Distinct Differences in Gastroesophageal Junction and Gastric Adenocarcinoma in 2194 Patients: In Memory of Rebecca A. Carr, February 24, 1988-January 19, 2021

Risk Factors of Lymph Node Metastasis and Prognosis in 891 Chinese Patients With Submucosal Early Gastric Carcinoma, Emphasizing Differences Between Gastric Cardiac and Noncardiac Origins

Differences in risk factors (RF) of lymph node metastasis (LNM) and prognosis between submucosal early gastric cardiac (SEGCC) and noncardiac (SEGNCC) carcinomas remain unclear. In this study, we investigated and compared RF of LNM and prognosis in 891 patients with radical gastrectomy for SEGCC (n=217) or SEGNCC (n=674). Compared with SEGNCC, SEGCC displayed significantly higher proportion of elderly patients (70 y or above), the elevated macroscopic type, well/moderately differentiated tubular and low-grade papillary adenocarcinomas, as well as low-grade tumor budding, but lower prevalence of the depressed macroscopic type, poorly differentiated tubular adenocarcinoma, mixed adenocarcinoma, poorly cohesive carcinoma, lymphovascular invasion (LVI), perineural invasion, and high-grade tumor budding. By univariate analysis, significant RF for LNM of the cohort included female sex, poor differentiation, SM2 invasion, LVI, intermediate-grade and high-grade tumor budding, whereas tumor size, histology type, and perineural invasion were the significant RF for LNM in SEGNCC. By multivariate analysis, significant independent RF for LNM included female sex and LVI in SEGCC but were female sex, mixed adenocarcinoma, LVI, and high-grade tumor budding in SEGNCC. The 5-year overall survival was significantly worse in SEGCC than in SEGNCC for patients with LNM, but not for those without. For overall survival, LNM was the only significant independent RF in SEGCC, whereas age 70 years or above and LNM were independent RF in SEGNCC. The results of our study provided the clinicopathologic evidence for individualized clinical management strategies for these 2 groups of patients and suggested different pathogenesis mechanisms between SEGCC and SEGNCC.

Peritoneal Tumor DNA as a Prognostic Biomarker in Gastric Cancer: A Systematic Review and Meta-Analysis

PURPOSE

Gastric cancers commonly spread to the peritoneum. Its presence significantly alters patient prognosis and treatment-intent; however, current methods of peritoneal staging are inaccurate. Peritoneal tumor DNA (ptDNA) is tumor-derived DNA detectable in peritoneal lavage fluid. ptDNA positivity may indicate peritoneal micrometastasis and may be more sensitive than cytology in staging the peritoneum. In this meta-analysis, we evaluated the prognostic potential of ptDNA in gastric cancer.

METHODS

PubMed, Embase, Scopus, and Web of Science databases were searched using PRISMA guidelines. Studies published between January 1, 1990, and April 30, 2023, containing quantitative data relating to ptDNA in gastric cancer were meta-analyzed.

RESULTS

Six studies were analyzed. Of the total 757 patients with gastric adenocarcinoma, 318 (42.0%) were stage I, 311 (41.0%) were stage II/III, 116 (15.3%) were stage IV, and 22 (2.9%) were undetermined. Overall, ptDNA detected cytology-positive cases with a sensitivity and specificity of 85.2% (95% CI, 66.5 to 100.0) and 91.5% (95% CI, 86.5 to 96.6), respectively. Additionally, ptDNA was detected in 54 (8.5%) of 634 cytology-negative patients. The presence of ptDNA negatively correlated with pathological stage I (relative risk [RR], 0.29 [95% CI, 0.13 to 0.66]) and positively correlated with pathological stage IV (RR, 8.61 [95% CI, 1.86 to 39.89]) disease. Importantly, ptDNA positivity predicted an increased risk of peritoneal-specific metastasis (RR, 13.81 [95% CI, 8.11 to 23.53]) and reduced 3-year progression-free (RR, 5.37 [95% CI, 1.39 to 20.74]) and overall (hazard ratio, 4.13 [95% CI, 1.51 to 11.32]) survival.

CONCLUSION

ptDNA carries valuable prognostic information and can detect peritoneal micrometastases in patients with gastric cancer. Its clinical utility in peritoneal staging for gastric cancer deserves further investigation.

Comparative single-cell analysis reveals heterogeneous immune landscapes in adenocarcinoma of the esophagogastric junction and gastric adenocarcinoma

Adenocarcinoma of the esophagogastric junction (AEG) is a type of tumor that arises at the anatomical junction of the esophagus and stomach. Although AEG is commonly classified as a subtype of gastric adenocarcinoma (GAC), the tumor microenvironment (TME) of AEG remains poorly understood. To address this issue, we conducted single-cell RNA sequencing (scRNA-seq) on tumor and adjacent normal tissues from four AEG patients and performed integrated analysis with publicly available GAC single-cell datasets. Our study for the first time comprehensively deciphered the TME landscape of AEG, where heterogeneous AEG malignant cells were identified with diverse biological functions and intrinsic malignant nature. We also depicted transcriptional signatures and T cell receptor (TCR) repertoires for T cell subclusters, revealing enhanced exhaustion and reduced clone expansion along the developmental trajectory of tumor-infiltrating T cells within AEG. Notably, we observed prominent enrichment of tumorigenic cancer-associated fibroblasts (CAFs) in the AEG TME compared to GAC. These CAFs played a critical regulatory role in the intercellular communication network with other cell types in the AEG TME. Furthermore, we identified that the accumulation of CAFs in AEG might be induced by malignant cells through FGF-FGFR axes. Our findings provide a comprehensive depiction of the AEG TME, which underlies potential therapeutic targets for AEG patient treatment.

The prognostic impact of peritoneal tumour DNA in gastrointestinal and gynaecological malignancies: a systematic review

Peritoneal metastases from various abdominal cancer types are common and carry poor prognosis. The presence of peritoneal disease upstages cancer diagnosis and alters disease trajectory and treatment pathway in many cancer types. Therefore, accurate and timely detection of peritoneal disease is crucial. The current practice of diagnostic laparoscopy and peritoneal lavage cytology (PLC) in detecting peritoneal disease has variable sensitivity. The significant proportion of peritoneal recurrence seen during follow-up in patients where initial PLC was negative indicates the ongoing need for a better diagnostic tool for detecting clinically occult peritoneal disease, especially peritoneal micro-metastases. Advancement in liquid biopsy has allowed the development and use of peritoneal tumour DNA (ptDNA) as a cancer-specific biomarker within the peritoneum, and the presence of ptDNA may be a surrogate marker for early peritoneal metastases. A growing body of literature on ptDNA in different cancer types portends promising results. Here, we conduct a systematic review to evaluate the prognostic impact of ptDNA in various cancer types and discuss its potential future clinical applications, with a focus on gastrointestinal and gynaecological malignancies.