Predictive Factors for Lymph Node Metastasis in Undifferentiated Early Gastric Cancer: a Systematic Review and Meta-analysis

Identification of maximal tumor size associated with negligible lymph node metastasis for endoscopic submucosal dissection of undifferentiated-type early gastric cancer

BACKGROUND AND AIMS

When treating undifferentiated-type early gastric cancer (UD-EGC) that is limited to the mucosa (clinically T1a), endoscopic submucosal dissection (ESD) can be considered if the tumor is 2 cm or less and is not ulcerated. However, there is insufficient evidence to determine the relationships between tumor size and oncological safety of ESD in UD-EGC.

METHODS

The pathology reports of Korean patients who were diagnosed with UD-EGC (n = 5286) were retrospectively reviewed. The cumulative incidence of lymph node metastasis (LNM) according to tumor size was evaluated in subgroups. The tumor-size cut-off was identified as the upper limit of the 95% confidence interval (CI) of cumulative LNM incidence that did not exceed 1.0%.

RESULTS

We identified 1516 patients with non-ulcerated T1a tumors ≤2 cm in size. Among patients without lymphatic invasion, 1.5% (95% CI 0.91-2.16%) had LNM. In patients with poorly differentiated tubular adenocarcinoma (PD), LNM increased from 0 to 0.74% based on a tumor size of 1.0 cm. Regardless of tumor size, smaller percentages of undifferentiated-type (UD) and poorly cohesive carcinoma (PCC) patients experienced LNM than did those with PD. In non-ulcerated mucosal cancer without lymphatic invasion and tumor size ≤0.9 cm, no LNM was observed in patients with UD (95% CI 0-0.53%), PCC (95% CI 0-0.59%), or PD (95% CI 0-0.86%) histologic type.

CONCLUSION

In patients diagnosed with non-ulcerated T1a UD-EGC, ESD can be performed if the tumor size is 0.9 cm or less, regardless of histologic type.

Clinicopathologic factors correlated with lymph node metastasis in gastric cancer: a retrospective cohort study involving 5606 patients

BACKGROUND

The identification of risk factors associated with lymph node metastasis (LNM) in gastric cancer will establish a crucial foundation for the implementation of endoscopic operation and multidisciplinary treatment programs.

METHODS

A total of 5606 patients with gastric cancer with comprehensive clinicopathologic data were enrolled through systematic searching and rigorous screening. Of the 5606 patients, 1438 were diagnosed with early gastric cancer (EGC), which would be used for further analysis. Subsequently, univariate and multivariate logistic regression analyses were performed to identify the risk factors.

RESULTS

The rates of LNM in T1a, T1b, T2, T3, T4a, and T4b stage gastric cancer were 7.0%, 19.4%, 48.4%, 77.1%, 83.8%, and 89.6%, respectively. Female (odds ratio [OR], 1.559; P = .032), lower tumor location (OR, 1.773; P = .023), tumor size of >2 cm (OR, 2.007; P < .001), mixed (OR, 2.371; P = .001) and undifferentiated histologic types (OR, 2.952; P < .001), T1b stage (OR, 2.041; P < .001), presence of ulceration (OR, 1.758; P = .027), and lymphovascular invasion (OR, 5.722; P < .001) were identified as independent risk factors for LNM in EGC. A nomogram was constructed using appropriate predictors to preoperatively predict the risk of LNM in patients with EGC.

CONCLUSION

This study identified the clinicopathologic factors associated with LNM in patients with EGC and developed a prediction model, thereby facilitating the integration of diverse treatment modalities in managing patients with EGC.

Value of quantitative microsurface structure analysis for evaluating the invasion depth of type 0-II early gastric cancer

Background and Aim

The microsurface structure reflects the degree of damage to the glands, which is related to the invasion depth of early gastric cancer. To evaluate the diagnostic value of quantitative microsurface structure analysis for estimating the invasion depth of early gastric cancer.

Methods

White-light imaging and narrow-band imaging (NBI) endoscopy were used to visualize the lesions of the included patients. The area ratio and depth-predicting score (DPS) of each patient were calculated; meanwhile, each lesion was examined by endoscopic ultrasonography (EUS).

Results

Ninety-three patients were included between 2016 and 2019. Microsurface structure is related to the histological differentiation and progression of early gastric cancer. The receiver operating characteristic curve showed that when an area ratio of 80.3% was used as a cut-off value for distinguishing mucosal (M) and submucosal (SM) type 0-II gastric cancers, the sensitivity, specificity, and accuracy were 82.9%, 80.2%, and 91.6%, respectively. The accuracies for distinguishing M/SM differentiated and undifferentiated early gastric cancers were 87.4% and 84.8%, respectively. The accuracy of EUS for distinguishing M/SM early gastric cancer was 74.9%. DPS can only distinguish M-SM1 (SM infiltration <500 μm)/SM (SM infiltration ≥500 μm) with an accuracy of 83.8%. The accuracy of using area ratio for distinguishing 0-II early gastric cancers was better than those of using DPS and EUS (P < 0.05).

Conclusion

Quantitative analysis of microsurface structure can be performed to assess M/SM type 0-II gastric cancer and is expected to be effective for judging the invasion depth of gastric cancer.

[Fluorescence lymphoscopy with sentinel lymph node biopsy in research of lymphatic flow in early gastric cancer]

OBJECTIVE

To analyze the incidence and risk factors of regional lymph node metastatic lesions, as well as patterns of lymphatic drainage in early gastric cancer using indocyanine green (ICG).

MATERIAL AND METHODS

A prospective single-center non-randomized study included 67 patients with early gastric cancer between 2016 and 2019. All patients underwent endoscopic dissection or surgical resection with sentinel lymph node biopsy.

RESULTS

Regional lymph node metastatic lesions were detected in 12 (20.2%) out of 59 patients with examined lymph nodes. Of these, 11 out of 12 patients had sentinel lymph node lesion, and only 1 patient had metastasis outside this lymph node. The proposed technique for sentinel lymph node biopsy demonstrated high sensitivity, specificity and accuracy (93.2%, 100% and 98.3%, respectively). Risk factors for metastasis of early gastric cancer to regional lymph nodes were high grade adenocarcinoma (p=0.038) and tumor of anterior gastric wall (p=0.013). All patients with tumors of the upper third of the stomach had sentinel lymph node in the left gastric artery basin. Lymph flow was multidirectional in patients with tumors of the middle third of the stomach. In tumors of the lower third of the stomach, sentinel lymph node was located in the right gastroepiploic artery (50%) and left gastric artery basins (36.84%) (p=0.002). Sentinel lymph node was located in the left gastric artery basin in 84% of patients with tumors of the lesser curvature (p<0.001). Lymphatic drainage was multidirectional if tumors were localized on anterior and posterior walls, as well as on the greater curvature.

CONCLUSION

The proposed technique for sentinel lymph node biopsy demonstrated high sensitivity, specificity and accuracy (93.2%, 100% and 98.3%, respectively). ICG is valuable to identify the first lymph node in lymphatic drainage pathway in 83.6% of cases that makes it possible to assess the regional lymphatic collector. In addition, sentinel lymph node biopsy with ICG contributes to analysis of lymphatic drainage in early gastric cancer. The last one has both scientific and practical significance.

Worse Survival of Patients With T1 Stage II Gastric Cancer Following Radical Gastrectomy

PURPOSE

Lymph node (LN) metastasis is a crucial factor in the prognosis of patients with gastric cancer (GC) and is known to occur more frequently in cases with an advanced T stage. This study aimed to analyze the survival data of patients with advanced LN metastasis in T1 GC.

MATERIALS AND METHODS

From January 2008 to June 2018, 677 patients with pathological stage II GC who underwent radical gastrectomy were divided into an early GC group (EG: T1N2 and T1N3a, n=103) and an advanced GC (AGC) group (AG: T2N1, T2N2, T3N0, T3N1, and T4aN0, n=574). Short- and long-term survival rates were compared between the 2 groups.

RESULTS

A total of 80.6% (n=83) of the patients in the EG group and 52.8% (n=303) in the AG group had stage IIA AGC. The extent of LN dissection, number of retrieved LNs, and short-term morbidity and mortality rates did not differ between the 2 groups. The 5-year relapse-free survival (RFS) of all patients was 87.8% and the overall survival was 84.0%. RFS was lower in the EG group than in the AG group (82.2% vs. 88.7%, P=0.047). This difference was more pronounced among patients with stage IIA (82.4% vs. 92.9%, P=0.003).

CONCLUSIONS

T1 GC with multiple LN metastases seems to have a worse prognosis compared to tumors with higher T-stages at the same level. Adjuvant chemotherapy is highly recommended for these patients, and future staging systems may require upstaging T1N2-stage tumors.

A nomogram for predicting lymph node metastasis in early gastric signet ring cell carcinoma

At present, the risk factors for lymph node metastasis in early gastric signet ring cell carcinoma (SRCC) remain unclear. However, it is worth noting that the LNM rate and prognosis of early gastric SRCC are superior to those of other undifferentiated cancers. With advancements in endoscopic technology, the 5-year survival rate following endoscopic treatment of early gastric cancer is comparable to traditional surgery while offering a better quality of life. The objective of this study was to develop a nomogram that can predict lymph node status in early gastric SRCC before surgery, aiding clinicians in selecting the optimal treatment strategy. A research cohort was established by retrospectively collecting data from 183 patients with early gastric SRCC who underwent radical gastrectomy with lymph node dissection at our hospital between January 2014 and June 2022. The predictors of early gastric signet ring cell carcinoma lymph node metastasis were identified in the study cohort using the least absolute selection and shrinkage operator (Lasso) and multivariate regression analysis, and a nomogram was developed. The discrimination, accuracy, and clinical practicability of the nomogram were assessed using receiver operating characteristic (ROC) curve analysis, calibration curve analysis, and decision curve analysis. The incidence of lymph node metastasis was 21.9% (40/183) overall. Multivariate logistic regression analysis revealed that tumor size and lymphovascular invasion (LVI) were independent risk factors for lymph node metastasis. Lasso regression analysis demonstrated that tumor size, invasion depth, LVI, E-cadherin expression, dMMR, CA242, NLR, and macroscopic type were associated with lymph node metastasis. The integrated discrimination improvement (IDI) (P = 0.034) and net reclassification index (NRI) (P = 0.023) were significantly improved when dMMR was added to model 1. In addition, the area under curve (AUC) (P = 0.010), IDI (P = 0.001) and NRI (P < 0.001) of the model were significantly improved when type_1 was included. Therefore, we finally included tumor size, invasion depth, dMMR, and macroscopic type to establish a nomogram, which had good discrimination (AUC = 0.757, 95% CI 0.687-0.828) and calibration. Decision curve analysis showed that the nomogram had good clinical performance. We have developed a risk prediction model for early gastric signet ring cell carcinoma that accurately predicts lymph node involvement, providing clinicians with a valuable tool to aid in patient counseling and treatment decision-making.

Performance of endoscopic submucosal dissection for undifferentiated early gastric cancer: a multicenter retrospective cohort

Background and study aims Undifferentiated early gastric cancer (UD-EGC) represents an extended indication for endoscopic submucosal dissection (ESD) based on the existing guidelines. This study evaluated the prevalence of UD-EGC recurrence after ESD, and potentially implicated risk factors. Patients and methods Data from 17 centers were collected retrospectively including demographics, endoscopic and pathological findings, and follow-up data from UD-EGC cases treated by ESD. Patients with incomplete resection or advanced disease were excluded. Descriptive statistics quantified variables and calculated the incidence of recurrence. Chi-square test was applied to assess any link between independent variables and relapse; significantly associated variables were inserted to a multivariable regression model. Results Seventy-one patients were eligible, with 2:1 female to male ratio and age of 65.8 ± 11.8 years. Mean lesion size was 33.5 ± 18.8 mm and the most frequent histological subtype was signet ring-cells UGC (2:1). Patients were followed-up every 5.6 ± 3.7 months with a mean surveillance period of 29.3 ± 15.3 months until data collection. Four patients (5.6%) developed local recurrence 8.8 ± 6.5 months post-ESD, with no lymph node or distal metastases been reported. Lesion size was not associated with recurrence ( P = 0.32), in contrast to lymphovascular and perineural invasion which were independently associated with local recurrence ( P = 0.006 and P < 0.001, respectively). Conclusions ESD could be considered as the initial step to manage UD-EGC, providing at least an "entire-lesion" biopsy to guide therapeutic strategy. When histology confirms absence of lymphovascular and perineural invasion, this modality could be therapeutic, providing low recurrence rates.

Analysis of risk factors for lymph node metastasis and prognosis study in patients with early gastric cancer: A SEER data-based study

Background

Lymph node status is an important factor in determining the prognosis of patients with early gastric cancer (EGC) and preoperative diagnosis of lymph node metastasis (LNM) has some limitations. This study explored the risk factors and independent prognostic factors of LNM in EGC patients and constructed a clinical prediction model to predict LNM.

Methods

Clinicopathological data of EGC patients was collected from the public Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate logistic regression was used to identify risk factors for LNM in EGC patients. The performance of the LNM model was evaluated by C-index, calibration curve, receiver operating characteristic (ROC) curve, decision curve analysis (DCA) curve, and clinical impact curve (CIC) based on the results of multivariate regression to develop a nomogram. An independent data set was obtained from China for external validation. The Kaplan-Meier method and Cox regression model were used to identify potential prognostic factors for overall survival (OS) in EGC patients.

Results

A total of 3993 EGC patients were randomly allocated to a training cohort (n=2797) and a validation cohort (n=1196). An external cohort of 106 patients from the Second Hospital of Lanzhou University was used for external validation. Univariate and multivariate logistic regression showed that age, tumor size, differentiation, and examined lymph nodes count (ELNC) were independent risk factors for LNM. Nomogram for predicting LNM in EGC patients was developed and validated. The predictive model had a good discriminatory performance with a concordance index (C-index) of 0.702 (95% CI: 0.679-0.725). The calibration plots showed that the predicted LNM probabilities were the same as the actual observations in both the internal validation cohort and external validation cohort. The AUC values for the training cohort, internal validation cohort and external validation cohort were 0.702 (95% CI: 0.679-0.725), 0.709 (95% CI: 0.674-0.744) and 0.750(95% CI: 0.607-0.892), respectively, and the DCA curves and CIC showed good clinical applicability. The Cox regression model identified age, sex, race, primary site, size, pathological type, LNM, distant metastasis, and ELNC were prognostic factors for OS in EGC patients, while a year at diagnosis, grade, marital status, radiotherapy, and chemotherapy were not independent prognostic factors.

Conclusion

In this study, we identified risk factors and independent prognostic factors for the development of LNM in EGC patients, and developed a relatively accurate model to predict the development of LNM in EGC patients.

Machine learning-based gray-level co-occurrence matrix signature for predicting lymph node metastasis in undifferentiated-type early gastric cancer

BACKGROUND

The most important consideration in determining treatment strategies for undifferentiated early gastric cancer (UEGC) is the risk of lymph node metastasis (LNM). Therefore, identifying a potential biomarker that predicts LNM is quite useful in determining treatment.

AIM

To develop a machine learning (ML)-based integral procedure to construct the LNM gray-level co-occurrence matrix (GLCM) prediction model.

METHODS

We retrospectively selected 526 cases of UEGC confirmed through pathological examination after radical gastrectomy without endoscopic treatment in four tertiary hospitals between January 2015 to December 2021. We extracted GLCM-based features from grayscale images and applied ML to the classification of candidate predictive variables. The robustness and clinical utility of each model were evaluated based on the following factors: Receiver operating characteristic curve (ROC), decision curve analysis, and clinical impact curve.

RESULTS

GLCM-based feature extraction significantly correlated with LNM. The top 7 GLCM-based factors included inertia value 0° (IV_0), inertia value 45° (IV_45), inverse gap 0° (IG_0), inverse gap 45° (IG_45), inverse gap full angle (IG_all), Haralick 30° (Haralick_30), Haralick full angle (Haralick_all), and Entropy. The areas under the ROC curve (AUCs) of the random forest classifier (RFC) model, support vector machine, eXtreme gradient boosting, artificial neural network, and decision tree ranged from 0.805 [95% confidence interval (CI): 0.258-1.352] to 0.925 (95%CI: 0.378-1.472) in the training set and from 0.794 (95%CI: 0.237-1.351) to 0.912 (95%CI: 0.355-1.469) in the testing set, respectively. The RFC (training set: AUC: 0.925, 95%CI: 0.378-1.472; testing set: AUC: 0.912, 95%CI: 0.355-1.469) model that incorporates Entropy, Haralick_all, Haralick_30, IG_all, IG_45, IG_0, and IV_45 had the highest predictive accuracy.

CONCLUSION

The evaluation results indicate that the method of selecting radiological and textural features becomes more effective in the LNM discrimination against UEGC patients. Additionally, the ML-based prediction model developed using the RFC can be used to derive treatment options and identify LNM, which can hence improve clinical outcomes.

Early gastric cancer: A challenge in Western countries

Early gastric cancer (EGC) is an invasive carcinoma involving only the stomach mucosa or submucosa, independently of lymph node status. EGC represents over 50% of cases in Japan and in South Korea, whereas it accounts only for approximately 20% of all newly diagnosed gastric cancers in Western countries. The main classification systems of EGC are the Vienna histopathologic classification and the Paris endoscopic classification of polypoid and non-polypoid lesions. A careful endoscopic assessment is fundamental to establish the best treatment of EGC. Generally, EGCs are curable if the lesion is completely removed by endoscopic resection or surgery. Some types of EGC can be resected endoscopically; for others the most appropriate treatment is surgical resection and D2 lymphadenectomy, especially in Western countries. The favorable oncological prognosis, the extended lymphadenectomy and the reconstruction of the intestinal continuity that excludes the duodenum make the prophylactic cholecystectomy mandatory to avoid the onset of biliary complications.

Comparison of long-term outcomes of endoscopic submucosal dissection and surgery for undifferentiated-type early gastric cancer meeting the expanded criteria: a systematic review and meta-analysis

BACKGROUND

There have been concerns over the long-term outcomes of endoscopic submucosal dissection (ESD) for undifferentiated-type early gastric cancer (UD EGC). We aimed to compare the long-term outcomes of ESD and surgery for patients with UD EGC.

METHODS

We searched PubMed, Embase, and Cochrane Library databases through March 2021 to identify studies that compared the long-term outcomes of ESD and surgery for UD EGC meeting expanded criteria for curative resection. The risk of bias was assessed with the Cochrane tool for non-randomized studies. The risk ratio (RR) was estimated using a fixed-effect model.

RESULTS

Overall, 1863 patients from five retrospective cohort studies, including 908 patients with propensity score matching (PSM), were eligible for meta-analysis. ESD was associated with inferior overall survival (OS) compared to surgery in the overall cohort (RR 2.11; 95% CI 1.26-3.55) but not in the PSM cohort (RR 1.18; 95% CI 0.60-2.32). In the PSM cohort, ESD had a lower disease-free survival (DFS) (RR 2.49; 95% CI 1.42-4.35) and higher recurrence (RR 12.61; 95% CI 3.43-46.37), gastric recurrence (RR 11.25; 95% CI 3.06-41.40), and extragastric recurrence (RR 4.23; 95% CI 0.47-37.93). Recurrence outcomes were similar between the overall and PSM cohorts. Disease-specific survival was not significantly different between the two groups in both the overall and PSM cohorts.

CONCLUSION

Although OS after curative ESD for UD EGC was not different from that after surgery in the PSM cohort, DFS and recurrence were inferior after ESD. Limitations included a lack of randomized trials. Further prospective studies comparing the long-term outcomes of ESD and surgery for UD EGC are needed (PROSPERO CRD 42021237097).

Risk Factors of Lymph Node Metastasis and Its Prognostic Significance in Early Gastric Cancer: A Multicenter Study

Background

Early gastric cancer (EGC) is invasive gastric cancer that invades no deeper than the submucosa, regardless of lymph node metastasis (LNM). It is mainly treated by surgery. Recently, the resection range of EGC has been minimized, but cancer recurrence and overall survival in some patients should be given high status. LNM is an important indicator of prognosis and treatment in gastric cancer. The law of the number and location of metastatic lymph nodes in EGC is not yet clear. Therefore, we aimed to identify the risk factors of LNM in radically resected EGC and guide treatment.

Methods

The clinicopathological factors of 611 patients with EGC were retrospectively analyzed in six hospitals between January 2010 and December 2016. The relationship between clinicopathological factors and LNM, as well as their prognostic significance, were analyzed by univariate and multivariate analyses.

Results

The rate of LNM was 20.0% in the 611 EGC patients. The depth of invasion, differentiation type, tumor diameter, morphological ulceration, and lymphovascular invasion were independent risk factors for LNM (P<0.05) by logistic regression analysis. Tumor location in the proximal third of the stomach and morphological ulceration were significant factors for group 2 LNM. Moreover, the 5-year survival rate was 94.9% for patients with no positive nodes, 88.5% for patients with 1-2 positive nodes, 64.3% for patients with 3-6 positive nodes, and 41.8% for patients with >6 metastatic nodes. Interestingly, the 7-year risk of relapse diminished for patients with no LNM or retrieved no less than 15 lymph nodes.

Conclusions

Fifteen lymph node dissection and D2 radical operation are the surgical options in case of high risk factors for LNM. Extended lymph node dissection (D2+) is recommended for morphological ulceration or disease located in the proximal third of the stomach due to their high rate of group 2 LNM. Furthermore, LNM is a significant prognostic factor of EGC. Moreover, lymph nodes can also play a significant role in the chemotherapeutic and radiotherapy approach for non-surgical patients with EGC.

Beyond the Guidelines: The Grey Zones of the Management of Gastric Cancer. Consensus Statements from the Gastric Cancer Italian Network (GAIN)

BACKGROUND

Management of gastric and gastroesophageal junction (GEJ) adenocarcinoma remains challenging, because of the heterogeneity in tumor biology within the upper gastrointestinal tract. Daily clinical practice is full of grey areas regarding the complexity of diagnostic, staging, and therapeutic procedures. The aim of this paper is to provide a guide for clinicians facing challenging situations in routine practice, taking a multidisciplinary consensus approach based on available literature.

METHODS

The GAIN (GAstric cancer Italian Network) group was established with the aims of reviewing literature evidence, discussing key issues in prevention, diagnosis, and management of gastric and GEJ adenocarcinoma, and offering a summary of statements. A Delphi consensus method was used to obtain opinions from the expert panel of specialists.

RESULTS

Forty-nine clinical questions were identified in six areas of interest: role of multidisciplinary team; risk factors; diagnosis; management of early gastric cancer and multimodal approach to localized gastric cancer; treatment of elderly patients with locally advanced resectable disease; and treatment of locally advanced and metastatic cancer.

CONCLUSIONS

The statements presented may guide clinicians in practical management of this disease.

Risk of Lymph Node Metastasis and Feasibility of Endoscopic Treatment in Ulcerative Early Gastric Cancer

BACKGROUND

When the risk of lymph node metastasis (LNM) is considered minimal in patients with early gastric cancer (EGC), endoscopic submucosal dissection (ESD) is an effective alternative to radical resection. This study aims to estimate the feasibility of ESD for EGC with ulceration.

PATIENTS AND METHODS

We retrospectively reviewed data from 691 patients who underwent gastrectomy for EGC with ulceration. Subsequently, a stratification system for lesions was created based on the expanded ESD criteria, and the associations between the subgroups and the rate of LNM were analyzed.

RESULTS

LNM was confirmed in 16.5% (114/691) of patients. Univariate analysis demonstrated that age, sex, tumor size, macroscopic features, depth of invasion, tumor differentiation, Lauren type, lymphovascular invasion (LVI), and perineural invasion were associated with LNM. Multivariate analysis showed that LVI [odds ratio (OR) = 16.761, P < 0.001], SM1 invasion (OR = 2.159, P = 0.028), and SM2 invasion (OR = 3.230, P < 0.001) were independent risk factors for LNM. LNM occurred in undifferentiated mucosal tumors, with ulceration being 1.7% (2/116) when the lesion was smaller than 20 mm. Further stratification revealed that among lesions < 30 mm in size, undifferentiated tumors with SM1 invasion had a higher rate of LNM and a lower disease-free survival rate than differentiated tumors with SM1 invasion and tumors limited to the mucosal layer.

CONCLUSIONS

Depth of invasion and LVI were strongly associated with LNM in ulcerative EGC. Endoscopic resection may be applicable for undifferentiated mucosal ulcerative EGC < 30 mm in size, and additional investigation is needed to evaluate its safety.

Prognostic factors in stage I gastric cancer: A retrospective analysis

Purpose

The purpose of this research is to investigate the prognostic factors of patients with stage I gastric cancer (GC) and to determine whether adjuvant chemotherapy improves the prognosis for high-risk patients.

Methods

We performed a retrospective analysis at Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, and HwaMei Hospital, University of Chinese Academy of Sciences from January 2001 to December 2015. Cox regression and Kaplan-Meier were used to evaluate the relationship between the patients’ clinicopathologic characteristics and prognosis.

Results

A total of 1,550 patients were eligible for the study. The 5-year disease-free survival (DFS) rate of all enrolled patients was 96.5%. The pT and pN stages were significantly associated with the prognosis. The 5-year DFS rates of the three subgroups (T1N0, T2N0, and T1N1) were 97.8%, 95.7%, and 90.5%, respectively (p < 0.001). In the T1N1 subgroup, patients not undergoing chemotherapy showed a lower 5-year DFS rate compared to those undergoing chemotherapy, although the difference was not statistically significant.

Conclusions

Both the pT and pN stages were closely associated with the prognosis of patients with stage I GC. We also found that the danger coefficient of the pN stage was higher than that of the pT stage, and that postoperative adjuvant chemotherapy might be a reasonable approach to improve outcomes of high-risk patients, particularly in the T1N1 group.

Multidisciplinary Approach in Improving Survival Outcome of Early-Stage Gastric Cancer

BACKGROUND

The necessity of extensive lymph node (LN) dissection/examination and adjuvant therapy for patients with early gastric cancer (EGC, Tis-T1, any N) remains controversial. We aim to refine treatment recommendations for patients with EGC through a reflective analysis for the survival gap between Eastern and Western countries.

METHODS

EGC patients diagnosed between 2004 and 2014 were identified from the National Cancer Database (NCDB) and a large medical center in China. Adequate LN yield was defined as ≥25 LNs examined.

RESULTS

In the US cohort, 14.4% of (1104/7641) patients with EGC had ≥25 LNs examined. The 5-y overall survival (OS) was significantly better than those with <25 LNs (78.9% versus 68.5%, P < 0.001). Examination of ≥25 LNs was an independent predictor of better OS after adjusting all known prognostic factors. Patients with ≥25 LNs examined had significantly higher chance of having LN-positive disease compared to patients with <25 LNs (14.9% versus 10.7%, P < 0.001). A similar stage migration phenomenon was observed in Chinese cohort (LN positive: 25.2% versus 18.4% in ≥25 LNs and <25 LNs examined group, respectively, P = 0.02). In the US cohort, adjuvant therapy was associated with a significant survival benefit for LN-positive patients (5-y OS: 71.0% versus 43.0% for with/without adjuvant therapy, respectively, P < 0.001) but not in LN-negative patients (5-y OS: 71.2% versus 71.5%, P = 0.90).

CONCLUSIONS

Adequate lymphadenectomy and LN examination are critical components of EGC management. Adjuvant therapy should be strongly encouraged for all EGC patients with LN-positive disease in the United States.

Risk factors of tumor invasion and node metastasis in early gastric cancer with undifferentiated component: a multicenter retrospective study on biopsy specimens and clinical data

Background

Early gastric cancer (EGC) with undifferentiated component (UDC) is a more aggressive entity, where the significance of preoperative data to tumor invasion and lymph node metastasis (LNM) remains unclarified.

Methods

A total of 5,020 GC patients undergoing radical gastrectomy in three centers were reviewed, of which, EGC with UDC in preoperative biopsy specimens were enrolled. The histology of biopsy and surgical specimens was graded according to the proportion of UDC and signet ring cells (SRCs). Risk factors of tumor invasion and LNM were evaluated with histological, clinical and demographic data.

Results

Lower body mass index (BMI), melena and larger tumor size were the independent preoperative risk factors of both LNM and LVI, while ulcerative lesion (UL) and the lower third stomach were only correlated with LNM. No relevance was found between the histological features of biopsy specimens and LNM, but SRC or >50% UDC lowered the risk of lymphovascular invasion (LVI) and/or submucosal (SM) invasion. When surgical data (depth of invasion and LVI included) were added, lower BMI, melena and the lower third stomach were still the independent preoperative risk factors of LNM, and LVI, SRC and SM invasion also showed relevance to LNM. The performance of predictive models using pre- or postoperative histological data was comparable.

Conclusions

The preoperative data were significantly relevant to tumor invasion and LNM, showing comparable risk strength with surgical specimens in histology.

Sex-specific differences in risk factors of lymph node metastasis in patients with early gastric cancer

Accurate prediction of lymph node status is of crucial importance in the appropriate treatment planning for patients with early gastric cancer (EGC). Some studies have examined factors predicting lymph node metastasis (LNM) in EGC; however, these studies did not consider sex-specific differences. This study aimed to investigate sex-specific differences in predictive risk factors of LNM in EGC based on surgical specimens. Patients who underwent surgical treatment for EGC between January 2003 and February 2016 were retrospectively evaluated. Patients who underwent previous gastric surgery or treatment for gastric neoplasms were excluded. Finally, 1076 patients treated for EGC were included in the analysis. We analyzed risk factors of LNM by dividing patients into male and female groups. Of 1076 patients (mean age 59.6 years), 69% were men. The overall LNM rate was 9.4%. The LNM rate was lower in men (7.8%) than in women (12.9%). Multivariate analysis showed that elevated type (odds ratio [OR], 2.084; 95% confidence interval [CI]: 1.053–4.125; P = 0.035), submucosal invasion (OR, 2.162; 95% CI: 1.018–4.595; P = 0.045), undifferentiated type (OR, 2.044; 95% CI: 1.107–3.772; P = 0.022), and lymphovascular invasion (LVI) (OR, 7.210; 95% CI: 3.835–13.554; P<0.001) were independent predictive risk factors of LNM in EGC in men. However, only submucosal invasion (OR, 8.772; 95% CI: 2.823–27.259; P<0.001) and LVI (OR, 8.877; 95% CI: 3.861–20.410; P<0.001) were independent predictive risk factors of LNM in EGC in women. Submucosal invasion and LVI were risk factors of LNM in both men and women. However, elevated and undifferentiated types were risk factors in men but not in women. Clinicians should consider these sex-specific differences with regard to individualized management.

Low Frequency of Lymph Node Metastases in Patients in the United States With Early-stage Gastric Cancers That Fulfill Japanese Endoscopic Resection Criteria

BACKGROUND & AIMS

In the West, early gastric cancer is increasingly managed with endoscopic resection (ER). This is, however, based on the assumption that the low prevalence and risk of lymph node metastases observed in Asian patients is applicable to patients in the United States. We sought to evaluate the frequency of and factors associated with metastasis of early gastric cancers to lymph nodes, and whether the Japanese ER criteria are applicable to patients in the US.

METHODS

We performed a retrospective study of 176 patients (mean age 68.5 years; 59.1% male; 58.5% white) who underwent surgical resection with lymph node dissection of T1 and Tis gastric adenocarcinomas, staged by pathologists, at 7 tertiary care centers in the US from January 1, 1999, through December 31, 2016. The frequency of lymph node metastases and associated risk factors were determined.

RESULTS

The mean size of gastric adenocarcinomas was 23.0 ± 16.6 mm-most were located in the lower-third of the stomach (67.0%), invading the submucosa (55.1%), and moderately differentiated (31.3%). Lymphovascular invasion was observed in 18.2% of lesions. Overall, 20.5% of patients had lymph node metastases. Submucosal invasion (odds ratio, 3.9; 95% CI, 1.4-10.7) and lymphovascular invasion (odds ratio, 4.6; 95% CI, 1.8-12.0) were independently associated with increased risk of metastasis to lymph nodes. The frequency of lymph node metastases among patients fulfilling standard and expanded Japanese criteria for ER were 0 and 7.5%, respectively.

CONCLUSIONS

The frequency of lymph node metastases among patients with early gastric cancer in a US population is higher than that of published Asian series. However, early gastric cancer lesions that meet the Japanese standard criteria for ER are associated with negligible risk of metastasis to lymph nodes, so ER can be recommended for definitive therapy. Expanded criteria cancers appear to have a higher risk of metastasis to lymph nodes, so ER may be considered for select cases.

Is Radical Surgery Necessary for All Patients Diagnosed as Having Non-Curative Endoscopic Submucosal Dissection?

If a lesion does not meet the expanded indication criteria for treatment with endoscopic therapy for early gastric cancer or has a positive resection margin, it is regarded as suitable for non-curative resection. Non-curative resection is closely related to the risk of local recurrence, lymph node metastasis, and poor prognosis. If the result is confirmed as non-curative resection, additional treatment should be considered depending on the risks of residual tumor, local recurrence, and lymph node metastasis. As lymphatic invasion is the most important risk factor of recurrence and poor prognosis, surgical treatment should be considered if lymphatic invasion is present. If patients are not suitable for additional surgery owing to old age or coexisting severe disease, close surveillance can be an alternative treatment option.

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.

Low risk of lymph node metastasis in 495 early gastric cardiac carcinomas: a multicenter clinicopathologic study of 2101 radical gastrectomies for early gastric carcinoma

Clinical decision-making on endoscopic vs. surgical resection of early gastric cardiac carcinoma remains challenging because of uncertainty on risk of lymph node metastasis. The aim of this multicenter study was to investigate risk factors of lymph node metastasis in early gastric cardiac carcinoma. Guided with the World Health Organization diagnostic criteria, we studied 2101 radical resections of early gastric carcinoma for risk factors associated with lymph node metastasis, including tumor location, gross pattern, size, histology type, differentiation, invasion depth, lymphovascular, and perineural invasion. We found that the risk of lymph node metastasis was significantly lower in early gastric cardiac carcinomas (6.7%, 33/495), compared with early gastric non-cardiac carcinomas (17.1%, 275/1606) (p < 0.0001). In early gastric cardiac carcinoma, no lymph node metastasis was identified in intramucosal carcinoma (0/193) and uncommon types of carcinomas (0/24), irrespective of the gross pattern, size, histologic type, differentiation, and invasion depth. Ulceration, size > 3 cm, and submucosal invasion were not significant independent risk factors for lymph node metastasis. In 33 early gastric cardiac carcinomas with lymph node metastasis, either lymphovascular invasion or poor differentiation was present in 16 (48.5%) cases and together in six cases. By multivariate analysis, independent risk factors of lymph node metastasis in early gastric cardiac carcinoma included lymphovascular invasion (Odds Ratio (OR): 7.6, 95% Confidence Interval (CI): 2.8-20.2) (p < 0.0001) and poor differentiation (OR: 6.0, 95% CI: 1.4-25.9) (p < 0.05). In conclusion, lymph node metastasis was not identified in early gastric cardiac intramucosal carcinoma and uncommon types of carcinoma. The risk of lymph node metastasis was also significantly lower in tumors with submucosal invasion, especially for cases without lymphovascular invasion or poor differentiation. These results lend support to the role of endoscopic therapy in the treatment of patients with early gastric cardiac carcinoma.

A Risk-Scoring Model for Predicting Lymph Node Metastasis in Early Gastric Cancer Patients: a Retrospective Study and External Validation

BACKGROUND

The possibility of lymph node metastasis (LNM) is critical to the assessment of the indication for endoscopic submucosal dissection. Thus, the aim of this study is to identify the risk factors for LNM and construct a risk-scoring model for patients with early gastric cancer to guide treatment.

METHODS

A retrospective examination of reports and studies carried out January 2000 and December 2014 was conducted. A risk-scoring model for predicting LNM was developed based on the data thus collected. In addition, the model is subject to verification and validation by three institutions.

RESULTS

Of the 1029 patients, 228 patients (22%) had LNM. Multivariate analysis showed that female, depressed type, undifferentiated type, submucosa, tumor size, and lymphovascular invasion were significantly associated with LNM. An 11-point risk-scoring model was used to predict LNM risk. An area under the receiver operating characteristic (AUROC) of the risk-scoring model was plotted using the development set and the AUROC of the model [0.76 (95% CI 0.73-0.80)] to predict LNM risk. After internal and external validation, the AUROC curve for predicting LNM was 0.77 (95% CI 0.68-0.86), 0.82 (95% CI 0.72-0.91), and 0.82 (95% CI 0.70-0.94), respectively.

CONCLUSIONS

A risk-scoring model for predicting LNM was developed and validated. It could help with personalized care for patients with EGC.