Development and validation of a staging system for gastric adenocarcinoma after neoadjuvant chemotherapy and gastrectomy with D2 lymphadenectomy

Development and evaluation of the Newstage system: integrating tumor regression grade and lymph node status for improved prognostication in neoadjuvant treatment of gastric cancer

BACKGROUND

The predictive correlation of tumor depth of invasion changes after neoadjuvant therapy, and the 8th American Joint Committee on Cancer (AJCC) ypTNM system for gastric cancer may not accurately predict patient prognosis following neoadjuvant therapy.

METHODS

A retrospective analysis was conducted on a total of 258 patients who underwent radical surgery for gastric cancer after neoadjuvant therapy. The Newstage system was established based on tumor regression grade and pathological lymph node status. The 3-year survival rates of patients classified by the Newstage system were compared with those classified by the AJCC ypTNM system.

RESULTS

In a cohort of 258 patients, the 3-year overall survival rates based on the Newstage system were: (I) 94.6%, (II) 79.3%, (III) 54.5%, and (IV) 30.2%. The Newstage system exhibited a lower Akaike information criterion value (902.57 vs. 912.03). Additionally, the area under the ROC curve (0.756 vs. 0.733) and the C-index (0.731 vs. 0.718) was higher than the AJCC ypTNM system. Furthermore, a multivariate analysis indicated that the Newstage system was an independent prognostic factor (p = 0.001).

CONCLUSION

The Newstage system exhibits superior predictive performance in estimating survival rates for neoadjuvant therapy in gastric cancer. It also functions as an independent prognostic factor.

Does the ypTNM-stage adequately predict long-term survival rates in gastric cancer patients receiving neoadjuvant chemotherapy followed by radical resection?

BACKGROUND

Following neoadjuvant chemotherapy (NAC) for resectable gastric cancer, the prognostic adequacy of the UICC staging system needs to be investigated. In particular to explore whether the ypTNM curves for radically resected gastric cancer patients receiving NAC follow the stage-matched survival curves of radically resected chemo-naïve patients (pTNM). Further, to disclose any interaction between the TNM-response mode to NAC and stage-specific survival rates, i.e., whether survival for a particular pathological disease stage was dependent on whether this was reached through a downstaging or as stable disease following NAC.

MATERIAL AND METHODS

Retrospective study on radically resected patients ≤ 75 years of age with gastric adenocarcinoma stages I-III diagnosed during 2001-2016. The patients constitute two population-based cohorts; the SURG-group with n = 121 patients treated before 2007 when NAC was introduced, and the NAC-group with n = 126 patients diagnosed since early 2007, receiving NAC and subsequent radical resection.

RESULTS

Long-term survival rates were similar when specific ypTNM-stages were compared to their corresponding pTNM chemo-naïve counterparts. The dichotomised N0 vs. N + had a substantial impact on the long-term survival rates in both groups, however, no discrepancy in long-term survival rates between pN0 vs. ypN0, and pN + vs. ypN + was found. The pathological stage determined long-term survival rates irrespective of the baseline disease stage, as no interaction between the response mode and stage-specific survival rates was found.

CONCLUSIONS

Survival curves for specific ypTNM-stages following NAC did not differ from the corresponding survival curves of their chemo-naïve pTNM counterparts. The interpretation is that NAC affected the gastric cancer, lymph nodes, and micrometastases, in such a way that the final ypTNM-stage provided similar prognostic information as the chemo-naïve pTNM-stages. Survival rates were contingent on the final ypTNM-stages alone, and not influenced by the response mode to reach that particular disease stage, or predetermined by the original clinical TNM-stage.

A Novel ypTLM Staging System Based on LODDS for Gastric Cancer After Neoadjuvant Therapy: Multicenter and Large-Sample Retrospective Study

BACKGROUND

The accuracy of the eighth AJCC ypTNM staging system on the prognosis of gastric cancer (GC) patients after neoadjuvant therapy (NAT) is controversial. This study aimed to develop and validate a novel staging system using the log odds of positive lymph nodes scheme (LODDS).

METHODS

A retrospective analysis of 606 GC patients who underwent radical gastrectomy after neoadjuvant therapy was conducted as the development cohort. (Fujian Medical University Affiliated Union Hospital (n = 183), Qinghai University Affiliated Hospital (n = 169), Mayo Clinic (n = 236), Lanzhou University First Hospital (n = 18)). The validation cohort came from the SEER database (n = 1701). A novel ypTLoddsS (ypTLM) staging system was established using the 3-year overall survival. The predictive performance of two systems was compared.

RESULTS

Two-step multivariate Cox regression analysis in both cohorts showed that ypTLM was an independent predictor of overall survival of GC patients after neoadjuvant therapy (HR: 1.57, 95% CI: 1.30-1.88, p < 0.001). In the development cohort, ypTLM had better discrimination ability than ypTNM (C-index: 0.663 vs 0.633, p < 0.001), better prediction homogeneity (LR: 97.7 vs. 70.9), and better prediction accuracy (BIC: 3067.01 vs 3093.82; NRI: 0.36). In the validation cohort, ypTLM had a better prognostic predictive ability (C-index: 0.614 vs 0.588, p < 0.001; LR: 11,909.05 vs. 11,975.75; BIC: 13,263.71 vs 13,328.24; NRI: 0.22). The time-dependent ROC curve shows that the predictive performance of ypTLM is better than ypTNM, and the analysis of the decision curve shows that ypTLM achieved better net benefits.

CONCLUSION

A LODDS-based ypTLM staging system based on multicenter data was established and validated. The predictive performance was superior to the eighth AJCC ypTNM staging system.

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.

Extent of gastrectomy and lymphadenectomy for gastric adenocarcinoma

Gastric adenocarcinoma is one of the most common and lethal cancers worldwide and is associated with a high frequency of nodal metastasis. The value of multimodality therapy is well-established, but gastric resection and locoregional lymph node dissection are important mainstays in potentially curative therapy. However, there has been considerable regional variation in surgical approach and debate regarding the ideal extent of gastric resection, gastric reconstruction, and extent of lymphadenectomy. This chapter outlines the current evidence in the surgical management of gastric adenocarcinoma. The advent of minimally invasive approaches to gastric operations is also discussed.

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

PURPOSES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

In Gastric Cancer Patients Receiving Neoadjuvant Chemotherapy Systemic Inflammation Response Index is a Useful Prognostic Indicator

Background: The preoperative systemic inflammation response index (SIRI), based on peripheral neutrophil (N), monocyte (M), and lymphocyte (L) counts, has shown mounting evidence as an effective prognostic indicator in some malignant tumors. The aim of the present study was to evaluate the prognostic significance of pre-treatment SIRI in gastric cancer patients who received neoadjuvant chemotherapy (NACT).

Methods: This retrospective study comprised 107 patients with advanced gastric cancer treated with NACT between July 2007 and September 2015 in our hospital. SIRI was calculated from peripheral venous blood samples obtained prior to treatment. The best cutoff value for SIRI by receiver operating characteristic (ROC) curve was 1.2 (low SIRI <1.21, high SIRI ≥1.21). The clinical outcomes of disease-free survival (DFS) and overall survival (OS) were analyzed by Kaplan-Meier survival analysis and compared using the log-rank test. Univariate and multivariate analyses were performed by the Cox proportional hazards regression model.

Results: The results demonstrated that the low SIRI group was statistically associated with gender, primary tumor site, white blood cell, neutrophil, and monocyte counts, NLR (neutrophil to lymphocyte ratio), MLR (monocyte to lymphocyte ratio), and PLR (platelet to lymphocyte ratio). The SIRI was predictive for DFS and OS by univariate and multivariate analysis; the low SIRI group had better median DFS and OS than the high SIRI group (median DFS 27.03 vs. 22.33 months, median OS 29.73 vs. 24.43 months). The DFS and OS in the low SIRI group were longer than the high SIRI group.

Conclusions: SIRI may qualify as a useful, reliable, and convenient prognostic indicator in patients with advanced gastric cancer to help physicians to provide personalized prognostication for gastric cancer patients treated with NACT.

Multidisciplinary treatment strategy for locally advanced gastric cancer: A systematic review

BACKGROUND

Multidisciplinary management of patients with locally advanced gastric cancer (LAGC) remains unstandardized worldwide. We performed a systemic review to summarize the advancements, regional differences, and current recommended multidisciplinary treatment strategies for LAGC.

METHODS

Eligible studies were identified through a comprehensive search of PubMed, Web of Science, Cochrane Library databases and Embase. Phase 3 randomized controlled trials which investigated survival of patients with LAGC who underwent gastrectomy with pre-/perioperative, postoperative chemotherapy, or chemoradiotherapy were included.

RESULTS

In total, we identified 11 studies of pre-/perioperative chemotherapy, 38 of postoperative chemotherapy, and 14 of chemoradiotherapy. In Europe and the USA, the current standard of care is perioperative chemotherapy for patients with LAGC using the regimen of 5-FU, folinic acid, oxaliplatin and docetaxel (FLOT). In Eastern Asia, upfront gastrectomy and postoperative chemotherapy is commonly used. The S-1 monotherapy or a regimen of capecitabine and oxaliplatin (CapOx) are used for patients with stage II disease, and the CapOx regimen or the S-1 plus docetaxel regimen are recommended for those with stage III Gastric cancer (GC). The addition of postoperative radiotherapy to peri- or postoperative chemotherapy is currently not recommended. Additionally, clinical trials testing targeted therapy and immunotherapy are increasingly performed worldwide.

CONCLUSIONS

Recent clinical trials showed a survival benefit of peri-over postoperative chemotherapy and chemoradiotherapy. As such, this strategy may have a potential as a global standard for patients with LAGC. Outcome of the ongoing clinical trials is expected to establish the global standard of multidisciplinary treatment strategy in patients with LAGC.

Indications of neoadjuvant chemotherapy for locally advanced Gastric Cancer patients based on pre-treatment clinicalpathological and laboratory parameters

Objective: There are controversial indications for neoadjuvant chemotherapy (NAT) in the treatment of locally advanced gastric cancer (LAGC). Here, we aimed to identify indications for NAT based on pre-treatment clinicopathological and laboratory parameters.

Methods: This study included a retrospective cohort of 1083 LAGC patients who had underwent radical D2 gastrectomy in the Cancer Hospital of China Medical University between 2012 and 2016. After propensity score matching, 756 patients were recruited and were separated into NAT (n=378) or primary surgery (PS) (n=378) groups. Cox regression identified pre-treatment risk factors for overall survival (OS). A nomogram was established to predict OS and calculate scores for risk factors. Recursive partitioning analysis (RPA) determined cut off values, where the entire patient cohort was divided into low and high risk groups.

Results: Seven risk factors that were significantly related to OS were incorporated in the nomogram. These risk factors included age, tumor size, tumor site, carbohydrate antigen 199 (CA199), carcino-embryonic antigen (CEA), clinical T stage (cT) and clinical N stage (cN). The model contained a C-index of 0.637. The calibration curve revealed anticipated values that were reflective of actual values. The decision curve revealed an achievement of optimal clinical impact when threshold possibility was 0-54%. Next, the cohort was split into low (≤ 252 points) or high (> 252 points) risk groups based on the 5-year OS projected by RPA. The PS group showed a worse OS compared to the NAT group for high-risk patients (P =0.004). There was no significant difference when comparing OS between the PS and NAT groups for low-risk patients (P =0.407).

Conclusions: A feasible, quantifiable and practical prognostic tool was generated to screen for potential survival benefits for patients receiving NAT. Surgeons can use this model to identify optimal treatment regimens for individualized treatment strategies during the diagnosis of LAGC patients. For these patients, NAT is suggested for high-risk patients.

Overexpression of COX-2 and clinicopathological features of gastric cancer: a meta-analysis

Background

To evaluate the correlation between COX-2 overexpression and clinicopathological features of gastric cancer, thus providing theoretical basis for anti-COX-2 targeted therapy.

Methods

The literature about COX-2 expression and gastric cancer was searched in PubMed, Wangfang, VIP, CNKI from the inception to September 2019, with “gastric cancer”, “COX-2”, “cyclooxygenase” as keywords. Stata 15.0 was used to analyze. Age, gender, differentiation, infiltration depth, lymph node metastasis, tumor size, TNM staging were analyzed by OR (95% CI).

Results

Nine studies involving 1,289 patients with gastric cancer were identified, among which 878 cases existed COX-2 overexpression. COX-2 overexpression was related to the infiltration depth (OR=1.76; 95% CI: 1.01–1.306; P<0.01) and lymph node metastasis (OR=3.08; 95% CI: 1.64–5.79; P<0.01). While, it was not related to age, gender, differentiation and tumor size.

Conclusions

COX-2 overexpression is valuable in predicting infiltration depth and lymph node metastasis, and could be a predictor of poor prognosis in gastric cancer. COX-2-targeted therapy can be considered as one of the comprehensive treatments for gastric cancer.