A prospective multi-institutional validity study to evaluate the accuracy of clinical diagnosis of pathological stage III gastric cancer (JCOG1302A)

Gastrectomy after neoadjuvant chemotherapy in five cases of locally advanced gastric cancer with pancreatic head invasion

Locally advanced gastric cancer (LAGC) with pancreatic head invasion (T4b) carries a poor prognosis despite radical surgery. Herein, we report the effectiveness of neoadjuvant chemotherapy (NAC) in improving the resectability of advanced gastric cancer with pancreatic invasion. A total of 2191 cases of gastric cancer were retrospectively analyzed from 13 institutions within the Hiroshima Surgical Study Group of Clinical Oncology (Hisco) database from 2018 to 2020. Among them, 5 of the 24 patients with Stage cT4b gastric cancer underwent NAC for three-to-eight cycles. Following chemotherapy, three patients underwent total gastrectomy, two patients underwent distal gastrectomy, and no patient underwent pancreaticoduodenectomy (PD). All five patients achieved a chemotherapeutic response of Grade 1b or higher, and only one case showed residual pancreatic invasion on pathology. This study suggests that NAC for Stage T4b LAGC with pancreatic head invasion may have the potential to obviate the need for PD.

Dual-phase contrast-enhanced CT-based intratumoral and peritumoral radiomics for preoperative prediction of lymph node metastasis in gastric cancer

OBJECTIVE

To determine whether intratumoral and peritumoral radiomics derived from dual-phase contrast-enhanced CT imaging could predict lymph node metastasis (LNM) in gastric cancer.

METHODS

Patients with gastric cancer from January 2017 to January 2022 were retrospectively collected and were randomly divided into training cohort (n = 287) and test cohort (n = 121) with a ratio of 7: 3. Clinical features and traditional radiological features were analyzed to construct clinical model. Radiomics features based on intratumoral (ITV) and peritumoral volumetric (PTV) regions of the tumor were extracted and screened to construct radiomics models. Clinical-radiomics combined model was constructed by the most predictive radiomics features and clinical independent predictors. The correlation between LNM predicted by the best model and 2-year disease-free survival (DFS) was evaluated by the Kaplan-Meier analysis.

RESULTS

CT-LNM and CT-T stage were independent predictors of LNM. Compared with other radiomics models, ITV + PTV on atrial and venous phase (ITV + PTV-AP + VP) radiomics model presented moderate AUCs of 0.679 and 0.670 in the training cohort and validation cohort, respectively. Among the models, clinical-radiomics combined model achieved the highest AUC of 0.894 and 0.872 in the training and test cohorts, and 0.744 and 0.784 in the T1-2 and T3-4 subgroups, respectively. Clinical-radiomics combined model based LNM could stratify patients into high-risk and low-risk groups, and 2-year DFS of high-risk group was significantly lower than that of low-risk group (p < 0.001).

CONCLUSION

Clinical-radiomics combined model integrating CT-LNM, CT-T stage, and ITV-PTV-AP + VP radiomics features could predict LNM, and this combined model based LNM was associated with 2-year DFS.

Cost-effectiveness of open vs. laparoscopic gastrectomy for locally advanced gastric cancer in China

Locally advanced gastric cancer (LAGC) poses a significant surgical challenge. While laparoscopic gastrectomy (LG) offers potential advantages, its cost-effectiveness relative to open gastrectomy (OG) in China remains uncertain. To compare the cost-effectiveness of LG and OG for LAGC in China. A Markov model compared the cost-effectiveness of LG and OG for LAGC. Probabilities and utilities were derived from published literature. Direct medical costs were obtained from the First Hospital of Lanzhou University. The primary outcome was the incremental cost-effectiveness ratio (ICER), expressed as the cost per quality-adjusted life-year (QALY) gained, using a willingness-to-pay threshold of ¥268,074/QALY. Sensitivity analyses assessed model robustness. Across 1-, 3-, and 5-year time horizons, OG had lower total costs and greater effectiveness than LG for LAGC. At 5 years, OG had a total cost of ¥128,259 and 7.20 QALYs versus LG's ¥136,668 and 7.18 QALYs; the ICER for OG was -¥474,758/QALY. OG dominated at the ¥268,074 willingness-to-pay threshold. Sensitivity analysis indicated that variations in LG and OG costs minimally influenced the cost-effectiveness. Probabilistic sensitivity analysis, performed across 10,000 iterations, consistently identified OG as the optimal strategy (100% of iterations). From a Chinese health economics perspective-a framework essential for informing national healthcare resource allocation-OG consistently demonstrated a superior cost-effectiveness compared with LG for LAGC across 1, 3, and 5 years. This longitudinal observation of sustained cost-effectiveness persisted despite the statistically insignificant differences in overall costs and effectiveness between the two procedures.

Neoadjuvant therapy with immune checkpoint inhibitors in combination with chemotherapy vs . chemotherapy alone in HER2(-) locally advanced gastric cancer: A propensity score-matched cohort study

BACKGROUND

This study aims to compare the efficacy between neoadjuvant immune checkpoint inhibitors (ICIs) plus chemotherapy vs . chemotherapy, and neoadjuvant triplet vs . doublet chemotherapeutic regimens in locally advanced gastric/esophagogastric junction cancer (LAGC).

METHODS

We included LAGC patients from 47 hospitals in China's National Cancer Information Database (NCID) from January 2019 to December 2022. Using propensity score matching (PSM), we retrospectively analyzed the efficacy between neoadjuvant ICIs plus chemotherapy vs . chemotherapy alone, and neoadjuvant triplet vs . doublet chemotherapeutic regimens. The primary study result was the pathologic complete response (pCR) rate. The secondary study results were disease-free survival (DFS) and overall survival (OS).

RESULTS

A total of 1205 LAGC patients were included. After PSM, the ICIs plus chemotherapy and the chemotherapy cohorts had 184 patients each, while the doublet and triplet chemotherapy cohorts had 246 patients each. The pCR rate (14.13% vs . 7.61%, χ2 = 4.039, P = 0.044), and the 2-year (77.60% vs . 61.02%, HR = 0.67, 95% con-fidence interval [CI] 0.43-0.98, P = 0.048) and 3-year (70.55% vs . 61.02%, HR = 0.58, 95% CI 0.32-0.93, P = 0.048) DFS rates in the ICIs plus chemotherapy cohort were improved compared to those in the chemotherapy cohort. No significant increase was observed in the OS rates at both 1 year and 2 years. The pCR rates, DFS rates at 1-3 years, and OS rates at 1-2 years did not differ significantly between the doublet and triplet cohorts, respectively. No differences were observed in postoperative complications between any of the group comparisons.

CONCLUSIONS

Neoadjuvant ICIs plus chemotherapy improved the pCR rate and 2-3 years DFS rates of LAGC compared to chemotherapy alone, but whether short-term benefit could translate into long-term efficacy is unclear. The triplet regimen was not superior to the doublet regimen in terms of efficacy. The safety after surgery was similar between either ICIs plus chemotherapy and chemotherapy or the triplet and the doublet regimen.

Integrating Machine Learning and the SHapley Additive exPlanations (SHAP) Framework to Predict Lymph Node Metastasis in Gastric Cancer Patients Based on Inflammation Indices and Peripheral Lymphocyte Subpopulations

Background

The prediction of lymph node metastasis in gastric cancer, a pivotal determinant affecting treatment approaches and prognosis, continues to pose a significant challenge in terms of accuracy.

Methods

In this study, we employed a combination of machine learning methods and the SHapley Additive exPlanations (SHAP) framework to develop an integrated predictive model. This model utilizes the preoperatively obtainable parameter of the inflammatory index, aiming to enhance the accuracy of predicting lymph node metastasis in gastric cancer patients.

Results

Lymph node metastasis stands as an independent prognostic risk factor for gastric cancer patients. Among various models, XGBoost emerges as the optimal machine learning model. In the training set, the XGBoost model exhibited the highest AUC value of 0.705. In the test set, XGBoost demonstrated the highest AUC of 0.695, and the lowest Brier score of 0.218. Notably, in terms of feature importance, PLR emerged as the most significant factor influencing lymph node metastasis in gastric cancer patients. Through the screening of differentially expressed genes, we ultimately identified the prognostic value of six genes: IGFN1, CLEC11A, STC2, TFEC, MUC5AC, and ANOS1, in predicting survival.

Conclusion

The XGBoost model can predict lymph node metastasis (LNM) in gastric cancer patients based on the inflammation index and peripheral lymphocyte subgroups. Combined with SHAP, it provides a more intuitive reflection of the impact of different variables on LNM. PLR emerges as the most crucial risk factor for lymph node metastasis in the inflammation index among gastric cancer patients.

Oncological long-term outcomes of laparoscopic versus open gastrectomy for cT3-4 gastric cancer at surgical staging: a propensity-score matched cohort study

BACKGROUND

The oncological efficacy of laparoscopic surgery for advanced gastric cancer (AGC) has been evaluated by several randomized trials. However, the inclusion of earlier-stage disease was a limitation in previous studies.

METHODS

Patients with cT3-4 gastric cancer, determined by surgical staging to minimize migration of earlier stages, treated at a tertiary cancer center from 2009 to 2018 were included. Based on the surgical approach, the patients were divided into two groups: the laparoscopic gastrectomy (LG) and the open gastrectomy (OG) and matched for age, sex, macroscopic appearance (type 4 or non-type 4), body mass index, estimated tumor size, clinical stage T3'T4, clinical N stage, pathologic T stage (T3 or T4), and type of surgery (total or distal gastrectomy).

RESULTS

588 patients (221 LG, 367 OG) were included in the analysis. After 1:1 propensity-score matching, 386 patients (193 LG, 193 OG) were assigned for analysis. In the LG group, operation time was longer with lower blood loss. The incidence of postoperative complications (≥ grade III) did not differ significantly between the groups (OG: 8.3%, vs. LG: 9.3%). Overall survival (OS) was longer in the LG group (5-year OS: 79.3 vs. 73% HR 0.66, 95% CI 0.44-0.99, P = 0.0497). Relapse-free survival (RFS) did not show a statistical difference (5-year RFS: 69.5 vs. 68.7 HR 0.88, 95% CI 0.62-1.26, P = 0.487). Subgroup analysis for OS also demonstrated equivalent outcomes.

CONCLUSION

LG demonstrates comparable safety and efficacy to OG for advanced gastric cancer at surgical staging, with similar rates of severe complications and long-term oncological outcomes. Further research is needed to validate these findings, particularly for total gastrectomy and for patients from Western populations.

Management challenges and the role of adjuvant chemotherapy in remnant gastric cancer: an analysis of 313 patients from the KEGG multicenter observational study

BACKGROUND

Clinical findings and postoperative follow-up data on remnant gastric cancer (RGC) are limited due to its rarity. Additionally, the preoperative staging, radical surgery, and managing recurrence in RGC present significant clinical challenges.

METHODS

We analyzed the clinicopathological findings, adjuvant chemotherapy, and patterns of postoperative recurrence of 313 consecutive patients who underwent curative surgery for RGC at 17 Japanese institutions. This study investigated the optimal management of RGC and the impact of adjuvant chemotherapy (AC) on recurrence-free survival (RFS).

RESULTS

Pathological stages I, II, and III were observed in 55.9% (N = 175), 24.9% (N = 78), and 19.2% (N = 60) of the patients, respectively. The overall concordance rate between clinical and pathological T staging was 58.3%, with a clinical T4 sensitivity of 41.4% for diagnosing pathological T4. During the median follow-up period of 4.6 years, disease recurrence occurred in 24.3% of patients. Most recurrences (over 80%) occurred within 2.5 years, and 96.1% within 5 years after RGC surgery. Peritoneal recurrence was the most common in patients with advanced RGC, accounting for 14.1% in stage II and 28.3% in stage III. Multivariable regression analysis showed that AC was significantly associated with a longer RFS, with a hazard ratio of 0.45 (95% confidence interval: 0.26-0.76).

CONCLUSIONS

Our study underscores the importance of early detection, accurate preoperative staging, and postoperative surveillance in managing advanced RGC cases. Despite some limitations, our findings indicate that AC may provide survival benefits comparable to those seen in primary gastric cancer.

A transformer-based deep learning model for early prediction of lymph node metastasis in locally advanced gastric cancer after neoadjuvant chemotherapy using pretreatment CT images

Background

Early prediction of lymph node status after neoadjuvant chemotherapy (NAC) facilitates promptly optimization of treatment strategies. This study aimed to develop and validate a deep learning network (DLN) using baseline computed tomography images to predict lymph node metastasis (LNM) after NAC in patients with locally advanced gastric cancer (LAGC).

Methods

A total of 1205 LAGC patients were retrospectively recruited from three hospitals between January 2013 and March 2023, constituting a training cohort, an internal validation cohort, and two external validation cohorts. A transformer-based DLN was developed using 3D tumor images to predict LNM after NAC. A clinical model was constructed through multivariate logistic regression analysis as a baseline for subsequent comparisons. The performance of the models was evaluated through discrimination, calibration, and clinical applicability. Furthermore, Kaplan-Meier survival analysis was conducted to assess overall survival (OS) of LAGC patients at two follow-up centers.

Findings

The DLN outperformed the clinical model and demonstrated a robust performance for predicting LNM in the training and validation cohorts, with areas under the curve (AUCs) of 0.804 (95% confidence interval [CI], 0.752-0.849), 0.748 (95% CI, 0.660-0.830), 0.788 (95% CI, 0.735-0.835), and 0.766 (95% CI, 0.717-0.814), respectively. Decision curve analysis exhibited a high net clinical benefit of the DLN. Moreover, the DLN was significantly associated with the OS of LAGC patients [Center 1: hazard ratio (HR), 1.789, P < 0.001; Center 2:HR, 1.776, P = 0.013].

Interpretation

The transformer-based DLN provides early and effective prediction of LNM and survival outcomes in LAGC patients receiving NAC, with promise to guide individualized therapy. Future prospective multicenter studies are warranted to further validate our model.

Funding

National Natural Science Foundation of China (NO. 82373432, 82171923, 82202142), Project Funded by China Postdoctoral Science Foundation (NO. 2022M720857), Regional Innovation and Development Joint Fund of National Natural Science Foundation of China (NO. U22A20345), National Science Fund for Distinguished Young Scholars of China (NO. 81925023), Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application (NO. 2022B1212010011), High-level Hospital Construction Project (NO. DFJHBF202105), Natural Science Foundation of Guangdong Province for Distinguished Young Scholars (NO. 2024B1515020091).

Perioperative chemotherapy with nivolumab for HER2-negative locally advanced gastric cancer: a case series

BACKGROUND

Nivolumab with chemotherapy has been transformative for metastatic gastric cancer (GC). The potential of this regimen for local tumor control could be utilized for perioperative chemotherapy in locally advanced GC with bulky tumors or lymph node metastasis involving other organs.

CASE PRESENTATION

Five patients with HER2-negative advanced GC were treated with nivolumab and oxaliplatin-based chemotherapy. All patients presented with clinical stage III or IVA GC with tumors in contact with either the pancreas or liver. Following chemotherapy, all tumors demonstrated shrinkage, allowing successful radical gastrectomies including four minimally invasive approach without postoperative complications. Four patients avoided combined resection of other organs.

CONCLUSIONS

Perioperative chemotherapy with nivolumab was effective for local disease control in this case series. This regimen could be a promising treatment approach for locally advanced GC; however, its survival benefits should be evaluated in clinical trials.

Predicting tumor invasion depth in gastric cancer: developing and validating multivariate models incorporating preoperative IVIM-DWI parameters and MRI morphological characteristics

INTRODUCTION

Accurate assessment of the depth of tumor invasion in gastric cancer (GC) is vital for the selection of suitable patients for neoadjuvant chemotherapy (NAC). Current problem is that preoperative differentiation between T1-2 and T3-4 stage cases in GC is always highly challenging for radiologists.

METHODS

A total of 129 GC patients were divided into training (91 cases) and validation (38 cases) cohorts. Pathology from surgical specimens categorized patients into T1-2 and T3-4 stages. IVIM-DWI and MRI morphological characteristics were evaluated, and a multimodal nomogram was developed. The MRI morphological model, IVIM-DWI model, and combined model were constructed using logistic regression. Their effectiveness was assessed using receiver operating characteristic (ROC) curves, calibration curves, decision curve analysis (DCA), and clinical impact curves (CIC).

RESULTS

The combined nomogram, integrating preoperative IVIM-DWI parameters (D value) and MRI morphological characteristics (maximum tumor thickness, extra-serosal invasion), achieved the highest area under the curve (AUC) values of 0.901 and 0.883 in the training and validation cohorts, respectively. No significant difference was observed between the AUCs of the IVIM-DWI and MRI morphological models in either cohort (training: 0.796 vs. 0.835, p = 0.593; validation: 0.794 vs. 0.766, p = 0.79).

CONCLUSION

The multimodal nomogram, combining IVIM-DWI parameters and MRI morphological characteristics, emerges as a promising tool for assessing tumor invasion depth in GC, potentially guiding the selection of suitable candidates for neoadjuvant chemotherapy (NAC) treatment.

Histopathologic response in patients with curative resection with D2 dissection following neoadjuvant treatment for locally advanced gastric and esophagogastric junction adenocarcinoma

AIM

This study evaluated pathologic response rate, overall survival (OS), and postoperative complications in locally advanced gastric cancer (GC) and esophagogastric junction (EGJ) adenocarcinoma patients who underwent curative gastric resection D2 lymph node dissection with neoadjuvant treatment.

METHODS

We reviewed the medical records of 122 patients with locally advanced GC and EGJ adenocarcinoma who had neoadjuvant treatment and curative resection with D2 dissection between January 2014 and December 2022. Patients were divided into responders and nonresponders. Grades 1a-1b were responders, while 2-3 were non-responders. Patients' clinicopathological features, pathologic response rate, survival, and postoperative complications were evaluated. We assessed complications using the Clavien-Dindo (CD) classification. Total survival was assessed using the Kaplan-Meier model. Overall survival was assessed using univariate and multivariate Cox regression analysis.

RESULTS

The mean age of the study participants was 61 (N = 89 males; N = 33 females). There were 79 GC and 43 EGJ adenocarcinomas. Overall postoperative complications (CD ≥ II) were 27 %. Postoperative complications were similar in responders and non-responders (p = 0.316). YpT0N0 had a 2.5 % pathological complete response rate. Responders had better overall survival, but there was no statistical difference.

CONCLUSIONS

Both responder and non-responder groups have similar postoperative complications. A complete pathologic response is discouraging for assessing neoadjuvant chemotherapy for locally advanced gastric cancer, but a positive treatment response is acceptable. Pathologic response rate helps stage and predict gastric cancer prognosis. Responder groups survive slightly better.

Adjuvant treatment for locally advanced gastric cancer: an Asian perspective

Standard adjuvant treatment for locally advanced gastric cancer (LAGC) is regionally different. Whereas perioperative chemotherapy is the standard in Western populations, D2 gastrectomy followed by adjuvant chemotherapy has been the standard in East Asia. Recently, the pivotal phase 3 PRODIGY and RESOLVE studies have demonstrated survival benefits of adding neoadjuvant chemotherapy to surgery followed by adjuvant chemotherapy over up-front surgery followed by adjuvant chemotherapy in Asian patients. Based on these results, neoadjuvant chemotherapy is considered one of the viable options for patients with LAGC. In this review, various aspects of neoadjuvant chemotherapy will be discussed for its optimal application in Asia. Candidates for neoadjuvant chemotherapy should be carefully chosen in consideration of the inaccurate aspects of radiological clinical staging and its potential benefit over up-front surgery followed by a decision on adjuvant chemotherapy according to the pathological stage. Efforts should continuously be made to optimally apply neoadjuvant chemotherapy to patients with LAGC, considering various factors, including a more accurate radiological assessment of the tumor burden and the optimization of post-operative chemotherapy. Future neoadjuvant trials involving novel agents for Asian patients should be designed based on proven Asian regimens rather than adopting Western regimens.

Key nodal stations for predicting splenic hilar nodal metastasis in upper advanced gastric cancer without invasion of the greater curvature

Background

Standard surgery for upper advanced gastric cancer without invasion of the greater curvature (UGC-GC) is spleen-preserving D2 total gastrectomy without dissection of the splenic-hilar nodes (#10). However, some patients with nodal metastasis to #10 survive more than 5 years due to nodal dissection of #10. If nodal metastasis to #10 is predictable based on the positivity of other nodes dissected by the current standard surgery without #10 nodal dissection, physicians may be able to consider #10 dissection.

Methods

This study retrospectively reviewed data from the National Cancer Center Hospital in Japan between 2000 and 2012. We selected cases that met the following criteria: (1) D2 or more total gastrectomy with splenectomy, (2) UGC-GC, and (3) histological type is gastric adenocarcinoma. We performed univariate and multivariate analyses concerning lymph node stations associated with #10 metastasis.

Results

A total of 366 patients were examined. A multivariate analysis revealed that #10 metastasis was associated with positivity of the nodes along the short gastric arteries (#4sa) and distal nodes along the splenic artery (#11d) (#4sa: p = 0.003, #11d: p = 0.016). When either key node was positive, the metastatic rate of #10 was 24.4%, and the therapeutic value index was 13.3.

Conclusions

#4sa and #11d were key lymph nodes predicting #10 nodal metastasis in UGC-GC. When these key nodes are positive on computed tomography before surgery or according to a rapid pathological examination during surgery, dissection of #10 should be considered even if upper advanced tumors are not invading the greater curvature.

Predictive nomogram for lymph node metastasis and survival in gastric cancer using contrast-enhanced computed tomography-based radiomics: a retrospective study

Background

Lymph node involvement significantly impacts the survival of gastric cancer patients and is a crucial factor in determining the appropriate treatment. This study aimed to evaluate the potential of enhanced computed tomography (CT)-based radiomics in predicting lymph node metastasis (LNM) and survival in patients with gastric cancer before surgery.

Methods

Retrospective analysis of clinical data from 192 patients diagnosed with gastric carcinoma was conducted. The patients were randomly divided into a training cohort (n = 128) and a validation cohort (n = 64). Radiomic features of CT images were extracted using the Pyradiomics software platform, and distinctive features were further selected using a Lasso Cox regression model. Features significantly associated with LNM were identified through univariate and multivariate analyses and combined with radiomic scores to create a nomogram model for predicting lymph node involvement before surgery. The predictive performance of radiomics features, CT-reported lymph node status, and the nomogram model for LNM were compared in the training and validation cohorts by plotting receiver operating characteristic (ROC) curves. High-risk and low-risk groups were identified in both cohorts based on the cut-off value of 0.582 within the radiomics evaluation scheme, and survival rates were compared.

Results

Seven radiomic features were identified and selected, and patients were stratified into high-risk and low-risk groups using a 0.582 cut-off radiomics score. Univariate and multivariate analyses revealed that radiomics features, diabetes mellitus, Nutrition Risk Screening (NRS) 2002 score, and CT-reported lymph node status were significant predictors of LNM in patients with gastric cancer. A predictive nomogram model was developed by combining these predictors with the radiomics score, which accurately predicted LNM in gastric cancer patients before surgery and outperformed other models in terms of accuracy and sensitivity. The AUC values for the training and validation cohorts were 0.82 and 0.722, respectively. The high-risk and low-risk groups in both the training and validation cohorts showed significant differences in survival rates.

Conclusion

The radiomics nomogram, based on contrast-enhanced computed tomography (CECT ), is a promising non-invasive tool for preoperatively predicting LNM in gastric cancer patients and postoperative survival.

Prediction of lymph node metastasis in advanced gastric adenocarcinoma based on dual-energy CT radiomics: focus on the features of lymph nodes with a short axis diameter ≥6 mm

Objective

To explore the value of the features of lymph nodes (LNs) with a short-axis diameter ≥6 mm in predicting lymph node metastasis (LNM) in advanced gastric adenocarcinoma (GAC) based on dual-energy CT (DECT) radiomics.

Materials and methods

Data of patients with GAC who underwent radical gastrectomy and LN dissection were retrospectively analyzed. To ensure the correspondence between imaging and pathology, metastatic LNs were only selected from patients with pN3, nonmetastatic LNs were selected from patients with pN0, and the short-axis diameters of the enrolled LNs were all ≥6 mm. The traditional features of LNs were recorded, including short-axis diameter, long-axis diameter, long-to-short-axis ratio, position, shape, density, edge, and the degree of enhancement; univariate and multivariate logistic regression analyses were used to establish a clinical model. Radiomics features at the maximum level of LNs were extracted in venous phase equivalent 120 kV linear fusion images and iodine maps. Intraclass correlation coefficients and the Boruta algorithm were used to screen significant features, and random forest was used to build a radiomics model. To construct a combined model, we included the traditional features with statistical significance in univariate analysis and radiomics scores (Rad-score) in multivariate logistic regression analysis. Receiver operating curve (ROC) curves and the DeLong test were used to evaluate and compare the diagnostic performance of the models. Decision curve analysis (DCA) was used to evaluate the clinical benefits of the models.

Results

This study included 114 metastatic LNs from 36 pN3 cases and 65 nonmetastatic LNs from 28 pN0 cases. The samples were divided into a training set (n=125) and a validation set (n=54) at a ratio of 7:3. Long-axis diameter and LN shape were independent predictors of LNM and were used to establish the clinical model; 27 screened radiomics features were used to build the radiomics model. LN shape and Rad-score were independent predictors of LNM and were used to construct the combined model. Both the radiomics model (area under the curve [AUC] of 0.986 and 0.984) and the combined model (AUC of 0.970 and 0.977) outperformed the clinical model (AUC of 0.772 and 0.820) in predicting LNM in both the training and validation sets. DCA showed superior clinical benefits from radiomics and combined models.

Conclusion

The models based on DECT LN radiomics features or combined traditional features have high diagnostic performance in determining the nature of each LN with a short-axis diameter of ≥6 mm in advanced GAC.

Neoadjuvant chemotherapy for locally advanced gastric cancer in Japan: Consensus meeting at the 77th general meeting of the Japanese Society of Gastroenterological Surgery

Treatment strategy for locally advanced gastric cancer differs worldwide. Neoadjuvant chemotherapy (NAC) is considered one of the promising treatment options for locally advanced gastric cancer, even in Japan, and clinical trials have been conducted or are ongoing. A consensus meeting was organized at the 77th general meeting of the Japanese Society of Gastroenterological Surgery in 2022, in which the current status and future prospects of NAC for locally advanced gastric cancer were discussed. Participants at the meeting looked forward to the results of the JCOG1509 trial, providing solid evidence regarding NAC. The optimal indications and regimens for NAC were also debated. Patients with cStage III gastric cancer are the main targets of NAC in Japan, and a doublet regimen of S-1 and oxaliplatin was preferred by the participants. However, the feasibility of a triplet regimen with S-1, oxaliplatin, and docetaxel, and that with 5-FU, leucovorin, oxaliplatin, and docetaxel has been demonstrated, and these could become treatment options in Japan. Other points of discussion include perioperative chemotherapy to avoid peritoneal recurrence and for patients with dMMR/MSI-high tumors. The panel regarded NAC as a promising treatment option, and NAC will become the standard treatment for cStage III gastric cancer in Japan if an ongoing clinical trial successfully demonstrates its efficacy.

Perioperative chemotherapy versus adjuvant chemotherapy treatment for resectable locally advanced gastric cancer: a retrospective cohort study

BACKGROUND

Neoadjuvant chemotherapy (NAC) is increasingly used in locally advanced gastric cancer (LAGC), but the clinical safety and efficacy are still controversial. This study aims to compare perioperative chemotherapy (PEC) with adjuvant chemotherapy (AC) for resectable LAGC.

METHODS

Patients who underwent D2 gastrectomy for resectable LAGC were retrospectively reviewed, and divided into NSA group (NAC plus surgery and AC) and SA group (surgery followed by AC). The baseline characteristics and perioperative data were compared. Survival analysis was based on Kaplan-Meier method. Multivariate analyses for prognostic factors were based on the Cox regression.

RESULTS

A total of 450 patients were eligible for this study. 218 patients received NAC plus surgery and AC, while 232 upfront surgery followed by AC. The baseline characteristics were comparable between the two groups. NSA group showed significant superiority in R0 resection rate (P = 0.014), excised tumor size (P = 0.038), and tumor downstage (all P < 0.001). NAC did not affect postoperative complications or AC-related grade 3/4 adverse events. Patients in NSA group achieved significantly longer OS (P = 0.021) and DFS (P = 0.002). The Cox regression model showed that NAC was independently associated with better OS (HR 0.245, P = 0.039) and DFS (HR 0.591, P = 0.031).

CONCLUSIONS

Compared with SA, the administration of NSA was considered safe and feasible for achieving higher R0 resection rate without increasing the postoperative complications or AC-related grade 3/4 adverse events, and NAC was independently associated with better OS and DFS for resectable LAGC.

Perioperative TAS-118 plus oxaliplatin in patients with locally advanced gastric cancer: APOLLO-11 study

BACKGROUND

We investigated the feasibility of perioperative chemotherapy with S-1 and leucovorin (TAS-118) plus oxaliplatin in patients with locally advanced gastric cancer.

METHODS

Patients with clinical T3-4N1-3M0 gastric cancer received four courses of TAS-118 (40-60 mg/body, orally, twice daily for seven days) plus oxaliplatin (85 mg/m2, intravenously, day one) every two weeks preoperatively followed by gastrectomy with D2 lymphadenectomy, followed by postoperative chemotherapy with either 12 courses of TAS-118 monotherapy (Step 1) or eight courses of TAS-118 plus oxaliplatin (Step 2). The primary endpoints were completion rates of preoperative chemotherapy with TAS-118 plus oxaliplatin and postoperative chemotherapy with TAS-118 monotherapy (Step 1) or TAS-118 plus oxaliplatin (Step 2).

RESULTS

Among 45 patients enrolled, the preoperative chemotherapy completion rate was 88.9% (90% CI 78.0-95.5). Major grade ≥ 3 adverse events (AEs) were diarrhoea (17.8%) and neutropenia (8.9%). The R0 resection rate was 95.6% (90% CI 86.7-99.2). Complete pathological response was achieved in 6 patients (13.3%). Dose-limiting toxicity was not observed in 31 patients receiving postoperative chemotherapy (Step 1, n = 11; Step 2, n = 20), and completion rates were 90.9% (95% CI 63.6-99.5) for Step 1 and 80.0% (95% CI 59.9-92.9) for Step 2. No more than 10% of grade ≥ 3 AEs were observed in  patients receiving Step 1. Hypokalaemia and neutropenia occurred in 3 and 2 patients, respectively, receiving Step 2. The 3-year recurrence-free and overall survival rates were 66.7% (95% CI 50.9-78.4) and 84.4% (95% CI 70.1-92.3), respectively.

CONCLUSIONS

Perioperative chemotherapy with TAS-118 plus oxaliplatin with D2 gastrectomy is feasible.

Five-Year Survival Outcomes of Laparoscopy-Assisted vs Open Distal Gastrectomy for Advanced Gastric Cancer: The JLSSG0901 Randomized Clinical Trial

Importance

Evidence of implementation of laparoscopic gastrectomy for locally advanced gastric cancer is currently insufficient, as the primary end point in previous prospective studies was evaluated at a median follow-up time of 3 years. More robust evidence is necessary to verify noninferiority of laparoscopic gastrectomy.

Objective

To compare 5-year survival outcomes between laparoscopy-assisted distal gastrectomy (LADG) and open distal gastrectomy (ODG) with D2 lymph node dissection for locally advanced gastric cancer.

Design, Setting, and Participants

This was a multicenter, open-label, noninferiority, prospective randomized clinical trial. Between November 26, 2009, and July 29, 2016, eligible patients with histologically proven gastric carcinoma from 37 institutes in Japan were enrolled. Two interim analyses and final analysis were performed in October 2014, May 2018, and November 2021, respectively.

Interventions

Patients were randomly assigned (1:1) to either the ODG or LADG group. The procedures were performed exclusively by qualified surgeons.

Main Outcomes and Measures

The primary end point was 5-year relapse-free survival, and the noninferiority margin for the hazard ratio (HR) was set at 1.31. The secondary end points were 5-year overall survival and safety.

Results

A total of 502 patients were included in the full-analysis set: 254 (50.6%) in the ODG group and 248 (49.4%) in the LADG group. Patients in the ODG group had a median (IQR) age of 67 (33-80) years and included 168 males (66.1%). Patients in the LADG group had a median (IQR) age of 64 (34-80) years and included 169 males (68.1%). No significant differences were observed in severe postoperative complications between the 2 groups in the safety analysis (ODG, 4.7% [11 of 233] vs LADG, 3.5% [8 of 227]; P = .64). The median (IQR) follow-up for all patients after randomization was 67.9 (60.3-92.0) months. The 5-year relapse-free survival was 73.9% (95% CI, 68.7%-79.5%) and 75.7% (95% CI, 70.5%-81.2%) for the ODG and LADG groups, respectively, and the HR was 0.96 (90% CI, 0.72-1.26; noninferiority 1-sided P = .03). Further, no significant difference was observed in overall survival time between the 2 groups, and the HR was 0.83 (95% CI, 0.57-1.21; P = .34). The pattern of recurrence was similar between the 2 groups.

Conclusions and Relevance

Results of this study show that on the basis of 5-year follow-up data, LADG with D2 lymph node dissection for locally advanced gastric cancer, when performed by qualified surgeons, was proved noninferior to ODG. This laparoscopic approach could become a standard treatment for locally advanced gastric cancer.

Trial Registration

UMIN Clinical Trial Registry: UMIN000003420.

Computed Tomography-Based Deep Learning Nomogram Can Accurately Predict Lymph Node Metastasis in Gastric Cancer

BACKGROUND

Computed tomography is the most commonly used imaging modality for preoperative assessment of lymph node status, but the reported accuracy is unsatisfactory.

AIMS

To evaluate and verify the predictive performance of computed tomography deep learning on the presurgical evaluation of lymph node metastasis in patients with gastric cancer.

METHODS

347 patients were retrospectively selected (training cohort: 242, test cohort: 105). The enhanced computed tomography arterial phase images of gastric cancer were used for lesion segmentation, radiomics and deep learning feature extraction. Three methods were used for feature selection. Support vector machine (SVM) or random forest (RF) was used to build models. The classification performance of the models was evaluated using the area under the receiver operating characteristic curve (AUC). We also established a nomogram that included clinical predictors.

RESULTS

The model based on ResNet50-RF showed favorable classification performance and was verified in the test cohort (AUC = 0.9803). The nomogram based on deep learning feature scores and the lymph node status reported by computed tomography showed excellent discrimination. AUC of 0.9978 was achieved in the training cohort and verified in the test cohort (AUC = 0.9914). Decision analysis curve showed the value of nomogram in clinical application.

CONCLUSION

The computed tomography-based deep learning nomogram can accurately and effectively evaluate lymph node metastasis in patients with gastric cancer before surgery.

Possible candidates for splenic hilar nodal dissection among patients with upper advanced gastric cancer without invasion of the greater curvature

BACKGROUND

Spleen preserving D2 total gastrectomy without dissection of the splenic hilar nodes (#10) is a standard operation for upper advanced gastric cancer without invasion of the greater curvature (UGC-wGC). However, some patients with #10 metastasis have survived after splenectomy with dissection of #10. This study explored possible candidates for dissection of #10 among patients with UGC-wGC by examining the metastatic rate and the therapeutic index.

METHODS

This study retrospectively reviewed data of patients treated in National Cancer Center Hospital (Japan) between 2000 and 2012. We applied the following inclusion criteria: (1) ≥ D2 total gastrectomy with splenectomy, (2) UGC-wGC, and (3) gastric adenocarcinoma histology. Univariate and multivariate analyses were performed to identify risk factors for #10 metastasis.

RESULTS

A total of 366 patients were examined; #10 metastasis was observed in 4.4% (16/366). The multivariate analysis revealed that location (posterior vs. others, P = 0.025) and histology (undifferentiated vs. differentiated, P = 0.048) were significant factors for #10 metastasis among sex, age, tumor size, dominant circumferential location, macroscopic type, depth of invasion, and histology. The incidence of #10 metastasis was 14.9% (7/47) for tumors located on the posterior wall with undifferentiated type histology. The 5-year overall survival rate of these patients was 42.9%, and the therapeutic index was 6.38, which was the second highest value among the second-tier nodal stations.

CONCLUSION

Even for upper advanced gastric cancer without invasion of the greater curvature, dissection of #10 could be justified for tumors located on the posterior wall with undifferentiated type histology.

Fibrinogen-to-Lymphocyte Ratio Was an Independent Predictor of Lymph Node Metastasis in Patients with Clinically Node-Negative Advanced-Stage Gastric Cancer

Purpose

Various hematological indicators have been reported to predict lymph node metastasis (LNM) in gastric cancer (GC) patients, but the relationship between FLR and LNM has not been studied. Therefore, the aim of this study was to evaluate the role of preoperative fibrinogen-to-lymphocyte ratio (FLR) in predicting LNM in patients with clinically node-negative (cN0) advanced gastric cancer (AGC).

Patients and Methods

We retrospectively reviewed 571 eligible patients with primary AGC adenocarcinoma who underwent radical gastrectomy (discovery cohort). Patients were divided into high and low FLR groups according to the optimal cutoff value determined by Youden index. FLR is an independent predictor of LNM determined by logistic regression and validated in the validation cohort of 207 patients. Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive value of FLR for LNM. The nonlinear relationship between FLR and LNM risk was assessed using restricted cubic spline. Sensitivity analyses were performed according to FLR quartiles to further assess the robustness of the results. The nomogram was built based on FLR and clinicopathological characteristics, and was evaluated by calibration curves, ROC curve analysis and decision curve analysis.

Results

In the discovery cohort, the area under the curve (AUC) value for FLR to predict LNM was 0.592. There is a linear relationship between the FLR value and the risk of LNM, and the risk of LNM increased with FLR value. High FLR level is an independent risk factor for LNM, and the results of sensitivity analysis robust this finding. The nomogram for individual risk assessment performed well. Furthermore, we verified the FLR was an independent predictor of LNM in the validation cohort.

Conclusion

FLR was an independent predictor of LNM in patients with cN0 AGC.

Perioperative pectoral nerve block type II and postoperative recurrence in breast cancer: a randomized controlled trial

BACKGROUND

A new technique for analgesia called pectoral nerve block is widely used in surgeries of breast cancer. Pectoral nerve block type II (Pecs II) block has less influence on immunity when compared with general anesthesia method. The purpose of this research is to demonstrate whether Pecs II block has influence on the recurrence of breast cancer after surgical operation.

METHODS

526 breast cancer patients were recruited in this research and randomized into general anesthesia group and general anesthesia with Pecs II block group. Recurrence-free survival (RFS), distant recurrence-free survival (DRFS), and overall survival (OS) were evaluated for the two groups.

RESULTS

Based on the statistical data, only the consumption of remifentanil was dramatically reduced by the performance of Pecs II block when compared with general anesthesia method. The performance of Pecs II block had no significant influence on OS, RFS, and DRFS of breast cancer patients after surgery. ASA physical status III, TNM stage 2 + 3, and mastectomy were proved to have association with lower recurrence-free survival.

CONCLUSION

In conclusion, the performance of Pecs II block declined the remifentanil consumption during surgery of breast cancer. Meanwhile, the performance of Pecs II block had no significant influence on the OS, RFS, and DRFS of breast cancer patients after surgical resection.

The value of CT-based radiomics nomogram in differential diagnosis of different histological types of gastric cancer

To establish and verify a nomogram based on computed tomography (CT) radiomics analysis to predict the histological types of gastric cancer preoperatively for patients with surgical indications. A sum of 171 patients with gastric cancer were included into this retrospective study. The least absolute shrinkage and selection operator (LASSO) was used for feature selection while the multivariate Logistic regression method was used for radiomics model and nomogram building. The area under curve (AUC) was used for performance evaluation in this study. The radiomics model got AUCs of 0.755 (95% CI 0.650-0.859), 0.71 (95% CI 0.543-0.875) and 0.712 (95% CI 0.500-0.923) for histological prediction in the training, the internal and external verification cohorts. The radiomics nomogram based on radiomics features and Carbohydrate antigen 125 (CA125) showed good discriminant performance in the training cohort (AUC: 0.777; 95% CI 0.679-0.875), the internal (AUC: 0.726; 95% CI 0.5591-0.8933) and external verification cohort (AUC: 0.720; 95% CI 0.5036-0.9358). The calibration curve of the radiomics nomogram also showed good results. The decision curve analysis (DCA) shows that the radiomics nomogram is clinically practical. The radiomics nomogram established and verified in this study showed good performance for the preoperative histological prediction of gastric cancer, which might contribute to the formulation of a better clinical treatment plan.

The validity of neoadjuvant chemotherapy with paclitaxel plus S-1 is not inferior to that of SOX regimen for locally advanced gastric cancer: an observational study

BACKGROUND

Paclitaxel plus S-1(PTXS) has shown definite efficacy for advanced gastric cancer. However, the efficacy and safety of this regimen in neoadjuvant setting for locally advanced gastric cancer (LAGC) are unclear. This study aimed to compare the efficacy of neoadjuvant chemotherapy (NAC) PTXS and oxaliplatin plus S-1 (SOX) regime for patients with LAGC.

METHODS

A total of 103 patients with LAGC (cT3/4NanyM0/x) who were treated with three cycles of neoadjuvant SOX regimen (n = 77) or PTXS regimen (n = 26) between 2011 and 2017 were enrolled in this study. NAC-related clinical response, pathological response, postoperative complication, and overall survival were analyzed between the groups.

RESULTS

The baseline data did not differ significantly between both groups. After NAC, the disease control rate of the SOX group (94.8%) was comparable with that of the PTXS group (92.3%) (p = 0.641). Twenty-three cases (29.9%) in the SOX group and 10 cases (38.5%) in the PTX group got the descending stage with no statistical difference (p = 0.417). No significant differences were observed in the overall pathological response rate and the overall postoperative complication rate between the two groups (p > 0.05). There were also no differences between groups in terms of 5-year overall and disease-free survival (p > 0.05).

CONCLUSIONS

The validity of NAC PTXS was not inferior to that of SOX regimen for locally advanced gastric cancer in terms of treatment response and overall survival. PTXS regimen could be expected to be ideal neoadjuvant chemotherapy for patients with LAGC and should be adopted for the test arm of a large randomized controlled trial.

Accurate preoperative staging and HER2 status prediction of gastric cancer by the deep learning system based on enhanced computed tomography

Purpose

To construct the deep learning system (DLS) based on enhanced computed tomography (CT) images for preoperative prediction of staging and human epidermal growth factor receptor 2 (HER2) status in gastric cancer patients.

Methods

The raw enhanced CT image dataset consisted of CT images of 389 patients in the retrospective cohort, The Cancer Imaging Archive (TCIA) cohort, and the prospective cohort. DLS was developed by transfer learning for tumor detection, staging, and HER2 status prediction. The pre-trained Yolov5, EfficientNet, EfficientNetV2, Vision Transformer (VIT), and Swin Transformer (SWT) were studied. The tumor detection and staging dataset consisted of 4860 enhanced CT images and annotated tumor bounding boxes. The HER2 state prediction dataset consisted of 38900 enhanced CT images.

Results

The DetectionNet based on Yolov5 realized tumor detection and staging and achieved a mean Average Precision (IoU=0.5) (mAP_0.5) of 0.909 in the external validation cohort. The VIT-based PredictionNet performed optimally in HER2 status prediction with the area under the receiver operating characteristics curve (AUC) of 0.9721 and 0.9995 in the TCIA cohort and prospective cohort, respectively. DLS included DetectionNet and PredictionNet had shown excellent performance in CT image interpretation.

Conclusion

This study developed the enhanced CT-based DLS to preoperatively predict the stage and HER2 status of gastric cancer patients, which will help in choosing the appropriate treatment to improve the survival of gastric cancer patients.

Determinants of clinical outcomes of gastric cancer patients treated with neoadjuvant chemotherapy: a sub-analysis of the PRODIGY study

BACKGROUND

In this post hoc analysis of the PRODIGY study, we aimed to investigate factors associated with survival outcomes and provide evidence for designing optimal perioperative treatment strategies for gastric cancer patients receiving neoadjuvant chemotherapy.

PATIENTS AND METHODS

A total of 212 patients in the neoadjuvant chemotherapy group of the PRODIGY study were included as the study population. The prognostic impact of clinicopathologic factors, including the initial radiological clinical stage (cStage) and post-neoadjuvant chemotherapy pathological stage (ypStage), was analyzed.

RESULTS

The median age was 58 years. The majority of patients (77.4%) had cStage III disease, and about 10% and 25% had ypStage 0 and I disease, respectively. According to the initial cStage, progression-free survival (PFS) and overall survival (OS) were significantly different (P < 0.01). PFS and OS were also different according to the ypStage (P < 0.01). In multivariate analyses, cStage IIIC disease (vs. cStage II) and ypStage II and III disease (vs. ypStage 0/I) were independent factors for poor survival outcomes. Based on the patterns of PFS and OS according to both cStage and ypStage, three patient groups were defined. These groups showed distinct PFS and OS (P < 0.01) with 5-year PFS rates of 95.7%, 77.9%, and 31.3% and 5-year OS rates of 95.7%, 82.4%, and 42.5%, respectively.

CONCLUSIONS

Both initial cStage and ypStage were independent factors for survival outcomes of gastric cancer patients treated with neoadjuvant chemotherapy. Efforts should be made to develop optimal peri-operative treatment strategies for patients at different risks according to cStage and ypStage.

A 9‑gene expression signature to predict stage development in resectable stomach adenocarcinoma

BACKGROUND

Stomach adenocarcinoma (STAD) is a highly heterogeneous disease and is among the leading causes of cancer-related death worldwide. At present, TNM stage remains the most effective prognostic factor for STAD. Exploring the changes in gene expression levels associated with TNM stage development may help oncologists to better understand the commonalities in the progression of STAD and may provide a new way of identifying early-stage STAD so that optimal treatment approaches can be provided.

METHODS

The RNA profile retrieving strategy was utilized and RNA expression profiling was performed using two large STAD microarray databases (GSE62254, n = 300; GSE15459, n = 192) from the Gene Expression Omnibus (GEO) and the RNA-seq database within the Cancer Genome Atlas (TCGA, n = 375). All sample expression information was obtained from STAD tissues after radical resection. After excluding data with insufficient staging information and lymph node number, samples were grouped into earlier-stage and later-stage. Samples in GSE62254 were randomly divided into a training group (n = 172) and a validation group (n = 86). Differentially expressed genes (DEGs) were selected based on the expression of mRNAs in the training group and the TCGA group (n = 156), and hub genes were further screened by least absolute shrinkage and selection operator (LASSO) logistic regression. Receiver operating characteristic (ROC) curves were used to evaluate the performance of the hub genes in distinguishing STAD stage in the validation group and the GSE15459 dataset. Univariate and multivariate Cox regressions were performed sequentially.

RESULTS

22 DEGs were commonly upregulated (n = 19) or downregulated (n = 3) in the training and TCGA datasets. Nine genes, including MYOCD, GHRL, SCRG1, TYRP1, LYPD6B, THBS4, TNFRSF17, SERPINB2, and NEBL were identified as hub genes by LASSO-logistic regression. The model achieved discrimination in the validation group (AUC = 0.704), training-validation group (AUC = 0.743), and GSE15459 dataset (AUC = 0.658), respectively. Gene Set Enrichment Analysis (GSEA) was used to identify the potential stage-development pathways, including the PI3K-Akt and Calcium signaling pathways. Univariate Cox regression indicated that the nine-gene score was a significant risk factor for overall survival (HR = 1.28, 95% CI 1.08-1.50, P = 0.003). In the multivariate Cox regression, only SCRG1 was an independent prognostic predictor of overall survival after backward stepwise elimination (HR = 1.21, 95% CI 1.11-1.32, P < 0.001).

CONCLUSION

Through a series of bioinformatics and validation processes, a nine-gene signature that can distinguish STAD stage was identified. This gene signature has potential clinical application and may provide a novel approach to understanding the progression of STAD.

Protocol digest of a phase III trial to evaluate the efficacy of preoperative chemotherapy with S-1 plus oxaliplatin followed by D2 gastrectomy with postoperative S-1 in locally advanced gastric cancer: Japan Clinical Oncology Group study JCOG1509 (NAGISA Trial)

In Japan, postoperative chemotherapy is a standard care for stage II/III gastric cancer after curative resection with D2 lymph node dissection, and the clinical outcomes of patients with stage III gastric cancer are unsatisfactory. A combination of oral S-1 and oxaliplatin, that is the standard chemotherapy regimen for unresectable advanced/recurrent gastric cancer associated with a high response rate, was considered the most promising preoperative chemotherapy regimen. This randomized phase III trial was started in September 2016 to confirm the superiority of preoperative chemotherapy with S-1 plus oxaliplatin followed by D2 gastrectomy with postoperative chemotherapy compared with D2 gastrectomy with postoperative chemotherapy for patients with clinical T3–4N1–3 M0 locally advanced gastric cancer in terms of overall survival. A total of 470 patients will be enrolled from 63 hospitals in Japan for 8.5 years. This trial has been registered in the Japan Registry of Clinical Trials as jRCTs031180350 [https://jrct.niph.go.jp/latest-detail/jRCTs031180350].

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.

Preoperative prediction of the pathological stage of advanced gastric cancer by 18F-fluoro-2-deoxyglucose positron emission tomography

In recent years, the usefulness of neoadjuvant chemotherapy for resectable advanced gastric cancer, particularly stage III, has been reported. Preoperative staging is mainly determined by computed tomography (CT), and the usefulness of ¹⁸F-fluoro-2-deoxyglucose positron emission tomography/CT (FDG-PET/CT) for gastric cancer has been limited in usefulness. The study aimed to evaluate the usefulness of FDG-PET/CT in preoperative diagnosis of advanced gastric cancer. We retrospectively enrolled 113 patients with gastric cancer who underwent preoperative FDG-PET/CT. All patients underwent gastrectomy with lymph-node dissection. The maximum standardized uptake value (SUVmax) of the primary tumor (T-SUVmax) and lymph nodes (N-SUVmax) were measured for all patients. The cutoff values of T-SUVmax for pathological T3/4 from receiver operating characteristic analysis were 8.28 for differentiated and 4.32 for undifferentiated types. The T-SUVmax and N-SUVmax cutoff values for pathological lymph-node metastasis were 4.32 and 1.82, respectively. Multivariate analysis showed that T-SUVmax for differentiated types was a significant predictor of pathological T3/4, and N-SUVmax was a significant predictor of lymph-node metastasis. In conclusion, the SUVmax of FDG-PET/CT was a useful predictor of pathological T3/4 and lymph-node metastasis in gastric cancer. The diagnosis by preoperative FDG-PET/CT is promising to contribute a more accurate staging of gastric cancer than by CT scan alone.

Is Prophylactic Splenectomy Necessary for Proximal Advanced Gastric Cancer Invading the Greater Curvature with Clinically Negative Splenic Hilar Lymph Node Metastasis? A Multi-Institutional Cohort Study (YCOG2003)

BACKGROUND

Prophylactic splenectomy for hilar lymph node (#10) dissection has shown no survival benefit for patients with proximal advanced gastric cancer that does not invade the greater curvature. However, the survival benefit of prophylactic splenectomy for proximal advanced gastric cancer invading the greater curvature side, particularly for clinically negative #10 lymph node metastasis (#10[-]) cases remains controversial.

METHODS

This multi-institutional retrospective study enrolled 146 consecutive patients with proximal advanced gastric cancers invading the greater curvature side with clinical #10(-) who underwent R0 total gastrectomy. For 33 of these patients, splenectomy was performed, and the remaining 113 underwent spleen-preservation gastrectomy. Short- and long-term results were compared between the splenectomy and spleen-preservation groups, with the incidence of #10 metastasis in the splenectomy group and recurrence in the spleen-preservation group compared.

RESULTS

In the splenectomy group, longer operative time, greater blood loss, more frequent postoperative abdominal infection, and longer hospital stay were observed than in the spleen-preservation group. The two groups exhibited no differences in median relapse-free survival time (31.1 vs 59.8 months; P = 0.684) or median overall survival time (64.9 vs 65.1 months; P = 0.765). The pathologic #10 lymph node metastasis rate was 3% in the splenectomy group, and the #10 lymph node recurrence rate was 2.7% in the spleen-preservation group.

CONCLUSIONS

Prophylactic splenectomy showed more frequent postoperative morbidities and a longer hospital stay than spleen preservation, without any long-term survival benefits.

Impact of tumor-related factors and inter-institutional heterogeneity on preoperative T staging for gastric cancer

Background: To improve the diagnostic accuracy of preoperative T staging in gastric cancer, the authors evaluated tumor-related factors that might affect the diagnosis. Materials & methods: The authors analyzed the data of cT2-4b gastric cancer patients enrolled in the prospective, multicenter JCOG1302A study. They used contrast-enhanced computed tomography to analyze the association between tumor-related factors and the diagnostic accuracy of T3-4b staging for gastric cancer. Results: Among 876 cT3-4b tumors, the diagnostic accuracy was relatively low in the lower third of the stomach compared with those in the upper or middle. A multivariable analysis revealed that accuracy was higher in the lesser curvature or entire circumference region than in other areas (p < 0.001), in macroscopic types 3/5 than in types 0/1/2 (p = 0.003) and in the undifferentiated histological type than in the differentiated type (p = 0.011). Conclusion: The authors found tumor-related factors affecting preoperative T staging by enhanced computed tomography.

Current and future imaging modalities in gastric cancer

Gastric adenocarcinoma treatment can include endoscopic mucosal resection, surgery, chemotherapy, radiation, and palliative measures depending on staging. Both invasive and noninvasive staging techniques have been used to dictate the best treatment pathway. Here, we review the current imaging modalities used in gastric cancer as well as novel techniques to accurately stage and screen these patients.

Diagnosis of Serosal Invasion in Gastric Adenocarcinoma by Dual-Energy CT Radiomics: Focusing on Localized Gastric Wall and Peritumoral Radiomics Features

Objectives

To build a radiomics model and combined model based on dual-energy CT (DECT) for diagnosing serosal invasion in gastric adenocarcinoma.

Materials and methods

231 gastric adenocarcinoma patients were enrolled and randomly divided into a training (n = 132), testing (n = 58), and independent validation (n = 41) cohort. Radiomics features were extracted from the rectangular ROI of the 120-kV equivalent mixed images and iodine map (IM) images in the venous phase of DECT, which was manually delineated perpendicularly to the gastric wall in the deepest location of tumor infiltration, including the peritumoral adipose tissue within 5 mm outside the serosa. The random forest algorithm was used for radiomics model construction. Traditional features were collected by two radiologists. Univariate and multivariate logistic regression was used to construct the clinical model and combined model. The diagnostic efficacy of the models was evaluated using ROC curve analysis and compared using the Delong's test. The calibration curves were used to evaluate the calibration performance of the combined model.

Results

Both the radiomics model and combined model showed high efficacy in diagnosing serosal invasion in the training, testing and independent validation cohort, with AUC of 0.90, 0.90, and 0.85 for radiomics model; 0.93, 0.93, and 0.89 for combined model. The combined model outperformed the clinical model (AUC: 0.76, 0.76 and 0.81).

Conclusion

The radiomics model and combined model constructed based on tumoral and peritumoral radiomics features derived from DECT showed high diagnostic efficacy for serosal invasion in gastric adenocarcinoma.

Machine learning analysis for the noninvasive prediction of lymphovascular invasion in gastric cancer using PET/CT and enhanced CT-based radiomics and clinical variables

PURPOSE

Lymphovascular invasion (LVI) is associated with metastasis and poor survival in patients with gastric cancer, yet the noninvasive diagnosis of LVI is difficult. This study aims to develop predictive models using different machine learning (ML) classifiers based on both enhanced CT and PET/CT images and clinical variables for preoperatively predicting lymphovascular invasion (LVI) status of gastric cancer.

METHODS

A total of 101 patients with gastric cancer who underwent surgery were retrospectively recruited, and the LVI status was confirmed by pathological analysis. Patients were randomly divided into a training dataset (n = 76) and a validation dataset (n = 25). By 3D manual segmentation, radiomics features were extracted from the PET and venous phase CT images. Image models, clinical models, and combined models were constructed by selected enhanced CT-based and PET-based radiomics features, clinical factors, and a combination of both, respectively. Three ML classifiers including adaptive boosting (AdaBoost), linear discriminant analysis (LDA), and logistic regression (LR) were used for model development. The performance of these predictive models was evaluated with respect to discrimination, calibration, and clinical usefulness.

RESULTS

Ten radiomics features and eight clinical factors were selected for the development of predictive models. In the validation dataset, the area under curve (AUC) values of clinical models using AdaBoost, LDA, and LR classifiers were 0.742, 0.706, and 0.690, respectively. The image models using AdaBoost, LDA, and LR classifiers achieved an AUC of 0.849, 0.778, and 0.810, respectively. The combined models showed improved performance than the image models and the clinical models, with the AUC values of AdaBoost, LDA, and LR classifier yielding 0.944, 0.929, and 0.921, respectively. The combined models also showed good calibration and clinical usefulness for LVI prediction.

CONCLUSION

ML-based models integrating PET/CT and enhanced CT radiomics features and clinical factors have good discrimination capability, which could serve as a noninvasive, preoperative tool for the prediction of LVI and assist surgical treatment decisions in patients with gastric cancer.

Accuracy of preoperative staging of gastric stump cancer

BACKGROUND

In this study, the accuracy of preoperative staging for gastric stump cancer, which has not been thoroughly investigated since the condition is rare, was investigated using computed tomography and gastroscopic imaging.

METHODS

Between February 1994 and April 2018, 49 patients with gastric stump cancer, following subtotal or total gastrectomy, were reviewed retrospectively. Preoperative diagnoses of clinical T and clinical N categories were compared with post-operative pathological diagnoses (pT and pN categories). Positive predictive values, accuracy, sensitivity and specificity were also evaluated.

RESULTS

The overall accuracy of T staging was 40.8%. The positive predictive value for cT3/T4 was 96.3%, whereas the positive predictive value for cT1/T2 was 72.7%. The overall accuracy for N staging was 61.2%. The positive predictive value of lymph node positive patients was 73.3%. The positive predictive value and sensitivity of over stage II were 96.6% and 84.8%, respectively.

CONCLUSIONS

The accuracy of preoperative diagnosis using both computed tomography and gastroscopy imaging may be feasible for T3/T4 advanced gastric stump cancer, whereas diagnosing T1/2 gastric stump cancer must be carefully considered due to high misdiagnosis rates, relating to depth.

Impact of preoperative endoscopy for predicting treatment response and prognosis in patients with gastric cancer after neoadjuvant chemotherapy

Background and study aims  Response evaluation criteria in solid tumors (RECIST) have been the gold standard to preoperatively predict treatment response and prognosis in patients with gastric cancer (GC) after neoadjuvant chemotherapy (NAC); however, methods for patients without evaluable lesions by RECIST are not yet confirmed. The aim of this study was to assess the utility of preoperative endoscopy for predicting treatment response and prognosis in patients with GC after NAC. Patients and methods  This retrospective study included 105 patients with initially resectable GC who underwent NAC followed by surgical treatment. Preoperative factors for predicting treatment response and survival outcomes were analyzed. Results  The number of patients classified as responders using preoperative endoscopic assessment, RECIST, and postoperative pathological evaluation were 25 (23.8 %), 28 (26.7 %), and 18 (17.1 %), respectively. Forty-three patients (41 %) were classified as non-targeted disease only, and their treatment responses were not evaluable by RECIST. Multivariate analysis identified endoscopic response as an independent preoperative factor to predict postoperative histological treatment response (odds ratio = 4.556, 95 % CI = 1.169-17.746, P  = 0.029). Endoscopic treatment response was the only independent preoperative predictive factor for overall survival (OS) (hazard ratio = 0.419, 95 % confidence interval (CI) = 0.206-0.849, P  = 0.016). Further, endoscopic treatment response was available for 33 patients (76.7 %) with non-targeted disease only, which showed significantly different OS between endoscopic responders (80.0 %) and non-responders (43.5 %) ( P  = 0.025). Conclusions  Endoscopic evaluation was an independent preoperative factor to predict treatment response and prognosis in patients with GC after NAC. Endoscopic assessment may be especially valuable for patients who could not be assessed by RECIST.

Significance of Lymph Node Metastasis in the Treatment of Gastric Cancer and Current Challenges in Determining the Extent of Metastasis

The stomach exhibits abundant lymphatic flow, and metastasis to lymph nodes is common. In the case of gastric cancer, there is a regularity to the spread of lymph node metastasis, and it does not easily metastasize outside the regional nodes. Furthermore, when its extent is limited, nodal metastasis of gastric cancer can be cured by appropriate lymph node dissection. Therefore, identifying and determining the extent of lymph node metastasis is important for ensuring accurate diagnosis and appropriate surgical treatment in patients with gastric cancer. However, precise detection of lymph node metastasis remains difficult. Most nodal metastases in gastric cancer are microscopic metastases, which often occur in small-sized lymph nodes, and are thus difficult to diagnose both preoperatively and intraoperatively. Preoperative nodal diagnoses are mainly made using computed tomography, although the specificity of this method is low because it is mainly based on the size of the lymph node. Furthermore, peripheral nodal metastases cannot be palpated intraoperatively, nodal harvesting of resected specimens remains difficult, and the number of lymph nodes detected vary greatly depending on the skill of the technician. Based on these findings, gastrectomy with prophylactic lymph node dissection is considered the standard surgical procedure for gastric cancer. In contrast, several groups have examined the value of sentinel node biopsy for accurately evaluating nodal metastasis in patients with early gastric cancer, reporting high sensitivity and accuracy. Sentinel node biopsy is also important for individualizing and optimizing the extent of uniform prophylactic lymph node dissection and determining whether patients are indicated for function-preserving curative gastrectomy, which is superior in preventing post-gastrectomy symptoms and maintaining dietary habits. Notably, advancements in surgical treatment for early gastric cancer are expected to result in individualized surgical strategies with sentinel node biopsy. Chemotherapy for advanced gastric cancer has also progressed, and conversion gastrectomy can now be performed after downstaging, even in cases previously regarded as inoperable. In this review, we discuss the importance of determining lymph node metastasis in the treatment of gastric cancer, the associated difficulties, and the need to investigate strategies that can improve the diagnosis of lymph node metastasis.

Radiological criteria for selecting candidates for neoadjuvant chemotherapy for gastric cancer: an exploratory analysis from the PRODIGY study

BACKGROUND

In this exploratory analysis from the PRODIGY study, we aimed to define the radiological criteria to identify patients with gastric cancer who may derive maximal clinical benefit from neoadjuvant chemotherapy.

PATIENTS AND METHODS

There were 246 patients allocated to receive surgery followed by adjuvant S-1 (SC group) and 238 allocated to receive neoadjuvant chemotherapy (CSC group). As the PRODIGY's radiological method of lymph node (LN) evaluation considers short diameter and morphology (the size and morphology method), a method considering only short diameter was also employed. In the SC group, the correlation between radiologic and pathologic findings was analyzed. The hazard ratio (HR) for the progression-free survival (PFS) of the CSC group was analyzed in subgroups with different cT/N stages.

RESULTS

cT4 disease showed a sensitivity of 85.6% for detecting pT4 and had a low proportion of pathologic stage (pStage) I disease (4.5%). Among the criteria determined by different cT/N stages by each method of LN positivity, those involving cT4Nany or cT4N + by both methods had a minimal proportion of pStage I disease (≤ 5%), while cT4Nany by both methods and cT4N + by the size and morphology method exhibited ≥ 75.9% sensitivity for detecting pStage III disease. The relative risk reduction in PFS of the CSC group was greatest in patients meeting the cT4Nany criterion defined by both methods (HR 0.67, 95% confidence interval 0.48-0.93).

CONCLUSIONS

The cT4Nany criterion, regardless of the radiological method used for LN evaluation, may help select patients with resectable gastric cancer for neoadjuvant chemotherapy.

Clinical Research of Combined Application of DCEUS and Dynamic Contrast-Enhanced MSCT in Preoperative cT Staging of Gastric Cancer

Purpose

To investigate the clinical value of double contrast-enhanced ultrasound (DCEUS) combined with dynamic contrast-enhanced multislice CT (MSCT) in preoperative T staging of gastric cancer (GC).

Methods

206 patients with GC confirmed by preoperative gastroscopy from February 2019 to February 2021 were collected, all patients were examined by DCEUS and dynamic contrast-enhanced MSCT before operation, and the invasion depth (T staging) of GC was evaluated. The diagnosis results of DCEUS, dynamic contrast-enhanced MSCT, and combined diagnosis of DCEUS and MSCT methods (D&M method) were compared with the pathological staging results (gold standard).

Results

The correct diagnosis rate of MSCT was 27.27% in T1 staging, 55.56% in T2 staging, 42.11% in T3 staging, 59.29% in T4 staging, and 55.34% in summation. The correct diagnosis rate of DCEUS was 90.91% in T1 staging, 88.89% in T2 staging, 78.95% in T3 staging, 82.86% in T4 staging, and 83.98% in summation. The correct diagnosis rate of the D&M method was 100.00% in T1 staging, 94.44% in T2 staging, 89.47% in T3 staging, 93.57% in T4 staging, and 93.69% in summation. The D&M method had higher correct diagnosis rate than MSCT or DCEUS alone, the correct diagnosis rate of the D&M method in T1, T2, T3, and T4 staging was significantly higher than that of MSCT (P < 0.05). The correct diagnosis rate of the D&M method in T1, T3, and T4 was significantly higher than that of DCEUS (P < 0.05). The Youden index of preoperative T1, T2, T3, and T4 staging of GC by the D&M method was 99.49%, 94.44%, 84.13%, and 90.54%, respectively, and the Kappa values of these were 0.954, 0.966, 0.707, and 0.881, respectively.

Conclusions

Dynamic contrast-enhanced MSCT combined with DCEUS in the diagnosis of preoperative cT staging of GC has more validity, reliability, and revenue than the using of MSCT or DCEUS alone, which is an image evaluation method worthy of clinical promotion.

Diagnosis of advanced gastric cancer using image enhancement and autofluorescence imaging systems

INTRODUCTION

The indication of laparoscopic gastrectomy for advanced cases such as serosal invasion or peritoneal dissemination is still controversial. We report the clinical experiences of laparoscopic diagnosis with image enhancement and autofluorescence (AF) systems for laparoscopic gastric cancer surgery.

METHODS

The image enhancement system was introduced to 164 patients who underwent laparoscopic gastric cancer surgery as the AF group. The control group was defined as 165 cases who underwent bright light observation without the image enhancement system. The operative findings were recorded during surgery. All image findings were retrospectively compared with the pathological findings. Furthermore, the relationship between the image and pathological findings for peritoneal dissemination and subserosal invasion was evaluated.

RESULTS

This study included 329 patients, divided into the control group of 165 patients (50.2%) and the AF group of 164 patients (49.8%). There was no statistically significant difference in patient background between the two groups. In seven cases of peritoneal dissemination, AF was positive, and macroscopic abnormal vascularization was detected. The sensitivity, specificity, and positive and negative predictive values were 100%, 99.4%, 87.5%, and 100%, respectively. In 29 cases of serosal invasion, AF was positive, and macroscopic abnormal vascularization was detected. In the detection accuracy of subserosal invasion, the sensitivity, specificity, and positive and negative predictive values were 75.7%, 97.6%, 90.3%, and 93.2%, respectively.

CONCLUSION

The image enhancement with the AF system is useful for the laparoscopic intraoperative diagnosis of serosal invasion and peritoneal dissemination for advanced gastric cancer.

Machine learning in gastrointestinal surgery

Machine learning (ML) is a collection of algorithms allowing computers to learn directly from data without predetermined equations. It is used widely to analyze "big data". In gastrointestinal surgery, surgeons deal with various data such as clinical parameters, surgical videos, and pathological images, to stratify surgical risk, perform safe surgery and predict patient prognosis. In the current "big data" era, the accelerating accumulation of a large amount of data drives studies using ML algorithms. Three subfields of ML are supervised learning, unsupervised learning, and reinforcement learning. In this review, we summarize applications of ML to surgical practice in the preoperative, intraoperative, and postoperative phases of care. Prediction and stratification using ML is promising; however, the current overarching concern is the availability of ML models. Information systems that can manage "big data" and integrate ML models into electronic health records are essential to incorporate ML into daily practice. ML is fundamental technology to meaningfully process data that exceeds the capacity of the human mind to comprehend. The accelerating accumulation of a large amount of data is changing the nature of surgical practice fundamentally. Artificial intelligence (AI), represented by ML, is being incorporated into daily surgical practice.

Survival Benefit of Neoadjuvant Chemotherapy for Locally Advanced Adenocarcinoma of Esophagogastric Junction

BACKGROUND/AIM

Adenocarcinoma of the esophagogastric junction (AEG) is refractory even when curative resection is followed by adjuvant chemotherapy. This study evaluated the efficacy of neoadjuvant chemotherapy (NAC) using an oral fluoropyrimidine-platinum regimen for AEG.

PATIENTS AND METHODS

Out of 35 patients with locally advanced AEG who underwent curative resection, 21 who underwent surgery first and 14 who received NAC were retrospectively compared in terms of survival.

RESULTS

The NAC regimens comprised of S-1 or capecitabine plus oxaliplatin or cisplatin; trastuzumab was added to six borderline resectable cases. The downstaging rate was 50% and the pathological response rate including complete response (29%) was 50%. The three-year relapse-free survival in the NAC group was significantly superior than the surgery-first group (78% vs. 22%, p=0.011). The NAC group had a significantly longer median survival time than the surgery-first group (NR vs. 29 months, p=0.032).

CONCLUSION

NAC using an oral fluoropyrimidine-platinum regimen may provide survival benefit in AEG.

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.

Comparison of neoadjuvant chemotherapy followed by surgery vs. surgery alone for locally advanced gastric cancer: a meta-analysis

BACKGROUND

The neoadjuvant chemotherapy is increasingly used in advanced gastric cancer, but the effects on safety and survival are still controversial. The objective of this meta-analysis was to compare the overall survival and short-term surgical outcomes between neoadjuvant chemotherapy followed by surgery (NACS) and surgery alone (SA) for locally advanced gastric cancer.

METHODS

Databases (PubMed, Embase, Web of Science, Cochrane Library, and Google Scholar) were explored for relative studies from January 2000 to January 2021. The quality of randomized controlled trials and cohort studies was evaluated using the modified Jadad scoring system and the Newcastle-Ottawa scale, respectively. The Review Manager software (version 5.3) was used to perform this meta-analysis. The overall survival was evaluated as the primary outcome, while perioperative indicators and post-operative complications were evaluated as the secondary outcomes.

RESULTS

Twenty studies, including 1420 NACS cases and 1942 SA cases, were enrolled. The results showed that there were no significant differences in overall survival (P = 0.240), harvested lymph nodes (P = 0.200), total complications (P = 0.080), and 30-day post-operative mortality (P = 0.490) between the NACS and SA groups. However, the NACS group was associated with a longer operation time (P < 0.0001), a higher R0 resection rate (P = 0.003), less reoperation (P = 0.030), and less anastomotic leakage (P = 0.007) compared with SA group.

CONCLUSIONS

Compared with SA, NACS was considered safe and feasible for improved R0 resection rate as well as decreased reoperation and anastomotic leakage. While unbenefited overall survival indicated a less important effect of NACS on long-term oncological outcomes.