We report results of the final analysis of overall survival (OS) and patient-reported outcomes from the phase III KEYNOTE-585 (ClinicalTrials.gov identifier: NCT03221426 ) study. Participants with previously untreated, locally advanced, resectable gastric and gastroesophageal junction (G/GEJ) cancer were enrolled into the main (n = 804) and fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT; n = 203) cohorts, and randomly assigned 1:1 to neoadjuvant and adjuvant pembrolizumab plus chemotherapy or placebo plus chemotherapy. The primary end points were pathologic complete response (pathCR) by central review, event-free survival (EFS) by investigator, OS, and safety. Patient-reported outcomes was an exploratory end point. After a median follow-up of 59.9 months (range, 39-76), median OS was 71.8 versus 55.7 months (hazard ratio [HR], 0.86 [95% CI, 0.71 to 1.06]) with pembrolizumab plus chemotherapy versus placebo plus chemotherapy in the main cohort. The EFS HR was 0.81 (95% CI, 0.67 to 0.98). Grade ≥3 drug-related adverse event rates were 65% versus 63%. Perioperative pembrolizumab plus chemotherapy did not worsen health-related quality of life versus placebo. Pembrolizumab plus chemotherapy continued to show improved outcomes in pathCR and a trend toward longer EFS versus placebo in the main and main plus FLOT cohorts. Efficacy and safety outcomes with perioperative pembrolizumab plus chemotherapy followed by adjuvant pembrolizumab in participants with untreated, locally advanced resectable G/GEJ cancer were consistent with previous analyses.

Introduction: The programmed death receptor ligand 1 (PD-L1) immunohistochemistry (IHC) assay is a widely used selection method for pembrolizumab treatment in gastric cancer (GC) patients. PD-L1 is the main regulator of immunity in oncogenesis. Material and methods: The study included 38 patients with GC. The combined treatment consisted of neoadjuvant FOLFOX6, or FLOT, chemotherapy and surgery. PD-L1 + tumor status was recorded in 12 patients (CPS > 5), with a negative status recorded in 26 patients. RT-PCR determined the expression of molecular markers. The level of LC3B protein was detected by Western Blotting analysis. Results: An overexpression of PD-1, PD-L2 in the tumor is associated with AKT/mTOR mRNA profile change and autophagy initiation in IHC PD-L1 positive GCs. NACT influences these biological features, modifying the expression of AKT/mTOR components and autophagic flux. In PD-L1 positive cancers, the effect of NACT and molecular markers rearrangements are essential compared to the PD-L1 negative cancers. Conclusion: The IHC PD-L1 status in gastric cancers is the significant marker of cancer progression, recovering the multiple inner mechanisms of cancer spreading and leading to ineffective therapy. Autophagy induction and angiogenesis are found in PD-L1 positive gastric cancers.

A simple approach for isolation of exosomes from the blood plasma, which allows to obtain highly purified preparations of microvesicles no larger than 100 nm has been proposed. The presence of different subpopulations of exosomes in the blood plasma of healthy donors and cancer patients has been recognized. We found the presence of the universal markers CD9, CD24 and CD81 on exosomes isolated from blood plasma that can be used to their routine typing.

Colorectal cancer (CRC) is the most frequently occurring malignancy in the world. However, the mortality from CRC can be reduced through early diagnostics, selection of the most effective treatment, observation of the therapy success, and the earliest possible diagnosis of recurrences. A comprehensive analysis of genetic and epigenetic factors contributing to the CRC development is needed to refine diagnostic, therapeutic, and preventive strategies and to ensure appropriate decision making in managing specific CRC cases. The liquid biopsy approach utilizing circulating markers has demonstrated its good performance as a tool to detect the changes in the molecular pathways associated with various cancers. In this review, we attempted to brief the main tendencies in the development of circulating DNA and RNA-based markers in CRC such as cancer-associated DNA mutations, DNA methylation changes, and non-coding RNA expression shifts. Attention is devoted to the existing circulating nucleic acid-based CRC markers, the possibility of their application in clinical practice today, and their future improvement. Approaches to the discovery and verification of new markers are described, and the existing problems and potential solutions for them are highlighted.

Exosomes are extracellular membrane structures involved in many physiological and pathological processes including cancerogenesis and metastasis. The clarification of the criteria for exosome isolating and identifying is the purpose of this study. Exosome samples from the plasma of patients with colorectal cancer and healthy donors were examined using transmission electron microscopy and flow cytometry in accordance with the minimum requirements of “International Society for Extracellular Vesicles”. The choice of the method for isolation of exosomes from the blood plasma by ultrafiltration and ultracentrifugation allowed obtaining highly purified samples of exosomes, in which all the structural components were clearly seen. The results obtained with flow cytometry suggest that exosomes of blood plasma from patients with colorectal cancer can be produced by epithelial cells. Moreover, cells produce different types of exosomes, which correspond to different mechanisms in sorting macromolecules in the membrane of multivesicular bodies. Determination of significant differences in the expression of specific exosomal proteins from colorectal cancer patients compared to healthy donors suggests a high diagnostic potential significance of circulating exosomes.