells were suppressed. Ectopic expression of SLC7A5 could drastically rescue the phenotypes induced by CRKL depletion in this study. Accordingly, we conclude that SLC7A5 functions as a promoter in gastric cancer metastasis, and CRKL could be one of its regulators modulating the expression of SLC7A5 and consequentially affect the metastatic feature of SGC-7901 cells. The findings in this study indicate a regulation relationship between CRKL and SLC7A5, and provide useful evidence for gastric cancer therapeutic strategies.

Applicability of the Proposed Japanese Model for the Classification of Gastric Cancer Location: The "PROTRADIST" Retrospective Study

BACKGROUND

The extension of lymphadenectomy for surgical treatment of gastric cancer remains discordant among European and Japanese surgeons. Kinami et al. (Kinami S, Fujimura T, Ojima E, et al. PTD classification: proposal for a new classification of gastric cancer location based on physiological lymphatic flow. Int. J. Clin. Oncol. 2008;13:320-329) proposed a new experimental classification, the "Proximal zone, Transitional zone, Distal zone" (PTD) classification, based on the physiological lymphatic flow of gastric cancer site. The aim of the present retrospective study is to assess the applicability of PTD Japanese model in gastric cancer patients of our Western surgical department.

METHODS

Two groups of patients with histologically documented adenocarcinoma of the stomach were retrospectively obtained: In the first group were categorized 89 patients with T1a-T1b tumor invasion; and in the second group were 157 patients with T2-T3 category. The data collected were then categorized according to the PTD classification.

RESULTS

In the T1a-T1b group there were no lymph node metastases within the r-GA or r-GEA compartments for tumors located in the P portion, and similarly there were no lymphatic metastases within the l-GEA or p-GA compartments for tumors located in the D portion. On the contrary, in the T2-T3 group the lymph node metastases presented a diffused spreading with no statistical significance between the two classification models.

CONCLUSIONS

Our results show that the PTD classification based on physiological lymphatic flow of the gastric cancer site is a more physiological and clinical version than the Upper, Medium And Lower classification. It represents a valuable and applicable model of cancer location that could be a guide to a tailored surgical approach in Italian patients with neoplasm confined to submucosa. Nevertheless, in order to confirm our findings, larger and prospective studies are needed.

Clinical significance of NOTCH1 intracellular cytoplasmic domain translocation into the nucleus in gastric cancer

Recent studies have shown constitutive activation of the Notch signaling pathway in various types of malignancies. However, it remains unclear whether this signaling pathway is activated in gastric cancer. In the present study, the aim was to investigate the role of Notch signaling in gastric cancer by investigating the subcellular localization of Notch-associated proteins in tissue samples from gastric cancer patients. Samples were obtained from 115 gastric cancer patients who had undergone surgery at the Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Science without pre-operative chemotherapy or radiation. Subsequently the correlation between translocation of NOTCH1 intracellular cytoplasmic domain (NICD) into the nucleus (as measured by immunostaining) and survival in gastric cancer patients after surgery was investigated. The results were analyzed in reference to the patients' clinicopathological characteristics and the effects of these results on patient prognosis were determined. Significant correlations were observed between NICD nuclear localization and clinicopathological characteristics, such as tumor status (T factor), lymph node status (N factor), pathological stage and differentiation status. No significant correlations were observed between NICD nuclear localization and age, gender, tumor location, vein invasion or lymphatic invasion. Patients with >30% of cancer cell nuclei positively stained for NICD (as revealed by immunostaining) were associated with a significantly shorter survival following surgery than patients with <30% NICD-positive cancer cell nuclei (log-rank test, P=0.0194). Univariate analysis revealed that among the clinicopathological factors examined, T factor [risk rate (RR)=10.870; P=0.0016], N factor (RR=41.667; P=0.0003), lymphatic invasion (RR=13.158; P=0.0125), vein invasion (RR=25.000; P= 0.0019) and translocation of NICD to the nucleus (RR=3.937; P=0.0312) were all identified to be statistically significant prognostic factors. However, multivariate analysis revealed that translocation of NICD to the nucleus was not independently associated with an unfavourable prognosis in patients with gastric cancer. The present results suggest that NOTCH1 acts as an oncogene in gastric cancer. It is hypothesized that translocation of NICD into the nucleus may be used as a therapeutic target in gastric cancer.

Prognostic significance of intraoperative macroscopic serosal invasion finding when it shows a discrepancy in pathologic result gastric cancer

Purpose

Depth of wall invasion is an important prognostic factor in patients with gastric cancer, whereas the prognostic significance of intraoperative macroscopic serosal invasion (mSE) findings remain unclear when they show a discrepancy in pathologic findings. This study, therefore, assessed the prognostic significance of mSE.

Methods

Data from cohort of 2,835 patients with resectable gastric cancer who underwent surgery between 1990 and 2010 were retrospectively reviewed.

Results

The overall accuracy of mSE and pathologic results was 83.4%. The accuracy of mSE was 75.5% in pT2. On the other hand, the accuracy of pT3 dropped to 24.5%. According to mSE findings (+/–), the 5-year disease-specific survival (DSS) rate differed significantly in patients with pT2 (+; 74.2% vs. –; 92.0%), pT3 (+; 76.7% vs. –; 91.8%) and pT4a (+; 51.3% vs. –; 72.8%) (P < 0.001 each), but not in patients with T1 tumor. Multivariate analysis showed that mSE findings (hazard ratio [HR], 2.275; 95% confidence interval [CI], 1.148–4.509), tumor depth (HR, 6.894; 95% CI, 2.325–20.437), nodal status (HR, 5.206; 95% CI, 2.298–11.791), distant metastasis (HR, 2.881; 95% CI, 1.388–6.209), radical resection (HR, 2.002; 95% CI, 1.017–3.940), and lymphatic invasion (HR, 2.713; 95% CI, 1.424–5.167) were independent predictors of 5-year DSS rate.

Conclusion

We observed considerable discrepancies between macroscopic and pathologic diagnosis of serosal invasion. However, macroscopic diagnosis of serosal invasion was independently prognostic of 5-year DSS. It suggests that because the pathologic results could not be perfect and the local inflammatory change with mSE(+) could affect survival, a combination of mSE(+/–) and pathologic depth may be predictive of prognosis in patients with gastric cancer.

Comparison of Lymphatic System Staging Classifications in Patients with Gastric Cancer

Despite an observed decrease in the incidence of gastric cancer, it still remains an important clinical problem. It is the fourth most common cancer in the world and the second cause of death in cancer patients. The quality of lymphadenectomy procedure and the number of analysed lymph nodes are both important factors influencing the treatment of the patient. The aim of the study was to compare the lymph node ratio staging system with the 6th and 7th edition of the TNM classification.

MATERIAL AND METHODS

A group consisting of 493 patients who underwent surgery in 1998-2010 due to gastric cancer was used to compare the staging systems. Following statistical analysis, the following cut-off points were adopted for the lymph node ratio for the purpose of comparison: 0, from 0.05 to 0.3, from 0.3 to 0.5 and over 0.5. Subsequently the homogeneity (using chi-square test for linear trend) and the predictive value of the different classifications (using Akaike information criterion) were assessed in order to compare the lymph node ratio staging system with the 6th and 7th edition of the TNM classification.

RESULTS

The lymph node ratio classification has a higher discriminatory value than the TNM classifications (higher linear trend result). What is more, the lymph node ratio classification (LNR) had a lower Akaike information criterion value, which means that it has a higher prognostic value than the other classifications. ROC curves and the area under the curve (AUC) were utilised for the analysis of predictive value of the different classifications in patients with gastric cancer.

CONCLUSION

One may conclude, therefore, that the lymph node ratio staging system is the best classification of the lymphatic system in the presented group of patients.

Elevated HOXA1 expression correlates with accelerated tumor cell proliferation and poor prognosis in gastric cancer partly via cyclin D1

BACKGROUND

HOXA1 is a member of the Homeobox gene family, which encodes a group of highly conserved transcription factors that are important in embryonic development. However, it has been reported that HOXA1 exhibits oncogenic properties in many malignancies. This study focused on the expression and clinical significance of HOXA1 in gastric cancer (GC).

METHODS

To assess the mRNA and protein expression of HOXA1 and cyclin D1 in GC tissues, we utilized qRT-PCR and western blotting, respectively. The effects of HOXA1 on GC cell proliferation, migration, and invasion, as well as xenograft tumor formation and the cell cycle were investigated in our established stable HOXA1 knockdown GC cell lines. The protein expression of HOXA1 and cyclin D1 was examined by immunohistochemistry using GC tissue microarrays (TMA) to analyze their relationship on a histological level. The Kaplan-Meier method and cox proportional hazards model were used to analyze the relationship of HOXA1 and cyclin D1 expression with GC clinical outcomes.

RESULTS

HOXA1 mRNA and protein expression were upregulated in GC tissues. Knockdown of HOXA1 in GC cells not only inhibited cell proliferation, migration, and invasion in vitro but also suppressed xenograft tumor formation in vivo. Moreover, HOXA1 knockdown induced changes in the cell cycle, and HOXA1 knockdown cells were arrested at the G1 phase, the number of cells in S phase was reduced, and the expression of cyclin D1 was decreased. In GC tissues, high cyclin D1 mRNA and protein expression were detected, and a significant correlation was found between the expression of HOXA1 and cyclin D1. Survival analysis indicated that HOXA1 and cyclin D1 expression were significantly associated with disease-free survival (DFS) and overall survival (OS). Interestingly, patients with tumors that were positive for HOXA1 and cyclin D1 expression showed worse prognosis. Multivariate analysis confirmed that the combination of HOXA1 and cyclin D1 was an independent prognostic indicator for OS and DFS.

CONCLUSION

Our data show that HOXA1 plays a crucial role in GC development and clinical prognosis. HOXA1, alone or combination with cyclin D1, may serve as a novel prognostic biomarker for GC.

Comparison of the 6th and 7th editions of the AJCC/UICC TNM staging system for gastric cancer focusing on the "N" parameter-related survival: the monoinstitutional NodUs Italian study

Background

A large number of Asian population studies examined the difference between the 6th and the 7th tumor, node, metastasis (TNM) while it is still poorly validated among Caucasian populations. This is a retrospective study aimed at investigating the efficacy of the 7th edition American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system for gastric cancer focusing on the “N” parameter-related survival for prognostic assessment in gastric cancer patients of a single Western high-volume institution.

Methods

From January 2002 to December 2009, the data of 274 patients with gastric cancer who underwent gastric surgery at the 8th General and Gastrointestinal Surgical Centre of the Second University of Naples were analyzed retrospectively. We collected data for patient demographics, tumor characteristics, surgical characteristics, and TNM stage. Particularly, the nodal status, with the number of dissected nodes and metastatic nodes, was reviewed from the pathology records. The same patient dataset was used to stage patients according to both the 6th and 7th edition criteria.

Results

Age at surgery, tumor location, histological grade, Lauren’s classification subtypes, and 6th and 7th AJCC/UICC N categories were found to have statistically significant associations with overall survival on univariate analysis. In the 6th edition staging system, the Kaplan–Meier plot did not show significant overlapped survival curves: significant differences were found between N0 and N1, P < .001; N1 and N2, P = .04; and N2 and N3, P < .001. On the contrary, in the 7th edition, among all five substages, there were similar survival curves between N categories 2 and 3a (P = .98) with a statistically significant discriminatory ability only between N1 versus N3b and N2 versus N3b (P = .02 and .04, respectively).

Conclusions

Based on analysis, we found that several clinicopathological variables, especially histological grade and Lauren’s classification, were significant prognostic factors in our database. The 6th and 7th AJCC/UICC N classifications represent significantly independent prognostic factors, and the 6th AJCC/UICC N classification seems to be superior to the 7th AJCC/UICC N classification in terms of uniformity, differentiation, and monotonicity of gradients.

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.

Survival of proper hepatic artery lymph node metastasis in patients with gastric cancer: implications for D2 lymphadenectomy

BACKGROUND AND AIMS

There is a discrepancy between the American Joint Committee on Cancer (AJCC) guidelines (7th edition) and the Japanese treatment guidelines (3rd edition) with regard to the extent of D2 lymphadenectomy for gastric cancer. In the AJCC, hepatic artery station (No.12a) lymph node (LN) metastasis is classified as distant metastasis, whereas in the Japanese guidelines, this classified is regional metastasis. This study aimed to evaluate whether it is appropriate to reclassify No.12a LN metastasis as distant metastasis in consideration of survival outcome.

METHODS

In this retrospective analysis, data from patients with gastric cancer who underwent regular D2 or greater lymphadenectomy between 1996 and 2006 were evaluated to determine any association between the clinicopathological features of hepatic artery LNs and survival prognosis.

RESULTS

Among the 247 patients with gastric cancer who underwent No.12 LN harvest, 45 (18.2%) were positive for No.12a LN metastasis. No.12a LN metastasis was significantly associated with poor clinicopathological features, advanced tumor stage, and poor overall survival. The 5-year survival rate of patients with No.12a LN metastasis was significantly better than that of patients with distant metastasis (P < 0.05), but was similar to that of patients with LN involvement in the D2 lymphadenectomy region (P > 0.05). No.12a LN metastasis was shown to significantly influence survival outcome in univariate analysis, but was not identified as a significant independent predictor in multivariate analysis. In logistic multivariate regression analysis, T stage, N stage, and station No.3, 5, and 6 LN metastasis were independent predictors of No.12a LN involvement.

CONCLUSIONS

It is inappropriate to reclassify No.12a LN metastasis as distant metastasis. We propose that this be considered as regional metastasis and be included in the extent of D2 lymphadenectomy to improve survival outcomes in patients with gastric cancer.

N3 subclassification incorporated into the final pathologic staging of gastric cancer: a modified system based on current AJCC staging

The seventh edition of the American Joint Committee on Cancer (AJCC) TNM classification system for gastric cancer (GC) was established in 2009. We assessed the unmet medical needs of patients with the N3 classification of the seventh TNM staging system by comparing survival according to the extent of nodal involvement, with a particular focus on the cutoff points for the number of involved nodes in the N3 classification. We retrospectively reviewed 3178 patients with GC who were registered in the GC database of the Department of General Surgery at the Chang Gung Memorial Hospital between 1994 and 2010. Among them, 884 patients undergoing curative intent resection had N3 lymph node involvement. The clinicopathological features and surgical outcomes were compared among all patients with GC and between the N3a and N3b groups. N3b might impose GC patients with poor clinical outcome. We proposed a modified staging system, based on AJCC seventh edition, accordingly. T1-3N3 might be not simply categorized into stage IIIA as seventh AJCC suggested. Taking N3a and N3b into consideration, T1-3N3 might be further categorized into stage IIIB and IIIC, respectively, as we proposed, based on survival analysis. In addition, T4bN3bM0 is as dismal as M1 disease. In our proposed staging system, good discriminations between different stages are still maintained. The N3 category should be subclassified as N3a or N3b due to the survival differences. Furthermore, T1-3N3aM0 could be categorized as stage IIIB, T1-3N3bM0 could be categorized as stage IIIC, T4aN3bM0 could be categorized as stage IIID, and T4bN3bM0 might be regarded as stage IV as we proposed.

Survival in gastric cancer in relation to postoperative adjuvant therapy and determinants

AIM: To evaluate survival data in patients with gastric cancer in relation to postoperative adjuvant therapy and survival determinants

METHODS: A total of 201 patients (mean ± SD age: 56.0 ± 11.9 years, 69.7% were males) with gastric carcinoma who were operated and followed up at Lutfi Kirdar Kartal Training and Research Hospital between 1998 and 2010 were included in this retrospective study. Follow up was evaluated divided into two consecutive periods (before 2008 and 2008-2010, respectively) based on introduction of 3-D conformal technique in radiotherapy at our clinic in 2008. Data on patient demographics, clinical and histopathological characteristics of gastric carcinoma and the type of treatment applied after surgery [postoperative adjuvant treatment protocols including chemoradiotherapy (CRT) and chemotherapy (CT), supportive therapy or follow up without any treatment] were recorded. The median duration and determinants of local recurrence free (LRF) survival, distant metastasis free (DMF) survival and overall survival were evaluated in the overall population as well as with respect to follow up years [1998-2008 (n = 127) vs 2008-2010 (n = 74)].

RESULTS: Median duration for LRF survival, DMF survival and overall survival were 31.9, 24.1 and 31.9 mo, respectively in patients with postoperative adjuvant CRT. No significant difference was noted in median duration for LRF survival, DMF survival and overall survival with respect to treatment protocols in the overall population and also with respect to followed up periods. In the overall population, CT protocols FUFA [5-fluorouracil (400 mg/m²) and leucovorin-folinic acid (FA, 20 mg/m²)] (29.9 mo) and UFT^® + Antrex^® [a fixed combination of the oral FU prodrug tegafur (flouroprymidine, FT, 300 mg/m² per day) with FA (Antrex^®), 15 mg tablet, two times a day] (42.5 mo) was significantly associated with longer LRF survival times than other CT protocols (P = 0.036), while no difference was noted between CT protocols in terms of DMF survival and overall survival. Among patients received CRT, overall survival was significantly longer in patients with negative than positive surgical margin (27.7 mo vs 22.4 mo, P = 0.016) in the overall study population, while time of radiotherapy initiation had no significant impact on survival times. Nodal stage was determined to be independent predictor of LRF survival in the overall study population with 4.959 fold (P = 0.042) increase in mortality in patients with nodal stage N2 compared to patients with nodal stage N0, and independent predictor of overall survival with 5.132 fold (P = 0.006), 5.263 fold (P = 0.027) and 4.056 fold (P = 0.009) increase in the mortality in patients with nodal stage N3a (before 2008), N3b (before 2008) and N2 (overall study population) when compared to patients with N0 stage, respectively.

CONCLUSION: Our findings emphasize the likelihood of postoperative adjuvant CRT to have a survival benefit in patients with resectable gastric carcinoma.

Lymph node staging in gastric cancer: new criteria, old problems

PURPOSE

Our study aims to test the prognostic accuracy of the N parameter of the 7th TNM in a Western series of D1-gastrectomies for gastric cancer (GC).

METHODS

Retrospectively considering a series of 224 non-metastatic GC patients who underwent surgery with curative intent and limited lymphadenectomy, we analyzed 5-year overall survival (OS) related to pN status according to both TNM editions (pN6 and pN7) and to lymph node ratio (LNR; LNR0, 0%, LNR1, 1-19%; LNR2, > 20%). We stratified pN6- and pN7-related OS by LNR.

RESULTS

Both pN6 and pN7 were shown to significantly stratify different subsets of GC patients, but there was no significant difference between pN71 and pN72, nor between pN62 and pN63. A multivariate model specific for pN7 eliminated the N2 group, while the pN6 model maintained all 3 N groups with highly discriminating hazard ratios. LNR was able to further stratify one category of pN6 (N2) and two categories of pN7 (N1 and N2).

CONCLUSIONS

The 7th TNM edition for GC does not seem to be superior to the 6th edition in evaluating the prognostic relevance of lymph-nodal status: in particular, it does not allow an accurate stratification of OS in patients with less than 6 positive lymph nodes.

Evaluation of prognostic factors and survival results in gastric carcinoma: single center experience from Northeast Turkey

OBJECTIVE

To evaluate the prognostic factors affecting overall survival (OS), disease-free survival (DFS), and survival among patients undergoing chemoradiotherapy (CRT) for locally advanced gastric carcinoma.

METHODS

Between January 2001 and May 2014, 257 patients who presented to our clinic with a diagnosis of stage I-IIIC gastric cancer were evaluated. The male/female ratio of the cases was 2.02:1 and the median age was 55.16±11.8 (20-80) years. Four of the cases (1.6%) were stage IA, 13 (5.1%) were stage 1B, 41 (16%) were stage IIA, 40 (15.6%) were stage IIB, 50 (19.5%) were stage IIIA, 51 (19.8%) were stage IIIB, and 58 (22.6%) were stage IIIC.

RESULTS

The mean follow-up time was 22.5 months (3.3-155.0); loco-regional recurrence was noted in 34 (13.2%) patients who underwent postoperative chemoradiotherapy, and metastases were observed in 108 (42%) patients. The median OS duration was 26.7 months (95% confidence interval, 20-33.5) and the 2-, 5-, and 10-year OS was 52.8% (standard error [S.E.] 0.032), 36.1% (S.E. 0.032), and 26.9% (S.E. 0.034) respectively. The median DFS was 53.7 months and the 2-, 5-, and 10-year DFS were 58.9% (S.E. 0.034), 47.4% (S.E. 0.037), and 40.7% (S.E. 0.042), respectively. In multivariate analysis of prognostic factors, advanced T stage (p<0.0001), advanced nodal stage (p=0.001), and surgical margin status (p<0.0001) were related to decreased OS and DFS.

CONCLUSION

R1 resection, advanced T stage, and advanced nodal stage were adverse prognostic factors in gastric cancer patients who had undergone CRT after the operation.

Proposal of a new lymph node staging system for gastric cancer: study from two institutions in China

The aim of this study was to identify the best cutoff points for lymph node classification to improve the prognostic prediction of gastric cancer in China. Patients who had undergone surgery for gastric cancer were retrospectively evaluated in two high-volume institutions from Peking University People's Hospital (PKUPH, N=503) and Affiliated Hospital of Qingdao University (AHQU, N=1,003). The prognosis of these patients was assessed according to the number of metastatic lymph nodes with an increment of one node at one time. A new lymph node classification was proposed based on the relation between prognosis and the number of metastatic lymph nodes. According to the prognostic value, the proposed node (N) stage was categorized as N0 (no regional LNs metastasis), N1 (1-3 involved regional LNs), N2 (4-6 involved regional LNs), and N3 (≥7 involved regional LNs). The hazard ratio for the proposed N classification increased steadily and reasonably compared with the 7th edition. Moreover, the Cox regression multivariate analysis showed that the proposed N classification was superior to the 7th N classification as an independent prognostic factor. The proposed N category was superior to 7th edition N category of the American Joint Committee on Cancer (AJCC) for assessing the prognosis for gastric cancer patients in China.

Long term follow up and retrospective study on 533 gastric cancer cases

Background

Gastric cancer (GC) is the third leading cause of cancer death in China and the outcome of GC patients is poor. The aim of the research is to study the prognostic factors of gastric cancer patients who had curative intent or palliative resection, completed clinical database and follow-up.

Methods

This retrospective study analyzed 533 GC patients from three tertiary referral teaching hospitals from January 2004 to December 2010 who had curative intent or palliative resection, complete clinical database and follow-up information. The GC-specific overall survival (OS) status was determined by the Kaplan-Meier method, and univariate analysis was conducted to identify possible factors for survival. Multivariate analysis using the Cox proportional hazard model and a forward regression procedure was conducted to define independent prognostic factors.

Results

By the last follow-up, the median follow-up time of 533 GC patients was 38.6 mo (range 6.9-100.9 mo), and the median GC-specific OS was 25.3 mo (95% CI: 23.1-27.4 mo). The estimated 1-, 2-, 3- and 5-year GC-specific OS rates were 78.4%, 61.4%, 53.3% and 48.4%, respectively. Univariate analysis identified the following prognostic factors: hospital, age, gender, cancer site, surgery type, resection type, other organ resection, HIPEC, LN status, tumor invasion, distant metastases, TNM stage, postoperative SAE, systemic chemotherapy and IP chemotherapy. In multivariate analysis, seven factors were identified as independent prognostic factors for long term survival, including resection type, HIPEC, LN status, tumor invasion, distant metastases, postoperative SAE and systemic chemotherapy.

Conclusions

Resection type, HIPEC, postoperative SAE and systemic chemotherapy are four independent prognostic factors that could be intervened for GC patients for improving survival.

Clinical significance of lymph node metastasis in gastric cancer

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

Evaluation of the seventh AJCC TNM staging system for gastric cancer: a meta-analysis of cohort studies

The AJCC seventh edition TNM classification for gastric cancer was released in 2010 and included major revision. Large-volume gastric cancer centers have evaluated the prognostic significance of the new system and obtained paradoxical results. The authors performed a meta-analysis of these studies to evaluate the new classification. Fifteen eligible studies with 38,972 patients were included in the analysis. Hazard ratios (HRs) and associated 95 % confidence intervals were extracted from identified studies. The primary outcome was overall survival. The HRs for the seventh edition T classification and N classification were found to increase steadily and reasonably. The cumulative survival rates of the seventh edition subgroups of T classifications demonstrated obvious differences; meanwhile, the differences between subgroups of N classifications including N3a and N3b categories were also significant. The 5-year survival rates according to the seventh edition TNM staging system were 94.71 % (stage IA), 88.72 % (stage IB), 80.45 % (stage IIA), 67.24 % (stage IIB), 53.68 % (stage IIIA), 37.56 % (stage IIIB), and 21.26 % (stage IIIC), respectively. The results of this study indicate that the seventh edition of the TNM classification was considered valid, although further evaluation was needed for N3a and N3b categories.

Comparison of the staging of regional lymph nodes using the sixth and seventh editions of the tumor-node-metastasis (TNM) classification system for the evaluation of overall survival in gastric cancer patients: findings of a case-control analysis involving a single institution in China

BACKGROUND

It has recently been reported that the sixth edition of the tumor-node-metastasis (TNM) classification system for gastric cancer involving the staging of regional lymph nodes (N) has inappropriate cut-offs with regard to counts of metastatic lymph nodes. It remains controversial, however, as to whether the seventh edition of this classification system is completely accurate in staging N for the prediction of the prognosis of gastric cancer. Our aim was to determine which of these two editions of the TNM classification system was superior with regard to the prediction of the prognosis of Chinese patients with gastric cancer.

METHODS

We analyzed relevant clinicopathological data statistically from 1,563 patients with gastric cancer who had undergone curative resection to evaluate the sixth and seventh editions of the TNM classification system for N staging with regard to the prediction of overall survival (OS).

RESULTS

Our survival analyses demonstrated that N staging via use of both the sixth and seventh editions of the TNM classification system was correlated with OS. Furthermore, case-control analysis indicated that the seventh edition was significantly superior to the sixth edition in predicting the OS of patients, regardless of the extent of lymphadenectomy (D1 or D2) and the number of dissected lymph nodes (<16 or ≥16). By taking into consideration both the extent of lymphadenectomy and the number of dissected lymph nodes simultaneously, we determined that the seventh edition of the TNM classification system was superior to the sixth edition regarding the evaluation of the OS in the various subgroups of gastric cancer patients.

CONCLUSION

The seventh edition proved more reliable and accurate than the sixth edition of the TNM classification system in categorizing the number of metastatic lymph nodes for the purpose of predicting the OS of patients with gastric cancer after curative resection.