Evaluation of the seventh American Joint Committee on Cancer/International Union Against Cancer Classification of gastric adenocarcinoma in comparison with the sixth classification

Adjuvant Concurrent Chemoradiotherapy (CRT) plus Docetaxel-Cisplatin-Fluorouracil (DCF) versus CRT plus Fluorouracil-Folinic Acid (FUFA) in Stage III Gastric Cancer

INTRODUCTION

Adjuvant chemoradiotherapy (CRT) is the optimal management strategy in resectable gastric cancer. There is a debate about the efficacy of more aggressive CRT plus chemotherapy regimens in adjuvant setting. This study aimed to compare the efficacy of adjuvant CRT plus docetaxel-cisplatin-fluorouracil (DCF) versus CRT plus fluorouracil-folinic acid (FUFA) in stage III gastric cancer.

METHODS

Patients with a diagnosis of stage III gastric cancer treated with adjuvant therapy after curative resection were analyzed. Patients' disease characteristics and impacts of the regimens on median disease-free survival (DFS) and median overall survival (OS) were analyzed retrospectively.

RESULTS

One hundred sixty-one patients (102 in FUFA arm and 59 in DCF arm) with a median age of 56.0 (29-79) were evaluated. In the DCF arm, there were more renal toxicities (31.6% vs 6.4% P < 0.001), emergency department admissions (64.9% vs 23.7%, P < 0.001), and dose reductions/treatment modifications in the DCF arm (51.6% vs 37.2, P < 0.001). The median follow-up was 23 months (1-124) in the FUFA arm and 26.0 months (1-77) in the DCF arm. The median DFS was 25.0 months (%95 CI, 12.7-37.2) in the DCF arm and 17.0 months (%95 CI, 2.6-31.3) in the FUFA arm, P = 0.66. The median OS was 28.0 months (%95 CI, 17.0-38.9) in the DCF arm and 25.0 months (%95 CI, 11.9-36.0) in the FUFA arm, P = 0.70.

CONCLUSION

In conclusion, when compared with FUFA regimen, more aggressive therapy with DCF was more toxic and did not improve OS in adjuvant setting of stage III gastric cancer.

Applying artificial intelligence using routine clinical data for preoperative diagnosis and prognosis evaluation of gastric cancer

The present study employed artificial intelligence (AI) machine learning technology to evaluate the prognosis of gastric cancer using blood collection data, commonly used in clinical practice and subsequently performed a stratification distinct from conventional tumor-node-metastasis (TNM) classification. Experiments were conducted using four machine learning methods, namely, logistic regression (LR), random forest (RF), gradient boosting (GB) and deep neural network (DNN), to classify good or poor post-5-year prognosis based on clinicopathological data and post-5-year relapse occurrence. For each machine learning method, the importance was sorted in descending order (from the most to the least); the top features were used for clustering using the k-medoids method. The prediction accuracy and area under the curve (AUC) for 5-year survival were as follows: LR, 76.8% and 0.702; RF, 72.5% and 0.721; GB, 75.3% and 0.73; DNN, 76.9% and 0.682, respectively. The prediction accuracy and AUC for 5-year recurrence-free survival were as follows: LR, 85.5% and 0.692; RF, 79.0% and 0.721; GB, 80.5% and 0.718; DNN, 83.2% and 0.670. Clustering patients into three groups resulted in a stratification distinct from the TNM classification. In conclusion, AI machine learning using routine clinical data can help evaluate the prognosis of gastric cancer, with prognosis differing according to AI-identified clusters.

The value of lymph nodes ratios in the prognosis of resectable remnant gastric cancer through the retrospective propensity score matching analysis

PURPOSE

Currently, the characteristics and prognosis of remnant gastric cancer (RGC) are not fully understood yet. The present study aimed to describe the details of clinicopathological features of resectable RGC and investigated the factors affecting survival after the curative operation.

METHODS

From Jan. 2006 to Dec. 2015, a total of 118 resectable RGC patients (the RGC group) and 236 age-, sex- and TNM stages-matched resectable gastric cancer (GC) patients (the control group) were recruited retrospectively. Clinicopathological characteristics and overall survival were compared between the two groups.

RESULTS

The overall survival rate was 46.61% for RGC patients compared to 55.08% for control groups (P < 0.01), and the mean overall survival time of RGC patients was 40.23 ± 32.27 months, compared to 55.06 ± 34.29 months in the control group (P = 0.023 after matching). The overall survival (OS) of RGC patients with stage IIb was much worse than IIa (P < 0.001) and similar to IIIa (P = 0.463) and IIIb (P = 0.014). Multivariate Cox proportional hazards model analysis revealed that TNM stage (HR: 3.899, P < 0.001) and lymph nodes ratio (LNR) (HR: 2.405, P = 0.028) were independent prognostic significance to OS.

CONCLUSIONS

The OS of RGC was much worse than GC with similar TNM stages, and LNR might consider a highly reliable indicator to evaluate the prognostic in RGC.

Predicting postoperative gastric cancer prognosis based on inflammatory factors and machine learning technology

OBJECTIVE

There is a strong association between gastric cancer and inflammatory factors. Many studies have shown that machine learning can predict cancer patients' prognosis. However, there has been no study on predicting gastric cancer death based on machine learning using related inflammatory factor variables.

METHODS

Six machine learning algorithms are applied to predict total gastric cancer death after surgery.

RESULTS

The Gradient Boosting Machine (GBM) algorithm factors accounting for the prognosis weight outcome show that the three most important factors are neutrophil-lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR) and age. The total postoperative death model showed that among patients with gastric cancer from the predictive test group: The highest accuracy was LR (0.759), followed by the GBM algorithm (0.733). For the six algorithms, the AUC values, from high to low, were LR, GBM, GBDT, forest, Tr and Xgbc. Among the six algorithms, Logistic had the highest precision (precision = 0.736), followed by the GBM algorithm (precision = 0.660). Among the six algorithms, GBM had the highest recall rate (recall = 0.667).

CONCLUSION

Postoperative mortality from gastric cancer can be predicted based on machine learning.

Genomic analysis of matrix metalloproteinases affecting the prognosis and immunogenic profile of gastric cancer

This study systematically and comprehensively analyzed the characteristics of matrix metalloproteinases (MMPs) in gastric cancer (GC) and revealed the relationship between MMPs and prognoses, clinicopathological features, tumor microenvironment, gene mutations, and drug therapy response in patients with GC. Based on the mRNA expression profiles of 45 MMP-related genes in GC, we established a model that classified GC patients into three groups based on cluster analysis of the mRNA expression profiles. The 3 groups of GC patients showed significantly different prognoses as well as tumor microenvironmental characteristics. Next, we used Boruta's algorithm and PCA method to establish an MMP scoring system and found that lower MMP scores were associated with better prognoses, lower clinical stages, better immune cell infiltration, lower degrees of immune dysfunction and rejection, and more genetic mutations. Whereas a high MMP score was the opposite. These observations were further validated with data from other datasets, showing the robustness of our MMP scoring system. Overall, MMP could be involved in the tumor microenvironment (TME), clinical features, and prognosis of GC. An in-depth study of MMP patterns can better understand the indispensable role of MMP in the development of GC and reasonably assess the survival prognosis, clinicopathological features, and drug efficacy of different patients, thus providing clinicians with a broader vision of GC progression and treatment.

Expression and Prognostic Significance of Stem Cell Marker CD133 in Survival Rate of Patients with Colon Cancer

INTRODUCTION

Today, colon cancer is one of the most common types of gastrointestinal cancer worldwide. CD133 as a known cancer stem cell marker has been found effective in cell proliferation and differentiation in various cancers, including colon cancer. We aimed to investigate the relationship between CD133 expression in colon cancer with prognostic factors and survival rate of patients with colon cancer by immunohistochemistry.

METHODS

Formalin-fixed paraffin-embedded (FFPE) tissue was taken from patients with colon cancer. Histopathology examination was done using hematoxylin and eosin staining. Immunohistochemistry was performed to determine CD133 expression. Association between CD133 expression and clinicopathological profile was then assessed.

RESULTS

There was a statistically significant association between CD133 protein expression and sex , cancer stage, and lymphatic invasion (p = 0.044, p = 0.131, and p = 0.002, respectively). However, no significant correlation was identified between CD133 expression and other factors, including age of patients with colorectal cancer (CRC) (p = 0.267), tumor location (p = 0.494), tumor differentiation grade (p = 0.263), neural tissue invasion, and 5-year survival (p = 0.054).

CONCLUSION

CD133 is a useful predictive or prognostic biomarker for CRC in clinical assessment and may serve as a potential therapeutic target for CRC.

Assessment of indocyanine green tracer-guided lymphadenectomy in laparoscopic gastrectomy after neoadjuvant chemotherapy for locally advanced gastric cancer: results from a multicenter analysis based on propensity matching

BACKGROUND

This study evaluated the safety, effectiveness, and feasibility of indocyanine green (ICG) tracing in guiding lymph-node (LN) dissection during laparoscopic D2 radical gastrectomy in patients with advanced gastric cancer (AGC) after neoadjuvant chemotherapy (NAC).

METHOD

We retrospectively analyzed data on 313 patients with clinical stage of cT1-4N0-3M0 who underwent laparoscopic radical gastrectomy after NAC between February 2010 and October 2020 from two hospitals in China. Grouped according to whether ICG was injected. For the ICG group (n = 102) and non-ICG group (n = 211), 1:1 propensity matching analysis was used.

RESULTS

After matching, there was no significant difference in the general clinical pathological data between the two groups (ICG vs. non-ICG: 94 vs. 94). The average number of total LN dissections was significantly higher in the ICG group and lower LN non-compliance rate than in the non-ICG group. Subgroup analysis showed that among patients with LN and tumor did not shrink after NAC, the number of LN dissections was significantly more and LN non-compliance rate was lower in the ICG group than in the non-ICG group. Intraoperative blood loss was significantly lesser in the ICG group than in the non-ICG group, while the recovery and complications of the two groups were similar.

CONCLUSION

For patients with poor NAC outcomes, ICG tracing can increase the number of LN dissections during laparoscopic radical gastrectomy, reduce the rate of LN non-compliance, and reduce intraoperative bleeding. Patients with AGC should routinely undergo ICG-guided laparoscopic radical gastrectomy.

Development and validation of pretreatment nomogram for disease-specific mortality in gastric cancer-A competing risk analysis

Background

In several reports, gastric cancer nomograms for predicting overall or disease‐specific survival have been described. The American Joint Committee on Cancer (AJCC) introduced the attractiveness of disease‐specific mortality (DSM) as an endpoint of risk model. This study aimed to develop the first pretreatment gastric cancer nomogram for predicting DSM that considers competing risks (CRs).

Methods

The prediction model was developed using data for 5231 gastric cancer patients. Fifteen prognosticators, which were registered at diagnosis, were evaluated. The nomogram for DSM was created as visualizations of the multivariable Fine and Gray regression model. An independent cohort for external validation consisted of 389 gastric cancer patients from a different institution. The performance of the model was assessed by discrimination (Harrell's concordance (C)‐index), calibration, and decision curve analysis. DSM and CRs were evaluated, paying special attention to host‐related factors such as age and Eastern Cooperative Oncology Group performance status (ECOG PS), by using Gray's univariable method.

Results

Fourteen prognostic factors were selected to develop the nomogram. The new nomogram for DSM exhibited good discrimination. Its C‐index of 0.887 surpassed that of the American Joint Committee on Cancer (AJCC) clinical staging (0.794). The C‐index was 0.713 (AJCC, 0.582) for the external validation cohort. The nomogram showed good performance internally and externally, in the calibration and decision curve analysis. Host‐related factors including age and ECOG PS, were strongly correlated with competing risks.

Conclusions

The newly developed nomogram accurately predicts DSM, which can be used for patient counseling in clinical practice.

Comparative Outcomes of Laparoscopic Gastrectomy and Open Gastrectomy for Scirrhous Gastric Cancer: A Multicenter Retrospective Cohort Study

Objective

A multicenter retrospective cohort study was performed to compare the outcomes of laparoscopic gastrectomy (LG) versus open gastrectomy (OG) for scirrhous gastric cancer (GC) as a unique subtype also known as type 4 gastric cancer or linitis plastica.

Background

Although data on the efficacy and safety of LG as an alternative to OG are emerging, the applicability of LG to scirrhous GC remains unclear.

Methods

Patients with clinical type 4 GC undergoing gastrectomy at 13 hospitals from 2005 to 2015 were retrospectively reviewed. As the primary endpoint, we compared overall survival (OS) between the LG and OG groups. To adjust for confounding factors, we used multivariate Cox regression analysis for the main analyses and propensity-score matching for sensitivity analysis. Short-term outcomes and recurrence-free survival were also compared.

Results

A total of 288 patients (LG, 62; OG, 226) were included in the main analysis. Postoperative complications occurred in 25.8% and 30.1%, respectively (P = 0.44). No significant difference in recurrence-free survival was observed (P = 0.72). The 5-year OS rates were 32.4% and 31.6% in the LG and OG groups, respectively (P = 0.60). The hazard ratio (LG/OG) for OS was 0.98 (95% confidence interval [CI], 0.65-1.43) in the multivariate regression analysis. In the sensitivity analyses after propensity-score matching, the hazard ratio for OS was 0.92 (95% CI, 0.58-1.45).

Conclusions

Considering the hazard ratios and 95% CIs for OS, LG for scirrhous GC was not associated with worse survival than that for OG.

Hsa_circ_0076305 induces migration-proliferation dichotomy in gastric cancer

Recent studies have demonstrated that circular RNAs (circRNAs) play an important role in the development of gastric cancer (GC). The present study aimed to investigate the role of hsa_circ_0076305 (circPGC) in GC. The levels of circRNAs and mRNAs in AGS cell lines were detected via reverse transcription-quantitative PCR, and western blotting was performed to detect protein expression levels. Functional studies were explored by CCK8 assay and cell migration assay. Functional studies have indicated that circPGC orchestrates two cellular processes; it inhibits proliferation, and promotes migration and invasion in the GC AGS cell line, a phenomenon called ‘migration-proliferation dichotomy’, as well as epithelial-to-mesenchymal transition in AGS cells. In addition, circPGC degrades the extracellular matrix and basement membrane through matrix metallopeptidase (MMP)9 and MMP14, providing a microenvironment that facilitates cell migration. The results also demonstrated that circPGC expression is lower in clinical patients with later stages of GC, which is associated with poor prognosis. Taken together, these results suggest that circPGC exhibits migration-proliferation dichotomy during GC development, invasion and migration.

Tumor Epigenetic Signature and Survival in Resected Gastric Cancer Patients

BACKGROUND

Precision oncology can identify patient-specific molecular signatures to better inform the prognosis and management of surgical cancer patients. Specifically, microRNAs (miRs) hold promise as prognostic biomarkers because dysregulation of individual miRs is implicated in tumorigenesis, progression, and metastases of various malignancies, including gastric adenocarcinoma (GC).

STUDY DESIGN

To identify miRs prognostic of survival after radical gastrectomy, we studied GC patients within The Cancer Genome Atlas (TCGA) who had undergone R0 or R1 resection and had data on clinical characteristics, overall survival (OS), and tumor miR expression. The miRs expressed by at least 15% of tumors were eligible for study. From 10 replicate samples, each with 80% of patients, miRs were selected using age-adjusted proportional hazards regression with stepwise selection. Cross-validated miRs (selected by multiple replicates) were retained if they optimized an accelerated failure-time model of OS using all patients.

RESULTS

In this GC cohort (n = 270), half (916/1,870) of miRs screened met our criteria for evaluation. Cross-validation identified 20 miRs as prognostic, of which 14 (miR-129-1, miR-373, miR-490, miR-597, miR-1185-2, miR-3943, miR-4756, miR-5683, miR-6510, miR-6733, miR-6808, miR-6855, miR-6882, miR-8072) were independently informative. The age-adjusted 14-miRNA panel remained significantly associated with OS after adjustment for pathologic prognostic factors (number of lymph nodes examined, number of positive lymph nodes) and other clinical covariates (TNM stage, residual tumor, tumor microsatellite instability, targeted molecular therapy, sex, race, ethnicity). Panel-predicted survival estimates below the upper tertile cut-off were associated with worse outcome (30% vs 74% OS at 3 years, p < 0.0001).

CONCLUSIONS

In surgically resected GC patients, an epigenetic signature of miRs associated with survival has the potential to improve prognostication.

Artificial Intelligence-Based Multiclass Classification of Benign or Malignant Mucosal Lesions of the Stomach

Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide. It takes some time from chronic gastritis to develop in GC. Early detection of GC will help patients obtain timely treatment. Understanding disease evolution is crucial for the prevention and treatment of GC. Here, we present a convolutional neural network (CNN)-based system to detect abnormalities in the gastric mucosa. We identified normal mucosa, chronic gastritis, and intestinal-type GC: this is the most common route of gastric carcinogenesis. We integrated digitalizing histopathology of whole-slide images (WSIs), stain normalization, a deep CNN, and a random forest classifier. The staining variability of WSIs was reduced significantly through stain normalization, and saved the cost and time of preparing new slides. Stain normalization improved the effect of the CNN model. The accuracy rate at the patch-level reached 98.4%, and 94.5% for discriminating normal → chronic gastritis → GC. The accuracy rate at the WSIs-level for discriminating normal tissue and cancerous tissue reached 96.0%, which is a state-of-the-art result. Survival analyses indicated that the features extracted from the CNN exerted a significant impact on predicting the survival of cancer patients. Our CNN model disclosed significant potential for adjuvant diagnosis of gastric diseases, especially GC, and usefulness for predicting the prognosis.

A Modified ypTNM Staging System-Development and External Validation of a Nomogram Predicting the Overall Survival of Gastric Cancer Patients Received Neoadjuvant Chemotherapy

Purpose

Neoadjuvant chemotherapy is now widely used in gastric cancer patients. However, the current 8th ypTNM staging system is developed based on patients with less extensive lymph node dissection and the predictive value is relatively limited. In this study, we aim to develop and validate a nomogram that predicts overall survival in gastric cancer patients received neoadjuvant chemotherapy.

Patients and Methods

From January, 2007 to December, 2014, 471 patients receiving neoadjuvant chemotherapy at our center were enrolled in the study. Based on the Cox proportional hazard model, a nomogram was developed from them and then an external validation was conducted on a cohort of 239 patients from another cancer center.

Results

The overall survival (OS) rates of 1 year and 3 years were 90.0% and 64.1%, respectively. Body mass index category, tumor location, T stage and N stage were independent prognostic factors for the survival outcome. The C-index of the model was 0.74 in the development cohort and 0.69 in the validation cohort. Our nomogram also showed good calibration in both cohorts.

Conclusion

We developed and validated a nomogram to predict the 1- and 3-year OS of patients who received neoadjuvant chemotherapy and radical gastrectomy with D2 lymph node dissection. This nomogram predicts survival more accurately than the AJCC TNM staging system, which is the current golden standard.

Proposal of a novel stage grouping of the Eighth Edition of American Joint Committee on Cancer TNM Staging System for Gastric Cancer: results from a retrospective study of 30 years clinical data from a single institute in China

Objectives: To improve the prognostic accuracy of 8th edition of American Joint Committee on Cancer TNM staging system for gastric cancer by reclassifying N3a category.Methods: 1446 patients who underwent R0 surgery for histologically proven gastric cancers with ≥16 lymph nodes retrieved were selected.Results: Significant prognostic difference was observed among patients in N3a category ('7-10' group vs '11-15' group; P = 0.029). We proposed a revised pN category in which patients with '7-10' metastatic lymph nodes were categorized as r-N3a, '11-15' as r-N3b, and '>15' as r-N3c. Prognosis for patients in T2r-N3aM0 was similar to that of patients in T4aN0M0/T3N1M0/T2N2M0/T1r-N3bM0 (P = 0.584), but significantly better than that of patients in T4bN0M0/T4aN1-2M0/T3N2M0/T2r-N3bM0 (P = 0.031). Similarly, prognoses for patients in T3r-N3aM0 and T4ar-N3aM0 were similar to that of patients in T4bN0M0/T4aN1-2M0/T3N2M0/T2r-N3bM0 (P = 0.136; P = 0.193), but significantly better than that of patients in T4bN1-2M0/T4ar-N3bM0/T3r-N3bM0/T1-2r-N3cM0 (P = 0.011; P = 0.017). A revised TNM system was also proposed, in which T2r-N3aM0 was incorporated into stage IIB, T3r-N3aM0 and T4ar-N3aM0 into stage IIIA. The revised TNM system had better homogeneity, discriminatory ability, and monotonicity of gradients than the 8th edition system.Conclusion: Patients with 7-10 metastatic lymph nodes in T2-T4a categories should be considered lower stage in the final TNM stage.

How Should We Measure the Quality of Lymphadenectomy for Gastric Cancer? Anatomical Versus Numerical Criterion

AIM

To compare anatomical with numerical criterion to measure the quality of lymphadenectomy for gastric cancer.

PATIENTS AND METHODS

We analyzed 447 gastric cancer patients with resectable tumor stage (R0 resection) with at least 16 examined lymph nodes.

RESULTS

Of 447 patients, 82.6% underwent D2 lymphadenectomy for a median of total examined lymph nodes of 28. The 7-year disease-specific survival rate for the whole sample was 71.4%. Survival was significantly different between patients treated with D2 and D1 lymphadenectomy (77.4% versus 44.3%; p < 0.001) and between patients with total examined lymph nodes ≥ 28 and < 28 (74.5% versus 62.3%; p = 0.041). Anatomical criterion significantly differentiated 7-year survival in patients stratified according to a numerical parameter.

CONCLUSION

We should still consider the anatomical criterion as the best item to measure the quality of lymphadenectomy for gastric cancer.

Precision medicine in gastric cancer

Gastric cancer (GC) is a complex disease linked to a series of environmental factors and unhealthy lifestyle habits, and especially to genetic alterations. GC represents the second leading cause of cancer-related deaths worldwide. Its onset is subtle, and the majority of patients are diagnosed once the cancer is already advanced. In recent years, there have been innovations in the management of advanced GC including the introduction of new classifications based on its molecular characteristics. Thanks to new technologies such as next-generation sequencing and microarray, the Cancer Genome Atlas and Asian Cancer Research Group classifications have also paved the way for precision medicine in GC, making it possible to integrate diagnostic and therapeutic methods. Among the objectives of the subdivision of GC into subtypes is to select patients in whom molecular targeted drugs can achieve the best results; many lines of research have been initiated to this end. After phase III clinical trials, trastuzumab, anti-Erb-B2 receptor tyrosine kinase 2 (commonly known as ERBB2) and ramucirumab, anti-vascular endothelial growth factor receptor 2 (commonly known as VEGFR2) monoclonal antibodies, were approved and introduced into first- and second-line therapies for patients with advanced/metastatic GC. However, the heterogeneity of this neoplasia makes the practical application of such approaches difficult. Unfortunately, scientific progress has not been matched by progress in clinical practice in terms of significant improvements in prognosis. Survival continues to be low in contrast to the reduction in deaths from many common cancers such as colorectal, lung, breast, and prostate cancers. Although several target molecules have been identified on which targeted drugs can act and novel products have been introduced into experimental therapeutic protocols, the overall approach to treating advanced stage GC has not substantially changed. Currently, surgical resection with adjuvant or neoadjuvant radiotherapy and chemotherapy are the most effective treatments for this disease. Future research should not underestimate the heterogeneity of GC when developing diagnostic and therapeutic strategies aimed toward improving patient survival.

Proposal of a New TNM Classification for Gastric Cancer: Focusing on pN3b and Cytology-Positive (CY1) Disease

Purpose

Gastric cancer with lymph node metastasis (LNM) more than 15 (N3b) was defined as stage IV until the 6th AJCC system. However, it has been reclassified as a localized disease (stage IIb or III) since the 7th system. The aim of this study is to demonstrate that the survival of N3b is comparable to cytology-only positive (CY1-only) stage IV and to propose a new TNM system interpreting N3b as an eligibility criterion for receiving more intensive chemotherapy regimens.

Materials and Methods

1,430 patients who underwent gastric cancer surgery at Seoul National University Hospital from 2007 to 2012 were retrospectively analyzed. The 5-year survival rate (5YSR) and 3-year recurrence-free survival (RFS) were evaluated according to the 7th and 8th systems, as well as a new categorization based on N-classification; N0-2 (LNM<7), N3a (LNM 7–15), or N3b (LNM>15).

Results

The survival of N3b is comparable to that of CY1-only stage IV (log rank test, P=0.671) and is distinct from that of grossly stage IV (log rank test, P<0.001). The survival of the remaining stage IIIc (T4bN3a) was comparable to those of N3b and CY1-only stage IV. Most N3b patients had significantly shorter 3-year RFS and mean RFS than those with IIb–IIIc, as if N3b itself was a higher TNM stage.

Conclusions

In terms of survival, T4bN3a, N3b, and CY1-only stage IV were unified as stage IVa, while grossly stage IV was defined as stage IVb. N3b can be regarded as an eligibility criterion for undergoing more intensive chemotherapy regimens.

Multi-institutional validation of the 8th AJCC TNM staging system for gastric cancer: Analysis of survival data from high-volume Eastern centers and the SEER database

BACKGROUND

The clinical relevance and general applicability of the 8th American Joint Committee on Cancer TNM gastric cancer staging system vs the 7th version have not been examined using datasets from both the East and West.

METHODS

Patients (n = 29 984) treated for gastric adenocarcinoma at two high-volume centers (Severance Hospital [SH] and Gangnam Severance Hospital [GSH]) in Korea and data from the Surveillance, Epidemiology, and End Results (SEER) database were retrospectively analyzed. Survival curves, the performance of tumor staging, and the homogeneity of modified subgroups were compared.

RESULTS

Minute changes were noted in the stage IIB subgroup; most changes were noted in stage III. Applying the 8th staging system facilitated better prediction of survival than applying the 7th version for SH data according to the log-rank test, C-index, and AIC (8444.5 vs 9263.8, 0.796 vs 0.798, and 104152 vs 103909, respectively). Its performance was also superior for GSH and SEER data. In a subgroup analysis of stages IIB to IIIC in SH, GSH, and SEER data, the 8th staging system showed similar or more homogeneous survival for each sub-classification than the 7th version.

CONCLUSION

Compared with the 7th gastric cancer staging system, the newer version more accurately predicted prognosis and stratified subgroups more homogeneously.

Natural History of Gastric Cancer: Observational Study of Gastric Cancer Patients Not Treated During Follow-Up

BACKGROUND

Understanding the natural progression of untreated gastric cancer is critical for determining the disease prognosis as well as treatment options and timing. The aim of this study is to analyze the natural history of gastric cancer.

PATIENTS AND METHODS

We included patients with gastric cancer who had not received any treatment and were staged using endoscopy/endoscopic ultrasonography and computed tomography on at least two follow-up visits during intervals of nontreatment. Tumor volumes were also measured in addition to the staging. Survival of each stage at diagnosis was also analyzed.

RESULTS

A total of 101 patients were included. The mean follow-up period was 35.1 ± 34.4 months. The gastric cancer doubling time was 11.8 months for T1 and 6.2 months for T4. The progression time from early gastric cancer to advanced gastric cancer was 34 months. It decreased as the stages advanced: from 34 months between tumor-nodes-metastasis stage I and II to 1.8 months between stage III and IV. No variable was identified as a risk factor for cancer progression. The 5-year survival rates of untreated patients were 46.2% in stage I and 0% in stage II, stage III, and stage IV.

CONCLUSIONS

The progression and doubling times of gastric cancer shorten as the stages advance. Objective data reported in this study can be a critical factor in determining treatment timing and screening interval.

Modified American Joint Committee on Cancer Tumor-Node-Metastasis Staging System Based on the Node Ratio Can Further Improve the Capacity of Prognosis Assessment for Gastric Cancer Patients

Background and Objectives: Our aim was to investigate whether the modified American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) staging system based on the node ratio can further improve the capacity of prognosis assessment for gastric cancer (GC) patients regardless of the number of lymph nodes examined (eLNs).

Methods: A total of 17,187 GC patients in the Surveillance, Epidemiology, and End Results (SEER) database were included. On the basis of a training set of 7,660 GC patients, we built the tumor-node ratio-metastasis (TNrM) staging system, which was then externally validated with a validation set of 9,527 GC patients.

Results: For the training set, the C-index value of the TNrM staging system was significantly higher than that of the AJCC 8th TNM staging system to predict survival for GC patients (C-index: 0.688 vs. 0.671, P < 0.001). Moreover, the C-index value of the TNrM staging system was significantly higher than that of the 8th TNM staging system to predict survival for GC patients with ≤15 eLNs (C-index: 0.682 vs. 0.673, P < 0.001), as well as for GC patients with >15 eLNs (C-index: 0.700 vs. 0.694, P < 0.001). Similar results were found in the validation set.

Conclusions: The TNrM staging system predicted survival more accurately and discriminatively than the AJCC 8th TNM staging system for GC patients regardless of the number of eLNs.

Implication of lymph node staging in migration and different treatment strategies for stage T2N0M0 and T1N1M0 resected gastric cancer: a SEER population analysis

PURPOSE

The purpose of this study was to explore the differences between stage T2N0M0 and stage T1N1M0 gastric cancer (GC) and to identify the necessity of adjuvant treatment (AT) for these stages.

METHODS

Between years 2004 and 2015, 1971 stage IB GC patients who underwent radical surgery were recruited using the Surveillance, Epidemiology and End Results database. We conducted univariate/multivariate analyses, the propensity score matching and evaluated gastric cancer-specific survival (GCSS) and overall survival (OS) with the log-rank test.

RESULTS

T1N1M0 had a significantly worse survival than T2N0M0 in both GCSS and OS before and after the propensity score matching. Examined lymph nodes (ELN) ≤ 15 and T1N1M0 were independent risk factors for worse GCSS and OS in stage IB GC. The absence of adjuvant chemotherapy (CT) was an independent risk factor for worse GCSS and OS in T1N1M0 but not in T2N0M0. AT demonstrated similar GCSS and OS with surgery alone (SA) for T2N0M0 but better survival for T1N1M0. Compared to CT and adjuvant chemoradiotherapy (CRT) group, SA demonstrated significantly worse GCSS and OS for T1N1M0. There was no significant difference between CT and CRT in both T2N0M0 and T1N1M0 stages. T2N0M0 had a better survival than T1N1M0 in ELN ≤ 15 subgroup. However, similar survival was demonstrated in ELN > 15 subgroup.

CONCLUSIONS

T2N0M0 GC has a better survival rate than T1N1M0 GC when ELN are ≤ 15. Moreover, T2N0M0 GC may not benefit from AT. T1N1M0 GC requires CT but not adjuvant radiotherapy.

Proposed Modification of the 8th Edition of the AJCC Staging System for Gastric Cancer

Background: The American Joint Committee on Cancer (AJCC) staging system has been the standardized staging system for malignancies since the first edition in 1987. The 8th edition of gastric cancer was released in 2016, and is expected to be used in clinical practice in 2018. The aim of this study was to improve this new gastric cancer staging system. Methods: We conducted median overall survival analyses in a cohort of 8359 gastric cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database (2004-2014) via Kaplan-Meier curves and log-rank tests, and proposed a modified staging system based on median OS. The concordance index (C-index) was conducted to evaluate the predictive accuracy. Results: Using the 8th AJCC staging system, the median OS of patients at the same stage varied widely between the different substages, especially in stage III. Despite the definitions of T, N, and M, substages in the modified staging system were regrouped based on median OS. The C-index of stage III patients with the modified staging system [0.579, 95% confidence interval (CI) 0.564-0.593] was higher than the 8th AJCC staging system (0.567, 95% CI 0.552-0.581). Moreover, we divided these patients into two groups according to their examined lymph node counts (≥15 or 1-14), and studied the effectiveness of the modified staging system in the two groups. Conclusions: The modified 8th AJCC staging system for gastric cancer proposed in this study generates better prognostic stratifications and may be evaluated for further update. Abbreviations:AJCCAmerican Joint Committee on CancerOSOverall SurvivalSEERSurveillance, Epidemiology, and End Results.

Prognostic Value of the Number of Lymph Nodes Examined in Patients with Node-Negative Gastric Cancer

BACKGROUND

Our aim was to evaluate the prognostic value of the number of lymph nodes examined (eLNs) in patients with node-negative gastric cancer (GC) and further to adjust the American Joint Committee on Cancer (AJCC) 8th staging system based on the number of eLNs.

METHODS

Node-negative GC patients diagnosed during 1988-2015 from the Surveillance, Epidemiology, and End Results (SEER) database were included. On the basis of a primary cohort of 4159 node-negative GC patients, we built the adjusted AJCC 8th staging system, which was then internally validated by a bootstrap method, and externally validated with an independent cohort of 5565 node-negative GC patients.

RESULTS

The median number of eLNs was 10. For the training set, the optimal eLNs thresholds were determined to be 9 for node-negative GC patients. The adjusted AJCC 8th staging system for node-negative GC patients based on the number of eLNs had a significantly higher Harrell's concordance index than the initial AJCC 8th staging system (C-index, 0.635 versus 0.616; P < 0.001). Thus, the adjusted AJCC 8th staging system had superior prognostic stratification. Similar results were found in the validation set.

CONCLUSIONS

For node-negative GC patients in the United States, the adjusted AJCC 8th staging system based on the number of eLNs predicted survival more accurately and discriminatively.

A modified subclassification to evaluate the survival of patients with N3 gastric cancer: an international database study

BACKGROUND

The eighth TNM classification for gastric cancer categorizes N3 as N3a and N3b in the final pathologic stage. The cutoff for N3a/N3b is defined as 15 metastatic lymph nodes, but the rationale for this cutoff remains unclear. This study aimed to determine the optimal N3a/N3b cutoff and evaluate its prognostic significance.

METHODS

An international database was constructed by combining data from patients with N3 gastric cancer and complete five-year follow-up data from the Surveillance, Epidemiology, and End Results program database (n = 1833) and the Fujian Medical University Union Hospital database (n = 920) (total n = 2753). A log-rank test was performed to determine the optimal N3a/N3b cutoff, and its prognostic significance was confirmed in a two-step multivariate analysis and compared to that of the eighth TNM.

RESULTS

A cut-point analysis performed at each metastatic lymph node number identified the greatest survival difference between N3a and N3b at 13 metastatic lymph nodes (χ² = 157.671, P = 3.65 × 10^- 36). In patients with 14-15 metastatic lymph nodes, prognoses were significantly worse than those in patients with 7-13 metastatic lymph nodes (P < 0.001) but similar to those in patients with > 15 metastatic lymph nodes (P = 0.078). Therefore, patients with 14-15 metastatic lymph nodes were incorporated into a modified N3b classification. In the two-step multivariate analysis, the eighth N3 classification fell out of the model, while the modified N3 classification remained intact (HR 1.51, P < 0.001). Further analyses demonstrated that the modified TNM classification had superior homogeneity, discriminatory ability, and gradient monotonicity compared to the eighth TNM classification.

CONCLUSIONS

For improved prognostic stratification, we recommend adjusting the cutoff for subclassification of N3 gastric cancer to 13 metastatic lymph nodes.

Ten-year survival outcomes of patients with potentially resectable gastric cancer: impact of clinicopathologic and treatment-related risk factors

BACKGROUND

Despite therapeutic advancements, gastric cancer (GC) remains a leading cause of death worldwide.

METHODS

This retrospective cohort study statistically analyzed the clinicopathologic characteristics, treatments and outcomes of patients with potentially resectable GC managed at our institution between 2006 and 2010. The STROBE checklist was applied.

RESULTS

Preoperative assessment of 164 GC patients (male: female ratio 1.87, median age 65 years) assigned 132 (80.5%) to total (56; 42.4%) or subtotal (76; 57.6%) gastrectomy. Resection margins were microscopically tumor-free (R0) in 100 (75.8%), microscopically infiltrated (R1) in 25 (18.9%) and macroscopically infiltrated (R2) in 7 (5.3%) patients. Nodal plane dissection was D0 in 34 (25.8%), D1 in 62 (47.0%) and D2 in 36 (27.3%) patients. Early GC was diagnosed in 19 patients (14.4%). Fluorouracil-based chemotherapy was administered in 69.7% and chemoradiation in 18.2% of patients. The 5- and 10-year survival rates of patients with R0 resection were 74% and 65.4%, respectively. The 2-year survival rates for R1 and R2 resection were 28.9% and 0% respectively. The 5- and 10-year survival rates according to nodal plane dissection were 55.6% and 41.4% for D2, and 53.2% and 49.7% for D1, respectively. On multivariate analysis, T4, N3 and R1/R2 remained independent negative prognostic factors for overall survival. Microscopic or macroscopic infiltration of surgical margins was the worst adverse prognostic factor for survival.

CONCLUSION

These results are equivalent to those from centers of excellence and indicate the urgent need for improvements in the field, particularly in the development of predictive models to guide personalized therapy.

Validation of the prognostic impact of the new tumor-node-metastasis clinical staging in patients with gastric cancer

BACKGROUND

In the 8th edition of the tumor-node-metastasis (TNM) classification, the gastric cancer staging system includes two classifications: the clinical stage (cStage) and the postoperative pathologic stage. However, the correlation between the new cStage and overall survival has not been studied. Moreover, clinical N (cN) grade analysis is not included in the new clinical staging system. This study validated the prognostic value of cStage in the 8th edition of the TNM classification and the significance of N classification for pretreatment staging in gastric cancer.

METHODS

A total of 4374 patients with primary gastric cancer who underwent surgery at the Shizuoka Cancer Center were included. Survival analysis was conducted based on the newly proposed cStage criteria of the TNM 8th edition. Prognostic accuracy was evaluated using Harrell's concordance index (C-index).

RESULTS

The five-year survival rates according to cStage were as follows: cStageI, 91.2%, cStageIIA: 75.1%, cStageIIB: 57.7%, cStageIII: 43.2%, cStageIVA: 31.6%, and cStageIVB: 7.7%. Significant differences were observed among all stages (P < 0.001). The cStage C-index was 0.802. Meanwhile, the five-year survival rates based on cN were as follows: cN0: 83.7%, cN1: 57.2%, cN2: 42.4%, cN3a: 22.1%, and cN3b: 0.0%. Significant differences were also observed among all cN grades (P < 0.001).

CONCLUSIONS

The cStage of the 8th edition of the TNM classification has a good capability to predict prognosis; thus, it may be a useful indicator for selecting appropriate gastric cancer treatment modalities. In addition, cN can be included in developing a more precise clinical staging of gastric cancer.

Assessment of the 8th edition of TNM staging system for gastric cancer: the results from the SEER and a single-institution database

AIM

To investigate whether the 8th edition of Tumor, Node, Metastasis (TNM) staging could properly evaluate the prognosis of gastric cancer patients.

METHODS

The prognostic performance between the 7th and 8th edition of TNM staging was compared and clinicopathologic features were analyzed.

RESULTS

The stage shifts in the 8th edition staging resulted in the increased numbers of stage IIIA patients and decreased numbers of stage IIB, stage IIIB and stage IIIC patients. Compared with the previous edition, the 8th edition of TNM staging provided a better prognostic stratification for stage III patients. However, whether it is reasonable to incorporate T4aN2, T4aN3a and T4bN3b into stage IIIA, stage IIIB and stage IIIC respectively, which still need further validation.

CONCLUSION

Despite the obvious superiority, several deficiencies may still exist in the new edition staging. To better provide prognostic information and therapeutic guidance for gastric cancer patients, the TNM staging system should be further improved in the future.

Extensive intraperitoneal lavage to eliminate intraperitoneal tumor cells in gastrectomy with D2 lymphadenectomy for gastric cancer

INTRODUCTION:

Survival in gastric cancer is often limited by peritoneal carcinomatosis, which supposedly develops from serosal tumor infiltration or tumor cell spread during gastrectomy with lymphadenectomy. To eliminate peritoneal tumor cells, extensive intraperitoneal lavage (EIPL) has been suggested. Impressive results have been achieved in Japanese trials. In this trial, we assessed EIPL in Western patients.

METHODS:

This prospective trial included patients with non-metastatic gastric adenocarcinoma undergoing gastrectomy with D2 lymphadenectomy. Peritoneal fluid samples at laparotomy, after lymphadenectomy, and after EIPL were analyzed for tumor cells using cytology and EpCAM antibodies. The primary endpoint was peritoneal conversion rate (PCR; proportion of patients in whom EIPL eliminated tumor cells after lymphadenectomy). Secondary endpoints were peritoneal release rate (PRR; proportion of patients with peritoneal tumor cells after gastrectomy/lymphadenectomy among all patients without cells before gastrectomy/lymphadenectomy) and prevalence of peritoneal tumor cells before resection. EIPL was considered ineffective if PCR ⩽ 0.2 and warranted further exploration if PCR ⩾ 0.5. Clinicaltrials.gov identifier is NCT01476553.

RESULTS:

The trial was stopped early because tumor cells after gastrectomy/lymphadenectomy were detected in only 3/27 (11.1%) patients. In none of these did EIPL eliminate tumor cells (PCR 0, 95% confidence interval [CI] 0%-12.5%). In 8/27 (29.6%) patients, tumor cells were detected after EIPL. PRR was 11.1% (95% CI 2.4%-29.2%). There were no perioperative complications higher than Clavien-Dindo grade 3a.

CONCLUSIONS:

In Western patients, free peritoneal tumor cells after gastrectomy with D2 lymphadenectomy for gastric cancer were detected only sporadically. Although based on few cases, the findings suggest that EIPL spreads tumor cells into the peritoneal cavity, thus being potentially harmful. Therefore, EIPL cannot be generally recommended.

Characteristics of overlooked synchronous gastric epithelial neoplasia after endoscopic submucosal dissection

Since endoscopic submucosal dissection (ESD) has been accepted as the treatment of choice for early gastric cancer (EGC) without risk of lymph node metastasis, synchronous gastric epithelial neoplasia is no longer rare in the clinical practice. Knowledge about the characteristics associated with synchronous gastric epithelial neoplasia is of great importance to prevent delayed diagnosis.Between November 2008 and December 2014, a retrospective study was conducted in a single tertiary referral hospital. Consecutive patients who underwent ESD due to EGC or high-grade dysplasia were analyzed to evaluate the incidence of synchronous gastric epithelial neoplasia and the factors associated with synchronous and overlooked synchronous lesions.A total of 488 patients were analyzed in this study. Synchronous lesions were found in 59 patients (12.1%) during the mean 37.7 months of follow-up. Among 77 synchronous lesions, 25 lesions (32.4%) were overlooked at the time of initial ESD. Age of ≥ 65 years, moderate to severe endoscopic atrophic gastritis, and elevated morphology of primary lesions were associated with synchronous gastric epithelial neoplasia. An important factor associated with overlooked lesions is the non-elevated morphology of lesions.Careful endoscopic examination of the whole stomach is necessary in patients who are older and who have moderate to severe atrophic gastritis and elevated morphology of lesions to prevent delayed diagnosis of synchronous gastric epithelial neoplasia, especially non-elevated lesions.

Recent updates in perioperative chemotherapy and recurrence pattern of gastric cancer

Gastrectomy with D2 lymph node dissection has become the global standard procedure for locally advanced gastric cancer to maximally reduce locoregional recurrence. In East Asia, based on the evidence of the ACTS‐GC and the CLASSIC trials, postadjuvant chemotherapy with S‐1 monotherapy or capecitabine and oxaliplatin after curative D2 gastrectomy is the current standard strategy. However, approximately 20% to 30% of patients still develop distant recurrence even after these postadjuvant chemotherapies, especially in those with pathological stage III disease. This review summarizes recent (2008‐2018) evidence on the benefits of adjuvant therapy for locally advanced gastric cancer. JACRO GC‐07, a Phase III trial, recently showed a superior 3‐year recurrence‐free survival of the S‐1 plus docetaxel regimen in comparison to S‐1 monotherapy for patients with pathological stage III gastric cancer after curative D2 gastrectomy. With regard to recent new evidence on neoadjuvant strategy, JCOG0501, a Phase III trial, did not show any superiority in 3‐year overall survival (OS) of additional neoadjuvant chemotherapy with S‐1/cisplatin over postadjuvant S‐1 monotherapy in scirrhous type gastric cancer. Further clinical trials of neoadjuvant chemotherapy are ongoing to improve the poor prognosis for gastric cancer with extensive lymph node metastases. These trials could lead to new evidence for improved treatment of gastric cancer in the near future.

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.

Prognostic differences in 8th edition TNM staging of esophagogastric adenocarcinoma after neoadjuvant treatment

BACKGROUND

Prognostic differences between pTN- and ypTN-categories and the prognostic accuracy of the 8th edition UICC-pTNM- and AJCC-ypTNM-staging-system for esophageal and gastric adenocarcinoma are unclear.

METHODS

We retrospectively analyzed data of 740 patients with esophagogastric adenocarcinoma, who underwent curative surgery (344 after neoadjuvant treatment [NT]) at our institution. Survival analyses were performed according to Kaplan-Meier (log-rank test). Multivariate analyses were performed using the Cox proportional hazard model.

RESULTS

Low ypT-categories did not discriminate overall survival (ypT0: reference; ypT1: HR1.0/p = 0.909; ypT2: HR0.9/p = 0.845; ypT3: HR1.5/p = 0.184; ypT4: HR2.8/p = 0.004) and no difference was found between ypN1- and ypN2-disease (ypN0: HR0.4/p < 0.001; ypN1: reference; ypN2: HR1.1/p = 0.653; ypN3: HR1.7/p = 0.014). In esophageal adenocarcinoma the UICC-TNM- and AJCC-ypTNM-staging-system was able to predict survival for patients after NT, while in gastric cancer it failed to provide sufficient prognostic information. A simplified staging system provided better stratification after NT and was an independent prognosticator for both esophageal and gastric adenocarcinoma (stage I: reference; stage II: HR2.2/p = 0.005; stage III: HR4.1/p < 0.001).

CONCLUSION

Prognostic value of ypTN-categories seems limited. After NT the current UICC/AJCC-staging-system is able to predict survival in esophageal adenocarcinoma, but needs to be reevaluated in gastric cancer patients and modified if needed. A novel simplified staging system might be more practicable for patients after NT.

Double Tract vs. Roux-en-Y Reconstruction in the treatment of Gastric Cancer

Objective

Functional outcomes were prospectively compared between the standard Roux-en-Y and Double-tract reconstruction following a total gastrectomy and D2 lymphadenectomy.

Methods

One hundred ten patients with gastric cancer were divided into two groups by the type of reconstruction. Age, gender, T stage, AJCC stage, length of operation, BMI (body mass index, kg/m2), time to soft diet, postoperative leakage of the esophagojejunostomy (EJS), stricture of the EJS, meal intake, and quality of life (QOL) were recorded.

Results

The mean age in the R-Y group was 61.57, with the SD of 9.53, while in the DT group the mean age was 60.17 with a SD of 9.92. The BMI decline in the R-Y group was 4.09 with a SD of 1.11, while in the DT group it was 2.85 with a SD of 1.27. We found a highly significant statistical difference between the two groups in the rate of the BMI decline (p<0,001). We found no statistically significant difference regarding QOL between the two groups, p>0.05.

Conclusions

The Double tract reconstruction is a simple procedure and the rate of the BMI decline is much smaller compared to the Roux-en-Y group.

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.

Gastric cancer: epidemiology, prevention, classification, and treatment

Gastric cancer is the second most common cause of cancer-related deaths in the world, the epidemiology of which has changed within last decades. A trend of steady decline in gastric cancer incidence rates is the effect of the increased standards of hygiene, conscious nutrition, and Helicobacter pylori eradication, which together constitute primary prevention. Avoidance of gastric cancer remains a priority. However, patients with higher risk should be screened for early detection and chemoprevention. Surgical resection enhanced by standardized lymphadenectomy remains the gold standard in gastric cancer therapy. This review briefly summarizes the most important aspects of gastric cancers, which include epidemiology, risk factors, classification, diagnosis, prevention, and treatment. The paper is mostly addressed to physicians who are interested in updating the state of art concerning gastric carcinoma from easily accessible and credible source.

Prognostic predictability of the new American Joint Committee on Cancer 8th staging system for distal bile duct cancer: limited usefulness compared with the 7th staging system

BACKGROUND

The new 8th American Joint Committee on Cancer (AJCC) staging has recently been released and there are major changes in distal bile duct (DBD) cancer staging. However, clinical validation is needed before the changes can be widely implemented.

METHODS

This study was performed to evaluate the prognostic predictability of the 8th AJCC staging compared with that of the 7th using C statistics.

RESULTS

A total of 293 consecutive patients who had curative-intended surgery were enrolled. There was no significant difference of the 5-year survival rate between 7th T1 and T2 (P = 0.123), but significant difference between T2 and T3 (P = 0.039). There were significant differences in pairwise comparisons between the 8th T stage (T1 vs. T2, P = 0.001; T2 vs. T3, P = 0.014). The number of regional lymph node metastases also showed prognostic predictability. The 8th T and N stage both showed comparable prognostic predictability with the 7th (95% confidential intervals for C; T, -0.043 -0.097, N, -0.001 - 0.008).

CONCLUSIONS

The 8th AJCC staging for DBD cancer does not have better prognostic predictability than the 7th stage does. The previous pathologic results would become useless unless they were reviewed entirely. Therefore, introduction of the AJCC 8th staging has to be reconsidered, especially for new T staging.

Positive prognostic value of HER2-HER3 co-expression and p-mTOR in gastric cancer patients

Background

The HER2-HER3 heterodimer significantly decreases survival in breast cancer patients. However, the prognostic value of HER2-HER3 overexpression remains unknown in gastric cancer (GC).

Methods

The expression levels of HER2, HER3, Akt, p-Akt, mTOR and p-mTOR were examined in specimens from 120 GC patients by immunohistochemistry and quantitative reverse transcription-PCR. The associations of HER proteins, PI3K/Akt/mTOR pathway-related proteins, clinicopathological features of GC, and overall survival (OS) were assessed. To comprehensively evaluate the prognostic values of pathway-related proteins, meta-analyses were conducted with STATA 11.0.

Results

HER2 overexpression was significantly associated with HER3 levels (P = 0.02). HER3 was highly expressed in gastric cancer tissues. High HER2 and HER3 levels were associated with elevated p-Akt and p-mTOR amounts (P < 0.05). Furthermore, HER2-HER3 co-expression was associated with high p-Akt and p-mTOR (P < 0.05) levels. Meanwhile, p-mTOR overexpression was tightly associated with differentiation, depth of invasion, lymph node metastasis, TNM stage and OS (P < 0.05). By meta-analyses, Akt, p-Akt, and mTOR levels were unrelated to clinicopathological characters. HER3 overexpression was associated with depth of invasion (OR = 2.39, 95%CI 1.62–3.54, P < 0.001) and lymph node metastasis (OR = 2.35, 95%CI 1.34–4.11, P = 0.003). Further, p-mTOR overexpression was associated with patient age, tumor location, depth of invasion (OR = 1.63, 95%CI 1.08–2.45, P = 0.02) and TNM stage (OR = 1.73, 95%CI 1.29–2.32, P < 0.001). In addition, HER2-HER3 overexpression corresponded to gradually shortened 5-year OS (P < 0.05), and significant relationships were shown among HER3, p-mTOR overexpression, and 1-, 3-, 5-year OS (P < 0.05).

Conclusions

HER2-HER3 co-expression may potentially enhance mTOR phosphorylation. HER2-HER3 co-expression and p-mTOR are both related to the prognosis of GC patients.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3851-y) contains supplementary material, which is available to authorized users.

Comparative study of the 7th and 8th AJCC editions for gastric cancer patients after curative surgery

Objectives

The classification of pathological tumor-node-metastasis (pTNM) staging of gastric cancer was revised in the 8^th American Joint Committee on Cancer (AJCC) edition. The major revision was the separation of pN3a and pN3b in the pTNM staging. The current study evaluated the prognostic impact of this change.

Methods

A total of 1,517 patients who underwent curative surgery for gastric cancer with a retrieved lymph node number ≥15 at our institution from January 1995 to December 2011 were enrolled. Survival was compared for the disease classified according to both the 7^th and 8^th editions.

Results

After separation of pN3a and pN3b in the pTNM stage definition, the 8^th edition still provides significant survival differences between each stage. The multivariate analysis demonstrated that the pTNM stage in both the 7^th and 8^th editions was an independent prognostic factors of overall survival and disease-free survival. The 8^th edition has a better homogeneity than the 7^th edition with a significantly higher likelihood ratio chi-square test. Regarding the OS and DFS, the time-dependent receiver operating characteristic (ROC) curves of the two staging systems are almost overlapping, indicating that the prognostic performance is comparable between the two staging systems.

Conclusions

Both the 7^th and 8^th edition-based stages are independent prognostic factors for gastric cancer. The 8^th edition has a better homogeneity than the 7^th edition; the 8^th edition provides discriminant survival differences among each pTNM stage that are comparable to those in the 7^th edition.

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.

Validation of the American Joint Commission on Cancer (8th edition) changes for patients with stage III gastric cancer: survival analysis of a large series from a Specialized Eastern Center

The 8th edition of the TNM was released in 2016 and included major revisions, especially for stage III. We aimed to compare the prognostic value of the 7th and 8th editions of the AJCC TNM classification for stage III gastric cancer. Clinical data from 1557 patients operated on for stage III gastric cancer according to the 7th edition between 2007 and 2014 were analyzed and compared using the 7th and 8th TNM classifications. A proposed staging system was established, and the three systems were compared in terms of prognostic performance. The stage shifted for 669 (42.96%) patients. It shifted from IIIA to IIIB (one patient, 0.06%), IIIB to IIIA (230 patients, 14.8%), IIIB to IIIC (94 patients, 6.0%), and IIIC to IIIB (344 patients, 22.1%). However, the new AJCC subgroupings did not prove distinctive for survival levels between T3N3aM0 (stage IIIB) and T3N3bM0 (stage IIIC) or between T4aN3aM0 (stage IIIB) and T4aN3bM0 (stage IIIC) when <30 lymph nodes (LNs) were resected. The performance of the 8th edition (c-index, 0.614; 95% confidence interval [CI], 0.596-0.633) revealed no relevant improvement compared to the 7th edition (c-index, 0.624; 95% CI, 0.605-0.643). The proposed staging system generated the best prognostic stratification. The 8th TNM edition may not provide better accuracy in predicting the prognosis of stage III gastric cancer. The proposed staging system, comprised of a combination of the number of LNs harvested and the 7th and 8th AJCC classifications, may improve predictive capacities for stage III gastric cancer.

Validation of the 8th Edition of the AJCC TNM Staging System for Gastric Cancer using the National Cancer Database

BACKGROUND

The 8th edition AJCC gastric cancer staging manual was refined using Japanese and Korean data from the International Gastric Cancer Association (IGCA). This study evaluated the eighth edition's validity for U.S.

POPULATIONS

METHODS

National Cancer Database (NCDB) was used to obtain data on gastric cancer patients diagnosed from 2004 to 2008 who underwent surgery and to examine differences in stage grouping and survival between AJCC 7th and 8th editions. Discrimination of models derived from NCDB and IGCA data was compared.

RESULTS

Of 12,041 patients, median age was 65, 57.6% were male, median lymph nodes retrieved was 2 (0-76), 30.9% underwent distal/partial gastrectomy, and 49.8% received no adjuvant treatment. The 8th edition differed in that T1-T3 disease was upstaged with N3b, T4aN3a was downstaged from IIIC to IIIB, and T4bN0 and T4aN2 were downstaged from IIIB to IIIA. These changes resulted in increased patients in IIIA (1436 in the 7th edition to 2310 in the 8th) and IIIB (1737-1896) and decreased in IIIC (2100-1067). This also resulted in lower median survival for IIIA (28.7-25.0 months), IIIB (19.6-17.4), IIIC (13.7-11.8). The concordance index for the 8th edition applied to NCDB data was 0.719 [95% confidence interval (CI) 0.703-0.734), which is comparable to that for the 8th edition developed from IGCA data (0.775, 95% CI 0.770-0.780) and the 7th edition applied to NCDB data (0.720, 95% CI 0.704-0.735).

CONCLUSIONS

The 8th edition is valid for U.S. populations, showing clear separation of data with preservation of group order.

Recurrence Pattern and Lymph Node Metastasis of Adenocarcinoma at the Esophagogastric Junction

BACKGROUND

The surgical approach for adenocarcinoma of the esophagogastric junction (AEJ) still is controversial despite revised tumor-node-metastasis (TNM) classification. This study aimed to evaluate the oncologic outcome of a routine transhiatal approach for AEJ in terms of recurrence and lymph node (LN) metastasis of AEJ.

METHODS

Recurrence patterns and LN metastasis of a single, primary AEJ (n = 463) treated by a surgical resection using a transhiatal approach without routine complete mediastinal LN dissection or routine splenectomy were analyzed respectively. To validate current treatment for recurrence, a validation index of recurrence (ViR; overall survival/incidence of solitary recurrence factor) was developed.

RESULTS

The overall recurrence rate for AEJ was 20.3%, which did not differ significantly between AEJ II (20.8%; n = 125) and AEJ III (20.1%; n = 338). Mediastinal recurrence did not differ significantly among the subtypes of AEJ, irrespective of gastroesophageal junction involvement. Splenic hilar LN recurrence-free survival did not differ significantly between the gastrectomy-only group, the gastrectomy-plus-splenectomy group, and the gastrectomy plus distal pancreatectomy group. The solitary recurrence rate for the mediastinal LN was 0.7% for AEJ, and the overall median survival with that recurrence was 30.5 months. The ViR for mediastinal LN recurrence (43.6) was higher than for regional LN (20.9) or distant LN (14.6) metastasis.

CONCLUSION

In terms of LN metastasis and recurrence, a transhiatal approach without complete mediastinal LN dissection can be acceptable, and routine splenectomy is not necessary for AEJ II or AEJ III arising within the stomach.

Consideration of clinicopathologic features improves patient stratification for multimodal treatment of gastric cancer

Preoperative staging of gastric cancer with computed tomography alone exhibits poor diagnostic accuracy, which may lead to improper treatment decisions. We developed novel patient stratification criteria to select appropriate treatments for gastric cancer patients based on preoperative staging and clinicopathologic features. A total of 5352 consecutive patients who underwent gastrectomy for gastric cancer were evaluated. Preoperative stages were determined according to depth of invasion and nodal involvement on computed tomography. Logistic regression analysis was used to identify clinicopathological factors associated with the likelihood of proper patient stratification. The diagnostic accuracies of computed tomography scans for depth of invasion and nodal involvement were 67.1% and 74.1%, respectively. Among clinicopathologic factors, differentiated tumor histology, tumors smaller than 5 cm, and gross appearance of early gastric cancer on endoscopy were shown to be related to a more advanced stage of disease on preoperative computed tomography imaging than actual pathological stage. Additional consideration of undifferentiated histology, tumors larger than 5 cm, and grossly advanced gastric cancer on endoscopy increased the probability of selecting appropriate treatment from 75.5% to 94.4%. The addition of histology, tumor size, and endoscopic findings to preoperative staging improves patient stratification for more appropriate treatment of gastric cancer.

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.

Validation of two prognostic models for recurrence and survival after radical gastrectomy for gastric cancer

BACKGROUND

Prognostic models from Korea and Italy have been developed that predict overall survival and cancer recurrence respectively after radical gastrectomy for gastric cancer. The aim of this study was to validate the two models in independent patient cohorts, and to evaluate which factors may explain differences in prognosis between Korean and Italian patients with gastric cancer.

METHODS

Patients who underwent radical gastrectomy for gastric cancer between January 2000 and December 2004 at Seoul National University Hospital and at eight centres in Italy were included. Discrimination of the models was tested with receiver operating characteristic (ROC) curves and calculation of area under the curve (AUC). Calibration was evaluated by plotting actual survival probability against predicted survival probability for the Korean nomogram, and actual against predicted risk of recurrence for the Italian score.

RESULTS

Some 2867 and 940 patients from Korea and Italy respectively were included. The Korean nomogram achieved good discrimination in the Italian cohort (AUC 0·80, 95 per cent c.i. 0·77 to 0·83), and the Italian model performed well in the Korean cohort (AUC 0·87, 0·85 to 0·89). The Korean nomogram also achieved good calibration, but this was not seen for the Italian model. Multivariable analyses confirmed that Italian ethnicity was an independent risk factor for cancer recurrence (odds ratio (OR) 1·72, 1·31 to 2·25; P < 0·001), but not for overall survival (OR 1·20, 0·95 to 1·53; P = 0·130).

CONCLUSION

Both prognostic models performed fairly well in independent patient cohorts. Differences in recurrence rates of gastric cancer may be partially explained by ethnicity.