Stage migration effect on survival in gastric cancer surgery with extended lymphadenectomy: the reappraisal of positive lymph node ratio as a proper N-staging. Ann Surg. 2012;255:50-58. [PMID: 21577089 DOI: 10.1097/sla.0b013e31821d4d75]

Examining more than 35 lymph nodes improves the staging and survival in resectable advanced gastric cancer: a multi-institutional study in China

PURPOSE

More examined lymph nodes (ELN) are correlated with better staging and a better prognosis of gastric cancer, although the optimal number of ELNs remains under dispute. This study explored the optimal number of ELNs for resectable advanced gastric cancer (AGC).

METHODS

Clinicopathological characteristics and survival data of 4739 AGC patients were collected from 3 GC centers in China. The series of odds ratios (ORs) for negative-to-positive node stage migration and hazard ratios (HRs) for the disease-specific survival with more ELNs were fitted using locally weighted scatterplot smoothing (LOWESS). The structural breakpoints were determined using the Chow test. A Kaplan-Meier survival analysis was used to validate the cutoff ELN count.

RESULTS

With increasing numbers of ELNs, the cohort exhibited significant proportional increases in stage migration (OR = 1.006, p = 0.024) and serial improvements in survival (HR = 0.979, p < 0.001) per additional ELN after adjusting for covariates. The optimal ELN count was identified as 36, which was further validated with good discrimination for survival stratification in an external cohort that included 5796 patients from the SEER database.

CONCLUSION

Having more than 35 LNs to examine could achieve more accurate staging and a better survival for AGC patients with stage N0-N2 disease.

The minimum number of lymph node retrieval in gastric cancer patients after neoadjuvant therapy: An international multi-institute cohort study

BACKGROUND

The minimum number of retrieved lymph nodes for radical gastrectomy after neoadjuvant therapy remains controversial. The objective of this study was to determine the minimum threshold for retrieved lymph nodes in patients with gastric cancer after neoadjuvant therapy to accurately evaluate staging and prognosis.

METHODS

Multivariate models were employed to investigate the correlation between the number of retrieved lymph nodes and survival outcomes and stage migration. The hazard ratio curves for each retrieved lymph node count compared with 1 retrieved lymph node (as a reference), including overall survival and disease-specific survival, were fitted using a LOWESS smoother, and the structural break points were determined by Chow test.

RESULTS

This international multicenter study analyzed the clinicopathological data of 2,490 patients with gastric cancer who underwent gastrectomy after neoadjuvant therapy. The median follow-up period for the overall population was 90.0 months, with a median of 22 retrieved lymph nodes. The study demonstrated that a greater number of retrieved lymph nodes was linked to a greater probability of detecting positive lymph nodes (odds ratio, 1.005; P = .030) as well as improved overall survival and disease-specific survival (overall survival: hazard ratio, 0.988; P < .001 and disease-specific survival: hazard ratio, 0.987; P < .001). The cutoff point analysis identified 24 as the minimum number of retrieved lymph nodes. The 5-year overall survival rate was significantly greater in the group with ≥24 retrieved lymph nodes (46.0%) compared with the group with 16-23 retrieved lymph nodes (35.3%) and the group with <16 retrieved lymph nodes group (29.3%) (P < .001). Similar trends were observed with regard to disease-specific survival. The time-dependent area under the curve analysis revealed that the group with ≥24 retrieved lymph nodes exhibited superior predictive performance for overall survival and disease-specific survival compared to the group with <24 retrieved lymph nodes, on the basis of ypN staging (overall survival: time-dependent areas under the receiver operating characteristic curve≥24, 0.71 vs time-dependent areas under the receiver operating characteristic curve<24, 0.67; disease-specific survival: time-dependent areas under the receiver operating characteristic curve≥24, 0.72 vs time-dependent areas under the receiver operating characteristic curve<24, 0.68).

CONCLUSION

The minimum number of retrieved lymph nodes for evaluation prognosis and reducing stage migration in patients with gastric cancer who undergo radical gastrectomy after neoadjuvant therapy was 24.

Prognostic Impact of Fluorescent Lymphography on Gastric Cancer After Neoadjuvant Chemotherapy

Importance

Indocyanine green (ICG)-guided lymphadenectomy has been increasingly used to treat gastric cancer. However, its oncologic impact remains unclear.

Objective

To investigate the effect of ICG tracing on long-term outcomes in patients diagnosed with locally advanced gastric cancer undergoing neoadjuvant chemotherapy (NAC) followed by laparoscopic radical gastrectomy.

Design, Settings, and Participants

This retrospective cohort study included patients diagnosed with cT2-4N0/+M0 gastric adenocarcinoma who underwent NAC and laparoscopic radical gastrectomy at 3 teaching hospitals in China between January 2015 and June 2021, with follow-up data examined until June 2024. Overlap weighting (OW) was used to compare outcomes between the ICG and non-ICG groups. Results were tested for robustness using propensity score matching (PSM) and instrumental variable analysis.

Exposure

ICG-guided lymphadenectomy during laparoscopic gastrectomy.

Main Outcomes and Measures

The primary end points were 3-year survival outcomes, including overall survival (OS) and recurrence-free survival (RFS).

Results

Data from 459 patients (338 men [73.6%] and 121 women [26.4%]; mean [SD] age, 60.8 [9.9] years), of whom 119 underwent ICG-guided lymphadenectomy, were included. After OW adjustment, the ICG group exhibited a higher number of lymph nodes harvested (47.4 vs 38.3; P < .001) and better 3-year OS (78.6% vs 66.6%; P = .04) and RFS (74.0% vs 57.0%; P = .03) compared with the non-ICG group. Multivariable Cox regression analysis revealed that ICG tracing was an independent prognostic factor for both OS (hazard ratio, 0.59; 95% CI, 0.39-0.90; P = .02) and RFS (hazard ratio, 0.59; 95% CI, 0.40-0.87; P = .01), with the results remaining significant in both doubly robust and instrumental variable-adjusted models. Furthermore, in the OW-adjusted population, the OS benefit of ICG tracing was more pronounced in subgroups with ypN2/3 gastric adenocarcinoma (70.3% vs 36.2%; P = .01) and those achieving major pathological response (97.7% vs 77.6%; P = .04) (both P for interaction = .04). Similar results were obtained after adjusting for PSM.

Conclusion and Relevance

In this study, ICG tracing was associated with enhanced lymphadenectomy and improved survival outcomes in patients with locally advanced gastric cancer after NAC. A prospective randomized clinical trial is needed to verify these findings.

Machine learning-based reconstruction of prognostic staging for gastric cancer patients with different differentiation grades: A multicenter retrospective study

BACKGROUND

The prognosis of gastric cancer (GC) patients is poor, and an accurate prognostic staging system would help assess patients' prognostic status before treatment and determine appropriate treatment strategies.

AIM

To develop positive lymph node ratio (LNR) and machine learning (ML)-based staging systems for GC patients with varying differentiation.

METHODS

This multicenter retrospective cohort study included 11772 GC patients, with 5612 in the training set (Harbin Medical University Cancer Hospital) and 6160 in the validation set (Surveillance, Epidemiology, and End Results Program database). X-tile software identified optimal cutoff values for the positive LNR, and five ML models were developed using pT and LNR staging. Risk scores were divided into seven stages, constructing new staging systems tailored to different tumor differentiation levels.

RESULTS

In both the training and validation sets, regardless of the tumor differentiation level, LNR staging demonstrated superior prognostic stratification compared to pN. Extreme Gradient Boosting exhibited better predictive performance than the other four models. Compared to tumor node metastasis staging, the new staging systems, developed for patients with different degrees of differentiation, showed significantly better predictive performance.

CONCLUSION

The new positive lymph nodes ratio staging and integrated staging systems constructed for GC patients with different differentiation grades exhibited better prognostic stratification capabilities.

Construction of a modified TNM staging system and prediction model based on examined lymph node counts for gastric cancer patients at pathological stage N3

Background

Examined lymph node (ELN) count is a critical factor affecting the number of metastatic lymph nodes (MLNs). The impact of the ELN number on survival and staging remains unclear.

Methods

This study included 4,291 stage N3 GC patients from the SEER database (training cohort) and 567 stage N3 GC patients from the FAHZZU database (validation cohort). The optimal ELN count and stage migration were investigated, and a modified TNM (mTNM) staging system including the ELN count was proposed. LASSO regression and random forest analyses were used to screen and evaluate the variables associated with survival, and an mTNM-based nomogram was constructed. The performance of the mTNM staging system and mTNM-based nomogram were compared with that of the 8th edition of the TNM staging system.

Results

The optimal threshold of the ELN count was identified as 21. An insufficient number of ELNs (≤ 21) was associated with poorer survival outcomes and led to stage migration in all N3 patients. A new mTNM staging system was proposed, integrating the ELN count into the TNM staging system (8th edition). LASSO regression analysis revealed that age, tumor size, adjuvant chemotherapy, adjuvant radiotherapy, and the mTNM system were associated with overall survival (OS) outcomes, and random forest analysis revealed that the mTNM system was the most important variable for predicting survival. An mTNM-based nomogram was constructed to predict 1-, 3-, and 5-year OS rates. Compared with the TNM staging system (8th edition), the mTNM staging system and mTNM-based nomogram showed superior prognosis discriminative ability, better predictive accuracy, and greater net improvement in survival outcomes.

Conclusions

The optimal ELN count for N3 GC patients was 21. The mTNM staging system and mTNM-based nomogram showed superior discriminative ability, predictive accuracy, and greater net benefit for OS outcomes.

Conversion Therapy for Stage IV Gastric Cancer: Report From the Expert Consensus Meeting at KINGCA WEEK 2024

Conversion therapy is a treatment strategy that shifts from palliative systemic therapy to curative surgical treatment for primary and/or metastatic stage IV gastric cancer (GC). To address its clinical statements, the Korean Gastric Cancer Association aims to present a consensus on conversion therapy among experts attending KINGCA WEEK 2024. The KINGCA Scientific Committee and Development Working Group for Korean Practice Guidelines prepared preformulated topics and 9 clinical statements for conversion therapy. The Delphi method was applied to a panel of 17 experts for consensus and opinions. The final comments were announced after the statement presentation and discussed during the consensus meeting session of KINGCA WEEK 2024. Most experts agreed that conversion therapy provides a survival benefit for selected patients who respond to systemic therapy and undergo R0 resection (88.3%). Patients with limited metastases were considered good candidates (94.2%). The optimal timing was based on the response to systemic therapy (70.6%). The regimen was recommended to be individualized (100%) and the duration to be at least 6 months (88.3%). A minimally invasive approach (82.3%) and D2 lymph node dissection (82.4%) were considered for surgery. However, resection for metastases with a complete clinical response after systemic therapy was not advocated (41.2%). All experts agreed on the need for large-scale randomized-controlled trials for further evidence (100%). Recent advancements in treatment may facilitate radical surgery for patients with stage IV GC. Further evidence is warranted to establish the safety and efficacy of conversion therapy.

Revolutionizing T3-4N0-2M0 gastric cancer staging with an innovative pathologic N classification system

BACKGROUND

The current pathologic N (pN) classification exhibits limitations in the prognostic stratification of patients with pT3-4N0-2M0 gastric cancer (GC). Therefore, this study aimed to develop and validate a new lymph nodal staging method based on the number of examined lymph nodes (ELNs) and lymph node ratio (LNR).

METHODS

Data from 7883 patients with pT3-4N0-2M0 GC were collected from the Surveillance, Epidemiology, and End Results (SEER) database and Zhejiang Cancer Provincial Hospital. Optimal cutoff values for ELNs and LNR were determined using X-tile software. Kaplan-Meier methods, Log-rank tests, and Cox regression analyses were employed in this study. Patients were categorized into 3 new pN stages: new pN0 (pN0 with ELNs of >16), new pN1 (pN0 with ELNs of ≤16 or pN1-2 with LNR of ≤0.15), and new pN2 (pN1-2 with LNR of >0.15). The prognostic predictive power of both current and new pN staging was evaluated using the Akaike information criterion (AIC), Bayesian information criterion, concordance index (C-index), and receiver operating characteristic curve.

RESULTS

The new pN classification exhibited excellent performance in Kaplan-Meier survival analysis. After adjusting for confounding factors, the new pN staging emerged as an independent prognostic indicator in patients with GC. In the SEER cohort, the new pN staging demonstrated enhanced prognostic prediction accuracy over the American Joint Committee on Cancer pN staging (AIC: 75578.85 vs 75755.06; C-index: 0.642 vs 0.630; P < .001). Similar findings were validated in the Chinese cohort.

CONCLUSION

This study developed and validated an improved pN classification for patients with pT3-4N0-2M0 GC. Surgeons should consider ELNs and LNR when assessing postoperative prognosis in patients with GC.

Screening high-risk individuals for primary gastric carcinoma: evaluating overall survival probability score in the presence and absence of lymphatic metastasis post-gastrectomy

OBJECTIVE

The aim of this study was to develop and validate prognostic models for predicting overall survival in individuals with gastric carcinoma, specifically focusing on both negative and positive lymphatic metastasis.

METHODS

A total of 1650 patients who underwent radical gastric surgery at Shanxi Cancer Hospital between May 2002 and December 2020 were included in the analysis. Multiple Cox Proportional Hazards analysis was performed to identify key variables associated with overall survival in both negative and positive lymphatic metastasis cases. Internal validation was conducted using bootstrapping to assess the prediction accuracy of the models. Calibration curves were used to demonstrate the accuracy and consistency of the predictions. The discriminative abilities of the prognostic models were evaluated and compared with the 8th edition of AJCC-TNM staging using Harrell's Concordance index, decision curve analysis, and time-dependent receiver operating characteristic curves.

RESULTS

The nomogram for node-negative lymphatic metastasis included variables such as age, pT stage, and maximum tumor diameter. The C-index for this model in internal validation was 0.719, indicating better performance compared to the AJCC 8th edition TNM staging. The nomogram for node-positive lymphatic metastasis included variables such as gender, age, maximum tumor diameter, neural invasion, Lauren classification, and expression of Her-2, CK7, and CD56. The C-index for this model was 0.674, also outperforming the AJCC 8th edition TNM staging. Calibration curves, time-dependent receiver operating characteristic curves, and decision curve analysis for both nomograms demonstrated excellent prediction ability. Furthermore, significant differences in prognosis between low- and high-risk groups supported the models' strong risk stratification performance.

CONCLUSION

This study provides valuable risk stratification models for lymphatic metastasis in gastric carcinoma, encompassing both node-positive and negative cases. These models can help identify low-risk individuals who may not require further intervention, while high-risk individuals can benefit from targeted therapies aimed at addressing lymphatic metastasis.

Assessment of Laparoscopic Indocyanine Green Tracer-guided Lymphadenectomy After Neoadjuvant Chemotherapy for Locally Advanced Gastric Cancer: A Randomized Controlled Trial

OBJECTIVE

To assess the effectiveness of indocyanine green (ICG)-guided lymph node (LN) dissection during laparoscopic radical gastrectomy after neoadjuvant chemotherapy (NAC) in patients with locally advanced gastric cancer (LAGC).

BACKGROUND

Studies on ICG imaging use in patients with LAGC on NAC are rare.

METHODS

Patients with gastric adenocarcinoma (clinical T2-4NanyM0) who received NAC were randomly assigned to receive ICG-guided laparoscopic radical gastrectomy or laparoscopic radical gastrectomy alone. Here, we reported the secondary endpoints including the quality of lymphadenectomy (total retrieved LNs and LN noncompliance) and surgical outcomes.

RESULTS

Overall, 240 patients were randomized. Of whom, 236 patients were included in the primary analysis (118 in the ICG group and 118 in the non-ICG group). In the ICG group, the mean number of LNs retrieved was significantly higher than in the non-ICG group within the D2 dissection (48.2 vs 38.3, P < 0.001). The ICG fluorescence guidance significantly decreased the LN noncompliance rates (33.9% vs 55.1%, P = 0.001). In 165 patients without baseline measurable LNs, ICG significantly increased the number of retrieved LNs and decreased the LN noncompliance rate ( P < 0.05). For 71 patients with baseline measurable LNs, the quality of lymphadenectomy significantly improved in those who had a complete response ( P < 0.05) but not in those who did not ( P > 0.05). Surgical outcomes were comparable between the groups ( P > 0.05).

CONCLUSIONS

ICG can effectively improve the quality of lymphadenectomy in patients with LAGC who underwent laparoscopic radical gastrectomy after NAC.

Textbook Neoadjuvant Outcome-Novel Composite Measure of Oncological Outcomes among Gastric Cancer Patients Undergoing Multimodal Treatment

The incidence of gastric cancer (GC) is expected to increase to 1.77 million cases by 2040. To improve treatment outcomes, GC patients are increasingly treated with neoadjuvant chemotherapy (NAC) prior to curative-intent resection. Although NAC enhances locoregional control and comprehensive patient care, survival rates remain poor, and further investigations should establish outcomes assessment of current clinical pathways. Individually assessed parameters have served as benchmarks for treatment quality in the past decades. The Outcome4Medicine Consensus Conference underscores the inadequacy of isolated metrics, leading to increased recognition and adoption of composite measures. One of the most simple and comprehensive is the "All or None" method, which refers to an approach where a specific set of criteria must be fulfilled for an individual to achieve the overall measure. This narrative review aims to present the rationale for the implementation of a novel composite measure, Textbook Neoadjuvant Outcome (TNO). TNO integrates five objective and well-established components: Treatment Toxicity, Laboratory Tests, Imaging, Time to Surgery, and Nutrition. It represents a desired, multidisciplinary care and hospitalization of GC patients undergoing NAC to identify the treatment- and patient-related data required to establish high-quality oncological care further. A key strength of this narrative review is the clinical feasibility and research background supporting the implementation of the first and novel composite measure representing the "ideal" and holistic care among patients with locally advanced esophago-gastric junction (EGJ) and GC in the preoperative period after NAC. Further analysis will correlate clinical outcomes with the prognostic factors evaluated within the TNO framework.

Development and external validation of a nomogram predicting overall survival for Gastric adenocarcinoma patients with radical gastrectomy

PURPOSE

The aim of this study was to develop and externally validate a nomogram to accurately predict the overall survival (OS) of patients with gastric adenocarcinoma who underwent radical gastrectomy.

MATERIALS AND METHODS

A total of 3492 patients with gastric adenocarcinoma who underwent radical gastrectomy from 2012 to 2017 were included as the training cohort. Survival analysis was performed via Kaplan Meier method and log-rank test. Independent postoperative prognostic factors in patients with gastric adenocarcinoma were analyzed using univariate and multifactorial COX analysis methods. The prognosis nomogram was established in the training cohort and verified externally in the Surveillance, Epidemiology and End Results (SEER) database.

RESULTS

According to the univariate and multifactorial COX analyses, metastatic lymph node ratio (MLNR) and five other independent prognostic factors (age at surgery, type of gastrectomy, tumor size, T stage, and pathological grade) were included in the prognostic nomogram. The nomogram had better prognostic predictive ability than the American Joint Committee on Cancer (AJCC) TNM staging in both the training (C-index: 0.736 VS. 0.668) and external validation cohort (C-index: 0.712 VS. 0.627). The calibration plots showed that the predicted survival rate was in good agreement with the actual survival rate. And the decision curve analysis (DCA) curves revealed that nomogram showed stronger ability in predicting 1-year, 3-year, and 5-year OS.

CONCLUSION

This study estimated the excellent prognostic predictive power and clinical application potential of the MLNR-based nomogram, which may be used to facilitate postoperative clinical treatment decisions and potentially improve patient survival outcomes.

Refining gastric cancer staging: examining the interplay between number and anatomical location of metastatic lymph nodes - a retrospective multi-institutional study

BACKGROUND

The current gastric cancer staging system relies on the number of metastatic lymph nodes (MLNs) for nodal stage determination. However, incorporating additional information such as topographic status may help address uncertainties. This study evaluated the appropriateness of the current staging system and relative significance of MLNs based on their anatomical location.

METHODS

Patients who underwent curative gastrectomy for gastric cancer between 2000 and 2019 at six Catholic Medical Center-affiliated hospitals were included. Lymph node-positive patients were classified into the perigastric (stations 1-6, group P) or extragastric (stations 7-12) groups. The extragastric group was further subdivided into the near-extragastric (stations 7-9, group NE) and far-extragastric (stations 10-12, group FE) groups.

RESULTS

We analyzed the data of 3,591 patients with positive lymph node metastases. No significant survival differences were found between group P and the extragastric group in each N stage. However, in N1 and N2, group FE showed significantly worse survival than the other groups (p = 0.013 for N1, p < 0.001 for N2), but not in N3. In the subgroup analysis, group FE had a significantly lower overall survival in N2, regardless of the cancer location.

CONCLUSIONS

Our large-scale multi-institutional big data analysis confirmed the superiority of the current numerical nodal staging system for gastric cancer. Nonetheless, in N1 and N2 in which there is an upper limit on metastatic nodes, attention should be paid to the potential significance of topographic information for specific nodal stations.

Positive lymph node ratio is an important index to predict long-term survival for advanced esophageal squamous carcinoma patients (II∼III) with R0 resection--a SEER-based analysis

Background

Esophageal squamous carcinoma (ESCC) is one of the most malignant cancers in the world due to nodal metastasis. Therefore, a reasonable nodal staging system is extremely important for further treatment strategies. Recently the positive lymph node ratio (PLNR) is an important prognostic factor in various solid tumors.

Method

In this study, we investigated the clinical significance of the PLNR in stage II∼III ESCC patients. We collected the pathological characteristics of 272 stage II∼III ESCC patients from the SEER database from 2004-2016. ROC curves were used to calculate the best cutoff value of the PLNR; Pearson's Chi-square (χ2) and Fisher's exact probability tests were used to compare the clinical baseline and characteristics of patients. For continuous variables, Student's t-test and ANOVA were performed to evaluate statistical significance. Clinical outcomes were estimated by using the Kaplan‒Meier method and log-rank test. Furthermore, univariate and multivariate Cox regression models were utilized to analyze independent prognostic factors of ESCC patients.

Results

Consequently, advanced ESCC patients were effectively stratified into two groups by prognosis using a PLNR cutoff value of 0.15 (P value = 0.04). The median survival time of patients with PLNR <0.15 (n = 145) was much higher than that of patients (n = 127) in the PLNR ≥0.15 group (20.0 vs. 13.0 months, P value < 0.0001). Notably, the PLNR significantly predicted the prognosis of ESCC patients with stage N1 (P value 0.01) and stage III (P value < 0.001) disease. The multivariate Cox proportional hazard model showed that T stage (HR 1.33, 95 % CI 0.97-1.82), tumor size >45 mm (HR 1.32, 95 % CI 1.02-1.70), N stage (HR 1.41, 95 % CI 0.98-2.01) and PLNR ≥0.15 (HR 1.35, 95 % CI 0.87-1.74) were independent risk factors for prognostic prediction in ESCC patients. Meanwhile, 117 II∼III ESCC patients from Shaanxi Provincial People's Hospital shown that the overall survival with a PLNR <0.15 (n = 96) was significantly longer than that with a PLNR ≥0.15 (n = 21) .

Conclusions

The PLNR is useful for accurately predicting clinical outcomes and determining postoperative strategies.

Indocyanine green fluorescence imaging-guided versus conventional laparoscopic lymphadenectomy for gastric cancer: long-term outcomes of a phase 3 randomised clinical trial

Indocyanine green (ICG) fluorescence imaging-guided lymphadenectomy has been demonstrated to be effective in increasing the number of lymph nodes (LNs) retrieved in laparoscopic gastrectomy for gastric cancer (GC). Previously, we reported the primary outcomes and short-term secondary outcomes of a phase 3, open-label, randomized clinical trial (NCT03050879) investigating the use of ICG for image-guided lymphadenectomy in patients with potentially resectable GC. Patients were randomly (1:1 ratio) assigned to either the ICG or non-ICG group. The primary outcome was the number of LNs retrieved and has been reported. Here, we report the primary outcome and long-term secondary outcomes including three-year overall survival (OS), three-year disease-free survival (DFS), and recurrence patterns. The per-protocol analysis set population is used for all analyses (258 patients, ICG [n = 129] vs. non-ICG group [n = 129]). The mean total LNs retrieved in the ICG group significantly exceeds that in the non-ICG group (50.5 ± 15.9 vs 42.0 ± 10.3, P < 0.001). Both OS and DFS in the ICG group are significantly better than that in the non-ICG group (log-rank P = 0.015; log-rank P = 0.012, respectively). There is a difference in the overall recurrence rates between the ICG and non-ICG groups (17.8% vs 31.0%). Compared with conventional lymphadenectomy, ICG guided laparoscopic lymphadenectomy is safe and effective in prolonging survival among patients with resectable GC.

Indocyanine Green Tracer-Guided Radical Robotic Distal Gastrectomy Using the Firefly™ System Improves the Quality of Lymph Node Dissection in Patients with Gastric Cancer

BACKGROUND

This study investigated indocyanine green (ICG) as an intraoperative tool for improving lymph node dissection quality in radical robotic distal gastrectomy (RDG) for gastric cancer by comparing the rate of lymph node (LN) noncompliance with or without use of the Firefly™ system.

METHODS

Patients with potentially resectable gastric cancer including cT1-T4a, N0/ + , M0 were registered in a prospective nonrandomized cohort study at our institution between March 2019 and December 2022. Patients were assigned to the da Vinci surgical system with Firefly system (F group) or that without Firefly system (non-F group). F group patients received endoscopic peritumoral injection of ICG to the submucosa one day before surgery. Rate of LN noncompliance, number of harvested LNs, and short-term outcomes were compared.

RESULTS

Of the 94 patients in this study, 55 underwent Firefly system-guided RDG and 39 underwent conventional RDG. The mean [SD] total number of harvested lymph nodes in F group, 31.2 [10.2], was significantly higher than that harvested in non-F group (25.6 [12.6]; p = 0.026). The LN noncompliance rate in F group was lower than that in non-F group (32.7% vs. 61.5%, p = 0.006). The mean number of LNs harvested in F group was significantly higher than that harvested in non-F group (31.2 [10.2] vs. 25.7 [12.6], p = 0.02). Significant differences were found between the F vs. non-F groups in blood loss and postoperative hospital stay (83.9 [75.1] vs. 301.9 [766.7] mL; p = 0.003 and 13.4 vs. 17.4 days, p = 0.049).

CONCLUSION

The Firefly system-assisted ICG tracer improved LN dissection quality without compromising safety.

Separating lymph node stations by the surgeon from the gastric cancer specimen improves the quality of nodal status evaluation

BACKGROUND

In gastric cancer (GC), the pN-stage is an important prognostic factor influencing treatment. Along with the depth of invasion of the tumor, the presence of nodal metastases is one of the most important prognostic factors guiding treatment strategies in gastric cancer. Examining a small number of lymph nodes may lead to understaging of the disease; hence, it is essential for the nodal status to be precisely assessed. In this study, we explored whether dissecting lymph node stations into separate samples by the surgeon from the gastric cancer surgical specimen affects the quality of nodal status evaluation and patient outcome.

METHODS

The clinical data of 130 GC patients treated at the Helsinki University Hospital between 2016 and 2019 was reviewed. The performed operations included 59 total and 71 subtotal gastrectomies. The processing of the surgical specimen before the pathological examination was assessed from the operation records and pathology reports. The association of the number of examined lymph nodes with other variables was assessed, and multivariate survival analysis was performed to explore the independent prognostic factors in disease-specific survival.

RESULTS

Dissecting lymph node stations into separate specimens before pathological evaluation yielded a significantly greater number of examined lymph nodes compared with a specimen without intervention (median 34.5 vs 21.0, p < 0.001). The pT-stage, the pN-stage, and the extent of lymphadenectomy were identified as independent prognostic factors, whereas dissecting the specimen's lymph node stations did not associate with survival.

CONCLUSIONS

Dissecting lymph node stations into separate specimens results in a greater number of examined lymph nodes, which has the potential to lead to a more reliable pN-stage assessment.

Prognostic significance of metastatic lymph node ratio in gastric cancer: a Western-center analysis

BACKGROUND

Tumor-node-metastasis (TNM) staging is the central gastric cancer (GC) staging system, but it has some disadvantages. However, the lymph node ratio (LNR) can be used regardless of the type of lymphadenectomy and is considered an important prognostic factor. This study aimed to evaluate the relationship between LNR and survival in patients who underwent curative GC surgery.

METHODS

All patients who underwent radical gastric surgery between January 2014 and June 2022 were retrospectively evaluated. Clinicopathological features of tumors, TNM stage, and survival rates were analyzed. LNR was defined as the ratio between metastatic lymph nodes and total lymph nodes removed. The LNR groups were classified as follows: LNR0 = 0, 0.01 < LNR1 ≤ 0.1, 0.1 < LNR2 ≤ 0.25 and LNR3 > 0.25. Tumor characteristics and overall survival (OS) of the patients were compared between LNR groups.

RESULTS

After exclusion, 333 patients were analyzed. The mean age was 62 ± 14 years. According to the LNR classification, no difference was found between groups regarding age and sex. However, TNM stage III disease was significantly more common in LNR3 patients. Most patients (43.2%, n = 144) were in the LNR3 group. In terms of tumor characteristics (lymphatic, vascular, and perineural invasion), the LNR3 group had significantly poorer prognostic factors. The Cox regression model defined LNR3, TNM stage II-III disease, and advanced age as independent risk factors for survival. Patients with LNR3 demonstrated the lowest 5-year OS rate (35.7%) (estimated mean survival was 30 ± 1.9 months) compared to LNR 0-1-2.

CONCLUSION

Our study showed that a high LNR was significantly associated with poor OS in patients who underwent curative gastrectomy. LNR can be used as an independent prognostic predictor in GC patients.

Optimal examined lymph node number for accurate staging and long-term survival in rectal cancer: a population-based study

BACKGROUND

Although the recommended minimal examined lymph node (ELN) number in rectal cancer (RC) is 12, this standard remains controversial because of insufficient evidence. We aimed to refine this definition by quantifying the relationship between ELN number, stage migration and long-term survival in RC.

METHODS

Data from a Chinese multi-institutional registry (2009-2018) and the Surveillance, Epidemiology, and End Results (SEER) database (2008-2017) on stages I-III resected RC were analysed to determine the relationship between ELN count, stage migration, and overall survival (OS) using multivariable models. The series of odds ratios (ORs) for negative-to-positive node stage migration and hazard ratios (HRs) for survival with more ELNs were fitted using a Locally Weighted Scatterplot Smoothing (LOWESS) smoother, and structural breakpoints were determined using the Chow test. The relationship between ELN and survival was evaluated on a continuous scale using restricted cubic splines (RCS).

RESULTS

The distribution of ELN count between the Chinese registry ( n =7694) and SEER database ( n =21 332) was similar. With increasing ELN count, both cohorts exhibited significant proportional increases from node-negative to node-positive disease (SEER, OR, 1.012, P <0.001; Chinese registry, OR, 1.016, P =0.014) and serial improvements in OS (SEER: HR, 0.982; Chinese registry: HR, 0.975; both P <0.001) after controlling for confounders. Cut-point analysis showed an optimal threshold ELN count of 15, which was validated in the two cohorts, with the ability to properly discriminate probabilities of survival.

CONCLUSIONS

A higher ELN count is associated with more precise nodal staging and better survival. Our results robustly conclude that 15 ELNs are the optimal cut-off point for evaluating the quality of lymph node examination and stratification of prognosis.

Evaluation of the prognostic value of negative to positive lymph node ratio in gastric cancer: results from multi-institutional cohorts from western and eastern datasets - Cohort study

Lymph node (LN) stage is important for prognosis evaluation of gastric cancer (GC) patients. This study aimed to evaluate the prognostic value of the ratio of negative to positive LNs (Rnp) in GC.

METHODS

The authors evaluated the clinical significance of the Rnp stage in 7660 GC patients from three high-volume institutions in China. Meanwhile, the authors verified the value of the Rnp stage in 11 234 GC patients from the Surveillance, Epidemiology, and End Results (SEER) database.

RESULTS

The patients were stratified into different subgroups based on the N stage of the eighth edition of the TNM staging system, the ratio of positive to detected LNs (Rpd) and Rnp. The survival analysis showed clear differences between the three LN stages in both the China and Surveillance, Epidemiology, and End Results cohorts. In univariate and multivariate analyses, the Rnp stage provided smaller Akaike information criterion or Bayesian information criterion values and a larger likelihood ratio χ2 than the N or Rpd stages in both two cohorts. For patients with inadequate examined LNs (<16), the Rnp stage showed better prognostic evaluation performance than the other two stages. In addition, the 5-year disease-specific survival of GC patients showed a slight variation with increasing LNs in the same subgroup classified by the Rnp or Rpd stages compared to the N stage.

CONCLUSIONS

Along with the higher prognostic value, the Rnp stage has excellent universality with GC patients compared to the N or Rpd stages. Studies with larger sample sizes are needed to predict the prognosis and provide more precise treatment for GC patients.

Development and validation of prognostic model based on extragastric lymph nodes metastasis and lymph node ratio in node-positive gastric cancer: a retrospective cohort study based on a multicenter database

BACKGROUND

Regional lymph node metastasis (LNM) is a competent and the most intensive predictor for the prognostic evaluation of patients after curative surgery. This study is based on the databases of two large medical centers in North and South China. It aims to establish a prognostic model based on extragastric LNM (ELNM) and lymph node ratio (LNR) in node-positive gastric cancer (GC).

METHODS

Clinical data of 874 GC patients with pathologically confirmed LNM in a large medical center in southern China, were included as the training cohort. In addition, the clinical data of 674 patients with pathologically confirmed LNM from a large medical center in northern China were used as the validation cohort.

RESULTS

In the training cohort, a modified N staging system (mNstage) based on ELNM and LNR was established; it has a significantly higher prognostic accuracy than the pN, LNR and ELNM staging system (Akaike Information Criterion, pN stage vs. LNR stage vs. ELNM stage vs. mN stage=5498.479 vs. 5537.815 vs. 5569.844 vs. 5492.123; Bayesian Information Criterion, pN stage vs. LNR stage vs. ELNM stage vs. mN stage=5512.799 vs. 5547.361 vs. 5574.617 vs. 5506.896; likelihood-ratio χ2 , pN stage vs. LNR stage vs. ELNM stage vs. mN stage=177.7 vs. 149.8 vs. 115.79 vs. 183.5). In the external validation, mNstage also has higher prognostic accuracy than the pN, LNR and ELNM staging system. Cox multivariate regression analysis showed that age, mNstage, pT stage, and perineural invasion were independent factors. A nomogram model was established according to the four factors (age, mNstage, pT stage, and perineural invasion). The nomogram model was greater than the traditional tumor-node-metastasis (TNM) staging in the training cohort [1-year area under the curve (AUC), American Joint Commission for Cancer (AJCC) 8th TNM vs. nomogram=0.692 vs. 0.746, 3-year AUC: AJCC 8th TNM vs. nomogram=0.684 vs. 0.758, 5-year AUC: AJCC 8th TNM vs. nomogram=0.725 vs. 0.762]. In the external validation, the nomogram also showed better prognostic value and greater prediction accuracy than the traditional TNM staging.

CONCLUSION

The prognostic model based on ELNM and LNR has good prognostic prediction in patients with node-positive GC.

Is there a survival difference between older adult and younger adult patients with locally advanced gastric cancer with the same lymph node ratio?

OBJECTIVE

The aim of this study was to clarify the prognostic value of the pathological lymph node ratio for older adult and younger adult gastric cancer patients and to evaluate whether there is a difference in the survival of patients with the same lymph node ratio (LNR).

MATERIALS AND METHODS

A total of 222 patients diagnosed with locally advanced gastric cancer who underwent upfront gastrectomy without neoadjuvant chemotherapy and had negative surgical margins were included. The patients were divided into two groups according to age. Clinicopathological properties of the two groups were compared. Potential prognostic factors affecting survival were analyzed. Subsequently, the effect of lymphadenectomy and LNR on survival in both groups was evaluated.

RESULTS

Thirty patients with perioperative mortality were excluded and 192 patients were analyzed. Significant differences were detected in terms of hemoglobin and albumin levels between older adult patients and younger adult patients (p < 0.05). Overall survival (OS) was significantly worse in older adult patients (22 months vs. 67 months, p < 0.001). The survival rates in older adult patients were significantly lower from those of younger adult in the subgroup LNR Stage 2 (12.1% vs. 47.9%, p = 0.004) and LNR Stage 3 classification (9.1% vs. 34.1%, p = 0.039). LNR was found to be significant for OS with a cut-off point of 0.18.

CONCLUSION

A survival difference was found between the older adult and younger adult patients with the same LNR. LNR was found to be an independent factor for survival especially in older adult patients. Survival was found to be further decreased in older adult patients compared to younger adult patients with increasing LNR.

Comparison of 4 lymph node staging systems for the prognostic prediction of esophagogastric junction adenocarcinoma with ≤15 retrieved lymph nodes

BACKGROUND

Directly applying the 8th American Joint Committee on Cancer (AJCC) Tumor Node Metastasis (TNM) staging system to evaluate the prognosis of patients with esophagogastric junction adenocarcinoma (AEG) might lead to under-staging, when insufficient lymph nodes were retrieved during surgery. The prognostic value of 4 lymph nodes staging systems, 8th AJCC TNM N stage, lymph node ratio (LNR), log odds of positive lymph nodes (LODDS), and negative lymph nodes (NLN), in AEG patients having ≤15 retrieved lymph nodes were compared.

METHODS

869 AEG patients diagnosed between 2004 and 2012 with ≤15 retrieved lymph nodes were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression analyses were conducted to assess the association of cancer-specific survival (CSS) and overall survival (OS) with 8th AJCC TNM N stage, LNR, LODDS, and NLN respectively. Predictive survival ability was assessed and compared using linear trend χ2 score, likelihood ratio (LR) test, Akaike information criterion (AIC), Harrell concordance index (C-index), and Receiver Operative Curve (ROC).

RESULTS

The N stage, LNR, LODDS, and NLN were all independent prognostic predictors for CSS and OS in multivariate Cox models. Comparatively, LODDS demonstrated higher linear trend χ2 score, LR test score, C-index and integrated area under the curve (iAUC) value, and lower AIC in CSS compared to the other three systems. Moreover, for patients without regional lymph node metastasis, NLN showed higher C-index and lower AIC.

CONCLUSIONS

LODDS showed better predictive performance than N, LNR, and NLN among patients with node-positive patients while NLN performed better in node-negative patients. A combination of LODDS and NLN has the potential to provide more prognostic information than the current AJCC TNM classification.

Impact of the Deep Neuromuscular Block on Oncologic Quality of Laparoscopic Surgery in Obese Gastric Cancer Patients: A Randomized Clinical Trial

BACKGROUND

Obesity can hinder laparoscopic procedures and impede oncological safety during laparoscopic cancer surgery. Deep neuromuscular block (NMB) reportedly improves laparoscopic surgical conditions, but its oncological benefits are unclear. We aimed to evaluate whether deep NMB improves the oncologic quality of laparoscopic cancer surgery in obese patients.

STUDY DESIGN

We conducted a double-blinded, parallel-group, randomized, phase 3 trial at 9 institutions in Korea. Clinical stage I and II gastric cancer patients with a BMI at or above 25 kg m -2 were eligible and randomized 1:1 ratio to the deep or moderate NMB groups, with continuous infusion of rocuronium (0.5-1.0 and 0.1-0.5 mg kg -1 h -1, respectively). The primary endpoint was the number of retrieved lymph nodes (LNs). The secondary endpoints included the surgeon's surgical rating score (SRS) and interrupted events.

RESULTS

Between August 2017 and July 2020, 196 patients were enrolled. Fifteen patients were excluded, and 181 patients were finally included in the study. There was no significant difference in the number of retrieved LNs between the deep (N = 88) and moderate NMB groups (N = 93; 44.6 ± 17.5 vs 41.5 ± 16.9, p = 0.239). However, deep NMB enabled retrieving more LNs in patients with a BMI at or above 28 kg/m2 than moderate NMB (49.2 ± 18.6 vs 39.2 ± 13.3, p = 0.026). Interrupted events during surgery were lower in the deep NMB group than in the moderate NMB group (21.6% vs 36.6%; p = 0.034). The SRS was not influenced by NMB depth.

CONCLUSION

Deep NMB provides potential oncologic benefits by retrieving more LNs in patients with BMI at or above 28 kg/m2 during laparoscopic gastrectomy.

Combination of the ratio between metastatic and harvested lymph nodes and negative lymph node count as a prognostic indicator in advanced gastric cancer: a retrospective cohort study

Background

The aim of our study was to examine the impact of the combination of the ratio between metastatic and harvested lymph nodes (RML) and negative lymph node (NLN) count on overall survival (OS) in patients with advanced gastric cancer (GC).

Methods

The clinicopathological data of 2,952 advanced GC patients who received curative resection between 1994 and 2015 were collected. They were divided into four groups according to the RML: 0, 0-0.1, 0.1-0.4, and >0.4. We distinguished survival differences through Kaplan-Meier analysis among the subgroups to investigate the impacts of the RML on OS in advanced GC patients. OS was examined according to clinicopathological variables. Spearman's correlation coefficient was used to assess the relationships between the RML and metastatic lymph node (MLN) count and NLN count.

Results

A total of 1,182 patients were enrolled into the study. The median follow-up time was 39 months (interquartile range 20 to 68 months). The 5-year OS rate of all 1,182 GC patients was 54.4%. Kaplan-Meier survival analysis showed that the median OS declined significantly with increasing RML (5-year survival rate 81.2% vs. 69.1% vs. 42.8% vs. 13.1%, P<0.001). As the NLN count increased, the survival rate of GC patients increased (5-year survival rate 12.8% vs. 25.2% vs. 60.2%, P<0.05). The RML, not NLN count, was identified as an independent factor for OS (P<0.001) through multivariate analysis. Spearman correlation analysis suggested that the RML was positively correlated with the number of MLNs (ρ=0.973, P<0.001) and inversely associated with the NLN count (ρ=-0.513, P<0.001).

Conclusions

The RML is an independent prognostic predictor of OS in advanced GC patients, and the NLN count may serve as a supplementary strategy for the present tumor-node-metastasis (TNM) classification to further improve the prognostic prediction efficiency. The combination of the RML and NLN count should be an important predictor for current clinical applications.

A Nomogram Based on the Log Odds of Positive Lymph Nodes Predicts the Prognosis of Patients With Distal Cholangiocarcinoma After Surgery

Background: Lymph node (LN) metastasis is considered one of the most important risk factors affecting the prognosis of distal cholangiocarcinoma (DCC). This study aimed to demonstrate the superiority of log odds of positive lymph nodes (LODDS) compared with other LN stages, and to establish a novel prognostic nomogram to predict the cancer-specific survival (CSS) of DCC.

Methods: From the Surveillance, Epidemiology and End Results (SEER) database, the data of 676 patients after DCC radical operation were screened, and patients were randomly divided into training (n = 474) and validation sets (n = 474). The prognostic evaluation performance of the LODDS and American Joint Commission on Cancer (AJCC) N stage and lymph node ratio (LNR) were compared using the Akaike information criteria, receiver operating characteristic area under the curve (AUC), and C-index. Multivariate Cox analysis was used to screen independent risk factors, and a LODDS-based nomogram prognostic staging model was established. The nomogram's precision was verified by C-index, calibration curves, and AUC, and the results were compared with those of the AJCC TNM staging system.

Results:Compared with the other two stages of LN metastasis, LODDS was most effective in predicting CSS in patients with DCC. Multivariate analysis proved that LODDS, histologic grade, SEER historic stage, and tumor size were independent risk factors for DCC. The C-index of the nomogram, based on the above factors, in the validation set was 0.663. The 1-, 3-, and 5-y AUCs were 0.735, 0.679, and 0.745, respectively. Its good performance was also verified by calibration curves. In addition, the C-index and Kaplan-Meier analysis showed that the nomogram performed better than the AJCC TNM staging system.

Conclusion:For postoperative patients with DCC, the LODDS stage yielded better prognostic efficiency than the AJCC N and LNR stages. Compared with the AJCC TNM staging system, the nomogram, based on the LODDS, demonstrated superior performance.

Current Status and Trends of Minimally Invasive Gastrectomy in Korea

Since its introduction in the early 1990s, laparoscopic gastrectomy has been widely accepted for the treatment of gastric cancer worldwide. In the last decade, the Korean Laparoendoscopic Gastrointestinal Surgery Study group performed important clinical trials and exerted various efforts to enhance the quality of scientific knowledge and surgical techniques in the field of gastric cancer surgery. Laparoscopic gastrectomy has shifted to a new era in Korea due to recent advances and innovations in technology. Here, we discuss the recent updates of laparoscopic gastrectomy—namely, reduced-port, single-incision, robotic, image-guided, and oncometabolic surgery.

Lymph node ratio-based the ypTNrM staging system for gastric cancer after neoadjuvant therapy: a large population-based study

PURPOSES

The lymph node ratio (LNR) has been considered a better prognostic factor than traditional N staging in patients with gastric cancer (GC), but its accuracy is unclear for those who receive neoadjuvant therapy (NAT). We aimed to compare the node ratio (Nr) staging with the ypN staging and to thereby develop a modified staging system incorporating Nr staging.

METHODS

A total of 1791 patients who underwent gastrectomy after NAT in the Surveillance, Epidemiology, and End Results database were retrospectively analyzed. ypTNrM staging was established based on the overall survival (OS).

RESULTS

The Nr staging was generated using 0.2 and 0.5 as the cutoff values of LNR and represented patients with more homogeneous OS compared with ypN staging. The 5-year OS rates for ypTNrM stages IA, IB, II, IIIA, and IIIB were 70.2%, 54.2%, 36.0%, 21.2%, and 6.6%, respectively, compared with 58.8%, 39.1%, and 21.6% for ypTNM stages I, II, and III, respectively. Compared with the ypTNM staging system, the ypTNrM staging system had a lower misclassification rate (3.0% vs. 50.9%) and better prognostic predictive power (C-index: 0.645 vs. 0.589, P < 0.001).

CONCLUSIONS

The ypTNrM staging system incorporating Nr staging may provide a more accurate assessment in the clinical decision-making process for GC after NAT.

Prognostic Value of the Anatomic Region of Metastatic Lymph Nodes in the Current TNM Staging of Gastric Cancer

Purpose

The numeric N stage has replaced the topographic N stage in the current tumor node metastasis (TNM) staging in gastric carcinoma. However, the usefulness of the topographic N stage in the current TNM staging system is uncertain. We aimed to investigate the prognostic value of the topographic N stage in the current TNM staging system.

Materials and Methods

We reviewed the data of 3350 patients with gastric cancer who underwent curative gastrectomy. The anatomic regions of the metastatic lymph nodes (MLNs) were classified into 2 groups: perigastric and extra-perigastric. The prognostic value of the anatomic region was analyzed using a multivariate prognostic model with adjustments for the TNM stage.

Results

In patients with lymph node metastasis, extra-perigastric metastasis demonstrated significantly worse survival than perigastric metastasis alone (5-year survival rate, 39.6% vs. 73.1%, respectively, P<0.001). Extra-perigastric metastasis demonstrated significantly worse survival within the same pN stage; the multivariate analysis indicated that extra-perigastric metastasis was an independent poor prognostic factor (hazard ratio=1.33; 95% confidence interval=1.01–1.75). The anatomic region of the MLNs improved the goodness-of-fit (likelihood ratio statistics, 4.57; P=0.033) of the prognostic model using the TNM stage.

Conclusions

The anatomic region of MLNs has an independent prognostic value in the numeric N stage in the current TNM staging of gastric carcinoma.

Pathologic Lymph Node Staging of Gastric Cancer

OBJECTIVES

The TNM classification is the main tool for lymph node (LN) staging in gastric cancer (GC). However, alternative LN staging systems have been proposed, and the role of features other than the number of metastatic LNs is being investigated. Our aim is to discuss the main challenges of LN assessment in GC.

METHODS

Comprehensive review of the literature on alternative LN staging systems, examined LNs, sentinel LN (SLN) biopsy, LN micrometastases (LNMIs), extracapsular extension (ECE), and tumor deposits (TDs) in GC.

RESULTS

Many controversies exist regarding LN assessment in GC. The TNM classification shows excellent prognostic performance, but alternative prognostic methods such as the LN ratio or log odds of positive LNs have demonstrated to be better than the TNM system in terms of prognostic accuracy. The value of SLN biopsy and LNMIs in GC is still unclear, and several challenges concerning their clinical impact and pathologic analysis must be overcome before their introduction in clinical practice. Most authors have identified ECE and TDs as independent prognostic factors for survival in GC.

CONCLUSIONS

Further studies should be performed to evaluate the impact of these features on the TNM classification and patient outcomes, as well as to standardize alternative LN staging systems.

Clinical Relevance of Splenic Hilar Lymph Node Dissection for Proximal Gastric Cancer: A Propensity Score-Matching Case-Control Study

BACKGROUND

The application of splenic hilar lymph node (no. 10 LN) dissection (no. 10 LND) for proximal gastric cancer (PGC) remains controversial. This study aimed to investigate the clinical relevance of no. 10 LND from the perspective of long-term survival.

METHODS

The main study population included 995 previously untreated patients who underwent laparoscopic radical total gastrectomy between January 2008 and December 2014. Of these 995 patients, 564 underwent no. 10 LND (no. 10D+ group) and the remaining 431 patients did not (no. 10D- group). Propensity score-matching was applied to reduce the effects of confounding factors. The study end points were overall survival (OS) and disease-free survival (DFS). Additionally, 39 patients who received neoadjuvant chemotherapy during the same period also were included as a separate population for analysis.

RESULTS

The metastasis rate for no. 10 LN was 10.5 % (59/564). No significant differences were observed in intra- and postoperative complications nor in mortality between the no. 10D+ and no. 10D- groups (all P > 0.05). After 1:1 matching, the two groups were comparable in clinicopathologic characteristics. The no. 10D+ group had significantly better survival than the no. 10D- group (5-year OS: 63.3 % vs 52.2 %, P = 0.003; 5-year DFS: 60.4 % vs 48.1 %, P = 0.013). For the patients who received neoadjuvant chemotherapy, the 5-year OS rates in the no. 10D+ and no. 10D- groups were respectively 50.6 % and 31.3 % (P = 0.150) and the 5-year DFS rates were respectively 51.5 % and 31.3 % (P = 0.123).

CONCLUSIONS

Patients with untreated PGC may achieve the benefit of long-term survival from no. 10 LND. For patients with PGC who undergo neoadjuvant chemotherapy, no. 10 LND may not bring survival benefits. However, further validation with a large-sample study is needed.

Prognostic performance of different lymph node classification systems in young gastric cancer

Background

Accurate staging plays a pivotal role in cancer care. The lymph node (LN) ratio (LNR) and the log odds of positive LNs (LODDS) have been suggested as alternatives to the N staging since the TNM system has the risk of stage migration. The prognostic significance of LNR and LODDS in young patients with gastric cancer (GC) has not been reported. This study aims to investigate the correlations between LNR and LODDS and survival of young patients with GC, and compare the predictive performance of these LN staging methods.

Methods

GC patients before the age of 40 from 2004 to 2016 in the Surveillance, Epidemiology and End Results database were enrolled. The prognostic evaluation of the N factor, LNR and LODDS was compared using the time-dependent receiver operating characteristic (ROC) analysis, area under the curve (AUC), C-index and Akaike information criterion (AIC).

Results

Multivariate survival analysis identified that the LNR and LODDS were significantly independent prognostic indicators for overall survival (OS) in young patients with GC and in the subgroups comprised of patients with ≤15 LNs examined. The time-dependent ROC curves of the LNR and LODDS were continuously superior to that of the N factor in predicting OS during the observation period. And the AUCs revealed that the predictive accuracy of the LNR and LODDS was remarkably superior to the N factor at 1 and 3 years (P<0.05). The model incorporating LNR or LODDS had higher C-index and lower AIC when comparing to the model incorporating the N factor.

Conclusions

The LNR and LODDS improve accuracy of survival risk prediction in young patients with GC when comparing to the N factor. These two novel LN classification methods should be considered as alternatives to the N staging for the prognostic prediction of young patients with GC.

The short-term and long-term outcomes of indocyanine green tracer-guided laparoscopic radical gastrectomy in patients with gastric cancer

Background

The safety and efficacy of indocyanine green (ICG) imaging navigational laparoscopic gastrectomy remain controversial. This study is to evaluate the short-term and long-term outcomes of ICG-guided laparoscopic radial gastrectomy in patients with gastric cancer.

Methods

Consecutive patients with definitive diagnosis of gastric cancer that underwent laparoscopic radical gastrectomy were collected retrospectively. Propensity score matching (PSM) at 1:1 ratio was performed to compare the outcomes of two groups.

Results

A total of 122 qualified patients were divided into ICG group (n = 34) and non-ICG group (n = 88). PSM yielded 28 patients with comparable baseline characteristics into each group. The number of retrieved lymph node in ICG group was significantly higher than that in non-ICG group (P = 0.0196). There was no statistical difference of perioperative, short-term, and long-term complications between the two groups.

Conclusion

ICG-guided laparoscopic radical gastrectomy is safe and effective, and ICG-navigated lymphadenectomy improves the number of retrieved lymph nodes for patients with gastric cancer.

Laparoscopic Compared with Open D2 Gastrectomy on Perioperative and Long-Term, Stage-Stratified Oncological Outcomes for Gastric Cancer: A Propensity Score-Matched Analysis of the IMIGASTRIC Database

BACKGROUND

The laparoscopic approach in gastric cancer surgery is being increasingly adopted worldwide. However, studies focusing specifically on laparoscopic gastrectomy with D2 lymphadenectomy are still lacking in the literature. This retrospective study aimed to compare the short-term and long-term outcomes of laparoscopic versus open gastrectomy with D2 lymphadenectomy for gastric cancer.

METHODS

The protocol-based, international IMIGASTRIC (International study group on Minimally Invasive surgery for Gastric Cancer) registry was queried to retrieve data on patients undergoing laparoscopic or open gastrectomy with D2 lymphadenectomy for gastric cancer with curative intent from January 2000 to December 2014. Eleven predefined, demographical, clinical, and pathological variables were used to conduct a 1:1 propensity score matching (PSM) analysis to investigate intraoperative and recovery outcomes, complications, pathological findings, and survival data between the two groups. Predictive factors of long-term survival were also assessed.

RESULTS

A total of 3033 patients from 14 participating institutions were selected from the IMIGASTRIC database. After 1:1 PSM, a total of 1248 patients, 624 in the laparoscopic group and 624 in the open group, were matched and included in the final analysis. The total operative time (median 180 versus 240 min, p < 0.0001) and the length of the postoperative hospital stay (median 10 versus 14.8 days, p < 0.0001) were longer in the open group than in the laparoscopic group. The conversion to open rate was 1.9%. The proportion of patients with in-hospital complications was higher in the open group (21.3% versus 15.1%, p = 0.004). The median number of harvested lymph nodes was higher in the laparoscopic approach (median 32 versus 28, p < 0.0001), and the proportion of positive resection margins was higher (p = 0.021) in the open group (5.9%) than in the laparoscopic group (3.2%). There was no significant difference between the groups in five-year overall survival rates (77.4% laparoscopic versus 75.2% open, p = 0.229).

CONCLUSION

The adoption of the laparoscopic approach for gastric resection with D2 lymphadenectomy shortened the length of hospital stay and reduced postoperative complications with respect to the open approach. The five-year overall survival rate after laparoscopy was comparable to that for patients who underwent open D2 resection. The types of surgical approaches are not independent predictive factors for five-year overall survival.

Lymph Node Ratio Is an Independent Prognostic Factor for Patients with Siewert Type II Adenocarcinoma of Esophagogastric Junction: Results from a 10-Year Follow-up Study

PURPOSE

Emerging evidences suggest that lymph node ratio (LNR), the number of metastatic lymph node (LN) to the total number of dissected lymph nodes (NDLN), may predict survival in multiple types of solid tumor. However, the prognostic role of LNR in adenocarcinoma of the esophagogastric junction (AEG) remains uninvestigated. The present study is intended to determine the prognostic value of LNR in the patients with Siewert type II AEG.

METHODS

A total of 342 patients with Siewert type II AEG who underwent R0 resection were enrolled in this study. The optimal cutoff of LNR was stratified into tertiles using X-tile software. The log-rank test was used to evaluate the survival differences, and multivariate Cox regression analyses were performed to determine the independent prognostic variables.

RESULTS

The optimal cutoff of LNR were classified as LNR = 0, LNR between 0.01 and 0.40, and LNR > 0.41. Patients with high LNR had a shorter 5- and 10-year disease-specific survival (DSS) rate (8.5%, 1.4%) compared with those with moderate LNR (20.4%, 4.9%) and low LNR (58.0%, 27.5%) (P < 0.001). Multivariate Cox regression analysis indicated that LNR was an independent factor for DSS after adjusting for confounding variables (P < 0.05). Furthermore, after stratification by NDLN between NDLN < 15 group and NDLN ≥ 15 group, the LNR remained a significant predictor for DSS (P < 0.05).

CONCLUSIONS

LNR is an independent predictor for DSS in patients with Siewert type II AEG regardless of NDLN. Patients with higher LNR have significantly shorter DSS.

A novel nomogram based on cardia invasion and chemotherapy to predict postoperative overall survival of gastric cancer patients

Background

We aimed to establish and externally validate a nomogram to predict the 3- and 5-year overall survival (OS) of gastric cancer (GC) patients after surgical resection.

Methods

A total of 6543 patients diagnosed with primary GC during 2004–2016 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. We grouped patients diagnosed during 2004–2012 into a training set (n = 4528) and those diagnosed during 2013–2016 into an external validation set (n = 2015). A nomogram was constructed after univariate and multivariate analysis. Performance was evaluated by Harrell’s C-index, area under the receiver operating characteristic curve (AUC), decision curve analysis (DCA), and calibration plot.

Results

The multivariate analysis identified age, race, location, tumor size, T stage, N stage, M stage, and chemotherapy as independent prognostic factors. In multivariate analysis, the hazard ratio (HR) of non-cardia invasion was 0.762 (P < 0.001) and that of chemotherapy was 0.556 (P < 0.001). Our nomogram was found to exhibit excellent discrimination: in the training set, Harrell’s C-index was superior to that of the 8th American Joint Committee on Cancer (AJCC) TNM classification (0.736 vs 0.699, P < 0.001); the C-index was also better in the validation set (0.748 vs 0.707, P < 0.001). The AUCs for 3- and 5-year OS were 0.806 and 0.815 in the training set and 0.775 and 0.783 in the validation set, respectively. The DCA and calibration plot of the model also shows good performance.

Conclusions

We established a well-designed nomogram to accurately predict the OS of primary GC patients after surgical resection. We also further confirmed the prognostic value of cardia invasion and chemotherapy in predicting the survival rate of GC patients.

Comparison of a Tumor-Ratio-Metastasis Staging System and the 8th AJCC TNM Staging System for Gastric Cancer

Background

Despite the implementation of the 8th American Joint Committee on Cancer (AJCC) TNM staging system for gastric cancer (GC) in 2017, it still holds a significant level of stage migration which affects patients’ proper classification and accurate prognosis. Here, to reduce this effect, we evaluated the prognostic value of a lymph node ratio (LNR) and established a novel tumor–ratio–metastasis (TRM) staging system.

Method

The data of 15,206 GC patients from the Sun Yat-sen University Cancer Center (Training set; n=2,032) and the US Surveillance, Epidemiology, and End Results (SEER) database (Validation set; n=13,174) were analyzed. The training set was classified into 5 LNR categories, based on which the novel TRM staging system was constructed. The overall survival (OS) between the TRM and AJCC TNM systems was compared in the training set and validated in the validation set. The likelihood ratio x², liner trend x², C-index, and Akaike information criterion (AIC) values were used to measure the discriminatory ability between the two different staging systems. Decision curve analyses (DCAs) were conducted to test the clinical value of the two staging systems.

Result

The patients were classified into the following categories: LNR0: 0%, LNR1: 0%<LNR ≤ 10%, LNR2: 10%<LNR ≤ 25%, LNR 3a: 25%<LNR ≤ 60%, and LNR 3b: LNR>60%. Univariate analyses demonstrated that the log-rank x² of the LNR stage (Training/Validation set: x² = 463.1/2880.8) was larger than the AJCC pN stage (Training/Validation set: x² = 281.5/2240.8). For both the training set and validation set, stratified analyses using the Kaplan-Meier method identified significantly heterogeneous OS in every pN category but only one using the LNR. The TRM staging system had higher likelihood ratio x², liner trend x², C-index and smaller AIC values than the TNM system.

Conclusion

The TRM staging system demonstrated improved homogeneity and discriminatory ability in predicting the prognosis of GC patients compared with the AJCC TNM staging system.

Benchmarks for nodal yield and ratio for node-positive gastric cancer

BACKGROUND

We aimed to elucidate prognostic markers of node-positive gastric cancers with a focus on examined lymph nodes and lymph node ratio.

METHODS

Patients treated with curative-intent gastrectomy at The University of Texas MD Anderson Cancer Center from 1995-2019 were evaluated. Patients with non-metastatic, node-positive gastric cancers were considered for analysis.

RESULTS

Of 775 patients, 281 met the inclusion criteria. The mean age was 58 years, 61% were male, 51% were White, 65% received preoperative therapy, and 71% of tumors were located in the gastric body. The median overall survival was 3.6 years, and 1-, 5-, and 10-year overall survival rates were 91%, 41%, and 29%, respectively. pN3 category was associated with worse overall survival (hazard ratio 1.79, P = .001) and recurrence-free survival (hazard ratio 1.92, P = .004). Nodal burden was associated with aggressive biologic traits in primary tumors, including higher rates of lymphovascular and perineural invasion and lower preoperative therapy response rates. By receiver-operative characteristic analysis, threshold values of ≥30 examined lymph nodes and <30% lymph node ratio were most discriminant for overall survival. On adjusted analysis, positive margins, additional organ resection, <30 examined lymph nodes, and ≥30% lymph node ratio were associated with worse recurrence-free survival and overall survival. Among patients with high node burden (pN3), <30 examined lymph nodes remained significant on adjusted survival analysis.

CONCLUSION

Greater than or equal to 30 examined lymph nodes and <30% lymph node ratio were significantly associated with longer recurrence-free survival and overall survival, independent of lymphadenectomy type. These prognostic benchmarks should be considered in the surgical management of gastric cancer in the United States.

Retrieval of 30 Lymph Nodes Is Mandatory for Selected Stage II Gastric Cancer Patients

BACKGROUND

According to the 8th edition AJCC staging manual, a least of 16 lymph nodes retrieval (LNRs) is the minimal requirement for lymph nodes (LNs) dissection of gastric cancer surgery. Previous studies have shown that increasing the number of LNRs (≥30) prolongs survival for selected patients. However, the necessity of retrieving 30 or more LN for stage II gastric cancer patients is still under debate.

AIM

This study aims to explore the impact of retrieving 30 or more lymph nodes on the survival of stage II cancer patients.

METHODS

A total of 1,177 patients diagnosed with stage II gastric cancer were enrolled in this study. The clinicopathological parameters and the impact of different LNRs (<30 or ≥30) and positive lymph node ratio (NR) on overall survival (OS) were retrospectively analyzed.

RESULTS

The mean number of LNRs was 34 ± 15. A total of 44% (518/1,177) of patients had an LNRs <30, while 56% (659/1,177) of patients had an LNRs ≥30. The 5-year survival rate was 81% for all patients, 76% for the LNRs <30 group, and 86% for LNRs ≥30 group, respectively (P = 0.003). The survival benefit of retrieving 30 lymph nodes was significant in certain subgroups: age >60 years/male/underwent total gastrectomy/stage IIB. For N+ patients, higher NR was significantly correlated with poor survival.

CONCLUSION

The survival benefit of retrieving 30 LNs varies in different subgroups. An LNRs of 30 is mandatory for selected stage II gastric cancer patients.

The Prognostic Value of Lymph Node Ratio after Neoadjuvant Chemotherapy in Patients with Locally Advanced Gastric Adenocarcinoma

Purpose

This study aimed to investigate the prognostic value of lymph node ratio (LNR) in patients with locally advanced gastric cancer who received neoadjuvant chemotherapy.

Materials and Methods

We retrospectively enrolled gastric cancer patients treated with neoadjuvant chemotherapy and curative surgery at the First Affiliated Hospital of Zhejiang University from 2004 to 2015 as the study cohort. Patients with the same inclusion criteria treated in 2016–2017 were enrolled as the validation cohort. Kaplan-Meier curves were assessed using the log-rank test to analyze the differences in overall survival (OS). Multivariate survival analysis was performed using the Cox proportional hazards model. The areas under the receiver operating characteristic curve of ypN and LNR categories for predicting the actual 3-year OS were compared.

Results

A total of 265 patients were included in the proposal cohort. The median number of retrieved lymph nodes (rLNs) was 32. The number of positive lymph nodes (pLNs) increased as rLN increased (P=0.037), but the LNR remained relatively constant (P=0.462). The LNR was categorized into 4 groups according to the prognosis: ypNr0, node-negative with rLN>25; ypNr1, node-negative with rLN≤25 or 0<LNR≤0.1; ypNr2, 0.1<LNR≤0.3; and ypNr3, LNR>0.3. In the validation cohort of 43 enrolled patients, there was a clear distinction in OS that significantly (P<0.001) varied depending on the LNR values and LNR was the only independent prognostic factor in multivariate analysis (P<0.001).

Conclusions

LNR was an independent prognostic factor for survival of patients with gastric cancer after preoperative chemotherapy and might be an alternative predictor for ypN stage.

Log odds of positive lymph nodes is a better prognostic factor for oesophageal signet ring cell carcinoma than N stage

BACKGROUND

Signet ring cell carcinoma is a rare type of oesophageal cancer, and we hypothesized that log odds of positive lymph nodes (LODDS) is a better prognostic factor for oesophageal signet ring cell carcinoma.

AIM

To explore a novel prognostic factor for oesophageal signet ring cell carcinoma by comparing two lymph node-related prognostic factors, log odds of positive LODDS and N stage.

METHODS

A total of 259 cases of oesophageal signet ring cell carcinoma after oesopha-gectomy were obtained from the Surveillance, Epidemiology, and End Results database between 2006 and 2016. The prognostic value of LODDS and N stage for oesophageal signet ring cell carcinoma was evaluated by univariate and multivariate analyses. The Akaike information criterion and Harrell’s C-index were used to assess the value of two prediction models based on lymph nodes. External validation was performed to further confirm the conclusion.

RESULTS

The 5-year cancer-specific survival (CSS) and 5-year overall survival (OS) rates of all the cases were 41.3% and 27.0%, respectively. The Kaplan-Meier method showed that LODDS had a higher score of log rank chi-squared (OS: 46.162, CSS: 41.178) than N stage (OS: 36.215, CSS: 31.583). Univariate analyses showed that insurance, race, T stage, M stage, TNM stage, radiation therapy, N stage, and LODDS were potential prognostic factors for OS (P < 0.1). The multivariate Cox regression model showed that LODDS was an significant independent prognostic factor for oesophageal signet ring carcinoma patients after surgical resection (P < 0.05), while N stage was not considered to be a significant prognostic factor (P = 0.122). Model 2 (LODDS) had a higher degree of discrimination and fit than Model 1 (N stage) (LODDS vs N stage, Harell’s C-index 0.673 vs 0.656, P < 0.001; Akaike information criterion 1688.824 vs 1697.519, P < 0.001). The results of external validation were consistent with those in the study cohort.

CONCLUSION

LODDS is a superior prognostic factor to N stage for patients with oesophageal signet ring cell carcinoma after oesophagectomy.

Evaluation of Lymph Node Staging Systems as Independent Prognosticators in Remnant Gastric Cancer Patients with an Insufficient Number of Harvested Lymph Nodes

BACKGROUND

The lymph node (LN) ratio (LNR) and the log odds of positive LNs (LODDS) have been proposed as sensitive prognosticators in patients with primary gastric cancer, especially in patients with an insufficient number of harvested LNs. We investigated the association of LNR and LODDS with survival in patients with remnant gastric cancer (RGC) and explored whether these staging methods are prognostic factors in patients with an insufficient number of harvested LNs.

METHODS

The present study retrospectively examined 95 patients with RGC who received gastrectomy between January 2000 and December 2018. The patients were classified according to the adjusted X-tile cutoff for LNR and LODDS. The association between survival rates and clinicopathological features was investigated. The predictive accuracy of the LNR and LODDS was compared with that of the Union for International Cancer Control pathological N factor.

RESULTS

Multivariate analysis revealed that the LNR and LODDS were independent risk factors for recurrence-free survival (RFS) [hazard ratio (HR) 2.623, p = 0.020; HR 3.404, p = 0.004, respectively] and overall survival (OS) (HR 3.694, p = 0.003; HR 2.895, p = 0.022, respectively) in patients with RGC. Moreover, even in patients with 15 or fewer harvested LNs, only the LNR was a significant independent risk factor for RFS (HR 21.890, p < 0.001) and OS (HR 6.597, p = 0.002). The receiver operating characteristic curves revealed that the prognostic accuracy of the three methods was comparable (p > 0.05).

CONCLUSION

LNR has significant prognostic value for patients with RGC, including those with an insufficient number of harvested LNs.

Nomogram for Predicting Survival in Advanced Gastric Cancer after Neoadjuvant Chemotherapy and Radical Surgery

BACKGROUND

Neoadjuvant chemotherapy (NAC) with subsequent radical surgery has become a popular treatment modality for advanced gastric cancer (AGC) worldwide. However, the survival benefit is still controversial, and prognostic factors remain undetermined.

AIM

To identify clinical parameters that are associated with the survival of AGC patients after NAC and radical surgery and to establish a nomogram integrating multiple factors to predict survival.

METHODS

We reviewed the medical profiles of 215 AGC patients who received NAC and radical resection, and clinical parameters concerning NAC, surgery, pathological findings, and adjuvant chemotherapy were analyzed using a Cox regression model to determine their impact on survival. Based on these factors, a nomogram was developed and validated.

RESULTS

The overall 1-year and 3-year survival rates were 85.8% and 55.6%, respectively. Younger age (<60 years old), increased examined lymph nodes (exLNs), successful R0 resection, the achievement of pathological complete response (pCR), and acceptance of adjuvant chemotherapy were positive predictors of survival. The C-index of the established nomogram was 0.785. The area under receiver operating curve (ROC) at 1/3 years of prediction was 0.694/0.736, respectively. The model showed an ideal calibration following internal bootstrap validation.

CONCLUSION

A nomogram predicting survival after NAC and surgery was established. Since this nomogram exhibited satisfactory and stable predictive power, it can be inferred that this is a practical tool for predicting AGC patient survival after NAC and radical surgery.

Prognostic value of a new staging system based on the retrieved number and metastatic rate of LNs in gastric cancer with ≤15 retrieved LNs

OBJECTIVE

To investigate a reasonable lymph node (N) staging system for gastric cancer patients with ≤15 retrieved lymph nodes (LNs).

METHODS

The clinicopathological and follow-up data of patients with ≤15 LNs were obtained from the US Surveillance, Epidemiology, and End Results (SEER) database to analyze the impact of the number of retrieved LNs and metastatic status on the prognosis. In addition, external validation was achieved with data from two medical centers in China.

RESULTS

A total of 18,139 gastric cancer patients with 1-15 retrieved LNs from the SEER database were enrolled and randomly divided into the training group and the internal validation group. A new LN staging system, mNr staging (mNr0-4; 5 stages), was established according to the number of retrieved LNs and the metastatic rate. Compared with the TNM and TNrM staging systems (established by Wang J; misclassification rates of 50.4% and 62.5%, respectively), the mTNrM staging system had a lower misclassification rate (23.4%). Furthermore, there was a significant difference in the 5-year overall survival (OS) rate between the mTNrM staging subgroups (p < 0.05); however, no significant difference was found in the 5-year OS rate of partial adjacent stages in the TNM (8th edition) and TNrM (p > 0.05) staging systems. Similar results were obtained in the external validation cohort.

CONCLUSION

mNr and mTNrM staging systems can efficiently distinguish a survival difference in patients who undergo gastrectomy with ≤15 retrieved LNs, with more accurate predictions of the 5-year OS rate of patients compared with the TNM and TNrM staging systems.

Proposed Modification of the 8th Edition of the AJCC Staging System for Gastric Cancer

Background: The American Joint Committee on Cancer (AJCC) staging system has been the standardized staging system for malignancies since the first edition in 1987. The 8th edition of gastric cancer was released in 2016, and is expected to be used in clinical practice in 2018. The aim of this study was to improve this new gastric cancer staging system. Methods: We conducted median overall survival analyses in a cohort of 8359 gastric cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database (2004-2014) via Kaplan-Meier curves and log-rank tests, and proposed a modified staging system based on median OS. The concordance index (C-index) was conducted to evaluate the predictive accuracy. Results: Using the 8th AJCC staging system, the median OS of patients at the same stage varied widely between the different substages, especially in stage III. Despite the definitions of T, N, and M, substages in the modified staging system were regrouped based on median OS. The C-index of stage III patients with the modified staging system [0.579, 95% confidence interval (CI) 0.564-0.593] was higher than the 8th AJCC staging system (0.567, 95% CI 0.552-0.581). Moreover, we divided these patients into two groups according to their examined lymph node counts (≥15 or 1-14), and studied the effectiveness of the modified staging system in the two groups. Conclusions: The modified 8th AJCC staging system for gastric cancer proposed in this study generates better prognostic stratifications and may be evaluated for further update. Abbreviations:AJCCAmerican Joint Committee on CancerOSOverall SurvivalSEERSurveillance, Epidemiology, and End Results.

Prognostic Impact of Frozen Section Investigation and Extent of Proximal Safety Margin in Gastric Cancer Resection

BACKGROUND AND AIMS

Guidelines propose different extents of macroscopic proximal margin for gastric cancer and frozen margin investigation in selected cases, but data is lacking. This study was to evaluate the necessary extent of macroscopic proximal margin, accuracy of frozen margin investigation, and prognostic impact of tumor-free proximal margin length in pT2-pT4 gastric cancer.

STUDY DESIGN

Proximal and distal frozen margins were routinely investigated intraoperatively in all pT2-pT4 gastric cancers resected between 2011 and 2017. Macroscopic and microscopic proximal margin lengths were correlated. For R0-resections, survival analysis was performed for distal gastrectomy (DG) with microscopic proximal margin length ≤3 cm versus >3 cm.

RESULTS

Overall, 1484 patients were included. Microscopic proximal margin lengths were macroscopically more often misestimated in diffuse histology (P = 0.0004), but extent of underestimation in centimeter was similar to intestinal and mixed/undetermined type (P = 0.134). Fifteen cases (1.0%) resulted in R1-resection, 10 at distal, and 5 at proximal margin but none with macroscopic proximal margin ≥3 cm and negative frozen section. Overall agreement of frozen margin and final pathology was 2951/2968 (99.4%). Proximal margin length in DG did not correlate with survival or recurrence in R0-resected patients.

DISCUSSION

Diffuse histology is at higher risk for underestimation of proximal margin length, but extent of underestimation is similar in other Laurén subtypes. If ≥3 cm macroscopic proximal margin length is applied with intraoperative frozen margin confirmation, R1-resection can be avoided.

CONCLUSION

In pT2-T4a gastric cancer, proximal margin of ≥3 cm plus frozen margin confirmation provides high oncological safety. In DG patients with R0-resection, proximal margin length does not correlate with survival or recurrence.

Comparison of three lymph node staging systems in evaluating the prognosis of patients with pT3 esophageal squamous cell carcinoma

To explore the prognostic value of three lymph node staging systems, including number of positive lymph nodes (pN), lymph node ratio (LNR), and log odds of positive lymph nodes (LODDS), in patients with pT3 stage esophageal squamous cell carcinoma (ESCC). Data from 1667 patients with pT3 stage ESCC who underwent surgical resection were reviewed. The log-rank test was used to assess the differences in overall survival (OS) between groups. Multivariate analysis was performed to identify independent prognostic factors. The receiver operating characteristic curve was used to assess the prognostic accuracy of the three staging methods. The median survival time for the entire group was 48.0 months, and the 1-, 3- and 5-year OS rates were 83.9%, 55.1% and 66.6%, respectively. All three lymph node staging systems were significantly correlated with OS in univariate and multivariate analyses. However, LNR and LODDS staging systems could more accurately predict survival than the pN staging system in patients with < 15 lymph nodes dissected, while LODDS have the best prognostic homogeneity. All three staging systems could be used for prognostic assessment in pT3 stage ESCC. But LODDS staging system might be superior to the others due to its prognostic homogeneity.

Proposal of a novel subclassification of pN3b for improvement the prognostic discrimination ability of gastric cancer patients

INTRODUCTION

In the recent edition of TNM staging system, pN3b gastric cancer were separated into the staging system for better prognosis accuracy. The definition of pN3b contains a large range of metastasis lymph nodes (mLNs). However, few studies have evaluated the prognosis of pN3b patients and it remains unknown whether these patients were reasonably assigned into the same substage.

MATERIALS AND METHODS

A total of 642 pN3b patients from a multi-institutional cohort in China were included. Disease-specific survival (DSS) was estimated using the Kaplan-Meier method and the Cox proportional hazards regression analysis was used to identify the independent prognostic factors. Restricted cubic spine model was used to specify the association between the continuous variables and the logarithm Hazard ratios (HRs). The optimal cut-off value of mLNs for DSS was identified using the X-tile software.

RESULTS

The 5-year DSS rate of total pN3b cohort was 15.4%. The smooth curves showed a non-linear association between the mLNs and the logarithm HRs. All pN3b gastric cancer patients were divided into two subclassifications (pN3b1: 16-24 mLNs, pN3b2: ≥25 mLNs). Significant survival difference was observed between two subclassifications (P = 0.048). Additionally, more LNs examined could decrease the death risk of pN3b patients and bring survival benefit only in pN3b1 patients, but not in pN3b2 patients.

CONCLUSIONS

We proposed a novel subclassification of pN3b patients, which assigned patients into two subclassifications with significant survival difference. Future study should explore the prognosis value based on this novel subclassification in TNM staging system.

Topographic lymph node staging system shows prognostic superiority compared to the 8th edition of AJCC TNM in gastric cancer. A western monocentric experience

INTRODUCTION

The current Tumor Node Metastasis staging system (TNM) for gastric cancer classifies the extent of lymph node metastasis based upon the number of lymph nodes involved. Choi et al. have recently proposed a new anatomical classification based upon the regionality of the involved nodes. This new classification seems to have a better predictive prognostic value than the traditional one. We investigated the prognostic role of the new anatomical based classification, reviewing our institutional gastric cancer database.

METHODS

We performed a retrospective chart review of 329 patients who underwent gastrectomy at our Institution from 2003 to 2017. We excluded from data analysis any patient with distant metastases at the time of first diagnosis and or surgery, pathology other than adenocarcinoma, lymphadenectomy less than D2, impossibility to identify location of lymph nodes (LNs) on pathological report and neoadjuvant chemotherapy. The extent of D2 lymphadenectomy was defined according to Japanese Gastric Cancer Association criteria. LN metastasis were reclassified into three topographic groups (lesser, greater curvature, and extraperigastric nodes) and staged according to Choi. The new N stage was combined with the current pT according to the 8th edition of TNM and a new hybrid TNM stage was established. All patients were followed up until June 2019. The prognostic performance of the new stage and of the current anatomical numeric based system (TNM) was analyzed and assessed by the C-index, AIC and likelihood ratio χ2 value.

RESULTS

In predicting both Overall Survival (OS) and Disease free Survival (DFS) the new N stage and the new TNM staging system had the highest C-index and likelihood ratio χ2 value and the lowest Akaike Information Criterion (AIC), showing a better accuracy and displaying a better prognostic performance.

CONCLUSIONS

Our study is the first from the Western world to compare the new hybrid classification, based on the anatomical location of metastatic nodes, to the 8th of American Joint Committee on Cancer (AJCC) TNM staging system. Our findings on a small, monocentric sample suggest that hybrid topographic lymph node staging system is more accurate than TNM.

Comparisons of remnant primary, residual, and recurrent gastric cancer and applicability of the 8th AJCC TNM classification for remnant gastric cancer staging

BACKGROUND

Because there is no well-established postoperative staging system for patients with remnant gastric cancer (RGC), we compared the overall survival of patients categorized with the 8th AJCC TNM staging system.

METHOD

A total of 391 patients underwent surgery for RGC at our institution between 1996 and 2019. Among them, 201 patients received their first surgery at our institution and 190 received primary surgery elsewhere. We retrospectively reviewed their medical records and classified each according to Kaminishi's classification and the 8th AJCC TNM staging system for comparison and analysis.

RESULTS

All 201 patients who underwent their first operation at our institution for malignancy were classified as primary (n = 41, 20.4%), residual (n = 103, 51.2%), and recurrent (n = 57, 28.4%) RGC. The 5-year overall survival (OS) rates for the primary, residual, and recurrent RGC groups were 78.1%, 73.8% and 56.0%, respectively (p = 0.004). In a multivariate analysis, RGC classification was an independent prognostic factor along with the TNM staging system (p = 0.001). However, there was no significant difference in OS between the three groups of the same TNM stage. In addition, the OS of each stage related to primary cancer was not significantly different from the OS of RGC patients classified in TNM staging.

CONCLUSION

The RGC classification system we used may reflect the comprehensive aspects of previous disease states and predict the prognosis of patients with gastric cancer. In addition, the 8th AJCC TNM classification is a practical and applicable staging system for RGC.