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

Learning curve of laparoscopic and robotic total gastrectomy: A systematic review and meta-analysis

PURPOSE

Minimally-invasive total gastrectomy (MITG) is associated with lower morbidity in comparison to open total gastrectomy but requires a learning curve (LC). We aimed to perform a pooled analysis of the number of cases required to surmount the LC (NLC) in MITG.

METHODS

A systematic review of PubMed, Embase, Scopus and the Cochrane Library from inception until August 2022 was performed for studies reporting the LC in laparoscopic total gastrectomy (LTG) and/or robotic total gastrectomy (RTG). Poisson mean (95% confidence interval [CI]) was used to determine the NLC. Negative binomial regression was performed as a comparative analysis.

RESULTS

There were 12 articles with 18 data sets: 12 data sets (n = 1202 patients) on LTG and 6 data sets (n = 318 patients) on RTG. The majority of studies were conducted in East Asia (94.4%). The majority of the data sets (n = 12/18, 66.7%) used non-arbitrary analyses. The NLC was significantly smaller in RTG in comparison to LTG [RTG 20.5 (95% CI 17.0-24.5); LTG 43.9 (95% CI 40.2-47.8); incidence rate ratio 0.47, p < 0.001]. The NLC was comparable between totally-laparoscopic total gastrectomy (TLTG) and laparoscopic-assisted total gastrectomy (LATG) [LATG 39.0 (95% CI 30.8-48.7); TLTG 36.0 (95% CI 30.4-42.4)].

CONCLUSIONS

The LC for RTG was significantly shorter for LTG. However existing studies are heterogeneous.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pathological Nodal Staging Score for Gastric Signet Ring Cell Carcinoma: A Clinical Tool of Adequate Nodal Staging

Background: Gastric signet ring cell carcinoma (GSRCC) is a subset of gastric cancer with distinct histological and inconsistent prognosis outcome. Currently, the association between the adequate regional lymph node and proper nodal staging in GSRCC is rarely noticed. Materials and methods: Clinical data of GSRCC were retrieved from the Surveillance, Epidemiology, and End Results database. Beta-binomial distribution model was employed for the estimation of the probability of missing nodal disease, followed by the development of a nodal staging score (NSS). Results: A total of 561 GSRCC patients were included in this study, with 193 in lymph node-negative and 368 in lymph node-positive diagnoses. As the number of examined lymph nodes increased, the probability of missing nodal disease decreased rapidly, with T stage-specific curves. The probability of missing nodal disease in T4 was lower than that in T1. NSS calculation indicated that T1 stage patients commonly had NSS > 0.8. However, with the NSS of T2−T4 to reach 0.8, the number of examined lymph node was required to be larger than 12 in T2, 17 in T3 and 27 in T4. NSS ≥ 0.75 (quantile 75%) subgroup in T2−T4 subgroups tended to have better outcome; however, without significant prognostic value. Conclusions: NSS is served as a reliable and feasible tool in adequate nodal staging of GSRCC with statistical basis and provides further evidence for clinical decision making.

Preoperative CA19-9 is a prognostic factor in pT3N0 gastric cancer patients undergoing curative resection

BACKGROUND

The standard treatment for pT3N0 gastric cancer (GC) in Japanese guidelines is radical surgery without adjuvant chemotherapy. However, certain percentages of these patients develop recurrences; therefore, detecting the high-risk subgroup of recurrence may contribute to improve patient's outcome by adjuvant chemotherapy. In this study, we aimed to identify a predictive indicator of poor prognosis in pT3N0 GC.

METHODS

Eighty-one patients who were diagnosed as pT3N0 GC after curative surgical resection and had not received adjuvant chemotherapy were included. The clinicopathological factors and laboratory parameters were evaluated by univariate and multivariate analyses to identify prognostic factors of tumor recurrence. Survival analysis was performed by Kaplan-Meier method.

RESULTS

Male (P = 0.027), a high body mass index (BMI) (P = 0.031), a high CA19-9 value (P = 0.025), and a lower number of retrieved lymph nodes (P = 0.018) were found to be significantly associated with a shorter recurrence free survival (RFS). In a multivariate analysis, high CA19-9 value (> 37 U/ml) [(hazard ratio (HR): 3.326; 95% confidence interval (CI): 1.044 to 10.596; P = 0.042] was found to be an independent predictor of RFS.

CONCLUSION

The preoperative high CA19-9 value is considered a useful prognostic marker for predicting cancer recurrence after curative surgery in pT3N0 GC patients. For those patients, adjuvant chemotherapy might be considered to improve the survival outcome.

Revisiting the 8th AJCC system for gastric cancer: A review on validations, nomograms, lymph nodes impact, and proposed modifications

Gastric cancer is the fifth most frequently diagnosed cancer worldwide, behind breast, lung, colorectal, and prostate cancers. In gastric cancer, multimodality treatment shows prospective benefits and also improves survival. Surgery, however, is the mainstay of curative treatment. The staging of gastric cancer patients is critical for harmonization of care. Accurate stages assure that informed clinical decisions are timely made. The American Joint Committee on Cancer (AJCC) staging system is the most widely applied system in to determine the disease's prognosis and survival prediction. The recently adopted 8th AJCC TNM staging system has been revised to enhance its survival predictive power. Subsequent studies have established the validity of the current edition, demonstrating improved stage stratification, discriminatory power, and survival prediction. However, other studies have cast doubt on the superiority of the new edition. Innovations aimed at further improving its prognosis have resulted in developing of novel models. Advances in our understanding of the tumor microenvironment and molecular categorization of cancer have resulted in proposals for their inclusion in TNM staging as potential complementary factors that enhance survival prediction and prognostic assessment ability. The purpose of this study is to conduct a review of the published literature regarding the validity of the 8th AJCC TNM staging system, proposed modifications, and nomograms.

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The 8th AJCC is valid in prognostic stratification of gastric cancer, however, revisions are still required.

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The yPT staging requires some modifications and inclusion of stages that currently don't exist in the 8th AJCC.

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High lymph nodes count and anatomical localization improve the prediction ability of the current AJCC.

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Nomograms comprising of individual prognostic factors are crucial to the current AJCC.

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Molecular markers positively influence survival prediction of gastric cancer.