Intramural Component of Venous, Lymphatic, and Perineural Invasion in Colon Cancer: A Threat or an Illusion?

Background: Extramural venous invasion is an independent predictor of poor outcome in colorectal cancer, whereas the significance of the intramural component of venous and lymphatic and perineural invasion is unclear. Aims: To evaluate the prognostic impact of intramural components for venous, lymphatic, and perineural invasions and the relation of these invasion patterns with clinicopathological features in patients with colon cancer. Study Design: A retrospective cross-sectional study. Methods: The analysis included 626 patients with colon cancer in stages II and III. All patients were divided into four categories (no invasion, intramural invasion only, extramural invasion only, or both intramural and extramural invasions) for vascular invasion, lymphatic invasion and perineural invasion. The primary outcomes were 5-year disease-free and overall survival. Results: Right-sided (for vascular invasion, 24.7% vs. 33.9%, p = 0.007; for perineural invasion, 34.5% vs. 41.5%, p = 0.034) and dMMR tumors (for vascular invasion, 13.5% vs. 33.5, p < 0.001; for perineural invasion, 25% vs. 41.4%, p = 0.004) exhibited less venous and perineural invasion. Compared with no invasion, presence of intramural invasion only, did not exert any effect on disease-free or overall survival for vascular invasion, lymphatic invasion, and perineural invasion. Multivariate analyses revealed that the presence of both intramural and extramural invasion was independently associated with poor disease-free and overall survival for venous (hazard ratios: 2.39, p = 0.001; hazard ratios: 2.46, p = 0.001), lymphatic (hazard ratios: 2.456, p < 0.001; hazard ratios: 2.13, p = 0.02) and perineural invasion (hazard ratios: 2.99, p < 0.001; hazard ratios: 2.68, p < 0.001), respectively. Conclusion: Our data strongly advocates the importance of reporting intramural and extramural components of invasion since the presence of intramural invasion alone may not be considered as a high-risk factor for systemic recurrence.

Endoscopic ultrasound-guided liver biopsy using a 20-gauge fine needle biopsy needle with the wet-heparinized suction technique.

OBJECTIVES: The primary aim of this study was to evaluate the histological adequacy of the liver tissue specimens obtained with a 20-gauge fine-needle biopsy needle and the secondary aim was to test the safety endoscopic ultrasound-guided liver biopsy with a 20-gauge fine-needle biopsy needle with the wet-heparinized suction technique. METHODS: Forty patients who underwent endoscopic ultrasound-guided liver biopsy were included in the study. A 20-gauge fine-needle biopsy needle was used with the wet-heparinized suction technique to make one pass each from the left and the right lobe. Histologic characteristics of the specimens were evaluated, and patients were observed after the procedure in order to intervene in case of an adverse event. RESULTS: The median longest core fragment was 22 mm from the left lobe [first quartile-third quartile 20-25 mm, interquartile range (IQR) 5 mm], and 20 mm (first quartile-third quartile 17-22 mm, IQR 5 mm) from the right lobe. The median cumulative core length per patient was 103 mm (91-108 mm, IQR 17 mm). The median cumulative number of complete portal triads per patient was 69.50 (52.25-82.25, IQR 30). The rate of diagnostic yield was 100%. Post-biopsy self-limiting abdominal pain was reported in two patients (5%). The most common histologic diagnosis was fatty liver disease (25%). CONCLUSION: Endoscopic ultrasound-guided liver biopsy with the wet-heparinized suction technique using a 20-gauge fine-needle biopsy needle is a safe alternative method in clinical practice.

Mechanisms of T-Cell Exhaustion in Pancreatic Cancer.

T-cell exhaustion is a phenomenon that represents the dysfunctional state of T cells in chronic infections and cancer and is closely associated with poor prognosis in many cancers. The endogenous T-cell immunity and genetically edited cell therapies (CAR-T) failed to prevent tumor immune evasion. The effector T-cell activity is perturbed by an imbalance between inhibitory and stimulatory signals causing a reprogramming in metabolism and the high levels of multiple inhibitory receptors like programmed cell death protein-1 (PD-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), and Lymphocyte-activation gene 3 (Lag-3). Despite the efforts to neutralize inhibitory receptors by a single agent or combinatorial immune checkpoint inhibitors to boost effector function, PDAC remains unresponsive to these therapies, suggesting that multiple molecular mechanisms play a role in stimulating the exhaustion state of tumor-infiltrating T cells. Recent studies utilizing transcriptomics, mass cytometry, and epigenomics revealed a critical role of Thymocyte selection-associated high mobility group box protein (TOX) genes and TOX-associated pathways, driving T-cell exhaustion in chronic infection and cancer. Here, we will review recently defined molecular, genetic, and cellular factors that drive T-cell exhaustion in PDAC. We will also discuss the effects of available immune checkpoint inhibitors and the latest clinical trials targeting various molecular factors mediating T-cell exhaustion in PDAC.