Increasing the Number of Examined Lymph Nodes is a Prerequisite for Improvement in the Accurate Evaluation of Overall Survival of Node-Negative Gastric Cancer Patients

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.

A Retrospective Study of Laparoscopic Distal Gastrectomy Guided by Carbon Nanoparticle Suspension Injection Lymphography for Gastric Cancer

BackgroundThe use of lymph node (LN) tracers can help obtain a complete dissection of the LNs and increase the detection rate of metastatic LNs. Carbon nanoparticle suspension injection (CNSI) has become increasingly used in radical gastrectomy procedures. This study is designed to evaluate the quality of LN dissection in gastric cancer patients with laparoscopic distal gastrectomy under the guidance of CNSI lymphography.MethodThis was a retrospective cohort study including patients with a pathological biopsy diagnosis of resectable gastric cancer who underwent laparoscopic distal gastrectomy. Data was focused on patients at [Renji Hospital of Shanghai Jiaotong University] from July 2023 to January 2024. Patients were divided into the CNSI group and control group after 1:1 propensity score matching analysis. The median number of LNs harvested was compared between groups. Perioperative status and any complications that arose within 30 days were also analyzed.ResultAfter 1:1 propensity matching analysis, there were 49 patients each in the CNSI group and control group. The median number of harvested LNs was larger in the CNSI group than the control group (P = 0.01). A significant difference between 2 groups was observed in surgery time (P = 0.008). The morbidity of any short-term postoperative complications within 30 days after surgery revealed a similar outcome (P > 0.05).DiscussionCNSI-guided laparoscopic distal gastrectomy is less time-consuming and harvests more LNs. For laparoscopic distal gastrectomy, CNSI-guided lymphography can be an excellent adjuvant.

Comparative study of ICG and non-ICG-guided laparoscopic gastrectomy for gastric cancer: a propensity score-matched analysis at a single center

ABSTRACT

Objectives

To investigate the effectiveness of indocyanine green (ICG) lymphography in improving lymph nodes (LNs) harvesting during laparoscopic radical distal gastrectomy for gastric cancer.

Design

Non-randomized trial, prospective study compared ICG and non-ICG group using 1:1 propensity score matching (PSM) method.

Setting

Preoperative clinical characteristics, operative outcomes, and follow-up results.

Participants

242 patients who underwent laparoscopic distal gastrectomy with D2 lymphadenectomy for gastric cancer between 2019 and 2023. After exclusion and PSM, 160 patients (Pts) were included, paired in two groups: ICG (80 Pts) and non-ICG (80 Pts).

Interventions

Patients in the ICG group underwent ICG injection submucosal via endoscopy 1 day before surgery.

Main outcome measures

Comparison of the number of retrieved LNs and complications between the ICG and non-ICG group.

Results

There were no significant differences in age, sex, height, tumor size, pathological Tumor-stage, histological differentiation, and complications between the two groups. There was a shorter operative time in the ICG group compared with the non-ICG group (median: 118 mins (IQR, 105-135) vs 146 mins (IQR, 120-180), respectively). Regarding the effectiveness of LN dissection: the ICG group had a higher median of retrieved LNs than the non-ICG group (36 LNs (IQR, 29-46) vs 27 LNs (IQR, 21-31); p<0.001). The mean number of metastatic LNs in the ICG group was significantly higher than in the non-ICG group, with 2.6±5.4 LNs compared with 0.9±3.1 LNs, respectively (p=0.018). The proportion of patients with more than 25 and 30 retrieved LNs was higher in the ICG group compared with the non-ICG group, with rates of 86% and 71% versus 64% and 31%, respectively (p<0.001).

Conclusions

Using ICG fluorescence-guided LNs dissection has increased both the number of total LNs and metastatic LNs dissection without increasing complications in laparoscopic distal gastrectomy for gastric cancer.

Opportunities and challenges of indocyanine green in gastrointestinal cancers for intraoperative and nano-medicine application

The morbidity and mortality of gastrointestinal tumours remain high worldwide. Surgical resection is currently the most critical radical therapeutic schedule, while postoperative complications and sentinel lymph node (SLN) identification are closely related to the outcome. Indocyanine green (ICG)-mediated fluorescence imaging is increasingly being used in gastrointestinal surgery. It has been embraced by various surgical disciplines as a potential method to improve lymph node detection and enhance surgical field visualization. ICG can passively concentrate in SLN because of enhanced permeation and retention effects. After excitation by near-infrared light devices, SLN can display higher intensity fluorescence, helping visualization for better lymph node dissection. In addition, visual assessment of intestinal blood flow through ICG may reduce the incidence of anastomotic leakage. Although it has good clinical application, ICG-imaging still faces some problems, such as a higher false-negative rate, poorly targeted biodistribution, and lower fluorescence contrast, due to the lack of active tumour targeting. Thus, different ICG-coupled nanoparticles with inherent characteristics or functional modification-enhanced SLN identification features for gastrointestinal cancers bring benefit through active tumour targeting, superior tumour-background ratio, and high resolution. Nano-ICG combined with potential substances, including enhanced imaging contrast and/or combination therapy (chemotherapy, targeted therapy, immunotherapy, etc.), have been packaged and accumulated in the tumour area through active targeting for multimodal imaging and treatment. In this review, we outline the intraoperative application and possible future nanodirections of ICG in gastrointestinal cancer. The prospects and challenges of nano-ICG diagnostic and therapeutic methods in clinical applications are also discussed.

Graphical Abstract

Current status and future trends of real-time imaging in gastric cancer surgery: A literature review

Technological advances are crucial for the optimization of gastric cancer surgery, and the success of any gastric cancer surgery is based on the correct and precise anatomical determination of the primary tumour and tissue structures. Real-time imaging-guided surgery is showing increasing potential and utility, mainly because it helps to aid intraoperative decision-making. However, intraoperative imaging faces many challenges in the field of gastric cancer. This article summarizes and discusses the following clinical applications of real-time optical imaging and fluorescence-guided surgery for gastric cancer: (1) the potential of quantitative fluorescence imaging in assessing tissue perfusion, (2) vascular navigation and determination of tumour margins, (3) the advantages and limitations of lymph node drainage assessment, and (4) identification of peritoneal metastases. In addition, preclinical study of tumour-targeted fluorescence imaging are discussed.

Textbook outcome as indicator of surgical quality in a single Western center: results from 300 consecutive gastrectomies

Textbook outcome (TO) has been proposed as a tool to evaluate surgical quality. Textbook oncological outcome (TOO) adds chemotherapeutic compliance to TO. This study was conducted to analyze the TO and TOO of patients with gastric adenocarcinoma who underwent surgery at our center. Data from a prospective database of patients operated on for gastric adenocarcinoma between September 2018 and September 2022 were analyzed. Postoperative management followed Enhanced Recovery After Surgery guidelines. The Dutch Upper Gastrointestinal Cancer Audit group defined TO as a multidimensional measure (10 items). TOO also considers guideline-accordant chemotherapeutic compliance. Three hundred patients underwent surgery during the study period (167 men, 133 women). One hundred seventy-six (58.7%) reached TO. Achieving TO was influenced by patients' comorbidities, calculated via the Charlson Comorbidity Score (3 vs. 4; p = 0.002) and surgery type (subtotal gastrectomy; p < 0.001), but not by the American Society of Anesthesiologists (ASA) score (p = 0.057) or surgical approach (laparoscopic vs. open; p = 0.208). The analysis of TOO included 213 patients. Of these, 71 (33%) underwent complete adequate systemic treatment. Compared with the non-TOO group, patients who achieved TOO had a lower median age (64 vs. 73 years; p < 0.001) and lower ASA score (p < 0.001) and more frequently underwent preoperative chemotherapy (p < 0.001). Our results represent the experience of a single team at a high-volume Western institute. Patients' comorbidities and surgery type influenced whether TO was achieved. Conversely, younger age, lower ASA score and preoperative chemotherapy were associated with TOO.

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.

Comparable long-term survival outcomes after endoscopic and gastrectomy treatment of pT1acN0M0 gastric adenocarcinoma in patients who met the expanded criteria

BACKGROUND

Whether the Western pT1acN0M0 gastric cancer (GC) patients who met the Japanese expanded criteria could be the candidates for endoscopic treatment (ET) remains unclear because of unknown long-term survival outcomes.

METHODS

A retrospective cohort study using data from the Surveillance, Epidemiology, and End Results (SEER) program was performed. The survival differences between pT1acN0M0 gastric adenocarcinoma patients who received ET or gastrectomy treatment (GT) were evaluated using multivariate survival analysis.

RESULTS

A total of 314 pT1acN0M0 gastric adenocarcinoma patients who met the expanded criteria were included, 46 patients received ET and 268 patients received GT. pT1acN0M0 gastric adenocarcinoma patients met the expanded criteria underwent ET experienced a similar hazard of cancer-specific death compared with those underwent GT both in the multivariate Cox survival analysis (adjusted hazard ratio [HR]; 1.18, 95% confidence interval [CI] 0.40-3.49; P = 0.766) and the multivariate competing risk model (subdistribution HR [SHR], 1.12, 95% CI 0.38-3.29; P = 0.845). The result that pT1acN0M0 gastric adenocarcinoma patients met the expanded criteria underwent ET experienced comparable survival outcomes to those who underwent GT did not change even compared with those who underwent GT with > 15 lymph nodes examined (adjusted HR, 1.55, 95% CI 0.44-5.49; P = 0.499; SHR, 1.47, 95% CI 0.44-4.88; P = 0.532).

CONCLUSIONS

The ET can be considered in Western pT1acN0M0 gastric adenocarcinoma patients who met the Japanese expanded criteria. However, a prospective study should be warranted.

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.

Impact of tumor stage and neoadjuvant chemotherapy in fluorescence-guided lymphadenectomy during laparoscopic gastrectomy for gastric cancer: A propensity score-matched study in a western center

BACKGROUND

The use of indocyanine green fluorescence has been shown to be a safe and effective method for improving lymph node retrieval in patients with gastric cancer. However, previous studies have focused on early-stage tumors and/or the Asian population and excluded patients who received neoadjuvant treatment.

METHODS

In this study, 142 patients with gastric adenocarcinoma underwent laparoscopic gastrectomy at a Spanish hospital between January 2017 and December 2022. Of these, 42 patients received preoperative indocyanine green injection to guide lymphadenectomy. Their outcomes were compared to a retrospective cohort of 42 patients after 1:1 propensity score matching.

RESULTS

The feasibility of indocyanine green lymphatic mapping was 95.5%. No complications associated with indocyanine green injection were observed. The indocyanine green group had a significantly higher number of retrieved lymph nodes than the non-indocyanine green group (32.67 vs 25.14; P = .013). This statistically significant difference was maintained across subgroups of neoadjuvant treatment, non-obese patients, pT0 to 2 stage, and pN0 stage. In 47.6% of patients from the indocyanine green group, lymphadenectomy was extended outside the standard D2 dissection area based on indocyanine green uptake, but none of the retrieved lymph nodes were metastatic. There were no differences in postoperative complications and length of hospital stay between the 2 groups.

CONCLUSION

Indocyanine green-guided lymphadenectomy is safe and feasible and increases the number of retrieved lymph nodes compared to conventional lymphatic dissection, as well as in patients receiving neoadjuvant chemotherapy. The use of indocyanine green should be routine if available for guiding lymph node dissection in gastric cancer, regardless of tumor stage or previous neoadjuvant treatment. However, further studies are needed to determine the impact of this technique on disease-free and overall survival.

Dual tracer navigation for lymph node dissection in laparoscopic radical gastrectomy (DANCE trial): a protocol for a prospective, randomized clinical trial

BACKGROUND

Lymph node (LN) metastasis is the most common metastasis route in gastric cancer. Extensive dissection of LNs can significantly improve the prognosis of patients with gastric cancer. Recently, multiple clinical studies have demonstrated that either indocyanine green (ICG) or carbon nanoparticles (CNs) can assist to promote the dissection of LNs during laparoscopic radical gastrectomy. Considering the pros and cons of the two tracers, this study proposed a novel method of dual tracer (ICG combined with CNs) for lymphatic tracing in laparoscopic gastric cancer surgery.

METHODS

This trial is a prospective, randomized controlled trial (RCT) with an estimation of 516 participants that randomize into 4 groups (1:1:1:1), namely control group, ICG group, CNs group, and dual tracer group. The primary outcome is the number of dissected LNs. The secondary outcomes include positive rate, false positive rate, negative rate, false negative rate, number of metastatic LNs, relationship between LN metastasis and tracer stained, operation duration, blood loss, incision length, morbidity and mortality rate, 3-year DFS (disease free survival), PFS (progression-free survival), and OS (overall survival).

DISCUSSION

This study will investigate the efficacy and safety of a novel strategy using dual tracers for laparoscopic gastrectomy. The protocol has been approved by the Ethics Committee of Nanjing Drum Tower Hospital (2021-361-02). The trial findings will be published in peer-reviewed journals.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2100051309). Registered 18 September 2021, https://www.chictr.org.cn/showproj.html?proj=133764 .

Prognostic Value of Tumor Size in Gastric Cancer: A Retrospective Cohort Study Based on SEER Database

Background. Although tumor size is regarded as the "T" stage of the tumor-node-metastasis (TNM) staging system for many solid tumors, its prognostic impact in gastric cancer remains uncertain and conflicting. Methods. We enrolled 6960 eligible patients from the Surveillance, Epidemiology, and End Results (SEER) database. The X-tile program was used to select the best cut-off value of tumor size. Then, the Kaplan-Meier method and the Cox proportional hazards model were applied to examine the efficacy of tumor size on prognostic prediction for overall survival (OS) and gastric cancer-specific survival (GCSS). The presence of nonlinear association was determined by the restricted cubic spline (RCS) model. Results. Tumor size was divided into 3 groups: small size (≤2.5 cm), medium size (2.6-5.2 cm), and large size (≥5.3 cm). After adjusting by covariates such as depth of tumor infiltration, the large and medium groups showed a worse prognosis than the small group; however, no survival difference in OS was suggested between the medium and large groups. Similarly, although there was a nonlinear relationship between tumor size and survival, increasing tumor size did not show an independent negative effect on prognosis in the RCS analysis. However, the stratified analyses proposed this 3-way cut of tumor size in prognostic prediction for patients with both inadequate lymphadenectomy and negative nodal metastasis. Conclusions. Tumor size as a prognostic predictor may not have good clinical applicability in gastric cancer. Otherwise, it was recommended for patients with both insufficient examinations of lymph nodes and stage N0 disease.

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.

Clinical implications of micro lymph node metastasis for patients with gastric cancer

BACKGROUND

Lymph node size is considered as a criterion for possible lymph node metastasis in imageology. Micro lymph nodes are easily overlooked by surgeons and pathologists. This study investigated the influencing factors and prognosis of micro lymph node metastasis in gastric cancer.

METHODS

191 eligible gastric cancer patients who underwent D2 lymphadenectomy from June 2016 to June 2017 in the Third Surgery Department at the Fourth Hospital of Hebei Medical University were retrospectively analyzed. Specimens were resected en bloc and the postoperative retrieval of micro lymph nodes was carried out by the operating surgeon for each lymph node station. Micro lymph nodes were submitted for pathological examination separately. According to the results of pathological results, patients were divided into the "micro-LNM (micro lymph node metastasis)" group (N = 85) and the "non micro-LNM" group (N = 106).

RESULTS

The total number of lymph nodes retrieved was 10,954, of which 2998 (27.37%) were micro lymph nodes. A total of 85 (44.50%) gastric cancer patients had been proven to have micro lymph node metastasis. The mean number of micro lymph nodes retrieved was 15.7. The rate of micro lymph node metastasis was 8.1% (242/2998). Undifferentiated carcinoma (90.6% vs. 56.6%, P = 0.034) and more advanced Pathological N category (P < 0.001) were significantly related to micro lymph node metastasis. The patients with micro lymph node metastasis had a poor prognosis (HR for OS of 2.199, 95% CI = 1.335-3.622, P = 0.002). For the stage III patients, micro lymph node metastasis was associated with shorter 5-year OS (15.6% vs. 43.6%, P = 0.0004).

CONCLUSIONS

Micro lymph node metastasis is an independent risk factor for poor prognosis in gastric cancer patients. Micro lymph node metastasis appears to be a supplement to N category in order to obtain more accurate pathological staging.

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.

Positive lymph node ratio as a prognostic factor for gastric cancer patients: Is it going to supersede positive lymph node number in guidelines?

Gastric malignancies constitute the sixth most common cancer with regards to incidence and have the fifth most mortality rates. Extended lymph-node dissection is the surgical modality of choice while treating advanced stage gastric cancer. It is yet a topic of debate, whether or not the amount of positive lymph nodes after a pathological examination following the surgical intervention is of prognostic value. In this study, it is aimed to evaluate the prognostic significance of positive lymph nodes following the surgery. A total of 193 patients who underwent curative gastrectomy between January 2011 and December 2015 have been considered for a retrospective data collection. The cases with R1-R2 resections, palliative or emergent surgeries are excluded. Metastatic to total number of lymph nodes, corresponded a ratio which was analyzed in this survey and practiced as a predictive parameter of disease outcome. This survey includes 138 male (71.5%) and 55 female (28.5%) patients treated between 2011 and 2015 in our clinic. The survey follow-up duration of the cases range between 0, 2, and 72 months, corresponding an average of 23.24 ± 16.99 months. We calculated cutoff value of 0.09 with, sensitivity is 76.32% for positive to total number of lymph nodes ratio, whereas specivity applies for 64.10%, positive predictive value for 58% and negative predictive value for 80.6%. Positive lymph node ratio has a prognostic value in terms of predicting the prognosis of the patients with gastric adenocarcinoma following a curative gastrectomy. This might in long term contribute to the prognostic analysis of patients if integrated in the current staging system.

Development and validation of a clinical cure marker based on negative lymph nodes for gastric cancer after gastrectomy

Objective

To explore lymph node (LN)-related derived indicators as clinical cure markers for gastric cancer (GC) after gastrectomy.

Methods

Data of resected GC patients were extracted from the SEER database and our own department. Propensity score matching (PSM) was used to balance the baseline differences between the clinical cure and the nonclinical cure groups. The area under the curve (AUC) and decision curve analysis (DCA) were used to choose the optimal marker, and survival analysis was used to validate the clinical value of the most effective marker.

Results

After PSM, the differences in age, sex, race, location, surgical type, and histologic type between the two groups were significantly reduced (all P > 0.05), and the AUCs of examined LNs (ELNs), negative LNs (NLNs), ESR (ELNs/tumor size), ETR (ELNs/T-stage), NSR (NLNs/tumor size), NTR (NLNs/T-stage), EPR (ELNs/PLNs) and NPR (NLNs/PLNs) were 0.522, 0.625, 0.622, 0.692, 0.706, 0.751, 7.43, and 7.50, respectively. When NTR was 5.9, the Youden index of 0.378 was the highest. The sensitivity and specificity were 67.5% and 70.3% in the training group and 66.79% and 67.8% in the validation group, respectively. DCA showed that NTR had the largest net clinical benefit, and patients with NTR greater than 5.9 had significantly prolonged overall survival in our own cohort.

Conclusion

NLNs, NTR, NSR, ESR, ETR, NPR and EPR can be used as clinical cure markers. However, NTR was the most effective, and the best cutoff value was 5.9.

Impact of HER2 on prognosis and benefit from adjuvant chemotherapy in stage II/III gastric cancer patients: a multicenter observational study

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) is a well-developed therapeutic target in breast and gastric cancer (GC). However, the impact of HER2 on survival and benefit from fluorouracil-based adjuvant chemotherapy remains unclear in patients with GC.

MATERIALS AND METHODS

This multicenter cohort study involved 5622 consecutive stage II/III GC patients. HER2 expression was assessed prospectively via immunohistochemistry (IHC). The staining intensity was graded on a scale of 0 to 3+. An IHC score of 2+or 3+was defined as high expression, and a score of 3+was defined as overexpression.

RESULTS

HER2 overexpression was independently associated with a lower 5-year overall survival (OS) in stage II [hazard ratio (HR), 2.10; 95% CI: 1.41-3.11], but not in stage III GC (HR, 1.00; 95% CI, 0.82-1.20). Further analysis revealed that stage II patients with high HER2 expression showed a poorer response to chemotherapy than stage II patients with low HER2 expression ( Pinteraction =0.024). The HRs for 5-year OS were 0.51 (95% CI, 0.38-0.70) for stage II patients with low HER2 expression, 0.58 (95% CI, 0.51-0.66) for stage III patients with low HER2 expression, 1.13 (95% CI, 0.61-2.09) for stage II patients with high HER2 expression, and 0.47 (95% CI, 0.36-0.61) for stage III patients with high HER2 expression.

CONCLUSIONS

Fluorouracil-based adjuvant chemotherapy is insufficient for stage II GC patients with high HER2 expression, indicating that prospective trials are required to validate alternative HER2-targeted adjuvant therapies in the individuals above.

Pattern of Distribution of Lymph Node Metastases in Individual Stations in Middle and Lower Gastric Carcinoma

(1) Background: Lymph node (LN) dissection is the cornerstone of curative treatment of GC. The pattern of distribution of LN metastases is closely related to several factors. The aim of this study is to evaluate the factors determining the distribution of nodal metastases in a population of N+ distal GC patients undergoing gastrectomy and D2 lymphadenectomy. (2) Methods: The medical charts of 162 N+ GC patients who underwent surgical resection over a 15-year period were retrospectively analyzed. Clinical, pathological and anatomical characteristics were evaluated to identify the factors affecting the patterns and prevalence of metastases in individual LN stations. (3) Results: LN metastasis is correlated with the depth of the tumor and to diffuse-type tumors. A higher number of metastatic nodes was documented in patients with middle-third tumors (8.2 ± 7.3 vs. 4.5 ± 5.0 in lower-third tumors, p = 0.0001) and in patients with tumors located on the lesser curve. Station 4 showed the highest rate of metastases (53.1%). Concerning stations 7 to 12, station 8 showed the highest metastasis rate (28.4%). Metastases at stations 1, 2, 4 and 7 to 11 were dominant in middle-third cancer, whereas stations 5 and 6 were dominant in lower-third cancers. Station 4, 5, 6, 10 and 11 metastases were dominant when the cancer was located on the greater curve, whereas stations 1, 2, 7, 8 and 12 were dominant in lesser-curve cancers. (4) Conclusions: The study documented that in patients with distal GC, the distribution of nodal metastases at individual stations is closely related to primary tumor location.

Examined lymph node count for gastric cancer patients after curative surgery

Lymph node (LN) metastasis is the most common form of metastasis in gastric cancer (GC). The status and stage of LN metastasis are important indicators that reflect the progress of GC. The number of LN metastases is still the most effective index to evaluate the prognosis of patients in all stages of LN metastasis. Examined LN (ELN) count refers to the number of LNs harvested from specimens by curative gastrectomy for pathological examination. This review summarizes the factors that influence ELN count, including individual and tumor factors, intraoperative dissection factors, postoperative sorting factors, and pathological examination factors. Different ELN counts will lead to prognosis-related stage migration. Fine LN sorting and regional LN sorting are the two most important LN sorting technologies. The most direct and effective way to harvest a large number of LNs is for surgeons to perform in vitro fine LN sorting.

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

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

A nomogram model based on the number of examined lymph nodes-related signature to predict prognosis and guide clinical therapy in gastric cancer

BACKGROUND

Increasing evidence suggests that the number of examined lymph nodes (ELNs) is strongly linked to the survivorship of gastric cancer (GC). The goal of this study was to assess the prognostic implications of the ELNs number and to construct an ELNs-based risk signature and nomogram model to predict overall survival (OS) characteristics in GC patients.

METHODS

This inception cohort study included 19,317 GC patients from the U.S. Surveillance, Epidemiology, and End Results (SEER) database, who were separated into a training group and an internal validation group. The nomogram was built with the training set, then internally verified with SEER data, and externally validated with two different data sets. Based on the RNA-seq data, ELNs-related DERNAs (DElncRNAs, DEmiRNAs, andDEmRNAs) and immune cells were identified. The LASSO-Cox regression analysis was utilized to construct ELNs-related DERNAs and immune cell prognostic signature in The Cancer Genome Atlas (TCGA) cohort. The OS of subgroups with high- and low-ELN signature was compared using the Kaplan-Meier (K-M) analysis. A nomogram was successfully constructed based on the ELNs signature and other clinical characteristics. The concordance index (C-index), calibration plot, receiver operating characteristic curve, and decision curve analysis (DCA) were all used to evaluate the nomogram model. The meta-analysis, the Gene Expression Profiling Interactive Analysis database, and reverse transcription-quantitative PCR (RT-qPCR) were utilized to validate the RNA expression or abundance of prognostic genes and immune cells between GC tissues and normal gastric tissues, respectively. Finally, we analyzed the correlations between immune checkpoints, chemotherapy drug sensitivity, and risk score.

RESULTS

The multivariate analysis revealed that the high ELNs improved OS compared with low ELNs (hazard ratio [HR] = 0.659, 95% confidence interval [CI]: 0.626-0.694, p < 0.0001). Using the training set, a nomogram incorporating ELNs was built and proven to have good calibration and discrimination (C-index [95% CI], 0.714 [0.710-0.718]), which was validated in the internal validation set (C-index [95% CI], 0.720 [0.714-0.726]), the TCGA set (C-index [95% CI], 0.693 [0.662-0.724]), and the Chinese set (C-index [95% CI], 0.750 [0.720-0.782]). An ELNs-related signature model based on ELNs group, regulatory T cells (Tregs), neutrophils, CDKN2B-AS1, H19, HOTTIP, LINC00643, MIR663AHG, TMEM236, ZNF705A, and hsa-miR-135a-5p was constructed by the LASSO-Cox regression analysis. The result showed that OS was remarkably lower in patients with high-ELNs signature compared with those with low-ELN signature (HR = 2.418, 95% CI: 1.804-3.241, p < 0.001). This signature performed well in predicting 1-, 3-, and 5-year survival (AUC [95% CI] = 0.688 [0.612-0.763], 0.744 [0.659-0.830], and 0.778 [0.647-0.909], respectively). The multivariate Cox analysis illustrated that the risk score was an independent predictor of survival for patients with GC. Moreover, the expression of prognostic genes (LINC00643, TMEM236, and hsa-miR-135a-5p) displayed differences between GC tissues and adjacent non-tumor tissues. The C-index of the nomogram that can be used to predict the OS of GC patients was 0.710 (95% CI: 0.663-0.753). Both the calibration plots and DCA showed that the nomogram has good predictive performance. Moreover, the signature was significantly correlated with the N stage and T stage. According to our analysis, GC patients in the low-ELN signature group may have a better immunotherapy response and OS outcome.

CONCLUSIONS

We explored the prognostic role of ELNs in GC and successfully constructed an ELNs signature linked to the GC prognosis in TCGA. The findings manifested that the signature is a powerful predictive indicator for patients with GC. The signature might contain potential biomarkers for treatment response prediction for GC patients. Additionally, we identified a novel and robust nomogram combining the characteristics of ELNs and clinical factors for predicting 1-, 3-, and 5-year OS in GC patients, which will facilitate personalized survival prediction and aid clinical decision-making in GC patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Prognostic value of lymph node density on cancer staging system for gastric cancer without distal metastasis: a population-based analysis of SEER database

Background

Accurate tumor staging is the cornerstone of tumor treatment. Current tumor staging system for gastric cancer (GC) is based on regional positive lymph nodes while ignoring the total number of examined lymph nodes. We aim to assess the prognostic value of lymph node density (LND), the ratio of positive nodes to the total number examined nodes, in GC without distal metastasis.

Methods

Clinical information of patients with histologically confirmed GC and without distal metastasis was identified from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2015. The X-Tile software was used to identify the ideal prognosis-related cutoff point for LND. The prognostic value of LND on cancer-specific survival (CSS) and overall survival (OS) was assessed in Cox regression models. Subgroup analysis stratified by LND was performed on current lymph node staging system to further explore the interaction between LND and current lymph node staging system.

Results

A total of 4281 participants were identified from the SEER database for the final analysis. The optimal prognosis-related cutoff values of LND were calculated as 0.1 and 0.4, and LND was divided into three levels: LND1 (< 0.1), LND2 (> = 0.1, < 0.4), and LND3 (> = 0.4). LND3 was associated with worse CSS and OS in GC patients. Compared to patients with LND1, those with LND2 and LND3 had 2.43 (HR = 2.43, 95% CI 2.09–2.84, P < 0.001) and 4.69 (HR = 4.69, 95% CI 4.02–5.48, P < 0.001) folds increase in mortality in CSS, respectively. Similar results were found in the evaluation of OS in GC patients. Subgroup analysis stratified by LND also found that patients in the same current lymph node stage still had different prognosis due to the different LND levels after adjustment for other prognosis-related covariates (all P values < 0.001).

Conclusion

LND is an independent prognostic factor for GC without distal metastasis. In the current lymph node staging system, LND has potential value in further accurately classifying GC patients without distal metastasis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02795-9.

Comparison of short-term outcomes between robotic-assisted and laparoscopic gastrectomy guided by carbon nanoparticle suspension injection in gastric cancer

Background

The clinical application of robotic-assisted gastrectomy remains controversial, especially as clinical studies of this operation navigated by carbon nanoparticle suspension injection (CNSI) have not been conducted. This study aims to assess the perioperative safety and efficacy of CNSI-guided robotic-assisted gastrectomy in patients with gastric cancer by focusing on short-term outcomes.

Methods

A retrospective analysis of patients who underwent CNSI-guided laparoscopic or robotic-assisted gastrectomy with a pathological diagnosis of gastric cancer was conducted. Data on demographics, surgical management, clinical-pathological results and short-term outcomes were compared among the groups.

Results

A total of 126 eligible patients were separated into the robotic-assisted gastrectomy (RAG) group (n = 16) and the laparoscopic gastrectomy (LG) group (n = 110) in total. The operation time of the RAG group is longer than the LG group (p = 0.0000). When it comes to perioperative and short-term complications, there exists no statistical difference between the two groups.

Conclusion

The time required for CNSI-guided robotic-assisted gastrectomy is longer than that for CNSI-guided laparoscopic gastrectomy. CNSI-guided robotic-assisted gastrectomy is safe and effective.

Detection Rate and Prognosis of Lymph Nodes in Gastric Cancer Using Nano Carbon Combined with In Vitro Anatomical Sorting

In this study, we are going to investigate the effect of nano carbon combined with ex vitro anatomical sorting on the detection rate of lymph nodes (LNs) in gastric cancer (GC) along with the analysis of the correlation between LNs detection rate and patients’ prognosis. The clinical data of patients undergoing radical gastrectomy in Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University from January 2018 to January 2019 were examined retrospectively. According to whether they adopt nano carbon tracing and specimen sorting method, patients were divided into nano carbon and control groups. The respective rate of detection and correlation of total and positive LNs, respectively, clinical treatment, tumor marker level, and long-term prognosis were matched between these groups. At the same time, the effects of the nano carbon tracer on the detection of total and positive LNs were evaluated. In nano carbon group, more LN specimens could be detected, and the number of positive LNs increased significantly. In addition, in patients with different infiltration stages and LN substations, more LNs could be detected in the nano carbon group for examination, and the detection rate of LNs with diameter less than 5 mm was also more. Furthermore, LNs (preferably positive in number) were correlated positively with the attained LNs number. Otherwise, the use of nano carbon suspension could better label LNs in each substation, especially N1 station, and improve micro-LN detection rate. At the same time, the positive metastasis rate in black-stained LNs was higher (31.67% vs. 13.51%). In relation to the clinical prognosis, CEA’s level, i.e., CA199 and CA125, in the nano carbon group is controlled more effectively. Their condition was not easy to progress and relapse, and their mortality was further reduced. As a result, nano carbon, coupled with ex vitro anatomical sorting, may considerably enhance the detection rate of total and positive LNs, thereby improving the accuracy of clinical staging in GC patients, which has a good influence on their long-term prognosis.

Laparoscopic Gastrectomy with ICG Guided D2 Lymph Node Dissection – A Case Report and Review of the Literature

Radical surgery for gastric cancer remains the only reliable therapeutic tool and cornerstone for definitive treatment. With improving resectability, patients are given a better opportunity for long-term survival. Indocyanine green (ICG) is able to define more precisely the boundaries of the tumor in early and advanced gastric cancer. In addition, it can noticeably improve lymph node dissection and reduce the risk of subsequent complications. In this paper we present our experience with laparoscopic gastrectomy together with a review of the available literature.

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.

Adjuvant chemotherapy indications for stage I gastric cancer patients with negative lymph node

PURPOSE

Whether adjuvant chemotherapy (AC) has a survival benefit for pathological stage Ⅰ (T1N0 and T2N0) gastric cancer (GC) patients with negative lymph node (N0) remains controversial.

METHODS

Patients with surgically resected, histologically confirmed pT1N0 and pT2N0 GC between January 2011 and December 2017 at the National Cancer Center, China, were retrospectively reviewed.

RESULTS

A total of 1601 patients who met the inclusion criteria were identified. Independent risk factors for reduced overall survival (OS) identified in the Cox regression analysis were male sex (hazard ratio [HR] 1.454, 95% confidence interval [CI] 1.127-1.876), age ≥ 65 years (HR 1.367; 95% CI 1.071-1.744 ), T2 stage (HR 1.283; 95% CI 1.005-1.638), tumor size > 3 cm (HR 1.704; 95% CI 1.346-2.158), examined lymph nodes (EN) ≤ 15 (HR 1.327; 95% CI 1.058-1.664), and non-signet ring cell carcinoma (Non-SRCC) (HR 1.639; 95% CI 1.123-2.392). While only T2 stage (HR 1.410; 95% CI 1.026-1.936), tumor size > 3 cm (HR 1.755; 95% CI 1.285-2.397), examined lymph nodes (EN) ≤ 15 (HR 1.489; 95% CI 1.101-2.015) were independent risk factors for cause-specific survival (CSS). We divided patients with pT2N0 into four sub-categories according to two significant prognostic factors (size and EN) and found that only patient in group 3 (EN ≤ 15, size >3 cm) with improved CSS benefit from AC (p = 0.049). More significant CSS benefit from AC was identified in Non-SRCC patients within group 3 (p = 0.034).

CONCLUSION

An additional survival benefit related to AC is expected for selected pT2N0 patients. Non-SRCC patients with EN ≤ 15 and tumor size >3 cm may be particularly appropriate candidates for AC.

Navigating Nodal Metrics for Node-Positive Gastric Cancer in the United States: An NCDB-Based Study and Validation of AJCC Guidelines

BACKGROUND

The optimal number of examined lymph nodes (ELNs) and the positive lymph node ratio (LNR) for potentially curable gastric cancer are not established. We sought to determine clinical benchmarks for these values using a large national database.

METHODS

Demographic, clinicopathologic, and treatment-related data from patients treated using an R0, curative-intent gastrectomy registered in the National Cancer Database during 2004 to 2016 were evaluated. Patients with node-positive (pTxN+M0) disease were considered for analysis.

RESULTS

A total of 22,018 patients met the inclusion criteria, with a median follow-up of 2.2 years. Mean age at diagnosis was 65.6 years, 66% were male, 68% were White, 33% of tumors were located near the gastroesophageal junction, and 29% of patients had undergone preoperative therapy. Most primary tumors (62%) were category pT3-4, 67% had a poor or anaplastic grade, and 19% had signet features. Clinical nodal staging was inaccurate compared with staging at final pathology. The mean [SD] number of nodes examined was 19 [11]. On multivariable analysis, the pN category, ELNs, and LNR were independently associated with survival (all P<.0001). Using receiver operating characteristic (ROC) analysis, an optimal ELN threshold of ≥30 was established for patients with pN3b disease and was applied to the entire cohort. Node positivity and LNR had minimal change beyond 30 examined nodes. Stage-specific LNR thresholds calculated by ROC analysis were 11% for pN1, 28% for pN2, 58% for pN3a, 64% for pN3b, 30% for total combined. By using an ELN threshold of ≥30, prognostically advantageous stage-specific LNR values could be determined for 96% of evaluated patients.

CONCLUSIONS

Using a large national cancer registry, we determined that an ELN threshold of ≥30 allowed for prognostically advantageous LNRs to be achieved in 96% of patients. Therefore, ≥30 examined nodes should be considered a clinical benchmark for practice in the United States.

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.

Exceeding 30 ELNs is strongly recommended for pT3-4N0 patients with gastric cancer: A multicenter study of survival, recurrence, and prediction model

The argument concerning the exact minimum number of examined lymph nodes (ELNs) has continued for a long time among various regions, and no consensus has been reached for stratified pathological T stages for data to date. Data from 4607 pN0 patients with gastric cancer were analyzed. Kaplan-Meier analysis showed the similar overall survival (OS) outcomes among the 3 groups (ELNs ≤ 15, 16 ≤ ELNs ≤ 29 and ELNs ≥ 30, P = .171). However, the ELNs ≥ 30 group had a better disease-free survival (DFS) outcome compared with the others (all P < .05). An increased ELN group (ELNs ≥ 30) showed an improved OS only for pT3 patients (hazard ratio [HR] = 0.397, 95% confidence interval (CI): 0.182-0.866, P = .020), while an improved DFS for pT3 patients (HR = 0.362, 95%CI: 0.152-0.860, P = .021) and pT4 patients (HR = 0.484, 95%CI: 0.277-0.844, P = .011) in the multivariate analysis. A well discriminated and calibrated nomogram was constructed to predict the probability of the OS and DFS, with the C-index for OS and DFS prediction of 0.782 (95%CI: 0.735 to 0.829) and 0.738 (95%CI: 0.685 to 0.791), respectively. This study provides new and useful insights into the impact of ELN count on reducing stage migration and postoperative recurrence of pN0 patients with gastric cancer in 2000-2017. In conclusion, a larger number of ELNs is suggested for surgeons to prolong the prognosis of pN0 gastric cancer, especially for pT3 patients.

Impact of Lymph Nodes Examined on Survival in ypN0 Gastric Cancer Patients: a Population-Based Study

BACKGROUND

Our aim was to evaluate the prognostic value of the number of lymph nodes examined (eLNs) on survival in ypN0 gastric cancer (GC) patients, and further to define the optimal number of lymph nodes needed to be examined during radical gastrectomy of ypN0 GC patients.

METHODS

A total of 1127 ypN0 GC patients during 2004-2015 from the Surveillance, Epidemiology, and End Results (SEER) database were included. The number of eLNs cutoff points that determined the greatest actuarial survival difference was calculated by the X-tile program. Univariate and multivariate analyses were performed to assess the impact of eLNs on overall survival (OS).

RESULTS

The optimal number of eLNs thresholds was determined to be 15 for ypN0 GC patients. Kaplan-Meier analysis revealed that ypN0 GC patients with ≥ 16 eLNs had a significantly better OS than those with ≤ 15 eLNs (5-year OS; 60.8 vs 45.4%, P < 0.001). Similarly, multivariate Cox analysis revealed that ypN0 GC patients with ≥ 16 eLNs experienced a significantly lower hazard of death than those with ≤ 15 eLNs (adjusted HR; 0.73, 95% CI, 0.60-0.90, P = 0.003).

CONCLUSIONS

The number of eLNs was an independent predictor of survival for ypN0 GC patients. A minimum of 15 eLNs is recommended as the cutoff point for the evaluation of the quality of postoperative or prognostic stratification in ypN0 GC patients.

Determinants of Survival for Patients with Neoadjuvant-Treated Node-Negative Gastric Cancer

BACKGROUND

This study sought to determine prognostic markers for disease recurrence and survival in a cohort of neoadjuvant-treated, node-negative gastric cancer patients (ypT0-4N0M0).

METHODS

Clinicopathologic data from patients treated with neoadjuvant therapy followed by curative-intent gastrectomy at the University of Texas MD Anderson Cancer Center from 1995 to 2017 were evaluated. Patients with AJCC TNM stage ypT0-4N0M0 were considered for analysis.

RESULTS

The inclusion criteria were met by 212 patients with a mean age of 58.3 years. Of these patients, 60 % were male, 53 % were Caucasian, 87 % received chemoradiation, and 13 % received chemotherapy. The findings showed a median overall survival (OS) rate of 11.3 years, a 5-year survival rate of 72 %, and a 10-year survival rate of 57 %. During a median follow-up period of 5.5 years, 38.2 % of the patients died. In the multivariable analysis, ypT4-stage and nodal yield fewer than 16 were significantly associated with reduced OS. Cancer classified as ypT4 had more aggressive biologic traits, including lymphovascular and perineural invasion, and was treated more aggressively with total gastrectomy and additional organ resection despite frequent positive margins. Depth of invasion remained significantly associated with worse outcome after the analysis controlled for nodal yield and possible stage migration. Compared with ypT0-3 tumors, ypT4 cancers were associated with significantly more recurrences (13 % vs. 45 %; p < 0.05), and the primary modes of failure for ypT4 lesions were local recurrence and peritoneal metastases (88 % of recurrences).

CONCLUSIONS

Depth of primary tumor invasion and nodal yield were significantly associated with OS among the patients with ypT0-4N0M0 gastric cancer. Serosal invasion (ypT4) was associated with a high rate of peritoneal recurrence, and trials of intraperitoneal therapy targeting these patients should be considered.

Low body mass index is an independent predictor of poor long-term prognosis among patients with resectable gastric cancer

BACKGROUND

The association between body mass index (BMI) and clinical outcomes remains unclear among patients with resectable gastric cancer.

AIM

To investigate the relationship between BMI and long-term survival of gastric cancer patients.

METHODS

This retrospective study included 2526 patients who underwent radical gastrectomy for gastric cancer between September 2013 and June 2018. The patients were divided into four groups: Group A (low BMI, < 18.5 kg/m2), group B (normal BMI, 18.5-24.9 kg/m2), group C (overweight, 25-29.9 kg/m2), and group D (obese, ≥ 30 kg/m2). Clinicopathological findings and survival outcomes were recorded and analyzed.

RESULTS

Preoperative weight loss was more common in the low-BMI group, while diabetes was more common in the obese group. Upper-third gastric cancer accounted for a large proportion of cases in the higher BMI groups. Major perioperative complications tended to increase with BMI. The 5-year overall survival rates were 66.4% for group A, 75.0% for group B, 77.1% for group C, and 78.6% for group D. The 5-year overall survival rate was significantly lower in group A than in group C (P = 0.008) or group D (P = 0.031). Relative to a normal BMI value, a BMI of < 18.5 kg/m2 was associated with poor survival (hazard ratio: 1.558, 95% confidence interval: 1.125-2.158, P = 0.008).

CONCLUSION

Low BMI, but not high BMI, independently predicted poor survival in patients with resectable gastric cancer.

Importance of Examined Lymph Node Number in Accurate Staging and Enhanced Survival in Resected Gastric Adenocarcinoma-The More, the Better? A Cohort Study of 8,696 Cases From the US and China, 2010-2016

BACKGROUND

While most guidelines advocate D2 lymphadenectomy for non-metastatic gastric adenocarcinoma (nmGaC), it is not always performed as standard of care outside East Asia. The recommended minimal examined lymph node (ELN) count in nmGaC to stage cancer accurately varies largely across guidelines, and the optimal count to satisfactorily stratify patient survival has yet to be determined. This large cohort study aimed at robustly defining the minimal and optimal thresholds of examined lymph node (ELN) number in non-metastatic gastric adenocarcinoma (nmGaC).

METHODS

Data on nmGaC patients operated in 2010-2016 and surviving ≥3 months were retrieved from the US SEER-18 Program and a Chinese multi-institutional gastric cancer database (MIGC). The correlation of ELN count with stage migration and patient survival were quantified with the use of the multivariable-adjusted logistic and proportional hazards Cox models, respectively. The sequences of odds ratios (ORs) and hazard ratios (HRs) for each additional ELN were smoothed, and the structural breakpoints were determined.

RESULTS

Together 7,228 patients from the US and 1,468 from China were analyzed, encompassing 23,114 person-years of follow-up. The mean ELN count was 20 in the US and 30 in China. With more ELNs, both cohorts significantly showed proportional increases from lower to higher nodal stage (ORSEER = 1.03, 95%-CI = 1.03-1.04; ORMIGC = 1.02, 95%-CI = 1.02-1.03) and sequential enhancements in postoperative survival (HRSEER = 0.97, 95%-CI = 0.97-0.97; HRMIGC = 0.98, 95%-CI = 0.97-0.99). Correlations for both stage migration and survival were still significant in most subgroups by patient, cancer, and management factors. Breakpoint analyses revealed a minimum threshold ELN count of 17 and an optimum count of 33, which were validated in both cohorts with good efficacy to differentiate probabilities of both stage migration and survival.

CONCLUSION

In resected nmGaC patients with anticipated survival ≥3 months, more ELNs are correlated with more accurate staging, which may partly explain the survival correlation. This observational investigation does not indicate causality. Our findings robustly conclude 17 ELNs as the minimum and propose 33 ELNs as the optimum thresholds, to assess the quality of lymph node examination and to stratify postsurgical survival.

Clinical and pathological staging of gastric cancer: Current perspectives and implications

Accurate categorization of invasive depth and lymph node metastasis or optimization of TNM categories is fundamentally critical for prognostic assessment and decision making regarding subsequent therapies after surgery for gastric cancer. Improving the precision of the TNM staging is the ongoing goal. The evolution of the staging system indicates that there is no "ideal staging". Every update has criticized the lack of a standard approach for the stages to date. T staging depends on the accurate determination of the depth of infiltration based on pathological continuous sections. N staging is susceptible to the influence of lymph node detection, and insufficient lymph node detection can lead to N staging migration. M staging is required to improve the detection rate of peritoneal positive free cancer cells to determine the high risk factors of peritoneal metastasis. At present, the quality of standardized pathological diagnosis of gastric cancer requires improvement. Based on a review of the literature and experience from multiple gastric cancer centers, we present a new development in TNM staging and a way to improve clinical and pathological quality control of gastric cancer.

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.

A novel lymph node staging system for gastric cancer including modified Union for cancer Control/American Joint Committee on cancer and Japanese Gastric Cancer Association criteria

BACKGROUND

The TNM system of the International Union for Cancer Control/American Joint Committee on Cancer (UICC/AJCC) and the Japanese Gastric Cancer Association (JGCA) systems are the most used lymph node (LN) staging systems in gastric cancer. This study estimated the influence of anatomic location-based node stations on survival and proposed a new staging method based on both the number and anatomical distribution of metastatic LNs (mLNs).

METHODS

Stage I-III gastric cancer patients with radical gastrectomy were retrospectively evaluated. Overall survival (OS) was estimated in 1786 patients with UICC/AJCC stage N1-N3b disease and compared with estimates obtained using JGCA group 1-3 mLN staging.

RESULTS

The OS of UICC/AJCC stage N1-N3b patients with group 2 JGCA mLNs was significantly worse than that of patients with only group 1 mLNs. The OS of the patients with group 2 mLNs was similar to that of patients with group 1 mLNs but in the next more advanced UICC/AJCC-N stage. The OS of patients with group 3 mLNs was worse than that of patients with any UICC/AJCC-N stage and was similar to that of N3b patients with group 2 mLNs. A new pathological node (pN) staging classification was developed that advanced the N-staging of patients with group 2 mLNs. It was a better indicator of prognosis than the eighth UICC/AJCC-N and the thirteenth JGCA group staging systems.

CONCLUSIONS

A simple, accurate pN staging system including both the number and location of mLNs had improved homogeneity, discriminatory ability, and gradient monotonicity.

Impact of examined lymph node count on staging and long-term survival of patients with node-negative stage III gastric cancer: a retrospective study using a Chinese multi-institutional registry with Surveillance, Epidemiology, and End Results (SEER) data validation

BACKGROUND

Accumulating evidence has confirmed the potential prognostic value of examined lymph nodes (ELNs) in patients with gastric cancer (GC). However, there is currently no consensus on the threshold ELN number for predicting both stage migration and long-term survival, especially in patients with stage III GC. This study aimed to validate the need to increase the ELN count to improve its prognostic accuracy in node-negative patients with stage III GC after curative gastrectomy.

METHODS

This retrospective, population-based study analyzed the clinical data of 84 patients with node-negative stage III GC from three high-volume institutions in China and 196 cases from the Surveillance, Epidemiology and End Results (SEER) program registry. The optimal number of ELNs was determined by receiver operating characteristic (ROC) curve analysis. Clinicopathological characteristics significantly related to survival were evaluated using the Kaplan-Meier method and Cox proportional hazards analysis. Stratified analyses were adopted to assess the prognostic predictive ability of the identified optimal number of ELNs in different populations. Survival differences among subgroups were analyzed to assess the impact of ELN count on stage migration according to overall survival (OS) among GC patients.

RESULTS

The optimal number of ELNs was >31 according to ROC analysis of patients with node-negative stage III GC who underwent gastrectomy. Multivariate analysis identified ELNs as an independent predictor of postoperative OS in patients with node-negative stage III GC in both the Chinese cohort [hazard ratio (HR) 0.235; P<0.001] and the SEER cohort (HR 0.421; P<0.010). Stratified analysis demonstrated that >31 ELNs was a prerequisite for accurate prognostic evaluation of patients with node-negative stage III GC, regardless of sex, tumor size, and other factors. Stage migration between pT4bN0M0 and pT4bN1M0 was detected in patients with >31 ELNs. A nomogram was created to predict OS among patients with node-negative stage III GC. These results were validated using data from the SEER cohort.

CONCLUSIONS

The number of ELNs was significantly associated with prognosis in patients with stage III GC after gastrectomy with systemic lymphadenectomy in both the Chinese and SEER cohorts. The results suggest that >31 ELNs are required for an accurate prognostic evaluation in patients with GC, especially those with node-negative stage III GC.

Impact of retrieved lymph node count on short-term complications in patients with gastric cancer

BACKGROUND

It is well established that retrieved lymph node (RLN) counts were positively correlated with better overall survival in gastric cancer (GC). But little is known about the relationship between RLN count and short-term complications after radical surgery.

METHODS

A total of 1487 consecutive GC patients between January 2016 and December 2018 at Nanjing Drum Tower Hospital were retrospectively analyzed. Univariate analyses were performed to elucidate the association between RLN count and postoperative complications. We further identified clinical factors that might affect the RLN count.

RESULTS

Among all of the patients, postoperative complications occurred in 435 (29.3%) patients. The mean RLN count was 25.1, and 864 (58.1%) patients were diagnosed with lymph node metastasis. Univariate analyses showed no significant difference between RLN count and postoperative complications (both overall and stratified by CDC grade). Univariate and multivariate analyses further revealed that type of resection, tumor invasion, and lymph node metastasis were associated with RLN count.

CONCLUSIONS

The current study demonstrated that RLN count was not associated with postoperative short-term complications following gastrectomy of GC, which provided a rationale for the determination of a proper RLN count of curative gastrectomy.

Efficacy of the fat-dissociation method for nodal harvesting in gastric cancer

BACKGROUND

There is an increased need for accurate staging for gastric cancer treatment. Consequently, it is necessary to carefully examine all dissected lymph nodes for precise staging. Recently, the fat-dissociation method has been developed as a quick and accurate method for harvesting dissected lymph nodes of colorectal cancer cases.

AIM

To investigate the usefulness of the fat-dissociation method for harvesting dissected lymph nodes of gastric cancer cases.

METHODS

Fifty-six resected specimens from gastric cancer patients who underwent standard curative gastrectomy and lymph node dissection at our hospital were used. Group 2 lymph nodes were separated from each specimen, and the remaining adipose tissue containing the group 1 lymph nodes was used. Some resected specimens were subjected to the fat-dissociation method. One vial of Imofully® was dissolved in 50 mL of saline and injected into the tissue. The tissue was incubated for 1 h and the dissolved fat was removed. Subsequently, the nodes were identified, picked up with scissors, and mapped. The number of nodes in each lymphatic compartment and duration of lymph node harvest and mapping were compared.

RESULTS

The fat-dissociation method was used for 24 samples, while the conventional dissection method was used for 32 samples. The total number of harvested lymph nodes was 45.9 in the fat dissociation group and 44.3 in the control group, and there was no significant difference between the two groups. There were also no significant differences in the number of lymph nodes between the two groups based on a comparison of the lymphatic compartments. However, the total median duration of the fat-dissociation method was 38.2 min, reflecting a reduced duration of approximately 60 min compared to the control group.

CONCLUSION

Based on our results, the fat-dissociation method is effective in shortening the duration of lymph node harvest in gastric cancer surgery.

Safety and Efficacy of Indocyanine Green Tracer-Guided Lymph Node Dissection During Laparoscopic Radical Gastrectomy in Patients With Gastric Cancer: A Randomized Clinical Trial

IMPORTANCE

The application of indocyanine green (ICG) imaging in laparoscopic radical gastrectomy is in the preliminary stages of clinical practice, and its safety and efficacy remain controversial.

OBJECTIVE

To investigate the safety and efficacy of ICG near-infrared tracer-guided imaging during laparoscopic D2 lymphadenectomy in patients with gastric cancer.

DESIGN, SETTING, AND PARTICIPANTS

Patients with potentially resectable gastric adenocarcinoma (clinical tumor stage cT1-cT4a, N0/+, M0) were enrolled in a prospective randomized clinical trial at a tertiary referral teaching hospital between November 2018 and July 2019. Patients were randomly assigned to the ICG group or the non-ICG group. The number of retrieved lymph nodes, rate of lymph node noncompliance, and postoperative recovery data were compared between the groups in a modified intention-to-treat analysis. Statistical analysis was performed from August to September 2019.

INTERVENTIONS

The ICG group underwent laparoscopic gastrectomy using near-infrared imaging after receiving an endoscopic peritumoral injection of ICG to the submucosa 1 day before surgery.

MAIN OUTCOMES AND MEASURES

Total number of retrieved lymph nodes.

RESULTS

Of 266 participants randomized, 133 underwent ICG tracer-guided laparoscopic gastrectomy, and 133 underwent conventional laparoscopic gastrectomy. After postsurgical exclusions, 258 patients were included in the modified intention-to-treat analysis, which comprised 129 patients (86 men and 43 women; mean [SD] age, 57.8 [10.7] years) in the ICG group and 129 patients (87 men and 42 women; mean [SD] age, 60.1 [9.1] years) in the non-ICG group. The mean number of lymph nodes retrieved in the ICG group was significantly more than the mean number retrieved in the non-ICG group (mean [SD], 50.5 [15.9] lymph nodes vs 42.0 [10.3] lymph nodes, respectively; P < .001). Significantly more perigastric and extraperigastric lymph nodes were retrieved in the ICG group than in the non-ICG group. In addition, the mean total number of lymph nodes retrieved in the ICG group within the scope of D2 lymphadenectomy was also significantly greater than the mean number retrieved in the non-ICG group (mean [SD], 49.6 [15.0] lymph nodes vs 41.7 [10.2] lymph nodes, respectively; P < .001). The lymph node noncompliance rate of the ICG group (41 of 129 patients [31.8%]) was lower than that of the non-ICG group (74 of 129 patients [57.4%]; P < .001). The postoperative recovery process was comparable, and no significant difference was found between the ICG and non-ICG groups in the incidence (20 of 129 patients [15.5%] vs 21 of 129 [16.3%], respectively; P = .86) or severity of complications within 30 days after surgery.

CONCLUSIONS AND RELEVANCE

Indocyanine green can noticeably improve the number of lymph node dissections and reduce lymph node noncompliance without increased complications in patients undergoing D2 lymphadenectomy. Indocyanine green fluorescence imaging can be performed for routine lymphatic mapping during laparoscopic gastrectomy, especially total gastrectomy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03050879.

Observation of tumor-associated macrophages expression in gastric cancer and its clinical pathological relationship

The present study was designed to investigate the expression of tumor-associated macrophages (TAMs) in gastric cancer and its clinicopathological relationship. In addition, we also aimed to analyze the relationship between helicobacter pylori (HP) infection and TAMs in gastric cancer.The protein expression of CD16 and CD163 in 90 gastric cancer tissues and 30 margin tissues was detected by immunohistochemistry. HP infection was detected in 90 gastric cancer tissues and 30 margin tissues by gram staining and immunohistochemistry.There was no clear correlation between CD16 macrophages and gastric cancer. The density of CD163 macrophages was not correlated with the general condition of tumor patients, but with tumor size, tumor differentiation, lymphatic metastasis, depth of invasion and TNM stage. Additionally, the infection rate of HP in gastric cancer tissues was significantly higher.In summary, TAMs are associated with tumor size, degree of differentiation, depth of invasion, lymph node metastasis and TNM stage, suggesting their critical role in the invasion and metastasis of gastric cancer.

Negative lymph node count as an independent prognostic factor in stage III patients after curative gastrectomy: A retrospective cohort study based on a multicenter database

OBJECTIVE

To examine the prognostic value of negative lymph node (NLN) count in stage III gastric cancer (GC) patients after curative gastrectomy.

METHODS

The clinicopathological data of 2942 stage III patients who underwent curative gastrectomy between 2001 and 2011 were analyzed. Only patients with ≥16 examined lymph nodes (ELNs) were included. After cut-point survival analysis, the 2942 patients were divided into three subgroups with NLN counts of 0, 1-9, and ≥10. Survival differences among the subgroups were analyzed to assess the effects of NLN count on stage migration and overall survival (OS) in stage III GC patients. Spearman's correlation coefficient was used to assess the relationships between the ELN count and the positive lymph node (PLN) count, the ELN count and the NLN count, and the NLN count and the PLN count.

RESULTS

Survival analyses revealed that the NLN count was significantly associated with OS (P = 0.001) and was an independent predictor (P < 0.01) of prognosis in stage III GC patients. Subgroup analysis showed that the prognostic evaluation accuracy was highest when the NLN count was ≥10 for stage III patients. Stage migrations were mainly detected in the following pathological tumor-node (pTN) subgroups: pT2N3a with 1-9 NLNs and pT2N3b with ≥10 NLNs, and pT3N3a with 1-9 NLNs and pT3N3b with ≥10 NLNs. NLN count was positively correlated with the ELN and the PLN counts for pT2N3 and pT3N3 stage GC patients (r = 0.694 and r = 0.881 for pT2N3 patients; r = 0.685 and r = 0.902 for pT3N3 patients, respectively; P < 0.001). These findings indicate that the NLN count may be a useful prognostic predictor in stage III GC patients.

CONCLUSIONS

The NLN count may improve the prognostic prediction efficiency of the tumor-node-metastasis (TNM) classification for GC, especially for stage III patients, and should be recommended for clinical applications.

Insufficient examined lymph node count underestimates staging in pN3a patients after curative gastrectomy: a multicenter study with external validation

PURPOSE

The present study aims to validate possible stage migration of lymph node metastasis related to the insufficient examined lymph node (ELN) count in pN3a gastric cancer (GC) patients.

METHODS

1976 pN3 patients who underwent the R0 surgery in three high-capacity institutions in China were enrolled to explore the stage migration of nodal involvement, and 3146 pN3 cases from the Surveillance, Epidemiology, and End Results (SEER) Program Registry were used as an external validation cohort.

RESULTS

After the propensity score matching of the Chinese cohort, the ELN count, as an independent predictor for GC outcome, was confirmed to be associated with the stage migration of lymph node metastasis in pN3a patients based on the univariate and multivariate survival analyses. Logistic regress was adopted to elucidate that the ELN count was an independent factor related to the long-term survival status of GC patients after curative surgery. Likelihood ratio test showed that the ELN count had the smallest Bayesian information criterion value among the clinicopathologic variables, corresponding to an efficient model to predict outcomes. Subsequently, stage migration of lymph node metastasis was predominantly detected in pN3a patient sub-group with insufficient (less than 16) ELN count, who presented with similar prognosis as the pN3b patients (P = 0.463) as per the stratum analysis with Kaplan-Meier. These methods were further validated using data from the SEER cohort, and the similar promising results were obtained.

CONCLUSION

pN3a patients with insufficient ELN count should be considered as pN3b cases to achieve accurate prognostic evaluation after curative gastrectomy.

The relationship between the number of examined lymph nodes and the efficacy of chemotherapy for gastric cancer

BACKGROUND

The purpose of this research was to investigate the relationship between the number of examined lymph nodes (eLNs) and the prognosis.

METHODS

A retrospective examination of reports and studies carried out at two institutions was conducted. According to TNM stages, the relationship between the number of eLNs and the prognosis was analyzed.

RESULTS

The 5-year disease-specific survival (DSS) of all enrolled patients was 66.3%. A multivariate analysis showed the type of gastrectomy, histologic type, perineural invasion, pT stage, pN stage, chemotherapy and eLNs to be independent prognostic markers. Additionally, with the exception of patients with stage I disease, the 5-year DSS of patients who had < 25 eLNs removed had a higher risk of having a worst prognosis compared to patients who had ≥ 25 eLNs removed. Through this study, a hypothetical TNM staging system was obtained for predicting the prognosis according to the number of eLNs. Chemotherapy was able to improve the prognosis of patients with stage III and < 25 eLNs in stage II.

CONCLUSIONS

Extended lymphadenectomy with a new goal of dissecting 25 LNs for the evaluation of stage II-III cancer cases is recommended. Our hypothetical TNM staging system may be able to stratify the risk more accurately compared to the current AJCC 8th system. Chemotherapy can improve the prognosis in advanced gastric cancer, but its benefit may be affected by the surgical quality.

Lymph Node Yield Following Packet Submission After Isolation By Surgeon During Gastrectomy

Purpose

To compare the lymph node yields of lymph node packet submission (PS), packet submission after isolation by surgeons (PSI), and en bloc lymph node submission (EBS) after gastrectomy.

Methods

We conducted a prospective study including 118 gastric cancer patients who underwent gastrectomy between June 2016 and August 2016. We also retrospectively reviewed 607 patients who underwent gastrectomy from May 2015 to May 2016. Following gastrectomy, lymph node specimens were either submitted en bloc (EBS group), divided into packets with accompanying adipose tissue according to the lymph node stations (PS group), or isolated individually based on the surgeon’s visualization and palpation before submission to the Pathology Department (PSI group).

Results

The average lymph node yield was significantly higher in the PSI compared with the PS group in the prospective study (46.5±19.4 vs 31.8±11.1), and significantly higher in the PS compared with the EBS group in the retrospective study (31.5±12.6 vs 23.9±8.9) (both P<0.001). There was no significant difference in positive lymph node yields in either of these comparisons (prospective study, P=0.581; retrospective study, P=0.489). The survival curve indicated no significant difference between the PS and PSI groups (log rank P=0.957); however, these three groups share different lymph node ratio (LNR).

Conclusion

PSI could yield more lymph nodes than PS or EBS with a lower LNR at pathological examination. However, the difference in lymph nodes harvested had no impact on survival, which may need further investigation.

Retrieved lymph nodes from different anatomic groups in gastric cancer: a proposed optimal number, comparison with other nodal classification strategies and its impact on prognosis

BACKGROUND

The optimal number of retrieved lymph nodes (LNs) in gastric cancer (GC) is still debatable and previous studies proposing new classification alternatives mostly focused on the number of retrieved LNs without proper consideration on the anatomic nodal groups' location. Here, we assessed the impact of retrieved LNs from different nodal location groups on the survival of GC patients.

METHODS

Stage I-III gastric cancer patients who had radical gastrectomy were investigated. LN grouping was determined according to the 13th edition of the JCGC. The optimal cut-off values of retrieved LNs in different LN groups (Group 1 and 2) were calculated, based on which a proposed nodal classification (rN) simultaneously accounting the optimal number and location of retrieved LNs was proposed. The performance of rN was then compared to that of LN ratio, log-odds of metastatic LNs (LODDs) and the 8th edition of the Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) N classification.

RESULTS

The optimal cut-off values for Group 1 and 2 were 13 and 9, respectively. The 5-year overall survival (OS) was higher for patients in retrieved Group 1 LNs > 13 (vs. Group 1 LNs ≤ 13, 63.2% vs. 57.9%, P = 0.005) and retrieved Group 2 LNs > 9 (vs. Group 2 LNs ≤ 9, 72.5% vs. 60.7%, P = 0.009). Patients staged as pN0-3b were sub classified using this Group 1 and 2 nodal analogy. The OS of pN0-N2 patients in retrieved Group 1 LNs > 13 or Group 2 LNs > 9 were superior to those in retrieved Group 1 LNs ≤ 13 and Group 2 LNs ≤ 9 (All P < 0.05); except for pN3 patients. The rN classification was formulated and demonstrated better 5-year OS prognostication performance as compared to the LNR, LODDs, and the 8th UICC/AJCC N staging system.

CONCLUSIONS

The retrieval of > 13 and > 9 LNs for Group 1 and Group 2, respectively, could represent an alternative lymph node retrieval approach in radical gastrectomy for more precise survival prognostication and minimizing staging migration, especially if > 16 LNs is found to be difficult.