Comparison of endoscopic ultrasonography and multislice spiral computed tomography for the preoperative staging of gastric cancer - results of a single institution study of 610 Chinese patients

Development and validation of a Radiopathomics model based on CT scans and whole slide images for discriminating between Stage I-II and Stage III gastric cancer

OBJECTIVE

This study aimed to develop and validate an artificial intelligence radiopathological model using preoperative CT scans and postoperative hematoxylin and eosin (HE) stained slides to predict the pathological staging of gastric cancer (stage I-II and stage III).

METHODS

This study included a total of 202 gastric cancer patients with confirmed pathological staging (training cohort: n = 141; validation cohort: n = 61). Pathological histological features were extracted from HE slides, and pathological models were constructed using logistic regression (LR), support vector machine (SVM), and NaiveBayes. The optimal pathological model was selected through receiver operating characteristic (ROC) curve analysis. Machine learnin algorithms were employed to construct radiomic models and radiopathological models using the optimal pathological model. Model performance was evaluated using ROC curve analysis, and clinical utility was estimated using decision curve analysis (DCA).

RESULTS

A total of 311 pathological histological features were extracted from the HE images, including 101 Term Frequency-Inverse Document Frequency (TF-IDF) features and 210 deep learning features. A pathological model was constructed using 19 selected pathological features through dimension reduction, with the SVM model demonstrating superior predictive performance (AUC, training cohort: 0.949; validation cohort: 0.777). Radiomic features were constructed using 6 selected features from 1834 radiomic features extracted from CT scans via SVM machine algorithm. Simultaneously, a radiopathomics model was built using 17 non-zero coefficient features obtained through dimension reduction from a total of 2145 features (combining both radiomics and pathomics features). The best discriminative ability was observed in the SVM_radiopathomics model (AUC, training cohort: 0.953; validation cohort: 0.851), and clinical decision curve analysis (DCA) demonstrated excellent clinical utility.

CONCLUSION

The radiopathomics model, combining pathological and radiomic features, exhibited superior performance in distinguishing between stage I-II and stage III gastric cancer. This study is based on the prediction of pathological staging using pathological tissue slides from surgical specimens after gastric cancer curative surgery and preoperative CT images, highlighting the feasibility of conducting research on pathological staging using pathological slides and CT images.

Whether the use of intravenous contrast-enhanced ultrasound can improve the accuracy of T stage diagnosis of gastric cancer?

OBJECTIVE

To explore whether the use of intravenous contrast-enhanced ultrasound (CEUS) can improve the diagnostic accuracy of T stage of gastric cancer on the basis of oral contrast-enhanced ultrasound (OCEUS).

METHODS

Eighty-one patients with gastric cancer who underwent preoperative CEUS. Criteria for T staging was AJCC Stage 8th Edition. To compare the diagnostic accuracy, sensitivity and specificity of OCEUS and CEUS for T staging of gastric cancer using pathological results as the gold standard.

RESULTS

There were differences in the diagnostic accuracy of T2 (P = 0.048), T3(P = 0.002) and T4 (P = 0.000) between OCEUS and CEUS. And there was no difference in diagnostic accuracy for T1 (P = 0.118). CEUS significantly improved diagnostic sensitivity and specificity in T3 (42.86% to 61.90% for sensitivity, 86.96% to 93.75% for specificity), and T4 (64.71% to 76.47% for sensitivity, 78.33% to 95.74% for specificity).

CONCLUSION

Compared with OCEUS, CEUS did improve the diagnostic accuracy of T2, T3, and T4 stages of gastric cancer.

Diagnostic value of conventional endoscopic ultrasound for lymph node metastasis in upper gastrointestinal neoplasia: A meta-analysis

BACKGROUND

Upper gastrointestinal neoplasia mainly includes esophageal cancer and gastric cancer, both of which have high morbidity and mortality. Lymph node metastasis (LNM), as the most common metastasis mode of both diseases, is an important factor affecting tumor stage, treatment strategy and clinical prognosis. As a new fusion technology, endoscopic ultrasound (EUS) is becoming increasingly used in the diagnosis and treatment of digestive system diseases, but its use in detecting LNM in clinical practice remains limited.

AIM

To evaluate the diagnostic value of conventional EUS for LNM in upper gastrointestinal neoplasia.

METHODS

Using the search mode of "MeSH + Entry Terms" and according to the predetermined inclusion and exclusion criteria, we conducted a comprehensive search and screening of the PubMed, EMBASE and Cochrane Library databases from January 1, 2000 to October 1, 2022. Study data were extracted according to the predetermined data extraction form. The quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool, and the results of the quality assessment were presented using Review Manager 5.3.5 software. Finally, Stata14.0 software was used for a series of statistical analyses.

RESULTS

A total of 22 studies were included in our study, including 2986 patients. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic score and diagnostic odds ratio of conventional EUS in the diagnosis of upper gastrointestinal neoplasia LNM were 0.62 [95% confidence interval (CI): 0.50-0.73], 0.80 (95%CI: 0.73-0.86), 3.15 (95%CI: 2.46-4.03), 0.47 (95%CI: 0.36-0.61), 1.90 (95%CI: 1.51-2.29) and 6.67 (95%CI: 4.52-9.84), respectively. The area under the summary receiver operating characteristic curve was 0.80 (95%CI: 0.76-0.83). Sensitivity analysis indicated that the results of the meta-analysis were stable. There was considerable heterogeneity among the included studies, and the threshold effect was an important source of heterogeneity. Univariable meta-regression and subgroup analysis showed that tumor type, sample size and EUS diagnostic criteria were significant sources of heterogeneity in specificity (P < 0.05). No significant publication bias was found.

CONCLUSION

Conventional EUS has certain clinical value and can assist in the detection of LNM in upper gastrointestinal neoplasia, but it cannot be used as a confirmatory or exclusionary test.

Prospective Comparison of Oral Contrast-Enhanced Transabdominal Ultrasound Imaging With Contrast-Enhanced Computed Tomography in Pre-operative Tumor Staging of Gastric Cancer

The aim of this prospective study was to compare the diagnostic accuracy of oral contrast-enhanced transabdominal ultrasound imaging (OCTU) with that of contrast-enhanced computed tomography (CT) for the pre-operative tumor staging of gastric cancer, with post-operative pathology as the standard. We included 108 cases of gastric cancer with simultaneous OCTU and enhanced CT pre-operative tumor staging diagnoses. Results were compared with post-operative pathology based on the eighth edition of the American Joint Committee on Cancer tumor-node-metastasis staging guidelines for gastric cancer. The accuracy of each tumor stage was obtained by comparing OCTU and enhanced CT diagnoses with post-operative pathology. The McNemar test was used to compare the overall accuracy of the two methods. There was no statistical difference in accuracy between OCTU (72.2%) and enhanced CT (75.9%, p = 0.644) for overall pre-operative tumor staging diagnosis. For stages T1 to T4, the accuracy rates of OCTU were 84.2%, 81.8%, 69.4% and 65.5%, respectively, and those for enhanced CT were 52.6%, 72.7%, 87.8% and 72.4%, respectively. OCTU is comparable to enhanced CT in the preoperative overall T-stage diagnosis of gastric cancer.

Korean Practice Guidelines for Gastric Cancer 2022: An Evidence-based, Multidisciplinary Approach

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

Effect of visceral adipose tissue on the accuracy of preoperative T-staging of gastric cancer

BACKGROUND

Due to the anatomical characteristics of the tumor and the specific variables of the patients, the accuracy of preoperative T-staging of gastric cancer needs to be further improved. This study investigated the effect of visceral adipose tissue (VAT) on the accuracy of clinical T-staging of gastric cancer.

METHODS

The clinical data of 455 patients who underwent gastrectomy from January 2013 to December 2018 were analyzed retrospectively. Taking the postoperative pathological results as the reference standard, the patients were divided into accurate staging group and mistaken staging group according to the comparison of clinical T stage (cT) and pathological T stage (pT). The individual characteristics of the two groups were compared, including visceral fat content at L2/L3 level calculated on computed tomography, age, sex, tumor size, tumor location (cardia, stomach body, stomach antrum), and degree of differentiation. Multivariate logistic regression was used to determine the independent factors affecting the accuracy of cT staging.

RESULTS

Among the 455 patients, 355 patients (78.0 %) had accurate preoperative cT staging and 100 patients (22.0 %) had inaccurate preoperative cT staging. The average area of VAT in the accurate staging group was (129.8 ± 72.6) cm² and that in the mistaken staging group was (74.6 ± 61.6) cm² (P < 0.001). The optimal cut-off value of VAT was 97.8 cm² calculated according to the Yoden index. Multivariate logistic regression analysis showed that VAT, tumor location and tumor size were independent predictors of cT accuracy.

CONCLUSIONS

Patients with lower visceral fat content (<97.8 cm²) based on L2/L3 level had a higher risk of false staging in preoperative clinical T staging.

Gastric hydrodistension CT versus CT without gastric distension in preoperative TN staging of gastric carcinoma: analysis of single-center cancer registry

Accurate staging of gastric cancer is essential for the selection and optimization of therapy. Hydrodistension of the stomach is recommended to improve the accuracy of preoperative staging with contrast-enhanced multidetector computed tomography (MDCT). This study compares the performance of contrast-enhanced gastric water distension versus a nondistension MDCT protocol for T and N staging and serosal invasion in comparison to surgical histopathology. After propensity score matching, 86 patients in each group were included for analysis. The overall accuracy of distension versus nondistension group in T staging was 45% (95% CI 35-56) and 55% (95% CI 44-65), respectively (p = 0.29). There was no difference in the sensitivity and specificity in individual T staging and assessment of serosal invasion (all p > 0.41). Individual stage concordance with pathology was not significantly different (all p > 0.41). The overall accuracy of N staging was the same for distension and nondistension groups (51% [95% CI 40-62]). The majority of N0 staging (78-81%) were correctly staged, whereas N3 staging cases (63-68%) were predominantly understaged. In summary, there was no significant difference in the diagnostic performance of individual TN staging and assessment of serosal invasion using MDCT with or without gastric water distension.

Accuracy of Endoscopic Ultrasonography for Gastric Cancer Staging

Gastric cancer remains a health problem, with treatment indications varying with the TNM stage. We aimed in this study to highlight the role of EUS in GC patients and also to calculate the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of EUS for T and N staging in our group of patients with this disease. In this study, we included 41 GC patients, and individual values for every T stage accuracy, sensitivity, specificity, PPV, NPV, correct staging, understaging, and overstaging were calculated. EUS overall accuracy for T staging was 58.53%, with the highest sensitivity reached for the T4 stage, 95.83%. For N+vs. N-staging, EUS accuracy was 68.29%, with a sensitivity of 75% and a specificity of 44.44%. The positive and negative predicted values for the presence or absence of nodal disease were 82.75%, respectively 33.33%. In conclusion, this study confirmed the importance of EUS for the assessment of GC T and N stage and highlighted the role of this tool in the detection of liver micrometastasis unrevealed by other imaging techniques like abdominal ultrasound or MSCT.

Recent Advances in the Diagnosis, Staging, Treatment, and Prognosis of Advanced Gastric Cancer: A Literature Review

Gastric cancer is one of the most common cause of cancer related deaths worldwide which results in malignant tumors in the digestive tract. The only radical treatment option available is surgical resection. Recently, the implementation of neoadjuvant chemotherapy resulted in 5-year survival rates of 95% for early gastric cancer. The main reason of treatment failure is that early diagnosis is minimal, with many patients presenting advanced stages. Hence, the greatest benefit of radical resection is missed. Consequently, the main therapeutic approach for advanced gastric cancer is combined surgery with neoadjuvant chemotherapy, targeted therapy, or immunotherapy. In this review, we will discuss the various treatment options for advanced gastric cancer. Clinical practice and clinical research is the most practical way of reaching new advents in terms of patients' characteristics, optimum drug choice, and better prognosis. With the recent advances in gastric cancer diagnosis, staging, treatment, and prognosis, we are evident that the improvement of survival in this patient population is just a matter of time.

Clinical TNM staging for esophageal, gastric, and colorectal cancers in the era of neoadjuvant therapy: A systematic review of the literature

AIM

Clinical staging is vital for selecting appropriate candidates and designing neoadjuvant treatment strategies for advanced tumors. The aim of this review was to evaluate diagnostic abilities of clinical TNM staging for gastrointestinal, gastrointestinal cancers.

METHODS

We conducted a systematic review of recent publications to evaluate the accuracy of diagnostic modalities on gastrointestinal cancers. A systematic literature search was performed in PubMed/MEDLINE using the keywords "TNM staging," "T4 staging," "distant metastases," "esophageal cancer," "gastric cancer," and "colorectal cancer," and the search terms used in Cochrane Reviews between January 2005 to July 2020. Articles focusing on preoperative diagnosis of: (a) depth of invasion; (b) lymph node metastases; and (c) distant metastases were selected.

RESULTS

After a full-text search, a final set of 55 studies (17 esophageal cancer studies, 26 gastric cancer studies, and 12 colorectal cancer studies) were used to evaluate the accuracy of clinical TNM staging. Positron emission tomography-computed tomography (PET-CT) and/or magnetic resonance imaging (MRI) were the best modalities to assess distant metastases. Fat and fiber mode of CT may be useful for T4 staging of esophageal cancer, CT was a partially reliable modality for lymph node staging in gastric cancer, and CT combined with MRI was the most reliable modality for liver metastases from colorectal cancer.

CONCLUSION

The most reliable diagnostic modality differed among gastrointestinal cancers depending on the type of cancer. Therefore, we propose diagnostic algorithms for clinical staging for each type of cancer.

Potential survival benefits of open over laparoscopic radical gastrectomy for gastric cancer patients beyond three years after surgery: result from multicenter in-depth analysis based on propensity matching

BACKGROUND

The oncologic efficacy of laparoscopic versus open surgery for advanced distal gastric cancer (ADGC) beyond 3 years after surgery remain obscure.

METHODS

A total of 1256 patients with ADGC at two teaching institutions in China from April 2007 to December 2014 were enrolled. The general data of the two groups were identified to enable rigorous estimation of propensity scores. Restricted mean survival time (RMST) and Landmark analysis was used to compare survival.

RESULTS

After matching 461 patients each in the open distal gastrectomy (ODG) and laparoscopic distal gastrectomy (LDG) groups, they were included into analysis. The 3- and 5-year overall survival (OS) and disease-free survival were comparable in two groups. RMST-stratified analysis showed that the 3-year RMST of ODG group was similar to that of LDG group in patients with cT4a (- 1.38 years, p = 0.163) or with cT4a and tumor size > 5 cm, whereas the 5-year RMST had significant differences between groups in cT4a patients(- 8.36 years, P = 0.005) or cT4a and tumor size > 5 cm patients(4.67 years, P = 0.042). In patients with cT4a and tumors > 5 cm, the number of peritoneal recurrences was significantly fewer in the ODG group than in the LDG group (4 vs. 17, P = 0.033), and the peritoneal recurrence time and multiple-site recurrence time were both later in the ODG group.

CONCLUSION

By reducing recurrence, ODG achieves a better survival for GC patients with serous infiltration and tumors larger than 5 cm beyond 3 years after surgery. The present findings can serve as a reference for surgical options and the setting of follow-up time point for clinical studies.

Can endoscopic ultrasonography (EUS) improve the accuracy of clinical T staging by computed tomography (CT) for gastric cancer?

INTRODUCTION

With the introduction of new therapeutic options for gastric cancer treatment, more precise preoperative staging of gastric cancer is needed. The purpose of this study was to evaluate the role of endoscopic ultrasonography (EUS) for improving the accuracy of clinical T staging by computed tomography (CT) for gastric cancer.

MATERIALS AND METHODS

A total of 2636 patients underwent stomach protocol CT (S-CT) and EUS, followed by gastrectomy for primary gastric adenocarcinoma between September 2012 and February 2018 at Seoul National University Hospital. The results of preoperative S-CT and EUS were compared to the postoperative pathologic staging.

RESULTS

The overall accuracy of S-CT and EUS for T staging were 69.4% and 70.4%, respectively. When T staging was divided into T1-2 and T3-4 for clinically advanced gastric cancer (AGC), the positive predictive value for T3-4 using S-CT, EUS, and a combination of both modalities was 73.8%, 79.3%, and 85.6%, respectively. In 114 cases of indeterminate lesions between cT1 and cT2 by S-CT, EUS had a better prediction rate than the final decision based on endoscopy or the agreement between the two experts (Match rate: EUS vs. final decision, 69.3% vs. 58.8%).

CONCLUSION

EUS can be a complementary diagnostic tool to clinical T staging of gastric cancer by CT for selecting T3-4 lesion.

Effect of Preoperative Tumour Under-Staging on the Long-Term Survival of Patients Undergoing Radical Gastrectomy for Gastric Cancer

Purpose

This study aimed to evaluate the effect of preoperative tumor staging deviation (PTSD) on the long-term survival of patients undergoing radical gastrectomy for gastric cancer (RGGC).

Materials and Methods

Clinicopathological data of 2,346 patients who underwent RGGC were retrospectively analyzed. The preoperative tumor-lymph node-metastasis (TNM) under-staging group (uTNM) comprised patients who had earlier preoperative TNM than postoperative TNM, and the no preoperative under-staging group (nTNM) comprised the remaining patients.

Results

There were 1,031 uTNM (44.0%) and 1,315 nTNM cases (56.0%). Cox prognostic analysis revealed that PTSD independently affected the overall survival (OS) after surgery. The 5-year OS was lower in the uTNM group (41.8%) than in the nTNM group (71.6%). The patients less than 65 years old, with lower American Society of Anaesthesiologists score, 2–5 cm tumor located at the lower stomach, and cT1 or cN0 preoperative staging would more likely undergo D1+ lymph node dissection (LND) in uTNM (p < 0.05). Logistic analyses revealed that tumor size > 2 cm and body mass index ≤ 22.72 kg/m² were independent risk factors of preoperative TNM tumor under-staging in patients with cT1N0M0 staging (p < 0.05).

Conclusion

Underestimated tumor staging is not rare, which possibly results in inadequate LND and affects the long-term survival for patients undergoing RGGC. D2 LND should be carefully performed in patients who are predisposed to this underestimation.

Accuracy of 18F-FDG PET/CT and CECT for primary staging and diagnosis of recurrent gastric cancer: A meta-analysis

Contrast-enhanced computed tomography (CECT) is commonly used for staging and diagnosing recurrent gastric cancer. Recently, 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET)/CT gained popularity as a diagnostic tool owing to advantages including dual functional and anatomical imaging, which may facilitate early diagnosis. The diagnostic performance of 18F-FDG PET/CT and CECT has been assessed in several studies but with variable results. Therefore, the present meta-analysis aimed to evaluate the accuracy of 18F-FDG PET/CT and CECT for primary TNM staging and the diagnosis of recurrent gastric cancers. A systematic search of the PubMed Central, Medline, Scopus, Cochrane and Embase databases from inception until January 2020 was performed. The Quality Assessment of Diagnostic Accuracy Study-2 tool was used to determine the quality of the selected studies. Pooled estimates of sensitivity and specificity were calculated. A total of 58 studies comprising 9,997 patients were included. Most studies had a low risk of bias. The sensitivity and specificity for nodal staging of gastric cancer were 49% (95% CI, 37-61%) and 92% (95% CI, 86-96%) for 18F-FDG PET/CT, respectively, and 67% (95% CI, 57-76%) and 86% (95% CI, 81-89%) for CECT, respectively. For metastasis staging, the sensitivity and specificity were 56% (95% CI, 40-71%) and 97% (95% CI, 87-99%) for 18F-FDG PET/CT, respectively, and 59% (95% CI, 41-75%) and 96% (95% CI, 83-99%) for CECT, respectively. For diagnosing cancer recurrence, the pooled sensitivity and specificity were 81% (95% CI, 72-88%) and 83% (95% CI, 74-89%) for 18F-FDG PET/CT, respectively, and 59% (95% CI, 41-75%) and 96% (95% CI, 83-99%) for CECT, respectively. Both 18F-FDG PET/CT and CECT were deemed highly useful for diagnosing recurrent gastric cancer due to their high sensitivities and specificities. However, these techniques cannot be used to exclude or confirm the presence of lymph node metastases or recurrent gastric cancer tumors, but can be used for the confirmation of distal metastasis.

Endoscopic Ultrasound vs. Computed Tomography for Gastric Cancer Staging: A Network Meta-Analysis

Gastric cancer preoperative staging is of outmost importance to assure proper management of the disease. Providing a relevant clinical stage relies on different imaging methods such as computed tomography (CT) or endoscopic ultrasound (EUS). We aimed to perform a network meta-analysis for gastric cancer clinical stage diagnostic tests, thus comparing the diagnostic accuracy of EUS vs. multidetector CT (MDCT) and EUS vs. EUS + MDCT. We plotted study estimates of pooled sensitivity and specificity on forest plots and summary receiver operating characteristic space to explore between-study variation in the performance of EUS, MDCT and EUS + MDCT for T1–T4, N0–N3, M0–M1 when data were available. Exploratory analyses were undertaken in RevMan 5. We included twelve studies with 2047 patients. Our results suggest that EUS was superior to MDCT in preoperative T1 and N staging. MDCT is more specific for the M stage but no significant difference in sensitivity was obtained. When comparing EUS vs. EUS + MDCT for T1 both sensitivity and specificity were not relevant. No significant differences were observed in T2–T4 stages. Even though EUS helped differentiate between the presence of invaded nodules, N stages should be carefully assessed by both methods since there is not sufficient data.

Application of ultrasound in the diagnosis of gastrointestinal tumors

Gastrointestinal tumors are common tumors in the digestive system. Early diagnosis of gastrointestinal tumors is the key to improve prognosis and curative effect of patients with tumors. Compared with other methods of examination and diagnosis, ultrasound examination has the advantages of simple operation, non-invasive, economical, and repeatable operation. With the advancement of ultrasound technology and the development of ultrasound contrast agents, ultrasound examination is more and more applied to gastrointestinal examination. Ultrasound cannot only observe the gastrointestinal wall, but also evaluate the surrounding lesions and metastases, as well as preoperative analysis and postoperative follow-up of gastrointestinal tumors. We reviewed the diagnostic applications of ultrasound in gastrointestinal tumors.

The value of multidetector-row computed tomography in lymph node staging of gastric cancer: a preliminary Vietnamese study

Introduction

Gastric cancer (GC) is the fourth most common malignant disease in the world, following breast cancer, colorectal cancer, and lung cancer. This study aimed to evaluate the usefulness of multidetector-row computed tomography (MDCT) in identifying the metastatic lymph node of GC.

Material and methods

A cross-sectional study was performed after receiving approval by the institutional review board. A total of 88 patients with GC, who underwent radical gastrectomy, were examined by MDCT. Categorical variables were compared using Fisher’s exact test. The discriminating ability of lymph node size was determined according to an area under the receiver operating curve(AUROC) analysis, and the optimal cut-off point was determined.

Results

The proportion of metastatic lymph node patients in the proximal group (32.3%) was significantly higher than that in the distal group (18.4%). T categorisation and lymph node sizes were significantly different between the non-metastatic lymph node and metastatic lymph node groups. The AUROC for lymph node size was 0.738, with an optimal cut-off point of 7.5 mm,producing a sensitivity of 71.5% and a specificity of 70.5%.

Conclusions

MDCT displayed medium accuracy for the determination of metastatic lymph nodes and N categorisation. Based on our findings, although MDCT is generally the first choice for preoperative assessments in GC patients, other diagnostic modalities should supplement MDCT in order to achieve more precise N staging.

Impact of ypT, ypN, and Adjuvant Therapy on Survival in Gastric Cancer Patients Treated with Perioperative Chemotherapy and Radical Surgery

BACKGROUND

Perioperative chemotherapy and surgery is the standard of care in advanced gastroesophageal cancer patients, but its impact among those treated with radical surgery still needs further assessment. We present the results of this multimodality treatment approach in a gastric cancer patients cohort treated with D2 lymphadenectomy. We aimed to identify prognostic factors associated with improved survival.

PATIENTS AND METHODS

This retrospective cohort study enrolled patients treated with perioperative chemotherapy and resection in a single cancer center in Brazil between 2006 and 2016. Subjects presenting tumors of the gastric stump, esophageal tumors, or treated with intraperitoneal chemotherapy were excluded. Intention-to-treat survival analysis was performed for all subjects who started neoadjuvant chemotherapy, and prognostic factors were determined among those who had R0 resection.

RESULTS

This study included 239 patients, of whom 198 had R0 resection. The mean age was 59.9 years, and most had clinical stage IIB or III disease (88%). Among the 239 patients who started neoadjuvant chemotherapy, 207 (86.6%) completed all neoadjuvant treatment cycles, and surgical resection was performed in 225 subjects (94.1%). Overall 60-day morbidity and mortality rates were 35.6% and 4.4%, respectively. For the entire cohort, median survival was 78 months and the 5-year survival rate was 55.3%. Factors associated with worse survival were ypT3-4 stage, ypN + stage, extended resection, and no adjuvant chemotherapy.

CONCLUSIONS

Perioperative chemotherapy resulted in very good outcomes for patients treated with radical surgery, and downstaging after chemotherapy was shown to be a major determinant of prognosis.

Role of D2 gastrectomy in gastric cancer with clinical para-aortic lymph node metastasis

BACKGROUND

Owing to the technical difficulty of pathological diagnosis, imaging is still the most commonly used method for clinical diagnosis of para-aortic lymph node metastasis (PALM) and evaluation of therapeutic effects in gastric cancer, which leads to inevitable false-positive findings in imaging. Patients with clinical PALM may have entirely different pathological stages (stage IV or not), which require completely different treatment strategies. There is no consensus on whether surgical intervention should be implemented for this group of patients. In particular, the value of D2 gastrectomy in a multidisciplinary treatment (MDT) approach for advanced gastric cancer with clinical PALM remains unknown.

AIM

To investigate the value of D2 gastrectomy in a MDT approach for gastric cancer patients with clinical PALM.

METHODS

In this real-world study, clinico-pathological data of all gastric cancer patients treated at the Cancer Hospital, Chinese Academy of Medical Sciences between 2011 and 2016 were reviewed to identify those with clinically enlarged PALM. All the clinico-pathological data were prospectively documented in the patient medical record. For all the gastric cancer patients with advanced stage disease, especially those with suspicious distant metastasis, the treatment methods were determined by a multidisciplinary team.

RESULTS

In total, 48 of 7077 primary gastric cancer patients were diagnosed as having clinical PALM without other distant metastases. All 48 patients received chemotherapy as the initial treatment. Complete or partial response was observed in 39.6% (19/48) of patients in overall and 52.1% (25/48) of patients in the primary tumor. Complete response of PALM was observed in 50.0% (24/48) of patients. After chemotherapy, 45.8% (22/48) of patients received D2 gastrectomy, and 12.5% (6/48) of patients received additional radiotherapy. The postoperative major complication rate and mortality were 27.3% (6/22) and 4.5% (1/22), respectively. The median overall survival and progression-free survival of all the patients were 18.9 and 12.1 mo, respectively. The median overall survival of patients who underwent surgical resection or not was 50.7 and 12.8 mo, respectively. The 3-year and 5-year survival rates were 56.8% and 47.3%, respectively, for patients who underwent D2 resection. Limited PALM and complete response of PALM after chemotherapy were identified as favorable factors for D2 gastrectomy.

CONCLUSION

For gastric cancer patients with radiologically suspicious PALM that responds well to chemotherapy, D2 gastrectomy could be a safe and effective treatment and should be adopted in a MDT approach for gastric cancer with clinical PALM.

The Diagnostic and Prognostic Value of Digital Rectal Examination in Gastric Cancer Patients with Peritoneal Metastasis

Background: Peritoneal metastasis (PM) is the most common cause of death in gastric cancer (GC) patients. However, diagnosis of PM is still difficult in clinical practice. This study aimed to explore the diagnostic and prognostic value of digital rectal examination (DRE) in GC.

Methods: 247 GC patients with PM confirmed by operation were included. The diagnostic yield of DRE compared with computed tomography (CT) was calculated. In another group of 1330 cases receiving radical gastrectomy, 38 cases with DRE (+) postoperatively were analyzed to identify risk factors. A nomogram was constructed to predict postoperative DRE (+).

Results: The specificity, positive predictive value and positive likelihood ratio of DRE in diagnosis of PM was 99.8%, 91.2% and 58.4, higher than CT (97.6%, 64.9% and 10.4). Though the sensitivity of DRE (12.6%) was lower than CT (24.7%), 17 of 31 patients with DRE (+) could not be found by CT. Moreover, the overall survival of confirmed PM patients with DRE (+) (PM-DRE (+)) was much lower than PM-DRE (-) patients (P<0.001). In addition, the nomogram to predict postoperative DRE (+) had a bootstrap-corrected concordance index of 0.73 and was well calibrated.

Conclusions: GC patients with DRE (+) could be regarded as a special subtype of stage IV ones with poorer prognosis. Supply of palliative care and chemotherapy rather than unnecessary operation might be a better alternative for these patients. DRE was an effective supplement for CT and should be generally recommended for GC patients.

Radiomics Signature on Computed Tomography Imaging: Association With Lymph Node Metastasis in Patients With Gastric Cancer

Background: To evaluate whether radiomic feature-based computed tomography (CT) imaging signatures allow prediction of lymph node (LN) metastasis in gastric cancer (GC) and to develop a preoperative nomogram for predicting LN status.

Methods: We retrospectively analyzed radiomics features of CT images in 1,689 consecutive patients from three cancer centers. The prediction model was developed in the training cohort and validated in internal and external validation cohorts. Lasso regression model was utilized to select features and build radiomics signature. Multivariable logistic regression analysis was utilized to develop the model. We integrated the radiomics signature, clinical T and N stage, and other independent clinicopathologic variables, and this was presented as a radiomics nomogram. The performance of the nomogram was assessed with calibration, discrimination, and clinical usefulness.

Results: The radiomics signature was significantly associated with pathological LN stage in training and validation cohorts. Multivariable logistic analysis found the radiomics signature was an independent predictor of LN metastasis. The nomogram showed good discrimination and calibration.

Conclusions: The newly developed radiomic signature was a powerful predictor of LN metastasis and the radiomics nomogram could facilitate the preoperative individualized prediction of LN status.

Imaging strategies in the management of gastric cancer: current role and future potential of MRI

Accurate preoperative staging of gastric cancer and the assessment of tumor response to neoadjuvant treatment is of importance for treatment and prognosis. Current imaging techniques, mainly endoscopic ultrasonography (EUS), computed tomography (CT) and ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET), have their limitations. Historically, the role of magnetic resonance imaging (MRI) in gastric cancer has been limited, but with the continuous technical improvements, MRI has become a more potent imaging technique for gastrointestinal malignancies. The accuracy of MRI for T- and N-staging of gastric cancer is similar to EUS and CT, making MRI a suitable alternative to other imaging strategies. There is limited evidence on the performance of MRI for M-staging of gastric cancer specifically, but MRI is widely used for diagnosing liver metastases and shows potential for diagnosing peritoneal seeding. Recent pilot studies showed that treatment response assessment as well as detection of lymph node metastases and systemic disease might benefit from functional MRI (e.g. diffusion weighted imaging and dynamic contrast enhancement). Regarding treatment guidance, additional value of MRI might be expected from its role in better defining clinical target volumes and setup verification with MR-guided radiation treatment.

Low periostin expression predicts poor survival in intestinal type gastric cancer patients

BACKGROUND AND AIM

Periostin is a protein from the Fascilin family. It is commonly present in normal tissues and is responsible for cell adhesion. Evidence has emerged showing that changes in periostin expression play an important role in tumor initiation, development, and progression. This study aims to investigate the effect of periostin in gastric cancer (GC) patients who underwent gastrectomy. Seven hundred and forty-seven GC patients who underwent gastrectomy between December 2006 and July 2011 were included in this study.

METHODS

Seven hundred and forty-seven cancer tissues and 70 paired adjacent normal tissues were collected. Periostin expression was evaluated by immunohistochemistry. The Gene Expression Omnibus database was used to study the association between the mRNA level and patient's overall survival. The tumor microenvironment was also studied.

RESULTS

Periostin expression in stroma was downregulated in tumor tissues but it was upregulated in the epithelial cells. After dividing the tissues according to the Lauren Classification, we found that periostin expression in stroma and epithelial cells was higher in intestinal type than in diffuse type (P<0.001 and P=0.010, respectively). Periostin was an independent predictor of lymph node (LN) metastasis in GC patients. The study of CD163(+) tumor-associated macrophages (TAMs) revealed that in diffuse type GC, periostin expression was associated with CD163(+) TAMs.

CONCLUSION

We found that the periostin expression can predict LN metastasis in patients undergoing curative gastrectomy. Intestinal type GC patients with high periostin level had both a favorable survival and lesser LN metastasis.

Accuracy of endoscopic ultrasound in gastric adenocarcinoma patient selection for neoadjuvant therapy

Background

Recent studies demonstrated the positive impact of neoadjuvant treatment in locally advanced gastric cancer.

Objective

To assess the accuracy of endoscopic ultrasound (EUS) in the selection of patients with gastric adenocarcinoma for neoadjuvant therapy (T ≥ 2 and/or N+).

Methods

Retrospective analysis of patients with an anatomopathological diagnosis of gastric adenocarcinoma between January 2011 and June 2017, who had EUS for staging and underwent surgery as a first therapeutic attempt. The concordance (k) and accuracy (area under the curve (AUC)) of EUS for T ≥ 2 and/or N+ were assessed using the anatomopathological staging of the resected surgical specimen as the gold standard.

Results

The final sample included 152 patients (66.4% male, 67.1 ± 12.2 years). The concordance, accuracy, sensitivity and specificity of the EUS for T ≥ 2 and/or N+ were 0.72, 0.86 ± 0.03, 88.5% and 83.1%, respectively. The results were higher in proximal (k = 0.93, AUC = 0.96 ± 0.05, sensitivity (S) = 99.0% and specificity (E) = 90.9%) compared with distal lesions (k = 0.67, AUC = 0.84 ± 0.04, S = 85.7% and E = 81.5%), and in intestinal subtype (k = 0.77, AUC = 0.88 ± 0.04, S = 92.6% and E = 84.1%) compared with diffuse (k = 0.58, AUC = 0.79 ± 0.10, S = 85.0% and E = 72.7%) or mixed-subtype tumours (k = 0.65, AUC = 0.84 ± 0.10, S = 76.9% and E = 90.0%).

Conclusion

In one of the largest series of patients, we showed that EUS has overall high agreement and accuracy in the selection of patients with gastric adenocarcinoma for neoadjuvant therapy, although the agreement and accuracy are greater for proximal and intestinal lesions.

Nomogram analysis and external validation to predict the risk of lymph node metastasis in gastric cancer

Aim

To identify risk factors for lymph node metastasis using a nomogram for gastric cancer patients to predict lymph node metastasis.

Results

The Chi-square test and the logistic regression showed that the Boarrmann type, preoperative CA199 level, T stage and N stage by CT scan were independent risk factors. The concordance index (C-index) was 0.786 in the internal validation of the Nomogram model. In the external validation, the C-index was 0.809, and the AUC was 0.894. The total accuracy of the prediction was 82.2%, and the false-negative rate was 5.4% with a cut-off value set at 0.109.

Materials and Methods

The study consisted of 451 patients with a histological diagnosis of gastric cancer with 0 or 1 lymph node metastasis from the Sun Yat-sen University Cancer Center as the development set, and the validation set consisted of 186 gastric cancer patients from the Sixth Affiliated Hospital of Sun Yat-Sen University. A Chi-square test and a logistic regression analysis were used to compare the clinicopathological variables and lymph node metastasis. The C-index and ROC curve were computed for comparisons of the nomogram's predictive ability.

Conclusions

We developed and validated a nomogram to predict lymph node metastasis in gastric cancer before surgery. This nomogram can be broadly applied, even in general hospitals, and is useful for decisions regarding treatment programs for patients.

Value and impact factors of multidetector computed tomography in diagnosis of preoperative lymph node metastasis in gastric cancer: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Multidetector computed tomography (MDCT) exhibited wide ranges of sensitivities and specificities for lymph node assessment of gastric cancer (GC) in several individual studies. This present meta-analysis was carried out to evaluate the value of MDCT in diagnosis of preoperative lymph node metastasis (LNM) and to explore the impact factors that might explain the heterogeneity of its diagnostic accuracy in GC.

METHODS

A comprehensive search was conducted to collect all the relevant studies about the value of MDCT in assessing LNM of GC within the PubMed, Cochrane library and Embase databases up to Feb 2, 2016. Two investigators independently screened the studies, extracted data, and evaluated the quality of included studies. The sensitivity, specificity, and area under ROC curve (AUC) were pooled to estimate the overall accuracy of MDCT. Meta-regression and subgroup analysis were carried out to identify the possible factors influencing the heterogeneity of the accuracy.

RESULTS

A total of 27 studies with 6519 subjects were finally included. Overall, the pooled sensitivity, specificity, and AUC were 0.67 (95% CI: 0.56-0.77), 0.86 (95% CI: 0.81-0.90), and 0.86 (95% CI: 0.83-0.89), respectively. Meta-regression revealed that MDCT section thickness, proportion of serosal invasion, and publication year were the main significant impact factors in sensitivity, and MDCT section thickness, multiplanar reformation (MPR), and reference standard were the main significant impact factors in specificity. After the included studies were divided into 2 groups (Group A: studies with proportion of serosa-invasive GC subjects ≥50%; Group B: studies with proportion of serosa-invasive GC subjects <50%), the pooled sensitivity in Group A was significantly higher than in Group B (0.84 [95% CI: 0.75-0.90] vs 0.55 [95% CI: 0.41-0.68], P < .01). For early gastric cancer (EGC), the pooled sensitivity, specificity, and AUC were 0.34 (95% CI: 0.15-0.61), 0.91 (95% CI: 0.84-0.95), and 0.83 (95% CI: 0.80-0.86), respectively.

CONCLUSION

To summarize, MDCT tends to be adequate to assess preoperative LNM in serosa-invasive GC, but insufficient for non-serosa-invasive GC (particularly for EGC) owing to its low sensitivity. Proportion of serosa-invasive GC subjects, MDCT section thickness, MPR, and reference standard are the main factors influencing its diagnostic accuracy.

Accuracy of Multi-Slice Spiral Computed Tomography for Preoperative Tumor Node Metastasis (TNM) Staging of Colorectal Carcinoma

Background

With the advances in imaging technologies, multi-slice spiral computed tomography (MSCT) has demonstrated superiority in the diagnosis and staging of colorectal carcinoma. In the current study, preoperative TNM staging of colorectal carcinoma by using MSCT was conducted and compared with the corresponding postoperative pathological examination findings, in order to evaluate the accuracy of preoperative MSCT for TNM staging.

Material/Methods

Combinations of biphasic or triphasic enhanced-phase MSCT scans were obtained for 76 patients with colorectal carcinoma, and the TNM stage was determined based on imaging reconstruction from various angles and perspectives to display the size, location, and affected range of tumors. The preoperative TNM stage was compared with the postoperative pathological stage, and the consistency between the 2 methods was tested by the κ test using SPSS 17.0 software.

Results

Among the different combinations of enhanced-phase MSCT scanning, triphasic MSCT imaging, comprising the arterial, portal venous, and delayed phases, showed the highest accuracy rates, at 81.6% (62/76), 82.89% (63/76), and 96.1% (73/76) for T, N, and M staging, respectively, with κ values of 0.72, 0.65, and 0.56, respectively, indicating consistency with the postoperative pathological staging.

Conclusions

Combined MSCT scanning comprising the arterial phase, portal venous phase, and delayed phase showed satisfying consistency with the postoperative pathological analysis results for TNM staging of colorectal carcinoma. Thus, MSCT is an important clinical value for improving the accuracy of TNM staging and for planning the appropriate colorectal cancer treatment.

Usefulness of conventional and low-dose hydro-CT in the diagnosis of gastric tumors in comparison to endoscopy

PURPOSE

The aim of this retrospective study was to evaluate the usefulness of hydro-CT in the diagnosis of gastric tumors in comparison to endoscopy.

MATERIAL AND METHODS

The study involved 40 patients with a diagnosis of gastric tumor established by histopathology who underwent endoscopy and conventional or low-dose hydro-CT. Hydro-CT images were retrospectively analyzed based on the consensus of two radiologists who were blinded to the endoscopy findings. The diagnostic accuracy of hydro-CT and endoscopy for the diagnosis of gastric tumors was evaluated using the results of the histopathological examination as the reference standard.

RESULTS

Histopathology confirmed the presence of gastric cancer in 28 patients (70%), while gastrointestinal stromal tumors (GISTs) were recognized in the remaining 12 cases (30%). Correct diagnoses of the type of gastric tumor in hydro-CT were obtained in 37 patients (92.5%). This was not significantly different from the 85% accuracy of endoscopy. Further analysis showed that the correctness of GIST diagnosis in endoscopy and hydro-CT also did not differ significantly (91.7% and 100% respectively). The percentage of correctly diagnosed malignant lesions in hydro-CT was lower than for GISTs at 89.29%, while in endoscopy it was insignificantly lower (82.14%). The diagnostic accuracy of conventional and low-dose hydro-CT in the diagnosis of gastric tumors (95% and 90% respectively) was not significantly different.

CONCLUSIONS

Conventional and low-dose hydro-CT may be a valuable non-invasive diagnostic method in the diagnosis of gastric tumors for patients who have contraindications to endoscopy or who are unable to undergo gastric biopsy.

Consistency mapping of 16 lymph node stations in gastric cancer by CT-based vessel-guided delineation of 255 patients

In order to refine the location and metastasis-risk density of 16 lymph node stations of gastric cancer for neoadjuvant radiotherapy, we retrospectively reviewed the initial images and pathological reports of 255 gastric cancer patients with lymphatic metastasis. Metastatic lymph nodes identified in the initial computed tomography images were investigated by two radiologists with gastrointestinal specialty. A circle with a diameter of 5 mm was used to identify the central position of each metastatic lymph node, defined as the LNc (the central position of the lymph node). The LNc was drawn at the equivalent location on the reference images of a standard patient based on the relative distances to the same reference vessels and the gastric wall using a Monaco® version 5.0 workstation. The image manipulation software Medi-capture was programmed for image analysis to produce a contour and density atlas of 16 lymph node stations. Based on a total of 2846 LNcs contoured (31-599 per lymph node station), we created a density distribution map of 16 lymph node drainage stations of the stomach on computed tomography images, showing the detailed radiographic delineation of each lymph node station as well as high-risk areas for lymph node metastasis. Our mapping can serve as a template for the delineation of gastric lymph node stations when defining clinical target volume in pre-operative radiotherapy for gastric cancer.

Endoscopic ultrasonography compared with multidetector computed tomography for the preoperative staging of gastric cancer: a meta-analysis

Background

The current study sought to perform a meta-analysis to compare the preoperative staging of endoscopic ultrasonography (EUS) and multidetector computed tomography (MDCT) in gastric carcinoma.

Methods

Articles published between January 1, 2000, and April 1, 2016, that compared EUS with MDCT were included, and data were presented as 2 × 2 tables. The sensitivities, specificities and summary receiver operating characteristic (ROC) curves for T and N staging were calculated using a bivariate mixed effects model. Data were weighted by generic variance and then pooled by random-effects modeling.

Results

Eight studies comprising 1736 patients were included in this meta-analysis. For T1 staging, the sensitivity value for EUS (82%) was significantly higher than that for MDCT (41%) (relative risk (RR): 2.06, 95% confidence interval (CI) 1.07–3.94; P = 0.030). For lymph node involvement, the sensitivity value for EUS (91%) was also significantly higher than that for MDCT (77%) (RR 1.14, 95% CI 1.05–1.23; P = 0.001). However, the specificity values of both EUS and MDCT were quite low, at 49 and 63%, respectively. No significant differences in T2–4 staging between EUS and MDCT were noted.

Conclusion

This meta-analysis indicates that EUS may be superior to MDCT in preoperative T1 and N staging. Additionally, the low specificity values of EUS and MDCT for N staging merits attention.

Endoscopic ultrasound in gastric cancer staging before and after neoadjuvant chemotherapy. A comparison with PET-CT in a clinical series

BACKGROUND

Treatment of gastric cancer is based on accurate staging. Emerging methods, such as PET-CT, are increasingly being used for this purpose. Our aim was to analyze the results of EUS and PET-CT in staging and restaging our patients with gastric cancer, comparing both of them with the histological results.

METHODS

Patients with confirmed gastric cancer were prospectively enrolled. Inclusion criteria for the final analysis included only patients who finally received a surgical resection. All patients underwent preoperative TNM staging by means of EUS and PET-CT within 21 days prior to the surgical treatment.

RESULTS

A total of 256 patients were included. The overall EUS accuracy for T staging was 78% and 80.2% in restaging. EUS showed its best accuracy when distinguishing T1-T2 tumors vs. T3-T4, with an increased accuracy in restaging. Regarding N staging, the overall accuracy of EUS was 76.2%, and 72.5% for PET-CT (p = 0.02). With regards to restaging, accuracy of EUS and PET-CT for N staging was 88.5% and 69%, respectively, with significant differences (p < 0.0001).

CONCLUSIONS

EUS performed better than PET-CT in gastric cancer N staging and restaging. EUS accuracy in this setting is still suboptimal and probably more than one single diagnostic procedure should be used.

Role of endoscopic ultrasonography in TNM staging of gastric cancer

Gastric cancer is a common malignancy that has a poor prognosis and high mortality. Cancer staging is the optimal method for evaluating prognosis. Endoscopic ultrasonography (EUS) has been considered the first-choice imaging modality for regional staging of gastric cancer because different structural layers of the gastric wall show remarkable differences in their echogenic appearance. However, the results of recent studies about the accuracy of EUS for staging of gastric cancer are contradictory. The aim of this article is to review the role of EUS in preoperative TNM staging of gastric cancer.

Gastric Cancer: Preoperative TNM Staging With Individually Adjusted Computed Tomography Scanning Phase

OBJECTIVE

The aim of this study was to evaluate test bolus scan technology on preoperative diagnostic performance, vascular enhancement, and artery visualization for gastric cancer.

METHODS

The institutional review board approved this study. Fifty-four patients in protocol 1 were resigned to a fixed delay time scan method, and their images were obtained in the late arterial phase (AP) and portal venous phase (PP), with start delays of 40 and 70 seconds, respectively. Fifty-six patients in protocol 2 had undergone the test bolus method first and received the time to peak enhancement of the aorta. Their images were obtained in the AP and PP with start delays in the time to peak enhancement and 20 seconds after the AP, respectively. Two radiologists performed consensus interpretation of the preoperative TNM staging, vascular enhancement, tumor contrast-to-noise ratio (CNR) and artery visualization between the 2 protocols.

RESULTS

There is no significant difference in the T, N, and M staging diagnostic accuracy between the protocols (P = 0.41, P > 0.99, and P = 0.34, respectively). For serosa-negative (T1, T2, and T3) tumors, the diagnostic accuracy obtained with protocol 2 was superior to that obtained with protocol 1 (P = 0.04). Protocol 2 was superior for perigastric vessel enhancement (left gastric artery, right gastroepiploic artery, and splenic artery; P < 0.001, P < 0.001, and P = 0.001, respectively). The stomach-to-tumor CNR during the PP of protocol 2 was significantly higher than that during either the AP or PP of protocol 1 (P = 0.004 and P = 0.001, respectively). The mean rankings of the artery visualization were significantly higher with protocol 2 than with protocol 1 (P < 0.001).

CONCLUSIONS

The dual-phase scan with test bolus technology could improve the tumor CNR and had high staging accuracy for serosa-negative tumors as well as high perigastric artery enhancement, yielding satisfactory artery visualization for diagnosis.

Combination of preoperative platelet/lymphocyte and neutrophil/lymphocyte rates and tumor-related factors to predict lymph node metastasis in patients with gastric cancer

OBJECTIVE

Lymph node (LN) metastasis is widely accepted as a poor prognosis indicator in patients with gastric cancer. An accurate preoperative prediction of LN status is of crucial importance for the planning treatment. The aim of the present study was to assess the predictive value of the preoperative platelet/lymphocyte (PLR) and neutrophil/lymphocyte rates (NLR) on the LN metastasis in gastric cancer patients and to develop a new preoperative score system to predict LN metastasis.

PATIENTS AND METHODS

A total of 492 operable patients with gastric cancer were enrolled in our study. The clinical utility of the PLR and NLR was evaluated by receiver operating characteristic (ROC) curves. The logistic analysis was used to identify the independent parameters associated with LN metastasis. Then, a score system including those independent parameters that can be detected preoperatively was established, which was also tested by an ROC curve.

RESULTS

The ideal cutoff values for predicting LN metastasis were 1.59 for NLR and 155.67 for PLR according to the ROC curve. Multivariate analyses showed that both PLR and NLR are significantly associated with LN metastasis independent of depth of invasion, lymphatic invasion, macroscopic type, and tumor size. The area under the ROC curve of the score system was 0.830 (95% confidence interval 0.782-0.878), showing a reliable ability to evaluate the status of nodal involvement.

CONCLUSION

Preoperative PLR and NLR are useful biomarkers to predict LN metastasis and the score system in our study may serve as a reliable instrument to predict LN metastasis in gastric cancer patients.

Is preoperative staging enough to guide lymph node dissection in clinically early gastric cancer?

BACKGROUND

Limited by the accuracy of preoperative staging, some cases of gastric cancer invading the muscularis propria (pT2) are underestimated as early gastric cancer (EGC) in the preoperative assessment. The aim of this present study was to determine prognostic factors and to propose indications for limited lymph node dissection in patients with clinically EGC (cEGC).

METHODS

Patients of cEGC (n = 2072) who were postoperatively diagnosed as pT1 (cT1pT1, n = 1858) and pT2 (cT1pT2, n = 214) from 2005 to 2009 at Seoul National University Hospital were retrospectively analyzed.

RESULTS

There was no difference in 5-year survival rate between the cT1pT1 and cT1pT2 group (95.5 % vs. 92.5 %, P = 0.059), and both groups had better overall survival than pT2 patients who were preoperatively diagnosed as locally advanced gastric cancer (cT2-4pT2), whose 5-year survival rate was 78.0 % (P < 0.001). Multivariate analysis indicated lymph node metastasis (LNM) was the independent prognostic factor for cEGC (P < 0.001). In cEGC patients, three preoperative factors, including N stage by multidetector-row computed tomography (MDCT) (P < 0.001), preoperative histological type (P < 0.001), and tumor size (P < 0.001), were associated with LNM by multivariate analysis. Regarding the possibility of LNM, low-risk (4.4 %) and high-risk (17.3 %) groups were developed based on weighted scores of the aforementioned independent three variables. Among 52 patients in the low-risk group, the extension of LNM was limited to the perigastric area.

CONCLUSIONS

Comprehensive evaluation based on MDCT, preoperative histological type, and tumor size is an effective method to predict LNM and guide tailored LN dissection for cEGC.

The predictive factors for lymph node metastasis in early gastric cancer: A clinical study

Objective:

To detect the clinicopathological factors associated with lymph node metastases in early gastric cancer.

Methods:

We retrospectively evaluated the distribution of metastatic nodes in 198 patients with early gastric cancer treated in our hospital between May 2008 and January 2015, the clinicopathological factors including age, gender, tumor location, tumor size, macroscopic type, depth of invasion, histological type and venous invasion were studied, and the relationship between various parameters and lymph node metastases was analyzed.

Results:

In this study, one hundred and ninety-eight patients with early gastric cancer were included, and lymph node metastasis was detected in 28 patients. Univariate analysis revealed a close relationship between tumor size, depth of invasion, histological type, venous invasion, local ulceration and lymph node metastases. Multivariate analysis revealed that the five factors were independent risk factors for lymph node metastases.

Conclusion:

The clinicopathological parameters including tumor size, depth of invasion, local ulceration, histological type and venous invasion are closely correlated with lymph node metastases, should be paid high attention in early gastric cancer patients.

Preoperative locoregional staging of gastric cancer: is there a place for magnetic resonance imaging? Prospective comparison with EUS and multidetector computed tomography

BACKGROUND

The aim of this study was to prospectively compare the diagnostic performance of magnetic resonance imaging (MRI), multidetector computed tomography (MDCT) and endoscopic ultrasonography (EUS) in the preoperative locoregional staging of gastric cancer.

METHODS

This study had Institutional Review Board approval, and informed consent was obtained from all patients. Fifty-two patients with biopsy-proven gastric cancer underwent preoperative 1.5-T MRI, 64-channel MDCT and EUS. All images were analysed blind, and the results were compared with histopathological findings according to the seventh edition of the TNM classification. After the population had been divided on the basis of the local invasion (T1-3 vs T4a-b) and nodal involvement (N0 vs N+), sensitivity, specificity, positive and negative predictive value, and accuracy were calculated and diagnostic performance measures were assessed using the McNemar test.

RESULTS

For T staging, EUS showed higher sensitivity (94%) than MDCT and MRI (65 and 76%; p = 0.02 and p = 0.08). MDCT and MRI had significantly higher specificity (91 and 89%) than EUS (60%) (p = 0.0009 and p = 0.003). Adding MRI to MDCT or EUS did not result in significant differences for sensitivity. For N staging, EUS showed higher sensitivity (92%) than MRI and MDCT (69 and 73%; p = 0.01 and p = 0.02). MDCT showed better specificity (81%) than EUS and MRI (58 and 73%; p = 0.03 and p = 0.15).

CONCLUSIONS

Our prospective study confirmed the leading role of EUS and MDCT in the staging of gastric cancer and did not prove, at present, the value of the clinical use of MRI.

Pre-operative lymph node status of gastric cancer evaluated by multidetector computed tomography

The purpose of the present study was to perform a meta-analysis to evaluate the diagnostic value of Multidetector computed tomography (MDCT) in the pre-operative lymph node (N) staging in gastric cancer (GC) patients. The Medline, Embase and Web of Knowledge were searched for studies assessing the diagnostic value of MDCT in the pre-operative evaluation of TNM staging in GC patients. We pooled the sensitivity, specificity, positive and negative Likelihood ratio (LR+ and LR-), Diagnostic Odds Ratio (DOR) and constructed summary receiver operating characteristic curves (ROC). A total of 30 studies including 6637 GC patients were analyzed. The pooled estimates of sensitivity, specificity, LR+, LR- and DOR of MDCT in the detection of pre-operative N staging in GC patients were 0.67 (95% CI: 0.66-0.69 ), 0.84 (95% CI: 0.83-0.85), 3.25 (95% CI: 2.69-3.93), 0.36 (95% CI: 0.28-0.46) and 10.31 (95% CI: 7.66-13.88), respectively. The results of a summary ROC showed that the AUC and Q* were 0.8338 and 0.7661, respectively. As a control, the AUC and Q* of endoscopic ultrasonography were 0.8063 and 0.7414, respectively. Currently, it is necessary to recommend the routine clinical application of MDCT in the preoperative evaluation of lymph node status in GC patients.

Modern imaging techniques for preoperative detection of distant metastases in gastric cancer

A substantial portion of patients with newly diagnosed gastric cancer has distant metastases (M1 disease). These patients have a very poor prognosis and it is generally accepted that they should be treated with noncurative intent. Because it dramatically changes prognosis and treatment plans, it is very important to diagnose distant metastases. In this article, the definition, pathways, incidence and sites of distant metastases in gastric cancer are described. Subsequently, the current performance of imaging in detecting distant metastases in newly diagnosed gastric cancer is outlined and future prospects are discussed.

Learning curve for EUS in gastric cancer T staging by using cumulative sum analysis

BACKGROUND

EUS is an operator-dependent procedure and requires more technical and cognitive skills than a routine endoscopic procedure. The learning curve for the staging of gastric cancer, however, has not been evaluated.

OBJECTIVE

To evaluate the threshold number of EUS examinations for gastric cancer T staging.

DESIGN

Retrospective study.

SETTING

University-affiliated tertiary care hospital in the Republic of Korea.

PATIENTS

Four trainees with no previous EUS experience.

INTERVENTION

Analyzing performance of EUS trainees in gastric cancer T staging by using cumulative sum (CUSUM) analysis.

MAIN OUTCOME MEASUREMENTS

CUSUM plot and a minimal number of procedures for reaching a plateau.

RESULTS

A total of 553 initial EUS examinations for treatment-naïve gastric cancers, performed by trainees, were enrolled in the study. The final T stage was determined by experts by using EUS in 332 gastric cancer cases, whereas the T stage of the other 221 lesions was determined by trainees by using EUS. The accuracy of EUS examinations performed by trainees and experts was 72.6% and 84.3%, respectively. The number of EUS examinations required to reach the first plateau in each trainee was 20, 41, 60, and 65.

LIMITATIONS

Retrospective study with a relatively small number of trainees.

CONCLUSION

The CUSUM scores of all of 4 trainees in the study reached a plateau by the 65th examination.

Diagnostic accuracy of endoscopic ultrasonography (EUS) for the preoperative locoregional staging of primary gastric cancer

BACKGROUND

Endoscopic ultrasound (EUS) is proposed as an accurate diagnostic device for the locoregional staging of gastric cancer, which is crucial to developing a correct therapeutic strategy and ultimately to providing patients with the best chance of cure. However, despite a number of studies addressing this issue, there is no consensus on the role of EUS in routine clinical practice.

OBJECTIVES

To provide both a comprehensive overview and a quantitative analysis of the published data regarding the ability of EUS to preoperatively define the locoregional disease spread (i.e., primary tumor depth (T-stage) and regional lymph node status (N-stage)) in people with primary gastric carcinoma.

SEARCH METHODS

We performed a systematic search to identify articles that examined the diagnostic accuracy of EUS (the index test) in the evaluation of primary gastric cancer depth of invasion (T-stage, according to the AJCC/UICC TNM staging system categories T1, T2, T3 and T4) and regional lymph node status (N-stage, disease-free (N0) versus metastatic (N+)) using histopathology as the reference standard. To this end, we searched the following databases: the Cochrane Library (the Cochrane Central Register of Controlled Trials (CENTRAL)), MEDLINE, EMBASE, NIHR Prospero Register, MEDION, Aggressive Research Intelligence Facility (ARIF), ClinicalTrials.gov, Current Controlled Trials MetaRegister, and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), from 1988 to January 2015.

SELECTION CRITERIA

We included studies that met the following main inclusion criteria: 1) a minimum sample size of 10 patients with histologically-proven primary carcinoma of the stomach (target condition); 2) comparison of EUS (index test) with pathology evaluation (reference standard) in terms of primary tumor (T-stage) and regional lymph nodes (N-stage). We excluded reports with possible overlap with the selected studies.

DATA COLLECTION AND ANALYSIS

For each study, two review authors extracted a standard set of data, using a dedicated data extraction form. We assessed data quality using a standard procedure according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. We performed diagnostic accuracy meta-analysis using the hierarchical bivariate method.

MAIN RESULTS

We identified 66 articles (published between 1988 and 2012) that were eligible according to the inclusion criteria. We collected the data on 7747 patients with gastric cancer who were staged with EUS. Overall the quality of the included studies was good: in particular, only five studies presented a high risk of index test interpretation bias and two studies presented a high risk of selection bias.For primary tumor (T) stage, results were stratified according to the depth of invasion of the gastric wall. The meta-analysis of 50 studies (n = 4397) showed that the summary sensitivity and specificity of EUS in discriminating T1 to T2 (superficial) versus T3 to T4 (advanced) gastric carcinomas were 0.86 (95% confidence interval (CI) 0.81 to 0.90) and 0.90 (95% CI 0.87 to 0.93) respectively. For the diagnostic capacity of EUS to distinguish T1 (early gastric cancer, EGC) versus T2 (muscle-infiltrating) tumors, the meta-analysis of 46 studies (n = 2742) showed that the summary sensitivity and specificity were 0.85 (95% CI 0.78 to 0.91) and 0.90 (95% CI 0.85 to 0.93) respectively. When we addressed the capacity of EUS to distinguish between T1a (mucosal) versus T1b (submucosal) cancers the meta-analysis of 20 studies (n = 3321) showed that the summary sensitivity and specificity were 0.87 (95% CI 0.81 to 0.92) and 0.75 (95% CI 0.62 to 0.84) respectively. Finally, for the metastatic involvement of lymph nodes (N-stage), the meta-analysis of 44 studies (n = 3573) showed that the summary sensitivity and specificity were 0.83 (95% CI 0.79 to 0.87) and 0.67 (95% CI 0.61 to 0.72), respectively.Overall, as demonstrated also by the Bayesian nomograms, which enable readers to calculate post-test probabilities for any target condition prevalence, the EUS accuracy can be considered clinically useful to guide physicians in the locoregional staging of people with gastric cancer. However, it should be noted that between-study heterogeneity was not negligible: unfortunately, we could not identify any consistent source of the observed heterogeneity. Therefore, all accuracy measures reported in the present work and summarizing the available evidence should be interpreted cautiously. Moreover, we must emphasize that the analysis of positive and negative likelihood values revealed that EUS diagnostic performance cannot be considered optimal either for disease confirmation or for exclusion, especially for the ability of EUS to distinguish T1a (mucosal) versus T1b (submucosal) cancers and positive versus negative lymph node status.

AUTHORS' CONCLUSIONS

By analyzing the data from the largest series ever considered, we found that the diagnostic accuracy of EUS might be considered clinically useful to guide physicians in the locoregional staging of people with gastric carcinoma. However, the heterogeneity of the results warrants special caution, as well as further investigation for the identification of factors influencing the outcome of this diagnostic tool. Moreover, physicians should be warned that EUS performance is lower in diagnosing superficial tumors (T1a versus T1b) and lymph node status (positive versus negative). Overall, we observed large heterogeneity and its source needs to be understood before any definitive conclusion can be drawn about the use of EUS can be proposed in routine clinical settings.

The clinical significance and risk factors of solitary lymph node metastasis in gastric cancer

AIMS

To assess the clinical significance and risk factors of solitary lymph node metastasis (SLM) in gastric carcinoma and establish a more accurate method to evaluate the possibility of lymph node metastasis (LM).

METHODS

A total of 385 patients with gastric carcinoma who underwent D2 lymphadenectomy at the Cancer Center of Sun Yat-Sen University were included in this research. Then we used a group of data from Sun Yat-sen University Gastrointestinal Hospital (SYSUGIH) to validate the accuracy of our developed method. The χ2 test, Kaplan-Meier analysis, log-rank test, COX model, and discriminate analysis were used to analyze the data with SPSS13.0.

RESULTS

We found that the LM number and pathological T staging were independent prognostic risk factors. CEA grading, LN status by CT, and T staging by CT were independent risk factors for LM in gastric carcinoma. In addition, we developed the equation Y = -5.0 + X1 + 1.8X3 + 0.7X4 (X1 = CEA grading, X3 = LN status by CT, X4 = T staging by CT) to evaluate the situation of LM. The data from SYSUGIH shows this equation has a better accuracy compared with CT.

CONCLUSIONS

SLM is an independent risk factor in gastric cancer. And there was no survival difference between the skip metastasis group and the other SLM group (P = 0.659). It is inappropriate for the patient with SLM doing a standard D2 lymphadenectomy, due to the fact that LM rarely occurs in the splenic artery, splenic hilum. The risk factors for LM include CEA grading, LN status by CT, and T staging by CT. And we can use Y = -5.0 + X1 + 1.8X3 + 0.7X4 (X1, CEA grading, X3 = LN status by CT, X4 = T staging by CT, the critical value is 0.3) to estimate the possibility of LM, which has a better accuracy compared with CT.

Gastric Carcinoma: Ex Vivo MR Imaging at 7.0 T-Correlation with Histopathologic Findings

PURPOSE

To determine the imaging detail and diagnostic information that can be obtained at 7.0-T magnetic resonance (MR) imaging with a voxel volume of 9.5-14.0 nL as a means of evaluating the depth of mural invasion by gastric carcinomas ex vivo.

MATERIALS AND METHODS

This study was approved by the institutional review board, and written informed consent was obtained from each patient. Twenty gastric specimens containing 20 carcinomas were studied with a 7.0-T MR imaging system equipped with a four-channel surface coil. MR images were obtained with a 50-60 × 25-30 mm field of view, a 512 × 256 matrix, and a 1.0-mm section thickness, resulting in a voxel volume of 0.0095-0.0140 mm(3) (9.5-14.0 nL). The signal intensity of the gastric wall layers, tumor tissue, and fibrosis was described as low, intermediate, or high by comparing it with the signal intensity of the muscularis propria. Depth of invasion initially was assessed by two reviewers independently and then by the two reviewers in consensus. MR images were compared with histopathologic findings.

RESULTS

The 7.0-T T2-weighted MR images clearly depicted the normal gastric wall in all 20 specimens (100%) as consisting of seven layers, which clearly corresponded to the tissue layers of the gastric wall. These MR images enabled clear differentiation between tumor tissue and fibrosis. Reviewers disagreed on the depth of invasion at the initial reading in three (15%) of 20 specimens (between mucosa and submucosa in two specimens and between muscularis propria and subserosa and serosa in one specimen); however, in all 20 gastric carcinomas, the depth of invasion could be accurately determined on T2-weighted images after consensus interpretation.

CONCLUSION

Ex vivo 7.0-T MR imaging enables clear delineation of the gastric wall layers and clear differentiation of tumor tissue from fibrosis and allows one to assess the depth of mural invasion by gastric carcinomas.

Techniques of imaging of nodal stations of gastric cancer by endoscopic ultrasound

Nodal staging is of crucial importance in the management of gastric cancer (GC). The available modalities of nodal imaging in GC do not provide a high sensitivity and specificity of lymph node status. Comparative study of endoscopic ultrasonography (EUS) and multislice spiral computed tomography in GC has shown greater accuracy of EUS for N staging. EUS is not used routinely in patients with GC as it is not available at all centers, and its accuracy is operator dependent. Standard techniques of identification of nodal station (as suggested by Japanese Research Society for the Study of Gastric Cancer) by EUS have not been described so far. Identification of each nodal station by EUS requires adequate knowledge of anatomy as well as understanding the proper technique to perform EUS. This review presents a method to identify the regional nodal stations of GC by linear EUS and hence will help in appropriate N staging of GC.