Risk of Lymph Node Metastasis in T1b Gastric Cancer: An International Comprehensive Analysis from the Global Gastric Group (G3) Alliance

Is Adjuvant Therapy Necessary for Stage IB Gastric Cancer: A Retrospective Cohort Study

BACKGROUND

The benefit of adjuvant therapy for patients with IB gastric cancer (GC) is a topic of debate. This study aimed to evaluate the benefit of adjuvant therapy for patients with IB GC.

METHODS

Overall, the study selected 510 IB GC patients after gastrectomy at the First Medical Center of the Chinese PLA General Hospital, Beijing, China between 2005 and 2018. Overall survival (OS) and disease-free survival (DFS) were analyzed using the Kaplan-Meier method and the log-rank test. Cox regression analyses were used to confirm the independent prognostic factors.

RESULTS

Patients who received postoperative adjuvant therapy had a longer 5-year OS (92.9 %) than those who received surgery alone (86.7 %; P < 0.05), but the 5-year DFS did not differ significantly between the two groups (92.6 vs. 95.0 %; P > 0.05). Moreover, DFS did not differ between monotherapy, and combination therapy. Uni- and multivariate analyses showed that older age was a significant risk factor for tumor recurrence. Subgroup analyses also failed to identify suitable candidates for chemotherapy.

CONCLUSIONS

Because adjuvant therapy did not demonstrate any benefits in terms of tumor recurrence or DFS, these treatment strategies may be unnecessary for IB GC patients after gastrectomy. Further studies are required to identify subgroups of IB GC patients who may benefit from adjuvant treatments.

Feasibility and Efficacy of Sentinel Lymph Node Mapping in Gastric Cancer

BACKGROUND

Lymph node metastasis is a critical prognostic factor for patients with gastric carcinoma (GC). Sentinel lymph node (SLN) mapping has the potential to identify the initial site of draining lymph node metastasis and reduce the extent of surgical lymphadenectomy. This study aimed to evaluate the diagnostic accuracy of SLN mapping in GC.

METHODS

The study enrolled 129 GC patients undergoing total or partial gastrectomy with D2 lymphadenectomy and indocyanine green fluorescence-guided SLN mapping. The primary outcomes were the negative predictive value (NPV) and sensitivity of SLN mapping. The secondary outcomes were clinicopathologic factors associated with SLN mapping accuracy and successful SLN mapping.

RESULTS

The SLN detection rate in this study was 86.8 %. The study had an overall NPV of 83.1 % and an overall sensitivity of 65.8 %. The NPV was found to be significantly higher in the patients with no lymphovascular invasion (LVI) than in those with LVI (96.0 % vs 59.3 %; p < 0.001) and in the patients whose pathologic T (pT) stage lower than 3 than in those whose T stage was 3 or higher (92.0 % vs 66.7 %; p = 0.009). The sensitivity of SLN mapping was 50 % in the patients with no LVI and 33 % in the patients with a pT stage lower than 3.

CONCLUSION

The study results showed that for patients with early-stage GC with no LVI, negative SLN findings may represent a potential additive predictor indicating the absence of regional LN metastasis. However, given the low sensitivity rates noted, further research is needed to identify specific patient populations that may benefit from SLN mapping in GC.

Machine learning models for prediction of lymph node metastasis in patients with T1b gastric cancer

The prognosis of early gastric cancer (EGC) patients is associated with lymph node metastasis (LNM). Considering the relatively high rate of LNM in T1b EGC patients, it is crucial to determine the factors associated with LNM. In this study, we constructed and validated predictive models based on machine learning (ML) algorithms for LNM in patients with T1b EGC. Data from patients with T1b gastric cancer were extracted from the Korean Gastric Cancer Association database. ML algorithms such as logistic regression (LR), random forest (RF), extreme gradient boosting (XGBoost), and support vector machine (SVM) were applied for model construction utilizing five-fold cross-validation. The performances of these models were assessed in terms of discrimination, calibration, and clinical applicability. Moreover, external validation of XGBoost models was performed using the T1b gastric cancer database of The Catholic University Medical Center. In total, 3,468 T1b EGC patients were included in the analysis, whom 550 (15.9%) had LNM. Eleven variables were selected to construct the models. The LR, RF, XGBoost, and SVM models were established, revealing area under the receiver operating characteristic curve values of 0.8284, 0.7921, 0.8776, and 0.8323, respectively. Among the models, the XGBoost model exhibited the best predictive performance in terms of discrimination, calibration, and clinical applicability. ML models are reliable for predicting LNM in T1b EGC patients. The XGBoost model exhibited the best predictive performance and can be used by surgeons for the identification of EGC patients with a high-risk of LNM, thereby facilitating treatment selection.

The Key Role of Tumor Budding in Predicting the Status of Lymph Node Involvement in Early Gastric Cancer Patients: A Clinical Multicenter Validation in China

BACKGROUND

Accurate preoperative prediction of lymph node (LN) involvement is essential for the management of early gastric cancer (EGC). Our objective was to formulate a potent nomogram for predicting LN involvement in EGC by leveraging an innovative predictor of tumor budding.

METHODS

We assembled a cohort of EGC patients who underwent radical surgery at two tertiary cancer centers. Tumor budding was stratified by using an optimal cutoff value and integrated with other clinicopathological variables to ascertain the risk factors associated with LN involvement. A nomogram was developed and its predictive performance was assessed by using receiver operating characteristic (ROC) curves and calibration plots. In addition, we conducted decision curve analysis to evaluate its clinical utility. Finally, an external validation was conducted by using an independent cohort.

RESULTS

Finally, 307 eligible patients (215 in the primary cohort and 92 in the validation cohort) were included. Tumor budding, categorized by a count of two, exhibited a robust association with LN involvement (OR 14.12, p = 0.012). Other significant risk factors include lymphovascular invasion, depth of tumor invasion, ulceration, and tumor differentiation. Notably, the nomogram demonstrated exceptional discriminative power (area under the ROC curve, 0.872 in the primary cohort and 0.885 in the validation cohort) and precise predictive capabilities. Furthermore, the nomogram showed notable clinical applicability through decision curve analysis, particularly in endoscopic curability C-2, by mitigating the risk of overtreatment.

CONCLUSIONS

Tumor budding is a robust predictor of LN involvement in EGC. The incorporation of tumor budding into a nomogram is an effective strategy, thereby informing and enhancing clinical decision-making.

Risk Factors for Lymph Node Metastasis in a Western Series of Patients with Distal Early Gastric Cancer

Background: Assessment of potential lymph node metastasis is mandatory in the appropriate treatment of early gastric cancers. This study analysed factors associated with lymph node metastasis to identify differences between node-negative and node-positive patients and between T1a and T1b cancers. Methods: The clinicopathological features of 129 early gastric cancer patients who had undergone radical gastrectomy were analysed to identify predictive factors for lymph node metastasis. Results: Lymph node metastasis was detected in 76 (59.0%) patients. Node-positive patients were younger (58.1 ± 11.3 years) than those without metastasis (61.9 ± 9.6 years, p = 0.02). Greater tumour sizes were observed in patients with lymph node metastasis (3.6 ± 1.0 cm) compared to node-negative patients (1.9 ± 0.5 cm, p = 0.00001). Depressed form, ulceration, diffuse histological type, and undifferentiated lesions were more frequent in node-positive patients than in the node-negative group. Tumour size > 3.0 cm showed a correlation with lymph node metastasis in both T1a (p = 0.0001) and T1b (p = 0.006) cancer. The male sex (p = 0.006) had a significant correlation with lymph node metastasis in T1a cancer. Depressed appearance (p = 0.02), ulceration (p = 0.03), differentiation (p = 0.0001), diffuse type (p = 0.0002), and lower third location (p = 0.005) were associated with lymph node metastasis in T1b cancer. Conclusions: Tumour size > 3 cm, undifferentiated lesions, ulceration, diffuse type, lower third location, and submucosal invasion are risk factors for lymph node metastasis in early gastric cancer.

Association of survival with adjuvant chemotherapy in patients with stage IB gastric cancer: a multicentre, observational, cohort study

Background

Recurrence following radical resection in patients with stage IB gastric cancer (GC) is not uncommon. However, whether postoperative adjuvant chemotherapy could reduce the risk of recurrence in stage IB GC remains contentious.

Methods

We collected data on 2110 consecutive patients with pathologic stage IB (T1N1M0 or T2N0M0) GC who were admitted to 8 hospitals in China from 2009 to 2018. The survival of patients who received adjuvant chemotherapy was compared with that of postoperative observation patients using propensity score matching (PSM). Two survival prediction models were constructed to estimate the predicted net survival gain attributable to adjuvant chemotherapy.

Findings

Of the 2110 patients, 1344 received adjuvant chemotherapy and 766 received postoperative observation. Following the 1-to-1 matching, PSM yielded 637 matched pairs. Among matched pairs, adjuvant chemotherapy was not associated with improved survival compared with postoperative observation (OS: hazard ratio [HR], 0.72; 95% CI, 0.52-1.00; DFS: HR, 0.91; 95% CI, 0.64-1.29). Interestingly, in the subgroup analysis, reduced mortality after adjuvant chemotherapy was observed in the subgroups with elevated serum CA19-9 (HR, 0.22; 95% CI, 0.08-0.57; P = 0.001 for multiplicative interaction), positive lymphovascular invasion (HR, 0.32; 95% CI, 0.17-0.62; P < 0.001 for multiplicative interaction), or positive lymph nodes (HR, 0.17; 95% CI, 0.07-0.38; P < 0.001 for multiplicative interaction). The survival prediction models mainly based on variables associated with chemotherapy benefits in the subgroup analysis demonstrated good calibration and discrimination, with relatively high C-indexes. The C-indexes for OS were 0.74 for patients treated with adjuvant chemotherapy and 0.70 for patients treated with postoperative observation. Two nomograms were built from the models that can calculate individualized estimates of expected net survival gain attributable to adjuvant chemotherapy.

Interpretation

In this cohort study, pathologic stage IB alone was not associated with survival benefits from adjuvant chemotherapy compared with postoperative observation in patients with early-stage GC. High-risk clinicopathologic features should be considered simultaneously when evaluating patients with stage IB GC for adjuvant chemotherapy.

Funding

National Natural Science Foundation of China; the National Key R&D Program of China.

The microprotein encoded by exosomal lncAKR1C2 promotes gastric cancer lymph node metastasis by regulating fatty acid metabolism

Lymph node metastasis (LNM) is the prominent route of gastric cancer dissemination, and usually leads to tumor progression and a dismal prognosis of gastric cancer. Although exosomal lncRNAs have been reported to be involved in tumor development, whether secreted lncRNAs can encode peptides in recipient cells remains unknown. Here, we identified an exosomal lncRNA (lncAKR1C2) that was clinically correlated with lymph node metastasis in gastric cancer in a VEGFC-independent manner. Exo-lncAKR1C2 secreted from gastric cancer cells was demonstrated to enhance tube formation and migration of lymphatic endothelial cells, and facilitate lymphangiogenesis and lymphatic metastasis in vivo. By comparing the metabolic characteristics of LN metastases and primary focuses, we found that LN metastases of gastric cancer displayed higher lipid metabolic activity. Moreover, exo-lncAKR1C2 encodes a microprotein (pep-AKR1C2) in lymphatic endothelial cells and promotes CPT1A expression by regulating YAP phosphorylation, leading to enhanced fatty acid oxidation (FAO) and ATP production. These findings highlight a novel mechanism of LNM and suggest that the microprotein encoded by exosomal lncAKR1C2 serves as a therapeutic target for advanced gastric cancer.

Safety and Efficacy of Carbon Nanoparticle-Labeled Lymph Node Dissection in Radical Resection of Gastric Cancer: A Systematic Review and Meta-Analysis

Objective: In this meta-analysis, we investigated the safety and efficacy of carbon nanoparticle (CNP) trace-guided lymph node (LN) dissection during radical gastrectomy. Methods: Literature on CNP tracing compared with non-CNP tracing in radical gastric cancer (GC) surgery was searched from PubMed, EMBASE (Ovid platform), Web of Science, and the Cochrane Library from the establishment of the library until October 2022. This meta-analysis was performed according to the preferred reporting items for systematic reviews and meta-analysis guidelines. Available data regarding the number of LNs dissected, number of metastatic LNs dissected, other surgical outcomes, and postoperative complications were analyzed in a pooled manner. Stata software (version 12.0) was used for the present meta-analysis. Results: This analysis included 7 studies with a total of 1827 GC patients (551 and 1276 in the CNP and non-CNP groups, respectively). The results of the meta-analysis showed that the CNP group had more intraoperative LNs detected [weighted mean difference (WMD) = 6.67, 95% confidence interval (CI): 3.71-9.62], more LN metastases (WMD = 1.60, 95% CI: 0.09-3.12), and less intraoperative bleeding (WMD = 11.33, 95% CI: 6.30-16.37) than the non-CNP group, all with statistically significant differences (P < .05). For postoperative complications (odds ratio [OR] = 0.88, 95% CI: 0.52-1.48) and operative time (WMD = -11.60, 95% CI: -40.53-17.34), there was no statistically significant difference between the 2 groups (P > 0.05). Conclusions: CNP was a significant tracer for the LNs of GC. It increased the number of LNs harvested while reducing intraoperative blood loss, without increasing the operative time or postoperative complications. CNP tracer-guided lymphadenectomy is considered safe and effective for gastrectomy.

Metastatic lymph nodes and prognosis assessed by the number of retrieved lymph nodes in gastric cancer

BACKGROUND

The prognostic value of quantitative assessments of the number of retrieved lymph nodes (RLNs) in gastric cancer (GC) patients needs further study.

AIM

To discuss how to obtain a more accurate count of metastatic lymph nodes (MLNs) based on RLNs in different pT stages and then to evaluate patient prognosis.

METHODS

This study retrospectively analyzed patients who underwent GC radical surgery and D2/D2+ LN dissection at the Cancer Hospital of Harbin Medical University from January 2011 to May 2017. Locally weighted smoothing was used to analyze the relationship between RLNs and the number of MLNs. Restricted cubic splines were used to analyze the relationship between RLNs and hazard ratios (HRs), and X-tile was used to determine the optimal cutoff value for RLNs. Patient survival was analyzed with the Kaplan-Meier method and log-rank test. Finally, HRs and 95% confidence intervals were calculated using Cox proportional hazards models to analyze independent risk factors associated with patient outcomes.

RESULTS

A total of 4968 patients were included in the training cohort, and 11154 patients were included in the validation cohort. The smooth curve showed that the number of MLNs increased with an increasing number of RLNs, and a nonlinear relationship between RLNs and HRs was observed. X-tile analysis showed that the optimal number of RLNs for pT1-pT4 stage GC patients was 26, 31, 39, and 45, respectively. A greater number of RLNs can reduce the risk of death in patients with pT1, pT2, and pT4 stage cancers but may not reduce the risk of death in patients with pT3 stage cancer. Multivariate analysis showed that RLNs were an independent risk factor associated with the prognosis of patients with pT1-pT4 stage cancer (P = 0.044, P = 0.037, P = 0.003, P < 0.001).

CONCLUSION

A greater number of RLNs may not benefit the survival of patients with pT3 stage disease but can benefit the survival of patients with pT1, pT2, and pT4 stage disease. For the pT1, pT2, and pT4 stages, it is recommended to retrieve 26, 31 and 45 LNs, respectively.

Establishment of a nomogram for predicting lymph node metastasis in patients with early gastric cancer after endoscopic submucosal dissection

Background

Endoscopic submucosal dissection (ESD) has been accepted as the standard treatment for the appropriate indication of early gastric cancer (EGC). Determining the risk of lymph node metastasis (LNM) is critical for the following treatment selection after ESD. This study aimed to develop a predictive model to quantify the probability of LNM in EGC to help minimize the invasive procedures.

Methods

A total of 952 patients with EGC who underwent radical gastrectomy were retrospectively reviewed. LASSO regression was used to help screen the potential risk factors. Multivariate logistic regression was used to establish a predictive nomogram, which was subjected to discrimination and calibration evaluation, bootstrapping internal validation, and decision curve analysis.

Results

Results of multivariate analyses revealed that gender, fecal occult blood test, CEA, CA19-9, histologic differentiation grade, lymphovascular invasion, depth of infiltration, and Ki67 labeling index were independent prognostic factors for LNM. The nomogram had good discriminatory performance, with a concordance index of 0.816 (95% CI 0.781–0.853). The validation dataset yielded a corrected concordance index of 0.805 (95% CI 0.770–0.842). High agreements between ideal curves and calibration curves were observed.

Conclusions

The nomogram is clinically useful for predicting LNM after ESD in EGC, which is beneficial to identifying patients who are at low risk for LNM and would benefit from avoiding an unnecessary gastrectomy.

Less Severe Intra-Abdominal Infections in Robotic Surgery for Gastric Cancer Compared with Conventional Laparoscopic Surgery: A Propensity Score-matched Analysis

BACKGROUND

The impact of robotic gastrectomy (RG) for gastric cancer (GC) on the incidence of postoperative complication is debatable and unclear.

METHODS

This study enrolled 200 patients with GC who were surgically treated and consisted of 100 RG and 100 laparoscopic gastrectomy (LG) cases using an ultrasonic scalpel. The short-term outcomes were compared between the two groups. These outcomes were compared using a 1:1 propensity score (PS)-matching analysis.

RESULTS

After PS matching, 76 cases in each group were well matched. Mean surgical time was significantly longer in the RG group than in the LG group (393 vs. 342 min, p < 0.005), whereas mean blood loss during surgery was significantly lower in the RG group than in the LG group (30.1 vs. 50.1 mL, p = 0.023). The median number of surgeons who attend the main part of the surgery was significantly less in the RG group than in the LG group (2.0 vs. 3.0, p = 0.01). The rate of severe intra-abdominal infectious complication was significantly lower in the RG group than in the LG group (0% vs. 9.2%, p = 0.014). The duration from surgery to adjuvant chemotherapy was significantly shorter in the RG group than in the LG group (29.6 ± 11.0 vs. 45.2 ± 27.8 days, p = 0.046).

CONCLUSIONS

RG using an ultrasonic scalpel may be a viable alternative to LG because of the improvement in the rate of postoperative intra-abdominal infectious complications after curative surgery for GC.