Gastric Cancer最新文献

Background: Gastric neuroendocrine carcinomas (NECs) are rare cancers with highly aggressive behavior. Although tertiary lymphoid structures (TLSs) are well-known prognostic factors in various cancers, their role in gastric NECs remain unexplored. Unique immunohistochemical subtypes of pulmonary NECs have been discovered, however, their feasibility in gastric NECs is unknown.

Methods: The presence and maturation of TLSs (lymphoid aggregates, primary and secondary follicles) were assessed in 48 surgically resected gastric NECs and were compared with immunohistochemical subtypes, using a panel of ASCL1, NeuroD1, POU2F3, YAP1, and DLL3 with three neuroendocrine (NE) markers.

Results: Patients with secondary follicles had significantly better overall survival (OS) and recurrence-free survival (RFS; both, p = 0.004) than those without them. Based on the hierarchical clustering, gastric NECs were classified into all low/negative (31%), high-YAP1 (19%), high-DLL3/low-NE (29%), and high-NE (21%) expression groups. The high-DLL3/low-NE group was associated with absent TLSs (p = 0.026) and showed the worst OS (p = 0.026). Distant metastasis and a lack of secondary follicles were poor independent prognostic factors of OS and RFS.

Conclusion: The assessment of TLSs is a feasible and potent biomarker for gastric NECs, thus enabling better prognosis and more effective immunotherapy. Furthermore, gastric NECs can be categorized as four immunohistochemically distinct groups, of which the high-DLL3/low-NE group has the worst OS with lack of TLSs.

Background: Gastric cancer is a common malignancy with a high incidence in East Asia. Gastric resection ranges from endoscopic resection to open total gastrectomy. However, nationwide data are lacking.

Methods: This observational study analyzed data from the publicly accessible National Database of Health Insurance Claims and Specific Health Checkups, which includes most national health insurance claims data in Japan. Trends in the types of resection performed for malignant gastric tumors between 2014 and 2021, patients' age and sex distributions, and regional disparities were investigated.

Results: The annual number of resections was highest in 2015 (109,000) and lowest in 2020 (90,000) after the COVID-19 pandemic. The proportion of endoscopic resections increased from 47% in 2014 to 57% in 2021 while that of total gastrectomies decreased from 17 to 10%. In 2021, 70% of patients who underwent resection were men. That year, 83.8% of all patients who underwent any type of gastric resection and 87.1% of those who underwent endoscopic submucosal dissection were aged ≥ 65 years. The annual incidence of gastric resection per million population was highest in Tottori (n = 1236) and lowest in Okinawa (n = 251). The proportion of endoscopic resections was highest in Miyagi (66%) and lowest in Aichi (45%) and that of open surgery was highest in Aomori (36%) and lowest in Wakayama (5%).

Conclusions: Gastric malignancy is increasingly treated by endoscopic submucosal dissection rather than open total gastrectomy. However, regional disparities remain in resection type. Standardization of treatment and a more even distribution of specialists are needed.

Background

Lipolysis-stimulated lipoprotein receptor (LSR), a lipid receptor, is associated with cancer progression. However, detailed effects on intracellular metabolism are unclear. We aimed to elucidate the mechanism of LSR-mediated lipid metabolism in gastric cancer.

Methods

We investigated lipid metabolic changes induced by lipoprotein administration in gastric cancer cells and evaluated the significance of LSR expression and lipid droplets formation in gastric cancer patients. The efficacy of inhibiting β-oxidation in gastric cancer cells was also examined in vitro and vivo.

Results

In gastric cancer cells, LSR promoted cellular uptake of lipoprotein and cell proliferation. Furthermore, the inhibition of LSR in gastric cancer cells expressing high levels of LSR counteracted both effects. Immunohistochemical analysis of human gastric cancer tissues showed that the increase in lipid droplets via LSR is a factor that influences prognosis. Lipidomics analysis of LSR-high-expressing gastric cancer cells revealed an increase in β-oxidation. Based on these results, we used etomoxir, a β-oxidation inhibitor, and found that it inhibited cell proliferation as well as the suppression of LSR. Similarly, in a mouse xenograft model of LSR-highly expressing gastric cancer cells, the tumor growth effect of high-fat diet feeding was counteracted by etomoxir, consistent with the Ki-67 labeling index.

Conclusions

We demonstrated that lipids are taken up into gastric cancer cells via LSR and cause an increase in β-oxidation, resulting in the promotion of cancer progression. Controlling LSR-mediated lipid metabolism may be a novel therapeutic strategy for gastric cancer.

The article by Shin et al. provides valuable insights into the correlation between the gastric mucosa-associated gastric microbiome (MAM) and metachronous recurrence. However, the use of the Cox proportional hazards model in their analysis presents several limitations. The study may result in mixed censoring outcomes, and the assumption of constant hazard ratios over time may not hold. Considering these limitations, future research should adopt alternative approaches, such as the accelerated failure time (AFT) model, to provide a more comprehensive understanding of the relationship between gastric MAM and metachronous recurrence.

Background

Accurate prediction of peritoneal recurrence for gastric cancer (GC) is crucial in clinic. The collagen alterations in tumor microenvironment affect the migration and treatment response of cancer cells. Herein, we proposed multitask machine learning-based tumor-associated collagen signatures (TACS), which are composed of quantitative collagen features derived from multiphoton imaging, to simultaneously predict peritoneal recurrence (TACS_PR) and disease-free survival (TACS_DFS).

Methods

Among 713 consecutive patients, with 275 in training cohort, 222 patients in internal validation cohort, and 216 patients in external validation cohort, we developed and validated a multitask machine learning model for simultaneously predicting peritoneal recurrence (TACS_PR) and disease-free survival (TACS_DFS). The accuracy of the model for prediction of peritoneal recurrence and prognosis as well as its association with adjuvant chemotherapy were evaluated.

Results

The TACS_PR and TACS_DFS were independently associated with peritoneal recurrence and disease-free survival in three cohorts, respectively (all P < 0.001). The TACS_PR demonstrated a favorable performance for peritoneal recurrence in all three cohorts. In addition, the TACS_DFS also showed a satisfactory accuracy for disease-free survival among included patients. For stage II and III diseases, adjuvant chemotherapy improved the survival of patients with low TACS_PR and low TACS_DFS, or high TACS_PR and low TACS_DFS, or low TACS_PR and high TACS_DFS, but had no impact on patients with high TACS_PR and high TACS_DFS.

Conclusions

The multitask machine learning model allows accurate prediction of peritoneal recurrence and survival for GC and could distinguish patients who might benefit from adjuvant chemotherapy.

Undifferentiated gastric carcinoma, characterized by anaplastic cells lacking distinct features of cytological or architectural differentiation, poses diagnostic and therapeutic challenges. Recent studies have suggested an association between this carcinoma and deficiencies in the SWI/SNF complex, particularly mutations in subunits such as SMARCA4. We herein report six cases of SMARCA4-deficient undifferentiated gastric carcinoma with molecular findings, highlighting the rarity and diagnostic pitfalls of this malignancy. Predominantly occurring in males over 50 years, these cases presented with nonspecific symptoms and were often diagnosed at an advanced stage. Histologically, the tumors exhibited a sheet-like growth pattern, reduced or absent epithelial markers, and loss of BRG-1 expression, with molecular analysis confirming SMARCA4 gene mutations. The response to conventional chemotherapy was poor, underscoring the importance of complete surgical resection and the development of alternative treatment modalities.

Background: The CDKN2A gene is frequently affected by somatic copy number variations (SCNVs, including deletions and amplifications [SCNdel and SCNamp]) in the cancer genome. Using surgical gastric margin tissue samples (SMs) as the diploid reference in SCNV analysis via CDKN2A/P16-specific real-time PCR (P16-Light), we previously reported that the CDKN2A SCNdel was associated with a high risk of metastasis of gastric carcinoma (GC). However, the status of CDKN2A SCNVs in SMs and their clinical significance have not been reported.

Methods: Peripheral white blood cell (WBC) and frozen GC and SM tissue samples were collected from patients (n = 80). Droplet digital PCR (ddPCR) was used to determine the copy number (CN) of the CDKN2A gene in tissue samples using paired WBCs as the diploid reference.

Results: A novel P16-ddPCR system was initially established with a minimal proportion (or limit, 10%) of the detection of CDKN2A CN alterations. While CDKN2A SCNamp events were detected in both SMs and GCs, fewer CDKN2A SCNdel events were detected in SMs than in GCs (15.0% vs. 41.3%, P = 4.77E-04). Notably, significantly more SCNamp and fewer SCNdel of the CDKN2A gene were detected in SMs from GC patients without metastasis than in those from patients with lymph node metastasis by P16-ddPCR (P = 0.023). The status of CDKN2A SCNVs in SM samples was significantly associated with overall survival (P = 0.032). No cancer deaths were observed among the 11 patients with CDKN2A SCNamp.

Conclusion: CDKN2A SCNVs in SMs identified by P16-ddPCR are prevalent and significantly associated with GC metastasis and overall survival.

Background: Robot-assisted minimally invasive gastrectomy (RAMIG) is increasingly used as a surgical approach for gastric cancer. This study assessed the effectiveness of RAMIG and studied which stages of the IDEAL-framework (1 = Idea, 2A = Development, 2B = Exploration, 3 = Assessment, 4 = Long-term follow-up) were followed.

Methods: The Cochrane Library, Embase, Pubmed, and Web of Science were searched for studies on RAMIG up to January 2023. Data collection included the IDEAL-stage, demographics, number of participants, and study design. For randomized controlled trials (RCTs) and long-term studies, data on intra-, postoperative, and oncologic outcomes, survival, and costs of RAMIG were collected and summarized.

Results: Of the 114 included studies, none reported the IDEAL-stage. After full-text reading, 18 (16%) studies were considered IDEAL-2A, 75 (66%) IDEAL-2B, 4 (4%) IDEAL-3, and 17 (15%) IDEAL-4. The IDEAL-stages were followed sequentially (2A-4), with IDEAL-2A studies still ongoing. IDEAL-3 RCTs showed lower overall complications (8.5-9.2% RAMIG versus 17.6-19.3% laparoscopic total/subtotal gastrectomy), equal 30-day mortality (0%), and equal length of hospital stay for RAMIG (mean 5.7-8.5 days RAMIG versus 6.4-8.2 days open/laparoscopic total/subtotal gastrectomy). Lymph node yield was similar across techniques, but RAMIG incurred significantly higher costs than laparoscopic total/subtotal gastrectomy ($13,423-15,262 versus $10,165-10,945). IDEAL-4 studies showed similar or improved overall/disease-free survival for RAMIG.

Conclusion: During worldwide RAMIG implementation, the IDEAL-framework was followed in sequential order. IDEAL-3 and 4 long-term studies showed that RAMIG is similar or even better to conventional surgery in terms of hospital stay, lymph node yield, and overall/disease-free survival. In addition, RAMIG showed reduced postoperative complication rates, despite higher costs.

Background: In the FIGHT study (NCT03694522) bemarituzumab, a humanized monoclonal antibody selective for fibroblast growth factor receptor 2b (FGFR2b), plus mFOLFOX6 showed clinically meaningful efficacy in patients with FGFR2b-positive (2+/3+ membranous staining by immunohistochemistry) locally advanced unresectable/metastatic gastric/gastroesophageal cancer (G/GEJC). A meaningful proportion of patients in FIGHT were enrolled in East Asia, reflecting global epidemiology of G/GEJC.

Methods: This subgroup analysis of the global, phase 2, double-blind FIGHT study included all patients enrolled in East Asian sites. Patients were randomized 1:1 to bemarituzumab-mFOLFOX6 (15 mg/kg and one 7.5 mg/kg dose on cycle 1, day 8) or matching placebo-mFOLFOX6. The primary endpoint was investigator-assessed progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate, and safety. Efficacy was evaluated after a minimum follow-up of 24 months.

Results: The East Asian subgroup comprised 89 patients (57% of overall study population); 45 were randomized to bemarituzumab-mFOLFOX6 and 44 to placebo-mFOLFOX6. Median PFS (95% confidence interval [CI]) was 12.9 months (8.8-17.9) with bemarituzumab-mFOLFOX6 and 8.2 months (5.6-10.3) with placebo-mFOLFOX6 (HR 0.50, 95% CI 0.29-0.87); median OS (95% CI) was 24.7 months (13.8-33.1) vs 12.9 months (9.3-21.4), respectively (HR 0.56, 95% CI 0.32-0.96). Treatment benefit was more pronounced in patients with FGFR2b-positive G/GEJC in ≥ 10% of tumor cells. No new safety signals were reported.

Conclusion: In East Asian patients with FGFR2b-positive advanced/metastatic G/GEJC enrolled in the global FIGHT study, bemarituzumab-mFOLFOX6 showed clinically meaningful outcomes over placebo-mFOLFOX6.

Background: The contribution of the tumor microenvironment and extracellular matrix to the aggressive biology of Gastric Cancer (GC) has been recently characterized; however, the role of EMILIN-1 in this context is unknown. EMILIN-1 is an essential structural element for the maintenance of lymphatic vessel (LV) integrity and displays anti-proliferative properties as demonstrated in skin and colon cancer. Given the key role of LVs in GC progression, the aim of this study was to investigate the role of EMILIN-1 in GC mouse models.

Methods: We used the syngeneic YTN16 cells which were injected subcutaneously and intraperitoneally in genetically modified EMILIN-1 mice. In alternative, carcinogenesis was induced using N-Methyl-N-nitrosourea (MNU). Mouse-derived samples and human biopsies were analyzed by IHC and IF to the possible correlation between EMILIN-1 expression and LV pattern.

Results: Transgenic mice developed tumors earlier compared to WT animals. 20 days post-injection tumors developed in EMILIN-1 mutant mice were larger and displayed a significant increase of lymphangiogenesis. Treatment of transgenic mice with MNU associated with an increased number of tumors, exacerbated aggressive lesions and higher levels of LV abnormalities. A significant correlation between the levels of EMILIN-1 and podoplanin was detected also in human samples, confirming the results obtained with the pre-clinical models.

Conclusions: This study demonstrates for the first time that loss of EMILIN-1 in GC leads to lymphatic dysfunction and proliferative advantages that sustain tumorigenesis, and assess the use of our animal model as a valuable tool to verify the fate of GC upon loss of EMILIN-1.