Prognostic impact of the number of retrieved lymph nodes in patients with gastric cancer

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.

A comprehensive review and meta-analysis comparing robot-assisted and 3D laparoscopic gastrectomy for gastric cancer

This review and meta-analysis evaluates the short-term surgical results of robot-assisted gastrectomy compared to 3D laparoscopic gastrectomy in individuals with gastric cancer. This study used scholarly articles from peer-reviewed articles of PubMed. Further, this study uses other sources, such as, Embase, CNKI, and the Cochrane Library, to gather relevant studies on gastrectomy for gastric cancer which are made public from the inception of these databases up to July 15, 2024. This study seeks to primarily draw similarities between the therapeutic efficacy of robot-assisted gastrectomy (RG) and the 3D laparoscopic gastrectomy (3D-LG). Similarly, this study will strictly adhere to the inclusion and exclusion guidelines, focusing on randomized controlled trials (RCTs) and cohort research. A total of 1231 gastric cancer patients were involved in incorporating seven retrospective cohort studies as the final analysis in the study with 533 undergoing robot-assisted gastrectomy and 698 undergoing 3D-LG. The results showed that patients who received robotic-assisted gastrectomy experienced superior outcomes regarding EBL and time-to-first postoperative exhaust compared to those who underwent 3D-LG. However, the robotic-assisted approach was related to a reduced number of LNY. Besides, there were similarities between the two surgical techniques in relation to OT, LOHS, and post-surgery complications. In summary, robot-assisted gastrectomy is acknowledged as a secure and efficient treatment option for individuals with stomach cancer. This approach demonstrated notable benefits compared to 3D-LG, particularly with regard to estimated intraoperative blood loss and the timing of the first postoperative exhaust.

Different prognostic effect of lymph node metastasis between remnant gastric cancers and primary proximal gastric cancers

BACKGROUND

Although the dissected lymph node number in remnant gastric cancer (RGC) may be smaller than in primary proximal gastric cancer (PGC), altered lymphatic flow provides different metastatic patterns in lymph nodes, which could potentially give rise to prognostic differences between RGC and PGC with nodal metastasis.

METHODS

Between 1993 and 2020, 2546 consecutive patients with gastric cancer underwent gastrectomy. Of these, 53 patients with RGC and 381 patients with PGC with pathologic TNM stage I-III gastric cancer underwent curative gastrectomy. We reviewed their hospital records retrospectively.

RESULTS

The number of dissected lymph nodes was significantly smaller in patients with RGC than in patients with PGC (P < .001; RGC, 13.0 vs PGC, 34.5). Although the 5-year overall survival (OS) rate did not differ between RGC and PGC in all patients, the prognosis in each pathologic N (pN) stage of RGC was worse than that of PGC, suggesting that each lymph node metastasis has a greater prognostic effect in RGC. In particular, even with patients with pN1 (20.0%) or pN2 RGC (40.0%), their 5-year OS rates were poor and similar to those of patients with pN3 PGC (35.7%). The presence of lymph node metastasis in RGC (hazard ratio [HR], 4.41; 95% CI, 1.02-18.9; P = .045) was an independent and a similar prognostic impact in pN3 PGC (HR, 2.82; 95% CI, 1.57-5.07; P < .001). Lymph node metastasis in RGC more strongly affected peritoneal or lymph node recurrence rather than hematogenous recurrence.

CONCLUSION

The presence of lymph node metastasis yielded a poorer prognosis in patients with RGC than patients with primary PGC. Patients with RGC with lymph node metastasis should be specifically targeted in an effort to improve their prognosis.

Robotic distal gastrectomy using a novel pre-emptive supra-pancreatic approach without duodenal transection in the dissection of D2 lymph nodes for gastric cancer

Background

Robot-assisted surgery has shown remarkable progress as a minimally invasive procedure for gastric cancer. This study aimed to compare the pre-emptive suprapancreatic approach without duodenal transection and the conventional approach in terms of perioperative feasibility and short-term surgical outcomes.

Methods

We retrospectively analyzed all patients who underwent robotic distal gastrectomy with D2 lymph node dissection using the da Vinci Xi robotic system between December 2021 and April 2023 and categorized them into two groups for comparison. Patients treated using the pre-emptive suprapancreatic approach (observation group) were compared with those who received the conventional approach (control group). Employing one-to-one propensity score matching, we evaluated the postoperative morbidity and short-term outcomes in these two distinct groups to assess the efficacy and safety of the novel surgical technique.

Results

This study enrolled 131 patients: 70 in the observation group and 61 in the control group. After propensity score matching, the operative times were significantly longer in the control group than in the observation group (229.10 ± 33.96 vs. 174.84 ± 18.37, p <0.001). The mean blood loss was lower in the observation group than in the control group (25.20 ± 11.18 vs. 85.00 ± 38.78, p <0.001). Additionally, the observation group exhibited a higher number of retrieved lymph nodes, including suprapyloric, perigastric, and superior pancreatic lymph nodes (28.69 ± 5.48 vs. 19.21 ± 2.89, p <0.001; 4.98 ± 1.27 vs. 4.29 ± 1.21, p = 0.012; 10.52 ± 2.39 vs. 5.50 ± 1.62, p <0.001; 6.26 ± 2.64 vs. 5.00 ± 1.72, p = 0.029). Drain amylase levels in the observation group were significantly lower than those in the control group (30.08 ± 33.74 vs. 69.14 ± 66.81, p <0.001).

Conclusion

This study revealed that using the pre-emptive suprapancreatic approach without duodenal transection in the dissection of D2 lymph nodes for gastric cancer is a safe and feasible procedure in terms of surgical outcomes.

Impact of Removal of Lymph Nodes on Survival in Stage I-III Gastric Signet-Ring Cell Cancer: The More, the Better?

BACKGROUND

There is an ongoing debate over the prognostic value of the number of examined lymph nodes (ELNs) in cases of gastric signet-ring cell cancer (GSRCC). In this study, we sought to evaluate the correlation between the number of ELNs and the prognosis of GSRCC and identify the optimal number of ELNs.

METHODS

A total of 1020 patients diagnosed with GSRCC between 2011 and 2018 in the National Cancer Center database were identified. Clinicopathological characteristics were retrospectively collected, and optimal cutoff values of ELNs were calculated by using X-tile. The impact of different ELNs on overall survival (OS) was compared by using Kaplan-Meier curves. We used univariate and multivariate Cox and subgroup analyses to explore the relationship between ELNs and OS. Furthermore, nonlinear correlations were investigated by using restricted cubic splines (RCSs).

RESULTS

X-tile showed that the optimal cutoff value of ELNs was 22. The 5-year OS was higher for patients with ELNs > 22 (vs. ELNs ≤ 22, 66.9% vs. 74.9%, P = 0.026). Multivariate Cox analyses showed that high ELNs were associated with superior OS (hazard ratio = 0.56, 95% confidence interval 0.43-0.74, P < 0.001). In subgroup analyses, the significant association between tumor size > 4 cm, and TNM III stage was still observed. The RCS regression model showed a U-shaped dose-response nonlinear relationship between ELNs and OS; the inflection point, as well as the lowest risk points, corresponded to 44-52 ELNs.

CONCLUSIONS

A U-shaped, nonlinear correlation with inflection points of 44-52 ELNs between ELNs and prognosis in GSRCC was identified.

A 3 M Evaluation Protocol for Examining Lymph Nodes in Cancer Patients: Multi-Modal, Multi-Omics, Multi-Stage Approach

Through meticulous examination of lymph nodes, the stage and severity of cancer can be determined. This information is invaluable for doctors to select the most appropriate treatment plan and predict patient prognosis; however, any oversight in the examination of lymph nodes may lead to cancer metastasis and poor prognosis. In this review, we summarize a significant number of articles supported by statistical data and clinical experience, proposing a standardized evaluation protocol for lymph nodes. This protocol begins with preoperative imaging to assess the presence of lymph node metastasis. Radiomics has replaced the single-modality approach, and deep learning models have been constructed to assist in image analysis with superior performance to that of the human eye. The focus of this review lies in intraoperative lymphadenectomy. Multiple international authorities have recommended specific numbers for lymphadenectomy in various cancers, providing surgeons with clear guidelines. These numbers are calculated by applying various statistical methods and real-world data. In the third chapter, we mention the growing concern about immune impairment caused by lymph node dissection, as the lack of CD8 memory T cells may have a negative impact on postoperative immunotherapy. Both excessive and less lymph node dissection have led to conflicting findings on postoperative immunotherapy. In conclusion, we propose a protocol that can be referenced by surgeons. With the systematic management of lymph nodes, we can control tumor progression with the greatest possible likelihood, optimize the preoperative examination process, reduce intraoperative risks, and improve postoperative quality of life.

Indocyanine Green (ICG) in Robotic Gastrectomy: A Retrospective Review of Lymphadenectomy Outcomes for Gastric Cancer

Radical gastrectomy is essential for gastric cancer treatment. While guidelines advise dissecting at least 16 lymph nodes, some research suggests over 30 nodes might be beneficial. This study assessed ICG-guided robotic gastrectomy's effectiveness in thorough lymph node dissection. We analyzed data from 393 stage II or III gastric cancer patients treated at Seoul St. Mary's Hospital from 2016-2022. Patients were categorized into conventional laparoscopy (G1, n = 288), ICG-guided laparoscopy (G2, n = 61), and ICG-guided robotic surgery (G3, n = 44). Among 391 patients, 308 (78.4%) achieved proper lymphadenectomy. The ICG-robotic group (G3) showed the highest success rate at 90.9%. ICG-guided robotic surgery was a significant predictor for achieving proper lymphadenectomy, with an odds ratio of 3.151. In conclusion, ICG-robotic gastrectomy improves lymphadenectomy outcomes in selected gastric cancer cases, indicating a promising surgical approach for the future.

Emerging roles of miR-145 in gastrointestinal cancers: A new paradigm

Gastrointestinal (GI) carcinomas are a group of cancers affecting the GI tract and digestive organs, such as the gastric, liver, bile ducts, pancreas, small intestine, esophagus, colon, and rectum. MicroRNAs (miRNAs) are small functional non-coding RNAs (ncRNAs) which are involved in regulating the expression of multiple target genes; mainly at the post-transcriptional level, via complementary binding to their 3'-untranslated region (3'-UTR). Increasing evidence has shown that miRNAs have critical roles in modulating of various physiological and pathological cellular processes and regulating the occurrence and development of human malignancies. Among them, miR-145 is recognized for its anti-oncogenic properties in various cancers, including GI cancers. MiR-145 has been implicated in diverse biological processes of cancers through the regulation of target genes or signaling, including, proliferation, differentiation, tumorigenesis, angiogenesis, apoptosis, metastasis, and therapy resistance. In this review, we have summarized the role of miR-145 in selected GI cancers and also its downstream molecules and cellular processes targets, which could lead to a better understanding of the miR-145 in these cancers. In conclusion, we reveal the potential diagnostic, prognostic, and therapeutic value of miR-145 in GI cancer, and hope to provide new ideas for its application as a biomarker as well as a therapeutic target for the treatment of these cancer.

A thirty-three gene-based signature predicts lymph node metastasis and prognosis in patients with gastric cancer

Recently, several studies have indicated the great potential of gene expression signature of the primary tumor in predicting lymph node metastasis; however, few current gene biomarkers can predict lymph node status and prognosis in gastric cancer (GC). Thus, we used the RNA-seq data from The Cancer Genome Atlas (TCGA) to identify differentially expressed genes between pathological lymph node-negative (pN0) and positive (pN+) patients and to establish a gene signature that could predict lymph node metastasis. Meanwhile, the robustness of identified gene signatures was validated in an independent dataset Asian Cancer Research Group (n = 300). In this study, our thirty-three gene-based signature was highly correlated with lymph node metastasis and could successfully discriminate pN + patients in the training set (Area under the receiver operating characteristic curve = 0.951). Moreover, Disease-free survival (P = 0.0029) and overall survival (P = 0.026) were significantly worse in high-risk compared with low-risk patients overall and when confined to pN0 patients only (P < 0.0001). Of note, this gene signature also proved useful in predicting lymph node status and survival in the validation cohort. The present study suggests a thirty-three gene-based signature that could effectively predict lymph node metastasis and prognosis in GC.

Regional Lymph Node Metastasis Distribution in Resectable Middle-Third Gastric Cancer: A Cross-Sectional Study

Introduction Lymph node (LN) metastasis happens even in early gastric cancer (GC) even in LN stations that are not adjacent to the primary tumor. Total or subtotal gastrectomy (TG or sTG) can be performed in the middle third of the GC if the negative proximal margin is maintained. These procedures differed in the extent of LN dissection; therefore, oncology considerations must be taken into consideration when selecting the appropriate procedure. Methods This was a cross-sectional study involving 98 patients suffering from middle-third GC. The metastatic lymph nodes (mLN) ratio was calculated in each case by the ratio between the number of mLN and the number of total LNs retrieved. We compare the difference in the total LN retrieved, number of mLN, and rate of positive LN (N+) between the two groups TG and sTG. Results The majority of patients had advanced GC (82.7% pT2-4). About 65.3% of patients had metastasis LN. The events of LN metastasis and skipped LN metastasis happened even in tumors contained in the submucosal layer. The metastasis rates in each LN station were also increasing in correlation with the depth of tumor invasion. For LN station No. 2, 4sa, 10, 11d (which are not mandatory) in sTG, the rate of mLN was 0% for the pT1-3 tumor, regardless of tumor longitudinal location. The rate of mLN for each station was higher in adjacent stations of the tumor (No. 1-3-5-7 in lesser curvature, No. 4sb-4d-6 in greater curvature, No.1-3-4sb in the anterior wall, No. 3-7-12a in the posterior wall). The total LN retrieved, number of mLN, and rate of positive LN were statistically higher in the TG group compared to the sTG group. However, the mean mLN ratios between the two groups were comparable (p = 0.116). Conclusion In accordance with the macroscopic and microscopic characteristics, we observed a stratified distribution of mLN in the middle third of the GC. With these early results, sTG combined with standard lymphadenectomy was an acceptable treatment for T1-T3 middle-third GC in terms of mLN distribution. Total No. 4sb LN dissection might also be reserved in gastrectomy for T1-T3 GC.

Short-term outcomes of reduced-port laparoscopic surgery versus conventional laparoscopic surgery for total gastrectomy: a single-institute experience

BACKGROUND

The efficacy of reduced-port laparoscopic surgery (RLS) for total gastrectomy remains unclear. This study focused on evaluating the short-term outcomes of RLS compared with conventional laparoscopic surgery (CLS) for total gastrectomy.

METHODS

One hundred and ten patients who underwent completed laparoscopic total gastrectomy for gastric cancer between September 2018 and June 2022 were retrospectively collected and classified into two groups (65 CLS and 45 RLS) according to different operation approach. Twenty-four RLS cases underwent single-incision plus two ports laparoscopic surgery (SILS + 2) and twenty-one underwent single-incision plus one port laparoscopic surgery (SILS + 1). Surgical outcomes, pain intensity, cosmetic and postoperative morbidity, and mortality were compared between groups.

RESULTS

The overall incidence of postoperative complications was similar between the CLS group and the RLS group (16.9% vs. 8.9%, P = 0.270). It was also comparable in the Clavien-Dindo classification (P = 0.774). However, compared with the CLS group, the RLS group had a significantly shorter total length of incision (5.6 ± 1.0 cm vs. 7.1 ± 0.7 cm, P = 0.000); shorter time to first ambulation (24.9 ± 5.9 h vs. 27.6 ± 5.0 h, P = 0.009), flatus (3.0 ± 0.8 d vs. 3.5 ± 1.0 d, P = 0.022) and oral intake (4.0 ± 1.6 d vs. 6.1 ± 5.1 d, P = 0.011); lower white blood cell count on the third day after the operation (9.8 ± 4.0*10⁹/L vs. 11.6 ± 4.7*10⁹/L, P = 0.037); and lower visual analogue scale score on postoperative days 1 and 3(3.0 ± 0.7 vs. 3.3 ± 0.7, P = 0.044 and 0.6 ± 0.7 vs. 1.6 ± 0.6, P = 0.000 respectively). On the other hand, it didn't find any difference in short-term outcomes between the SILS + 2 group and the SILS + 1 group (P > 0.05). But the proximal resection margin was longer in the SILS + 2 group than in the SILS + 1 group (2.6 ± 0.7 cm vs. 1.5 ± 0.9 cm, P = 0.046) in patients with adenocarcinoma of the esophagogastric junction (AEG).

CONCLUSIONS

RLS for total gastrectomy is a feasible and safe technique when performed by an experienced laparoscopic surgeon. Moreover, compared with SILS + 1, SILS + 2 might have some advantages in AEG patients.

Laparoscopic versus Open Total Gastrectomy for Locally Advanced Gastric Cancer: Short and Long-Term Results

BACKGROUND

Laparoscopic gastrectomy for early gastric cancer is widely accepted and routinely performed. However, it is still debated whether the laparoscopic approach is a valid alternative to open gastrectomy in advanced gastric cancer (AGC). The aim of this study is to compare short-and long-term outcomes of laparoscopic (LG) and open (OG) total gastrectomy with D2 lymphadenectomy in patients with AGC.

METHODS

A retrospective comparative study was conducted on patients who underwent LG and OG for ACG between January 2015 and December 2021. Primary endpoints were the following: recurrence rate, 3-year disease-free survival, 3-year and 5-year overall survival. Univariate and multivariate analysis was conducted to compare variables influencing outcomes and survival.

RESULTS

Ninety-two patients included: fifty-three OG and thirty-nine LG. No difference in morbidity and mortality. LG was associated with lower recurrence rates (OG 22.6% versus LG 12.8%, p = 0.048). No differences in 3-year and 5-year overall survival; 3-year disease-free survival was improved in the LG group on the univariate analysis but not after the multivariate one. LG was associated with longer operative time, lower blood loss and shorter hospital stay. Lymph node yield was higher in LG.

CONCLUSION

LG for AGC seems to provide satisfactory clinical and oncological outcomes in medium volume centers, improved postoperative results and possibly lower recurrence rates.

Reduced-port robotic radical gastrectomy for gastric cancer: a single-institute experience

Background

Reduced-port laparoscopic gastrectomy can potentially reduce postoperative pain and improve recovery time. However, the inherent difficulty caused by the narrow manipulation angle makes this operation difficult, especially during lymph node dissection. The intrinsic advantage of the da Vinci^® robotic system might offset this difficulty, maintaining adequate surgical quality with risks of surgical complications equal to those by the conventional four-port robotic approach. The aim of this study was to compare the reduced-port robotic approach and the conventional four-port approach in terms of postoperative pain and short-term surgical outcomes.

Methods

All patients who underwent radical gastrectomy with D2 lymph node dissection using the da Vinci Xi robotic system, including reduced-port or conventional four-port approach, were analyzed retrospectively. The primary outcome was postoperative pain assessed using the numerical rating scale (NRS). The secondary outcomes were the number of harvested lymph nodes, operation time, length of hospital stay, and postoperative 30-day complications.

Results

Forty-eight patients were enrolled in the study, 10 cases in the reduced-port and 38 in the conventional four-port group. Postoperative NRS revealed no significant difference between the reduced-port and conventional four-port groups [postoperative day (POD) 1: 4.5 vs. 3, p = 0.047, POD 3: 4 vs. 3, p = 0.178]. After propensity score matching, there were no significant differences in the median number of harvested lymph nodes, operation time, and length of hospital stay between the groups. The postoperative 30-day complications were more frequent in the conventional four-port group, but there was no significant difference compared with the reduced-port group after propensity score matching.

Conclusions

Reduced-port robotic gastrectomy with D2 lymph node dissection might be comparable to the conventional four-port robotic operation in terms of postoperative pain, surgical quality, and short-term outcomes. However, further studies are required to confirm our results and clarify the advantages of the robotic reduced-port approach.

Development and Validation of a Predictive Scoring System for Colorectal Cancer Patients With Liver Metastasis: A Population-Based Study

Liver metastasis in colorectal cancer (CRC) is common and has an unfavorable prognosis. This study aimed to establish a functional nomogram model to predict overall survival (OS) and cancer-specific survival (CSS) in patients with colorectal cancer liver metastasis (CRCLM). A total of 9,736 patients with CRCLM from 2010 to 2016 were randomly assigned to training, internal validation, and external validation cohorts. Univariate and multivariate Cox analyses were performed to identify independent clinicopathologic predictive factors, and a nomogram was constructed to predict CSS and OS. Multivariate analysis demonstrated age, tumor location, differentiation, gender, TNM stage, chemotherapy, number of sampled lymph nodes, number of positive lymph nodes, tumor size, and metastatic surgery as independent predictors for CRCLM. A nomogram incorporating the 10 predictors was constructed. The nomogram showed favorable sensitivity at predicting 1-, 3-, and 5-year OS, with area under the receiver operating characteristic curve (AUROC) values of 0.816, 0.782, and 0.787 in the training cohort; 0.827, 0.769, and 0.774 in the internal validation cohort; and 0.819, 0.745, and 0.767 in the external validation cohort, respectively. For CSS, the values were 0.825, 0.771, and 0.772 in the training cohort; 0.828, 0.753, and 0.758 in the internal validation cohort; and 0.828, 0.737, and 0.772 in the external validation cohort, respectively. Calibration curves and ROC curves revealed that using our models to predict the OS and CSS would add more benefit than other single methods. In summary, the novel nomogram based on significant clinicopathological characteristics can be conveniently used to facilitate the postoperative individualized prediction of OS and CSS in CRCLM patients.

Pathologic Lymph Node Staging of Gastric Cancer

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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 (OR_SEER = 1.03, 95%-CI = 1.03–1.04; OR_MIGC = 1.02, 95%-CI = 1.02–1.03) and sequential enhancements in postoperative survival (HR_SEER = 0.97, 95%-CI = 0.97–0.97; HR_MIGC = 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.

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.

Influence of endoscopic resection on additional laparoscopic distal gastrectomy: a propensity score-matching analysis

PURPOSE

There is no definite evidence of the feasibility and safety of laparoscopic distal gastrectomy (LDG) for patients who have undergone incomplete endoscopic resection (ER). We investigated the influence of ER prior to LDG by a propensity score matching analysis.

METHODS

We retrospectively analyzed the outcomes of gastric cancer patients who underwent LDG with or without prior ER from 2000 to 2014. Propensity score matching was performed to compare the two groups of patients.

RESULTS

After matching, 47 patients in the ER group and 94 patients in the non-ER group were selected from a total of 365 patients. A residual tumor was observed in 10 of 47 patients (21.3%). The mean number of dissected lymph nodes in the non-ER group (39.4 ± 14.5) was higher than that in the ER group (31.7 ± 13.5) (P = 0.003). However, other perioperative data, such as the operation time and blood loss volume were similar. The complication rate of the ER group (17.0%) and the non-ER group (9.6%) did not differ to a statistically significant extent (P = 0.2). Among these patients, 6 died during the 5-year follow-up period, but no patients showed signs of recurrence.

CONCLUSION

ER prior to surgical resection showed no significant influence on postoperative complications or mortality. LDG can be safely performed to achieve radical resection after incomplete ER.

Laparoscopic Versus Open D2 Gastrectomy for Gastric Cancer: A Case-Matched Comparative Study

Background: The role of the laparoscopic approach to D2 gastrectomy for gastric cancer remains controversial. The aim of this study was to compare the operative and short-term oncologic outcomes of laparoscopic versus open resections. Methods: Patients who underwent potentially curative D2 gastrectomy between 2017 and 2019 were retrospectively reviewed. Patients were randomly matched on 1:1 basis for age and extent of surgery (total versus subtotal gastrectomy, and additional organ resection). Exclusions included emergency or palliative surgery. The learning curve for laparoscopic resections was included. Analysis was conducted on intention to treat basis. The outcomes were reported as median (range) or per cent as appropriate. Results: Among 78 patients who had undergone potentially curative gastrectomy 36 were matched. The groups were comparable for age, sex, American Society of Anesthesiologists (ASA) score, preoperative serum albumin and hemoglobin, body mass index, frequency of previous abdominal surgery, anatomic distribution of disease, extent of gastrectomy, need for additional resection, and disease stage. There was one conversion to open surgery. Although laparoscopic surgery required longer operating time (393 versus 218 minutes, P < .001), it was associated with less blood loss (100 versus 200 mL, P = .001) and shorter hospital stay (3.0 versus 7.5 days, P < .001). There were no significant differences in the rates of clinically significant complications, mortality, readmissions, reoperations, lymph node retrieval, and R₁ resections. Conclusions: The laparoscopic approach to potentially curative D2 gastrectomy for gastric cancer is associated with less operative trauma and quicker recovery while offering an equivalent oncologic resection.

Thirty-year trends in clinicopathologic characteristics and prognosis after gastrectomy for gastric cancer: A single institution in Northern China

Background: We integrated changes in the trends in clinicopathologic characteristics and postoperative prognosis in patients with gastric cancer Northern China over a 30-year period. Methods: A retrospective analysis of patients undergoing gastric cancer resection and complete follow-up information from January 1981 to December 2010 in the first affiliated Hospital of China Medical University was carried out. We divided the patients into three consecutive periods. Results: A total of 3,520 patients were included in this study. The proportion of lower tumors increased (from 58.8 to 66.9%), while that of upper tumors decreased (from 21.3 to 13.4%). The proportion of tumors > 5cm decreased (from 58.6 to 41.1 %), but the increasing trend of poorly differentiated gastric cancer was obvious (from 60.1 to 75.7%). The percentage of early gastric cancer increased from 10.0 to 15.5 during the study periods, and that of TNM stage Ⅳ cancer decreased from 38.6 to 28.1. In surgery treatment, the rate of radical resection increased to 92.1% in recent period, and the average number of retrieved lymph nodes increased. The 5-year survival rate gradually increased from 36.5% to 48.5% (p<0.001). The Multivariate analysis showed that age, tumor size, T stage, N stage, number of retrieved lymph nodes and resection type were independent prognostic factors for gastric cancer. Conclusion: The patterns of clinicopathologic features for gastric cancer changed during the 30-year period in North China. Overall survival (OS) could be increased by early detection of tumors and standard surgical treatment.

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.

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.

Essential updates 2017/2018: Recent topics in the treatment and research of gastric cancer in Japan

Recent developments in diagnostic technology, accumulated clinical effort and established evidence have boosted early detection and drastically improved early and long-term outcomes of gastric cancer. However, gastric cancer continues to be one of the most aggressive and life-threatening malignancies among all cancers and is a global health problem. Between January 2017 and December 2018, various fascinating reports of managements and research were published, including the new 15th Japanese Classification of Gastric Carcinoma reflecting the 8th American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) tumor, node and metastasis (TNM) classification (October 2017) and the new Gastric Cancer Treatment Guidelines version 5 (January 2018). Moreover, pivotal molecular features of gastric cancer were clarified by the worldwide cancer genome project, and various treatment targets and biomarkers such as circulating DNAs and microRNAs were detected. Novel treatment options using programmed cell death protein 1 immune checkpoint inhibitors have been started. In this review, we summarize the recent topics of classification, guidelines, and clinical and basic research in order to bring new insights to gastric cancer treatment.

Effect of lymph nodes count in node-positive gastric cancer

Background: The retrieved lymph node (LN) count has been confirmed as a prognostic indicator in various cancers. However, the correlation between LN counts and patient prognosis in gastric cancer with node-positive is not fully studied.

Methods: A total of 8475 patients undergoing gastrectomy in Surveillance, Epidemiology, and End Results Program (SEER)-registered gastric cancer were analyzed. Kaplan-Meier methods and multivariable Cox regression models were used to analyze long-term outcomes and risk factors. Moreover, nomograms including LN counts were established to predict overall survival (OS) and cancer-specific survival (CSS), and Harrell's concordance index (c-index) was adopted to evaluate prediction accuracy.

Results: Patients were stratified into 1-6, 7-14, and > 14 subgroups according to the optimal cutoff for retrieved LNs in terms of 5-year CSS. Further analysis indicated that higher LN counts were an independent predictor of longer survival in each N category. Nomograms on CSS and OS were established according to all significant factors, and c-indexes were 0.663 and 0.654 (P< 0.001), respectively.

Conclusions: These results indicated that the more the LNs retrieved, the better the survival would be. Nomograms incorporating LN counts can be recommended as practical models to provide more accurate prognostic information for GC patients.

A meta-analysis of comparison of proximal gastrectomy with double-tract reconstruction and total gastrectomy for proximal early gastric cancer

Background

In theory, proximal gastrectomy with double-tract reconstruction (PG-DT) was superior to total gastrectomy (TG) in hematologic and nutritional outcomes. However, its clinical effects in proximal early gastric cancer (EGC) have been controversial.

Methods

The purpose of this study was to investigate the outcomes of laparoscopic proximal gastrectomy with double-tract reconstruction (LPG-DT) for proximal EGC. For this systematic review and meta-analysis, we searched for articles published before December of 2018 in the following databases: PubMed, Web of Science, EBSCO, Medline, and Cochrane Library.

Results

The results showed no significant difference in the anastomotic stenosis (OR = 0.91, 95%CI = 0.33–2.50, p = 0.85) and reflux esophagitis (OR = 1.87, 95%CI = 0.62–5.65, p = 0.27) between LPG-DT and laparoscopic total gastrectomy (LTG). The vitamin B12 supplementation rate in the LPG-DT group was lower than the LTG group (OR = 0.06, 95%Cl = 0.01–0.59, p = 0.02).

Conclusions

Due to comparable clinical effect, PG-DT is comparable to TG for patients with proximal EGC. In addition, LPG-DT not only appears superior to TG in terms of preventing vitamin B12 deficiency, but also does not increase the risk of anastomotic stricture and reflux esophagitis.

Electronic supplementary material

The online version of this article (10.1186/s12893-019-0584-7) contains supplementary material, which is available to authorized users.

Preoperative N stage evaluation in advanced gastric cancer patients using multidetector CT: can the sum of the diameters of metastatic LNs be used for N stage evaluation?

AIM

To compare the diagnostic performance of total counts of metastatic lymph nodes (LN-sum) and conventional multidetector (MD) computed tomography (CT) staging in the nodal evaluation of advanced gastric cancer (AGC) patients.

MATERIALS AND METHODS

In total, 127 consecutive patients who underwent preoperative MDCT and gastrectomy for AGC were identified. Metastatic LNs on MDCT were defined as LNs with a short axis ≥8 mm, marked or heterogeneous enhancement, and morphological features (central necrosis, round shape, clustering). The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the N-stage using LN-sum and conventional MDCT staging were generated and compared. In addition, metastatic LN counts between the MDCT and the histopathological examinations and correlation between LN-sum and histopathological nodal status were analysed.

RESULTS

The total counts of metastatic LNs on MDCT was significantly smaller than those detected in histopathological assessments (p<0.0001). LN-sum showed significant correlation with the pathological N stage and the number of metastatic LNs (rho=0.69, 0.73, p<0.0001). The areas under the receiver operating characteristic curve were 0.896, and 0.835, for N stage ≥N2 and N3, with cut-off values of 12.5 and 23.5 mm, respectively. LN-sum provided better diagnostic performance than conventional MDCT staging for discriminating N0-2 versus N3; sensitivity, accuracy, PPV and NPV of LN-sum were significantly higher (80.4 versus 52.2%, 81.1 versus 68.5%, 71.2 versus 57.1%, and 88 versus 74.1%).

CONCLUSION

LN-sum may be sufficiently useful in assessing the N3 stage of AGC and may help to plan appropriate therapy for AGC patients.

Number of retrieved lymph nodes is an independent prognostic factor after total gastrectomy for patients with stage III gastric cancer: propensity score matching analysis of a multi-institution dataset

BACKGROUND

The prognostic significance of the number of retrieved lymph nodes (RLNs) in gastric cancer remains controversial. Therefore, we designed a multicenter collaborative database to investigate the correlation between the number of RLNs and prognosis of patients with advanced gastric cancer after curative resection.

METHODS

We retrospectively analyzed 1103 patients who underwent gastrectomy for stage II/III gastric cancer between 2010 and 2014. Lymph nodes, which were retrieved by surgeons from surgically resected specimens, were validated by pathologists. A target population and the optimal cutoff were determined using receiver operating characteristic (ROC) curve analysis. After propensity score matching of eight variables, including splenectomy and adjuvant chemotherapy, the prognostic significance of RLNs was evaluated.

RESULTS

According to ROC curve analysis, the optimum cutoff score for predicting postoperative survival was 40. After matching, the backgrounds of patients in the RLN < 40 and RLN ≥ 40 groups (n = 87 each) became well-balanced. The RLN < 40 group experienced significantly shorter relapse-free and overall survival. The prevalence of peritoneal recurrence was significantly increased in the RLN < 40 group. RLN < 40 was an independent prognostic factor in multivariable analysis, although pathological N status was not. A forest plot revealed that the RLN < 40 group was at greater risk of recurrence in most subgroups.

CONCLUSIONS

RLN < 40 was associated with an adverse prognosis of patients with stage III gastric cancer who underwent total gastrectomy.

Does Lymphadenectomy with at Least 15 Perigastric Lymph Nodes Retrieval Promise an Improved Survival for Gastric Cancer: A Retrospective Cohort Study in Southern China

Background: Specific guidelines recommend at least 15 or 16 lymph nodes (LNs) be examined to adequately assess nodal category of gastric cancer (GC), but the requirement for minimum number of regional LNs retrieval is not mentioned. This study aims to investigate survival significance from various numbers of perigastric (N1) LNs retrieval and to determine an optimal number harvested in such region.

Study design: From April 1994 to March 2012, 1003 resectable GC patients with at least 15 LNs examined were included. Patients with at least 15 N1 nodes retrieval were assigned into study group, with the rest into control group. The 5-year overall survival (OS) rate was compared between two groups, and an optimal number of examined N1 nodes was detected by a survival joinpoint analysis.

Results: 635 (63.3%) patients in study group had median 22 (range, 15-75) N1 nodes and 3 (range, 0-74) positive N1 nodes retrieval, with median 10 (range, 0-14) N1 nodes and 1 (range, 0-29) metastatic N1 nodes examined in control group. The number of N1 nodes retrieval was associated with tumor location (P=0.007), tumor stage (P<0.001) and total number of harvested LNs (r=0.691, P<0.001). Median survival time (79.0 vs. 72.0 months, P=0.462) and actual 5-year OS rate (41.0% vs. 39.2%, P=0.463) were slightly improved in study group compared with control group, with significance obtained via stage-by-stage analysis. The joinpoint analysis indicated that at least seven N1 nodes retrieval achieved survival significance (81.0 vs. 35.0 months, P=0.036), with survival superiority remained until reaching up to 15 N1 nodes.

Conclusion: Adequate retrieval of perigastric LNs is essential for radical gastrectomy. A harvest of at least 7-15 perigastric LNs could achieve long-term survival benefit for GC patients.

Assessment of the 8th edition of TNM staging system for gastric cancer: the results from the SEER and a single-institution database

AIM

To investigate whether the 8th edition of Tumor, Node, Metastasis (TNM) staging could properly evaluate the prognosis of gastric cancer patients.

METHODS

The prognostic performance between the 7th and 8th edition of TNM staging was compared and clinicopathologic features were analyzed.

RESULTS

The stage shifts in the 8th edition staging resulted in the increased numbers of stage IIIA patients and decreased numbers of stage IIB, stage IIIB and stage IIIC patients. Compared with the previous edition, the 8th edition of TNM staging provided a better prognostic stratification for stage III patients. However, whether it is reasonable to incorporate T4aN2, T4aN3a and T4bN3b into stage IIIA, stage IIIB and stage IIIC respectively, which still need further validation.

CONCLUSION

Despite the obvious superiority, several deficiencies may still exist in the new edition staging. To better provide prognostic information and therapeutic guidance for gastric cancer patients, the TNM staging system should be further improved in the future.

External validation of a modified 8th AJCC TNM system for advanced gastric cancer: Long-term results in southern China

BACKGROUND

The 8th edition of AJCC TNM staging manual for gastric cancer (GC) has been validated by several studies. A modified staging system based on it and total harvested number of lymph nodes (LNs; cutoff: 30) is suggested to improve predictive capacities for advanced GC. This study is designed to validate the modified method using a single-center database in Southern China.

METHODS

Clinical data from 684 GC patients with stage II and III according to the 7th edition between 2001 and 2012 were reviewed. A modified staging system was applied to restage the cohort. The three staging systems were compared in terms of prognostic performance on long-term survival.

RESULTS

The median follow-up period of this cohort was 52 (range, 6-180) months, with a median 5-year overall survival rate of 52.4%. Stage migration was observed in 159 (23.2%) patients according to the 8th edition of TNM staging, and another migration was observed in 108 (15.8%) patients according to the modified TNM staging system. Compared with the modified staging system, both 7th and 8th edition of AJCC TNM staging systems did not prove survival concordance on stage IIIA (7th edition) and stage IIIC (8th edition) when <30 LNs were examined. The survival performance between two AJCC staging systems had no significant improvement (c-index, 0.607 vs. 0.609), with the best prognostic stratification obtained using the modified staging method (c-index, 0.631).

CONCLUSIONS

The modified staging system on basis of the 8th AJCC classification and the number of harvested LNs could provide an optimal predictive capacities for advanced gastric cancer.

Validation of clinical significance of examined lymph node count for accurate prognostic evaluation of gastric cancer for the eighth edition of the American Joint Committee on Cancer (AJCC) TNM staging system

Objective

To validate the necessity of increasing the examined lymph node (ELN) count for enhancing the accuracy of prognostic evaluation of gastric cancer (GC) patients after curative gastrectomy in multiple medical centers of China.

Methods

The clinicopathological data of 7,620 patients who underwent the curative resection for GC between 2001 and 2011 were included to demonstrate whether the ELN count is indispensable for enhancing the accuracy of prognostic evaluation of GC patients after surgery. After a meticulous stratification by using the cut-point survival analysis, all included 7,620 patients were allocated into three groups as: less than 16 (<16), between 16 and 30 (16−30), and more than 30 (>30) ELNs. Survival differences among various subgroups of GC patients were analyzed to assess the impact of the ELN count on the stage migration in accordance with the overall survival (OS) of GC patients.

Results

Survival analyses revealed that the ELN count was positively correlated with the OS (P=0.001) and was an independent prognostic predictor (P<0.01) of 7,620 GC patients. Stratum analysis showed that the accuracy of prognostic evaluation could be enhanced when the ELN count was no less than 16 (≥16) for node-negative patients and >30 for node-positive patients. Stage migrations were mainly detected in the various subgroups of patients with specific pN stages as follows: pN0 with 16−30 ELNs (pN0₁₆₋₃₀) and pN0 with >30 ELNs (pN0 _>30), pN0 with <16 ELNs (pN0 _<16) and pN1_>30, pN1_<16 and pN2₁₆₋₃₀, pN1₁₆₋₃₀ and pN2_>30, pN3a_<16 and pN3b₁₆₋₃₀, and pN3a_<16 and pN3b_>30. These findings indicate that increasing the ELN count is a prerequisite to guarantee precisely prognostic evaluation of GC patients.

Conclusions

The ELN count should be proposed to be >30 for acquiring the accurate prognostic evaluation for GC patients, especially for node-positive patients.

The retrieval of at least 25 lymph nodes should be essential for advanced gastric cancer patients with lymph node metastasis: A retrospective analysis of single-institution database study design: Cohort study

BACKGROUND

Recently, increased evidence have shown that the better prognosis of gastric cancer (GC) patients was associated with the larger number of retrieved lymph nodes (RLNs), but the optimal number of RLNs remains controversial. In the present study, we investigated whether adequate LN retrieval (≥15) was necessary to evaluate the prognosis of patients and attempted to propose an appropriate cutoff-point for the number of RLNs.

METHODS

We reviewed 2246 GC patients who underwent radical gastrectomy in our research institution between January 1986 and January 2008. All patients were divided into several groups based on the number of RLNs. The prognostic outcomes of different patient groups were compared and clinicopathologic features were analyzed.

RESULTS

In the present study, our results indicated that ≥15 RLNs showed a better survival outcome than inadequate LN retrieval (<15), regardless of the node-negative or node-positive GC patients (P < 0.001). For the more advanced GC patients (T2-T4 stage, N1-N3 stage, and stage II-stage III), the retrieval of 25-29 LNs could provide a better survival benefit compared with <25 or ≥30 RLNs (P < 0.05). In addition, for the patients who underwent proximal or total gastrectomy, the superior prognosis was still observed in the patient group with 25-29 RLNs.

CONCLUSION

The minimal goal of 15 RLNs may not be enough to accurately evaluate prognosis of all patients and at least 25 RLNs should be necessary for advanced GC patients with lymph node metastasis.

Survival Analysis with Extended Lymphadenectomy for Gastric Cancer: Removing Stage Migration from the Equation

The survival benefit of an extended versus standard lymphadenectomy for gastric cancer (GC) is often attributed to upstaging when more lymph nodes (LNs) are removed, i.e., stage migration. An extended lymphadenectomy is defined as 30 or more LNs examined, a surrogate for a D2 dissection. The aim of this study is to examine whether the survival benefit of extended lymphadenectomy persists when stage migration is not possible. The National Cancer Data Base was queried to identify patients with pathologic N3 (pN3, ≥7 positive LNs) gastric adenocarcinoma. Overall survival (OS) was compared by extent of lymphadenectomy (7-14, 15-29, and ≥30 LN) and stratified by T stage. Of 2101 pN3 patients, 419 (19.9%) had 7 to 14 LNs examined, 1164 (55.4%) had 15 to 29 LNs examined, and 518 (24.7%) had ≥30 LNs examined. Unadjusted three-year OS in the entire cohort was 24.6, 27.3, 30.5 per cent for 7 to 14 LNs, 15 to 29 LNs, and ≥30 LNs, respectively (P = 0.003). On adjusted survival analysis by stage for patients with pT1-T2N3 disease, removing ≥30 LNs significantly improved OS compared with removing 7 to 14 LNs (hazard ratio [HR] 2.45, 95% confidence interval = 1.25-4.82, P = 0.009). Extended lymphadenectomy may confer a survival benefit in select patients with pT1N3 and pT2N3 GC, highlighting the importance of the number of LNs examined rather than stage migration on survival. For the majority of the N3 population, pT3-pT4, the extent of lymphadenectomy did not significantly improve the OS.

Prognostic impact of nodal status and therapeutic implications

The prognostic impact of lymph node (LN) metastases in gastric cancer is generally accepted. In primarily resected patients the pN-category and LN ratio are independent prognostic factors. Number of involved LNs, number of resected LNs, lymphangiosis and micrometastases also influence the prognosis significantly. To guarantee a proper D2 lymphadenectomy (LAD) at least 25 LNs according to the German S3 guidelines for the treatment of gastric cancer should be removed. Also in neoadjuvantly treated patients the ypN-category and LN ratio play an important prognostic role, despite the fact that UICC staging system was development based only on primarily resected patients. The role of response of LNs in neoadjuvantly treated patients is still unclear and needs further investigation. It seems to be less important than the response of the primary tumor. Limited data exists, suggesting that preoperative treatment might reduce the number of LNs involved and improve ypN-category. Due to further development in gastric cancer like laparoscopic resection and effective perioperative treatment in locally advanced tumor the role and the prognostic impact of LAD is again in the focus of discussion.

Apparent diffusion coefficient by diffusion-weighted magnetic resonance imaging as a sole biomarker for staging and prognosis of gastric cancer

Objective

To investigate the role of apparent diffusion coefficient (ADC) from diffusion-weighted magnetic resonance imaging (DW-MRI) when applied to the 7th TNM classification in the staging and prognosis of gastric cancer (GC).

Methods

Between October 2009 and May 2014, a total of 89 patients with non-metastatic, biopsy proven GC underwent 1.5T DW-MRI, and then treated with radical surgery. Tumor ADC was measured retrospectively and compared with final histology following the 7th TNM staging (local invasion, nodal involvement and according to the different groups — stage I, II and III). Kaplan-Meier curves were also generated. The follow-up period is updated to May 2016.

Results

Median follow-up period was 33 months and 45/89 (51%) deaths from GC were observed. ADC was significantly different both for local invasion and nodal involvement (P<0.001). Considering final histology as the reference standard, a preoperative ADC cut-off of 1.80×10^–3 mm²/s could distinguish between stages I and II and an ADC value of ≤1.36×10^–3 mm²/s was associated with stage III (P<0.001). Kaplan-Meier curves demonstrated that the survival rates for the three prognostic groups were significantly different according to final histology and ADC cut-offs (P<0.001).

Conclusions

ADC is different according to local invasion, nodal involvement and the 7th TNM stage groups for GC, representing a potential, additional prognostic biomarker. The addition of DW-MRI could aid in the staging and risk stratification of GC.

Harvest of at Least 23 Lymph Nodes is Indispensable for Stage N3 Gastric Cancer Patients

BACKGROUND

The National Comprehensive Cancer Network (NCCN) recommends that at least 15 lymph nodes (LNs) be removed during radical gastrectomy. This study aims to investigate the optimal number of LNs resected for radical gastrectomy.

PATIENTS AND METHODS

From September 2008 to March 2015, a total of 1990 gastric cancer patients were enrolled in this study. Clinicopathological features and survivals were recorded, and the association between the number of LNs resected and the prognosis of gastric cancer were analyzed.

RESULTS

Overall, 1520 males (76.4%) and 470 females (23.6%) were included in the study, with a median age of 57 years (range 20-90). The median number of LNs resected was 24 (range 15-83) for stage N1, 25 (range 15-62) for stage N2, 25 (range 15-88) for stage N3a, and 28 (range 16-73) for stage N3b. The optimal cut-off value for the number of LNs resected was 22 for stage N3a (p = 0.000) and N3b (p = 0.003) patients, while no other cut-off value was significantly superior to 15 for stage N1-2 patients (both p > 0.05). Age, tumor size, tumor depth, and number of LNs resected were independent prognostic predictors for stage N3a patients, while resection type and number of LNs resected were independent prognostic predictors for stage N3b patients. Removing more than 22 LNs exhibited a significant survival benefit compared with removing 15-22 LNs for stage N3a and N3b patients (29.7 vs. 21.6%, p = 0.000; 12.9% vs. 0%, p = 0.003, respectively).

CONCLUSION

Removing at least 23 LNs could yield better survival outcomes in stage N3 gastric cancer patients.

Positive Lymph Node Ratio as an Indicator of Prognosis and Local Tumor Clearance in N3 Gastric Cancer

BACKGROUND

Nodal metastasis is an important clinical issue in gastric cancer patients. This study was designed to investigate the clinical usefulness of the positive lymph node ratio (PLNR), which reflects both metastatic and retrieved lymph node numbers, in patients with pN3 gastric cancer.

METHODS

We retrospectively analyzed the records of 138 consecutive pN3 patients who underwent curative gastrectomy with lymphadenectomy from 2000 to 2012.

RESULTS

A PLNR of 0.4 was proved to be the best cutoff value to stratify the prognosis of patients with pN3 gastric cancer (P < 0.001). Univariate and multivariate analyses revealed that older age, larger tumor size (≥10 cm), and PLNR ≥ 0.4 [P < 0.001, HR 3.1 (95 % CI 1.7-5.4)] were independent prognostic factors in pN3 gastric cancer. Regarding the recurrence, patients with PLNR <0.4 had a significantly lower rate of lymph node recurrence than those with PLNR ≥0.4 (P = 0.020). There was no significant difference in the lymph node recurrence rate between N3a and N3b patients in the PLNR <0.4 group [P = 0.546, 11.6 % (7/60) vs. 12.5 (1/8)], indicating a better local control regardless of pN3 subgroups.

CONCLUSIONS

PLNR is useful to stratify the prognosis and evaluate the extent of local tumor clearance in pN3 gastric cancer.