Greater Lymph Node Retrieval Improves Survival in Node-Negative Resected Gastric Cancer in the United States

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.

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.

The minimum number of examined lymph nodes was 24 for optimal survival of pathological T2-4 gastric cancer: a multi-center, hospital-based study covering 20 years of data

INTRODUCTION

The current National Comprehensive Cancer Network (NCCN) guidelines recommend that at least 16 lymph nodes should be examined for gastric cancer patients to reduce staging migration. However, there is still debate regarding the optimal management of examined lymph nodes (ELNs) for gastric cancer patients. In this study, we aimed to develop and test the minimum number of ELNs that should be retrieved during gastrectomy for optimal survival in patients with gastric cancer.

METHODS

We used the restricted cubic spline (RCS) to identify the optimal threshold of ELNs that should be retrieved during gastrectomy based on the China National Cancer Center Gastric Cancer (NCCGC) database. Northwest cohort, which sourced from the highest gastric cancer incidence areas in China, was used to verify the optimal cutoff value. Survival analysis was performed via Kaplan-Meier estimates and Cox proportional hazards models.

RESULTS

In this study, 12,670 gastrectomy patients were included in the NCCGC cohort and 4941 patients in the Northwest cohort. During 1999-2019, the average number of ELNs increased from 17.88 to 34.45 nodes in the NCCGC cohort, while the number of positive lymph nodes remained stable (5-6 nodes). The RCS model showed a U-curved association between ELNs and the risk of all-cause mortality, and the optimal threshold of ELNs was 24 [Hazard ratio (HR) = 1.00]. The ELN ≥ 24 group had a better overall survival (OS) than the ELN < 24 group clearly (P = 0.003), however, with respect to the threshold of 16 ELNs, there was no significantly difference between the two groups (P = 0.101). In the multivariate analysis, ELN ≥ 24 group was associated with improved survival outcomes in total gastrectomy patients [HR = 0.787, 95% confidence interval (CI): 0.711-0.870, P < 0.001], as well as the subgroup analysis of T2 patients (HR = 0.621, 95%CI: 0.399-0.966, P = 0.035), T3 patients (HR = 0.787, 95%CI: 0.659-0.940, P = 0.008) and T4 patients (HR = 0.775, 95%CI: 0.675-0.888, P < 0.001).

CONCLUSION

In conclusion, the minimum number of ELNs for optimal survival of gastric cancer with pathological T2-4 was 24.

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.

Survival Outcome of Gastric Signet Ring Cell Carcinoma Based on the Optimal Number of Examined Lymph Nodes: A Nomogram- and Machine-Learning-Based Approach

The optimal number of examined lymph nodes (ELNs) for gastric signet ring cell carcinoma recommended by National Comprehensive Cancer Network guidelines remains unclear. This study aimed to determine the optimal number of ELNs and investigate its prognostic significance. In this study, we included 1723 patients diagnosed with gastric signet ring cell carcinoma in the Surveillance, Epidemiology, and End Results database. X-tile software was used to calculate the cutoff value of ELNs, and the optimal number of ELNs was found to be 32 for adequate nodal staging. In addition, we performed propensity score matching (PSM) analysis to compare the 1-, 3-, and 5-year survival rates; 1-, 3-, and 5-year survival rates for total examined lymph nodes (ELNs < 32 vs. ELNs ≥ 32) were 71.7% vs. 80.1% (p = 0.008), 41.8% vs. 51.2% (p = 0.009), and 27% vs. 30.2% (p = 0.032), respectively. Furthermore, a predictive model based on 32 ELNs was developed and displayed as a nomogram. The model showed good predictive ability performance, and machine learning validated the importance of the optimal number of ELNs in predicting prognosis.

Adjuvant Chemotherapy in Node-Negative Advanced Gastric Cancer Patients

Currently, there is still controversy on postoperative adjuvant chemotherapy for node-negative advanced gastric cancer. Herein, we sought to evaluate the role of postoperative adjuvant chemotherapy in these patients. We retrospectively analyzed the clinical and pathological characteristics of 363 node-negative advanced gastric cancer patients in our hospital from 1996 to 2007 who underwent gastrectomy and D2 lymphadenectomy. We compared the survival rate of the surgery-only group with that of the adjuvant chemotherapy treatment group. The 5-year survival rates of patients in the surgery-only group and the chemotherapy treatment group were 70.7% and 73.8%, respectively. There was no significant difference in the survival rate between patients receiving postoperative chemotherapy and patients not receiving chemotherapy (P=0.328). However, postoperative chemotherapy treatment significantly increased the survival rate of pT4aN0M0 patients (P=0.020), although it did not exert a direct effect on the survival rate in pT2N0M0 and pT3N0M0 patients (P=0.990 and P=0.895). We also summarized and analyzed the side effects and safety of postoperative adjuvant chemotherapy. The rate of chemotherapy-related adverse events was 79.9%. Although 61 (36.1%) patients had to adjust their chemotherapy dose, no patient died from side effects. In conclusion, postoperative chemotherapy treatment is safe but did not show a direct impact on the survival rate of the node-negative advanced gastric cancer patients. However, pT4aN0M0 patients can benefit from postoperative adjuvant chemotherapy after undergoing D2 radical resections.

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.

Lymph Node Evaluation after Neoadjuvant Chemotherapy for Patients with Gastric Cancer

BACKGROUND

Adequate lymphadenectomy with at least 16 nodes retrieved at the time of gastrectomy is a quality measure recommended to ensure adequate staging. The minimum nodal retrieval recommended after receipt of neoadjuvant chemotherapy (NACT) is less defined.

METHODS

Patients with clinical stages 1 to 3 gastric adenocarcinoma who received NACT and surgical resection were identified from the 2004-2015 National Cancer Database. The optimal nodal harvest number was calculated with Cox spline regression modeling. Cohorts with a nodal harvest higher or lower than this number were 1:1 propensity score-matched. Overall survival (OS) was analyzed using Kaplan-Meier survival estimates.

RESULTS

Among 4337 patients receiving NACT, the optimal minimal nodal harvest at gastrectomy was 23 nodes. Compared with the patients who had fewer than 23 nodes retrieved, the patients with at least 23 nodes examined (n = 1073, 24.7%) were more likely to be female (26.1% vs 22%; p = 0.006) and non-white (29.3% vs 18.5%; p < 0.0001), to have a Charlson-Deyo score of 0 (71.5% vs 66.8%; p = 0.005), and to have undergone resection at an academic facility (67.9% vs 51.5%; p < 0.0001). The patients with at least 23 nodes examined had higher proportions of high-grade tumor (62% vs 57.4%; p = 0.030), pT3 or pT4 tumor (56.3% vs 48.7%; p < 0.0001), body tumor (21.3% vs 12.5%; p < 0.0001), or antrum/pylorus tumor (15.3% vs 11.4%; p < 0.0001). The patients with at least 23 nodes were more likely to have lymph node metastases identified (61% vs 51%; p < 0.0001). After matching, the patients with at least 23 nodes (n = 990) demonstrated an improved 5-year OS (57.9% vs 49%; p = 0.001).

CONCLUSIONS

The extent of lymphadenectomy during gastrectomy for gastric adenocarcinoma should not be reduced after NACT because adequate lymph node retrieval remains important for prognostication.

Textbook Outcome as a measure of surgical quality assessment and prognosis in gastric neuroendocrine carcinoma: A large multicenter sample analysis

OBJECTIVE

Quality assurance is crucial for oncological surgical treatment assessment. For rare diseases, single-quality indicators are not enough. We aim to develop a comprehensive and reproducible measurement, called the "Textbook Outcome" (TO), to assess the quality of surgical treatment and prognosis of gastric neuroendocrine carcinoma (G-NEC) patients.

METHODS

Data from patients with primary diagnosed G-NEC included in 24 high-volume Chinese hospitals from October 2005 to September 2018 were analyzed. TO included receiving a curative resection, ≥15 lymph nodes examined, no severe postoperative complications, hospital stay ≤21 d, and no hospital readmission ≤30 d after discharge. Hospital variation in TO was analyzed using a case mix-adjusted funnel plot. Prognostic factors of survival and risk factors for non-Textbook Outcome (non-TO) were analyzed using Cox and logistic models, respectively.

RESULTS

TO was achieved in 56.6% of 860 G-NEC patients. TO patients had better overall survival (OS), disease-free survival (DFS), and recurrence-free survival (RFS) than non-TO patients (P<0.05). Moreover, TO patients accounted for 60.3% of patients without recurrence. Multivariate Cox analysis revealed non-TO as an independent risk factor for OS, DFS, and RFS of G-NEC patients (P<0.05). Increasing TO rates were associated with improved OS for G-NEC patients, but not hospital volume. Multivariate logistic regression revealed that non-lower tumors, open surgery, and >200 mL blood loss were independent risk factors for non-TO patients (P<0.05).

CONCLUSIONS

TO is strongly associated with multicenter surgical quality and prognosis for G-NEC patients. Factors predicting non-TO are identified, which may help guide strategies to optimize G-NEC outcomes.

Fluorescent lymphography during minimally invasive total gastrectomy for gastric cancer: an effective technique for splenic hilar lymph node dissection

BACKGROUND

Fluorescent lymphography is an excellent technique for complete lymph node dissection during minimally invasive surgery for gastric cancer. This study aimed to evaluate the role of fluorescent lymphography in splenic hilar lymph node dissection during minimally invasive total gastrectomy.

METHODS

We retrospectively analyzed 168 gastric cancer patients who underwent minimally invasive total gastrectomy with D2 + No. 10 lymph node dissection from 2013 to 2018. Fluorescent lymphography was used whenever it is possible. However, when near-infrared imaging system and endoscopic indocyanine green injection were not available, we performed surgery without fluorescent lymphography. A total of 74 patients underwent surgery with fluorescent lymphography (FL group) and 94 underwent surgery without it (non-FL group). Perioperative and long-term outcomes including the number of retrieved lymph nodes at each nodal station were compared between groups.

RESULTS

The median number of retrieved lymph nodes at the splenic hilum was larger in the FL group {2.5 [Interquartile range (IQR), 1-5]} than in the non-FL group [1 (IQR, 1-3); P = 0.012]. The negative predictive value of fluorescent lymphography for lymph node metastasis at the splenic hilum was 97.1%, although the sensitivity was 66.7%. The overall survival (FL: 96.9% vs. non-FL: 88.9%; P = 0.334) and relapse-free survival (FL: 90.5% vs. non-FL: 65.5%; P = 0.054) were higher in the FL group, although there were no statistical differences. However, among the patients without lymph node metastasis, the relapse-free survival was significantly higher in the FL group (100%) than in the non-FL group (67.1%; P = 0.017).

CONCLUSIONS

Fluorescent lymphography is an effective tool for complete lymph node dissection at the splenic hilum. Moreover, it may help select patients who do not need splenic hilar lymph node dissection during a total gastrectomy.

Retrospective Evaluation of Factors Affecting Lymph Node Retrieval Following Gastrectomies with Oncologic Intent

BACKGROUND

Adequate lymphadenectomy is an important factor affecting survival in gastric cancer patients. Retrieval and examination of at least 15 lymph nodes is recommended in order to properly stage gastric malignancies. The objectives of this study were to evaluate the proportion of patients undergoing inadequate lymphadenectomies and possible risk factors for inadequate surgery.

METHODS

This was a retrospective study that included patients, 18 years and older, who underwent gastrectomies with oncologic intent in the Hillel Yaffe Medical Center. We analyzed the association of demographic, clinical, and pathological variables with adequate number of lymph nodes.

RESULTS

The retrieval of less than 15 lymph nodes was reported in 51% (53/104) patients undergoing gastrectomies with oncologic intent. The extent of surgery was the only variable associated with inadequate lymphadenectomy on univariate analysis: subtotal/proximal versus total gastrectomy (P=0.047). Differences observed for previous surgery (P=0.193), T stage (P=0.053), N stage (P=0.051), and lymphovascular invasion (P=0.14) did not reach significance. Subtotal/proximal gastrectomy resulted in inadequate resection of lymph nodes in 56% of the patients, while this occurred in only 30% of the patients undergoing total gastrectomy (relative risk 1.865; 95% CI 0.93, 3.741). Logistic regression confirmed that only subtotal/proximal versus total gastrectomy was associated with inadequate number of lymph nodes resected (P=0.043).

DISCUSSION AND CONCLUSION

In this study we analyzed the association of patient, tumor, and surgery-related factors on adequate lymphadenectomy in patients undergoing gastrectomies for possible gastric cancer. Larger extent of the surgery (total, rather than subtotal/proximal gastrectomy) was revealed to be the only indicator positively associated with adequate lymphadenectomy.

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.

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.

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

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

A Simplified Two-Step Technique for Extended Lymphadenectomy During Resection of Gastroesophageal Malignancy: Early Results Compared to En Bloc Dissection

BACKGROUND

Extended lymph node dissection (ELND) remains an important component of curative intent resection of mid-stage gastric cancer (GC). Benefits include enhanced staging accuracy, extending regional disease control, and optimizing potential curability. ELND during gastrectomy remains underutilized in US centers due to a low prevalence of GC operations.

METHODS

The traditional en bloc ELND was modified into a two-step technique to facilitate greater ease of dissection with better exposure. After completion of the gastrectomy component, retrogastric nodes are dissected in a separate, contiguous specimen. Resulting data were compared to outcomes after en bloc resection.

RESULTS

Of 179 consecutive patients undergoing gastrectomy, 129 underwent an ELND (73%). There were 97 men and 32 women, with a median age of 64 years (range 24-98). The median total LN count was 25 (3-86). The two-step dissection yielded an average of 18.3 (± 8.5 S.D.) perigastric and 12.1 (± 5.8) retrogastric nodes. Two-step LND was associated with lower estimated blood loss (265 vs. 448 ml, p = 0.0005), lower transfusion requirements (6 vs. 28%, p = 0.007), greater mean total LN counts (30 vs. 26, p = 0.03), and a greater rate of obtaining at least 15 or 20 LNs (91 vs. 77% and 83 vs. 65%, p = 0.05). Major morbidity (overall 16%), length of stay, and survival outcomes were not different.

CONCLUSIONS

The two-step LND technique as described was found to be associated with favorable operative and postoperative outcome parameters and an excellent LN yield. It can be recommended for standard ELND indications in the absence of macroscopically abnormal LNs.

Pancreatic Cancer Lymph Node Resection Revisited: A Novel Calculation of Number of Lymph Nodes Required

BACKGROUND

Pancreatic cancer is the third leading cause of cancer related deaths in the US. Although lymph node (LN) metastasis is a prognostic indicator, the extent of LN resection is still debated. Our goal was to use the distribution of the ratio of positive to negative LNs to derive a more adequate number of necessary examined LNs based on the target LN threshold (TLNT).

STUDY DESIGN

Using the National Cancer Database, we performed a retrospective study of surgically resected pancreatic adenocarcinoma (2010 to 2015). We evaluated the number of positive LNs and total LNs examined and the log of the ratio of positive LNs to negative LNs (LODDS). The distribution of LODDS was examined to determine a target LNs examined threshold sufficient to detect N1 disease. Using the LODDS distribution of N1 cases, target LNs examined threshold were calculated to encompass 90 of the N1 group distribution.

RESULTS

Of the total 24,038 resected patients included in this study, 26% underwent operation only, 18% received neoadjuvant therapy, and 56% underwent adjuvant therapy. In all, 8,144 (34%) patients had N0 disease and 15,894 (66%) had N1 disease. To capture 90% to 95% of the N1 group, the minimum number of LNs examined would be 18 (LODDS -2.74) to 24 (LODDS -3.04), respectively.

CONCLUSIONS

Although previous studies have suggested 11 to 17 LNs required for adequate LN sampling in pancreatic cancer, our findings suggest that to capture 90% of cases with N1 disease, 18 LNs is more appropriate.

Comparison of gastric cancer survival after R0 resection in the US and China

BACKGROUND AND OBJECTIVES

Gastric cancer (GC) outcomes differ between Asian and Western countries, even when controlling for contributing factors, but whether this difference holds true for China remains inadequately studied. We sought to compare the presentation, treatment, and outcomes of patients with GC undergoing curative intent (R0) resection between the US and China, and to ascertain whether geography/ institution is an independent predictor of disease-specific survival (DSS).

METHODS

Data were analyzed from patients with GC undergoing R0 resection at high-volume cancer centers in the US (Memorial Sloan Kettering Cancer Center [MSKCC], n = 1378) and China (Fujian Medical University Union Hospital [FMUUH], n = 4262) between 2000 and 2014. Factors associated with DSS were examined by multivariate analysis.

RESULTS

The 5-year DSS ( P < 0.001) for all patients was better at MSKCC than at FMUUH, even among patients not receiving preoperative chemotherapy ( P < 0.001), but stratification by substage eliminated this difference ( P > 0.05). Factors independently associated with DSS included age, histology, tumor size, T category, N category, gastrectomy type, and preoperative chemotherapy, but not institution.

CONCLUSIONS

Although the presentation of patients with GC between MSKCC and FMUUH differs, survival of patients with curatively resected GC, when matched for clinical stage, is comparable.