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

Correlation between Tomographic and Histopathological Staging in Upfront Resected Gastric Cancer: Enhancing Diagnostic Accuracy in the Era of Perioperative Therapy

PURPOSE

This study aimed to assess the diagnostic accuracy of multidetector contrast-enhanced computerised tomography (MDCT) and to establish a correlation between radiological and histopathological staging in upfront resected localised gastric cancers (GC).

METHODS

All consecutive patients of resectable, localised GC who underwent upfront elective resection between 2010 and 2022 were included. The initial clinical staging determined during multidisciplinary meetings was compared with the pathological stage obtained after surgery. Subsequently, a retrospective, blinded review was conducted to assign a revised clinical staging, and accuracy was correlated.

RESULTS

The analysis of 138 patients revealed varying accuracy of MDCT in determining the T stage (66.9% for T1/T2, 64.6% for T3, and 87.2% for T4) and N stage (60.8% for N0, 63.7% for N1, and 83.2% for N2). The accuracy for stage group ranged from 71 to 78.65%. There was weak agreement observed between the T, N, and overall stage on clinicopathological correlation. However, a blinded radiology review by oncoradiologists resulted in improved accuracy, particularly in T1/T2 disease, and also improved pathological stage correlation.

CONCLUSIONS

Although MDCT is a valuable initial staging tool for gastric cancer, we found weak agreement between the clinical and the pathological stages in upfront resected gastric cancers. By implementing an expert radiology review and standardising scanning and reporting protocols, we can significantly improve the accuracy and correlation of MDCT with pathology, even for T1/T2 disease. This may help in better selecting patients for upfront surgery versus perioperative chemotherapy, especially in resource-constrained settings.

Risk assessment of lymph node metastasis in early gastric cancer patients with vagus nerve-preserving gastrectomy: A multiple centers potential analysis in China

BACKGROUND

Vagus nerve-preserving gastrectomy is gaining popularity for early gastric cancer treatment. This study assesses vagus nerve-preserving gastrectomy's perioperative safety and impact on postoperative quality of life, and explores vagus nerve-associated lymph node metastasis to create a risk model for enhanced therapy.

METHODS

Clinicopathologic data from 1,210 early gastric cancer patients across 11 Chinese centers were analyzed, and the data of 800 patients with follow-up information and 48 patients who underwent vagus nerve-preserving gastrectomy for validation were collected. Propensity score matching was applied to the analysis of perioperative safety and quality of life in vagus nerve-preserving gastrectomy patients. A 6-point risk assessment model was devised and validated to evaluate the risk of vagus nerve-associated lymph node metastasis after vagus nerve-preserving gastrectomy in early gastric cancer patients.

RESULTS

Vagus nerve-preserving gastrectomy patients had shorter postoperative stays, quicker drainage cessation, and fewer incidences of diarrhea, acid reflux, and postoperative gallstones. Additionally, key independent risk factors for vagus nerve-associated lymph node metastasis included tumor size, differentiation type, invasion depth, and lymphatic vessel invasion. Using these factors, a 6-point risk assessment model was established. The values of the area under the receiver operating characteristic curve for the model were 0.796, 0.806, 0.808, and 0.829 in the training cohort, internal validation cohort, external validation cohort, and vagus nerve-preserving gastrectomy cohort, respectively. The model effectively differentiated between high- and low-risk groups in terms of postoperative survival.

CONCLUSIONS

Vagus nerve-preserving gastrectomy can improve the patients' postoperative quality of life and ensure safety in the perioperative period. The vagus nerve-associated lymph node metastasis risk assessment model is a crucial tool in guiding the selection of optimal surgical procedures and treatment strategies for early gastric cancer patients.

Radiomics analysis of dual-energy CT-derived iodine maps for differentiating between T1/2 and T3/4a in gastric cancer: A multicenter study

OBJECTIVE

To investigate the value of radiomic analysis of dual-energy CT (DECT)-derived iodine maps (IMs) for the differentiation between T1/2 and T3/4a stage tumors in gastric cancer (GC).

METHODS

A total of 263 patients who received upfront surgery and were pathologically confirmed with gastric adenocarcinoma were enrolled in this study. Dual-phase enhanced CT scans with gemstone spectral imaging (GSI) mode were performed within two weeks before surgery. 151 patients were retrospectively collected for the training (n = 105) and validation (n = 46) cohorts, and 112 patients were prospectively collected for the external test1 (n = 68) and external test2 (n = 44) cohorts. According to the postoperative pathological T stage, patients were classified into T1/2 and T3/4a stage groups. Clinical characteristics were recorded and quantitative iodine concentration (IC) of tumors was measured. Radiomics features were extracted from the venous phase (VP) IMs by three-dimensional region of interest (3D-ROI) segmentation. Feature selection was performed using the least absolute shrinkage and selection operator. Four machine learning algorithms, including random forest, logistic regression, naive Bayes, and support vector machine, were used to construct radiomics models. Finally, the most valuable clinical characteristics, DECT parameters, and the best radiomics model were combined to build a nomogram. The diagnostic performance of nomogram was evaluated by the area under receiver operating characteristic curve (AUC), calibration curve, and decision curve.

RESULTS

The nomogram combined tumor clinical T stage (cT), tumor thickness, venous-phase iodine concentration (ICVP), normalized arterial-phase iodine concentration (nICAP), and Radscore (derived from logistic regression model). This integrated model demonstrated favorable performance in the differentiation between T1/2 and T3/4a stage tumors in GC, with AUCs of 0.892 (95 %CI: 0.829-0.956), 0.846 (95 %CI: 0.734-0.958), 0.894 (95 %CI: 0.818-0.970) and 0.821 (95 %CI: 0.689-0.952) observed for the training, validation, external test 1, and external test 2 cohorts, respectively. Hosmer-Lemeshow test showed a good fit (all P > 0.05). Decision curves confirmed that the nomogram provided more net clinical benefit than the default simple strategy over a wide range of threshold probabilities.

CONCLUSION

We have developed and validated a multidimensional personalized nomogram that integrates a radiomics model based on DECT-derived IMs, DECT quantitative parameters, and traditional clinical features. The proposed model demonstrated favorable performance in preoperative identification of T3/4a stage tumors in GC.

Influence of visceral adipose tissue on the accuracy of tumor T-staging of gastric cancer in preoperative CT

OBJECTIVES

To evaluate the impact of the visceral adipose tissue (VAT) area and density on the accuracy of tumor T-staging of gastric cancer in preoperative computed tomography (CT).

METHODS

This study included 136 patients with gastric cancer in our research center from January 2021 to June 2022. The patients were divided into two groups based on their postoperative pathological results: accurate-staging (matched T-staging evaluated by preoperative CT and postoperative pathology) and inaccurate-staging (unmatched T-staging evaluated by preoperative CT and postoperative pathology) groups. Preoperative CT was performed to assess the VAT area and density, and logistic regression was employed to evaluate the effect of VAT on the accuracy of preoperative-CT-evaluated T-staging of patients with gastric cancer.

RESULTS

The accurate-staging group had a significantly higher VAT area (134.64 ± 70.55 cm2 vs 95.44 ± 66.18 cm2, P = 0.003) and significantly lower VAT density (-95.05 ± 12.28 Hounsfield Units [HU] vs - 89.68 ± 13.26 HU, P = 0.027) than the inaccurate-staging group. A low VAT area (P = 0.002) and tumor located in the upper stomach (P = 0.019) were significantly associated with and were independent risk factors for the error of CT-evaluated T-staging. Compared to a VAT area ≥ 81.04 cm2, which was used as a reference, the odds ratio (OR) of a VAT area < 81.04 cm2 for the probability of T-staging mis-assessment was 4.455 (95% confidence interval [CI]: 1.728-11.485).

CONCLUSIONS

A low VAT area in patients with gastric cancer had adverse effects on preoperative CT-evaluated T-staging.

AutoLNMNet: Automated Network for Estimating Lymph-Node Metastasis in EGC Using a Pyramid Vision Transformer and Data Derived From Multiphoton Microscopy

Lymph-node status is important in decision-making during early gastric cancer (EGC) treatment. Currently, endoscopic submucosal dissection is the mainstream treatment for EGC. However, it is challenging for even experienced endoscopists to accurately diagnose and treat EGC. Multiphoton microscopy can extract the morphological features of collagen fibers from tissues. The characteristics of collagen fibers can be used to assess the lymph-node metastasis status in patients with EGC. First, we compared the accuracy of four deep learning models (VGG16, ResNet34, MobileNetV2, and PVTv2) in training preprocessed images and test datasets. Next, we integrated the features of the best-performing model, which was PVTv2, with manual and clinical features to develop a novel model called AutoLNMNet. The prediction accuracy of AutoLNMNet for the no metastasis (Ly0) and metastasis in lymph nodes (Ly1) stages reached 0.92, which was 0.3% higher than that of PVTv2. The receiver operating characteristics of AutoLNMNet in quantifying Ly0 and Ly1 stages were 0.97 and 0.97, respectively. Therefore, AutoLNMNet is highly reliable and accurate in detecting lymph-node metastasis, providing an important tool for the early diagnosis and treatment of EGC.

Double contrast-enhanced ultrasonography improves diagnostic accuracy of T staging compared with multi-detector computed tomography in gastric cancer patients

BACKGROUND

Gastric cancer (GC) is the most common malignant tumor and ranks third for cancer-related deaths among the worldwide. The disease poses a serious public health problem in China, ranking fifth for incidence and third for mortality. Knowledge of the invasive depth of the tumor is vital to treatment decisions.

AIM

To evaluate the diagnostic performance of double contrast-enhanced ultrasonography (DCEUS) for preoperative T staging in patients with GC by comparing with multi-detector computed tomography (MDCT).

METHODS

This single prospective study enrolled patients with GC confirmed by preoperative gastroscopy from July 2021 to March 2023. Patients underwent DCEUS, including ultrasonography (US) and intravenous contrast-enhanced ultrasonography (CEUS), and MDCT examinations for the assessment of preoperative T staging. Features of GC were identified on DCEUS and criteria developed to evaluate T staging according to the 8^th edition of AJCC cancer staging manual. The diagnostic performance of DCEUS was evaluated by comparing it with that of MDCT and surgical-pathological findings were considered as the gold standard.

RESULTS

A total of 229 patients with GC (80 T1, 33 T2, 59 T3 and 57 T4) were included. Overall accuracies were 86.9% for DCEUS and 61.1% for MDCT (P < 0.001). DCEUS was superior to MDCT for T1 (92.5% vs 70.0%, P < 0.001), T2 (72.7% vs 51.5%, P = 0.041), T3 (86.4% vs 45.8%, P < 0.001) and T4 (87.7% vs 70.2%, P = 0.022) staging of GC.

CONCLUSION

DCEUS improved the diagnostic accuracy of preoperative T staging in patients with GC compared with MDCT, and constitutes a promising imaging modality for preoperative evaluation of GC to aid individualized treatment decision-making.

Prognostic Relevance of Preoperative Immune, Inflammatory, and Nutritional Biomarkers in Patients Undergoing Gastrectomy for Resectable Gastric Adenocarcinoma: An Observational Multicentre Study

Background: The aim of this study was to evaluate different preoperative immune, inflammatory, and nutritional scores and their best cut-off values as predictors of poorer overall survival (OS) and disease-free survival (DFS) in patients who underwent curative gastric cancer resection. Methods: This was a retrospective observational multicentre study based on data of the Spanish EURECCA Esophagogastric Cancer Registry. Time-dependent Youden index and log-rank test were used to obtain the best cut-offs of 18 preoperative biomarkers for OS and DFS. An adjusted Cox model with variables selected by bootstrapping was used to identify the best preoperative biomarkers, which were also analysed for every TNM stage. Results: High neutrophil-to-lymphocyte ratio (NLR), high monocyte systemic inflammation index (moSII), and low prognostic nutritional index (PNI) were identified as independent predictors of poor outcome: NLR > 5.91 (HR:1.73; 95%CI [1.23-2.43]), moSII >2027.12 (HR:2.26; 95%CI [1.36-3.78]), and PNI >40.31 (HR:0.75; 95%CI [0.58-0.96]) for 5-year OS and NLR > 6.81 (HR:1.75; 95%CI [1.24-2.45]), moSII > 2027.12 (HR:2.46; 95%CI [1.49-4.04]), and PNI > 40.31 (HR:0.77; 95%CI [0.60,0.97]) for 5-year DFS. These outcomes were maintained in the whole cohort for NLR and moSII (p < 0.05) but not in stage II and for PNI in all tumoral stages. The associations of NLR-PNI and moSII-PNI were also a relevant prognostic factor for OS. Conclusions: High NLR, high moSII (for stages I and III), and low PNI (regardless of tumour stage) were the most promising preoperative biomarkers to predict poor OS and DFS in gastric cancer patients treated with curative intent.

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.

Accuracy of preoperative clinical staging for locally advanced gastric cancer in KLASS-02 randomized clinical trial

PURPOSE

The discrepancy between preoperative and final pathological staging has been a long-standing challenge for the application of clinical trials or appropriate treatment options. This study aimed to demonstrate the accuracy of preoperative staging of locally advanced gastric cancer using data from a large-scale randomized clinical trial.

MATERIALS AND METHODS

Of the 1050 patients enrolled in the clinical trial, 26 were excluded due to withdrawal of consent (n = 20) or non-surgery (n = 6). The clinical and pathological staging was compared. Risk factor analysis for underestimation was performed using univariate and multivariate analyses.

RESULTS

Regarding T staging by computed tomography, accuracy rates were 74.48, 61.62, 58.56, and 85.16% for T1, T2, T3 and T4a, respectively. Multivariate analysis for underestimation of T staging revealed that younger age, ulcerative gross type, circular location, larger tumor size, and undifferentiated histology were independent risk factors. Regarding nodal status estimation, 54.9% of patients with clinical N0 disease were pathologic N0, and 36.4% of patients were revealed to have pathologic N0 among clinical node-positive patients. The percentage of metastasis involvement at the D1, D1+, and D2 lymph node stations significantly increased with the advanced clinical N stage. Among all patients, 29 (2.8%), including 26 with peritoneal seeding, exhibited distant metastases.

CONCLUSIONS

Estimating the exact pathologic staging remains challenging. A thorough evaluation is mandatory before treatment selection or trial enrollment. Moreover, we need to set a sufficient case number when we design the clinical trial considering the stage migration.

A potential decision-making algorithm based on endoscopic ultrasound for staging early gastric cancer: a retrospective study

BACKGROUND

Clinical staging of gastric cancer (GC) before treatment is essential. Endoscopic ultrasound (EUS) is a recommended staging tool, but its efficacy remains controversial. Our previous prospective study evaluated the potential value of EUS for T staging and presented discrepancies. In this study, we aimed to evaluate the efficacy of EUS in T staging by comparing it with pathological staging. We analyze the factors that can potentially affect accuracy to identify suitable subgroups for EUS staging.

METHODS

Data from a total of 1763 consecutive patients with GC from January 2015 to December 2017 were analyzed. Results from EUS and pathological T staging were compared. The factors that might affect EUS's accuracy were analyzed.

RESULTS

The sensitivity, specificity, positive predictive value, and negative predictive value of EUS in patients with early GC were 62.08%, 96.13%, 90.94%, and 80.21%, respectively. The accuracy rates of uT1, uT2-uT4, and uT3-uT4 were 90.94%, 79.02%, and 78.39%, respectively. In multivariate analysis, underestimation was more likely to be observed in patients with tumors located in the middle or upper third of the stomach. Overestimation was more likely to be observed in patients with tumors located in the lower third or those without ulcer. Other factors affecting accuracy included ulcer, differentiation, larger size and undergoing surgery.

CONCLUSION

Our findings highlight the role of EUS in determining the T staging of GC. Overestimation and underestimation in T-staging were significantly associated with the tumor location in early GC, and a decision-making algorithm was proposed for clinical practice in early cancers based on these findings.

Understanding the association between clinical staging accuracy, treatment response, and survival among gastric cancer patients through Bayesian analysis

BACKGROUND

Neoadjuvant therapy (NAT) improves survival among patients with locally advanced gastric cancer (GC), but it remains unclear whether its benefit is contingent on treatment response.

METHODS

This is a national cohort study of stage Ib-III GC patients in the National Cancer Data Base (2006-2015) treated with upfront resection or NAT followed by surgery. Bayesian analysis was used for NAT patients to ascertain staging concordance and to account for down-staging. We used multivariable Cox regression to evaluate the association between staging concordance, treatment, response to NAT, and survival.

RESULTS

The cohort included 13 340 patients treated at 1124 hospitals. Staging concordance ranged from 86.1% for cT3-4N+ to 34.7% for cT2N0 patients. Relative to accurately staged patients treated with upfront surgery, NAT was associated with a decreased risk of death if there was disease down-staging among those with cT1-2N+ (hazard ratio [HR]: 0.43 [0.30-0.61]), cT3-4N0 (HR: 0.69 [0.54-0.88]), and cT3-4N+ (HR: 0.51 [0.48-0.58]) tumors, and in the absence of down-staging among cT3-4N+ patients (HR: 0.83 [0.74-0.92]). Conversely, NAT without down-staging increased the risk of death among those with intermediate-stage disease.

CONCLUSIONS

NAT is associated with improved survival for GC, but it seems to be contingent on treatment response among patients with intermediate-stage disease.

Updated Evaluation of the Diagnostic Performance of Double Contrast-Enhanced Ultrasonography in the Preoperative T Staging of Gastric Cancer: A Meta-Analysis and Systematic Review

Objective

This study aimed to systematically evaluate the diagnostic performance of double contrast-enhanced ultrasonography (DCEUS) in the preoperative T staging of gastric cancer (GC).

Methods

Literature searches for eligible studies were performed using MEDLINE, EMBASE, and Cochrane Library. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the summary receiver operating characteristic curve of DCEUS in the diagnosis of each T stage tumor were calculated. Meta-analyses were performed to obtain the pooled effects of risk ratio (RR) with 95% confidence interval (CI) in the comparison of DCEUS with CT/endoscopic ultrasound (EUS).

Results

A total of 8 studies including 1,232 patients were identified for inclusion in this meta-analysis. The pooled sensitivity and specificity were 0.78 (95% CI = 0.64–0.88) and 0.98 (95% CI = 0.96–0.99) for T1, 0.81 (95% CI = 0.76–0.86) and 0.96 (95% CI = 0.91–0.98) for T2, 0.88 (95% CI = 0.84–0.91) and 0.85 (95% CI = 0.79–0.90) for T3, and 0.81 (95% CI = 0.69–0.89) and 0.96 (95% CI = 0.93–0.97) for T4. Moreover, DCEUS demonstrated significant superiority to CT in diagnosing T1 (RR = 1.57, 95% CI = 1.20–2.05, p = 0.001) and T2 (RR = 1.41, 95% CI = 1.16–1.71, p = 0.001) and to EUS in diagnosing T3 (RR = 1.24, 95% CI = 1.08–1.42, p = 0.003) and T4 (RR = 1.40, 95% CI = 1.09–1.79, p = 0.008). However, it showed a lower diagnostic accuracy than EUS in T1 tumors (RR = 0.77, 95% CI = 0.62–0.94, p = 0.013).

Conclusions

DCEUS is a feasible complementary diagnostic tool for clinical T staging of GC. However, it is still far from a definitive conclusion for DCEUS to be proposed for use in routine clinical practice.