Table. Pathological Features and Molecular Profile of Early-Onset Colorectal Cancer Pathological features Molecular profile Poor differentiation Microsatellite stability Mucinous tumors More likely to exhibit LINE-1 hypomethylation and TP53 sequence variations Signet-ring morphology Less frequently harbor KRAS, BRAF V600E, and APC sequence variations Perineural/venous invasion Promoter methylation of CpG islands Abbreviations: APC, adenomatous polyposis coli; BRAF, B-Raf; KRAS, K-Ras; LINE-1, long interspersed nuclear elements; TP53, tumor protein 53.

MicroRNA-21 (miR-21) expression was quantified by real-time qRT-PCR in peripheral blood and saliva samples obtained from patients diagnosed with colorectal cancer (CRC) of varying degrees of malignancy and healthy volunteers. All patients had adenocarcinoma located in the distal colon at different stages. Significant differences were detected between the control group and the total experimental group of CRC patients (plasma, P = 0.0001; saliva, P = 5e-12). MiR-21 expression was also significantly different in certain subgroups of patients with CRC disease stages II-IV as compared to the control group. No correlation of miR-21 expression was found with regard to gender and age of patents. Also, there were no significant individual correlations and linear regression of miR-21 expression in the plasma and saliva. The estimated diagnostic sensitivity and specificity of miR-21 expression were respectively 65 and 85% in the plasma, and 97 and 91% in the saliva. Our data suggest that miR-21 in both the saliva and plasma could be a proper biomarker for CRC screening, although the saliva miR-21 expression test looks preferable due to its higher sensitivity, specificity, and technical simplicity.

In recent times, terahertz (THz) technologies have been actively applied in many biomedical research work, including gastric cancer diagnosis. In order to provide an effective removal of tumor during surgery, it is necessary to clearly distinguish it from different membranes of the stomach. In this work, we reported an investigation of various normal and cancer fresh gastric tissues using terahertz time-domain spectroscopy in the reflection mode. Refractive index and absorption coefficient of moderately differentiated and poorly differentiated gastric adenocarcinomas, as well as both serosa and mucosa were obtained in the frequency range from 0.2 to 1 THz. All cancer tissues were distinguishable from normal ones. The influence of the morphology of the investigated tissues on the obtained optical properties is discussed. The obtained results demonstrated a potential of THz time-domain spectroscopy to discriminate a tumor from normal serous and mucous gastric membranes. Thus, this method might be applied to gastric cancer diagnosis.

Background The molecular profile of early-onset colonic cancer is undefined. This study evaluated clinicopathological features and oncological outcomes of young patients with colonic cancer according to microsatellite status. Methods Anonymized data from an international collaboration were analysed. Criteria for inclusion were patients younger than 50 years diagnosed with stage I–III colonic cancer that was surgically resected. Clinicopathological features, microsatellite status, and disease-specific outcomes were evaluated. Results A total of 650 patients fulfilled the criteria for inclusion. Microsatellite instability (MSI) was identified in 170 (26.2 per cent), whereas 480 had microsatellite-stable (MSS) tumours (relative risk of MSI 2.5 compared with older patients). MSI was associated with a family history of colorectal cancer and lesions in the proximal colon. The proportions with pathological node-positive disease (45.9 versus 45.6 per cent; P = 1.000) and tumour budding (20.3 versus 20.5 per cent; P = 1.000) were similar in the two groups. Patients with MSI tumours were more likely to have BRAF (22.5 versus 6.9 per cent; P < 0.001) and KRAS (40.0 versus 24.2 per cent; P = 0.006) mutations, and a hereditary cancer syndrome (30.0 versus 5.0 per cent; P < 0.001; relative risk 6). Five-year disease-free survival rates in the MSI group were 95.0, 92.0, and 80.0 per cent for patients with stage I, II, and III tumours, compared with 88.0, 88.0, and 65.0 per cent in the MSS group (P = 0.753, P = 0.487, and P = 0.105 respectively). Conclusion Patients with early-onset colonic cancer have a high risk of MSI and defined genetic conditions. Those with MSI tumours have more adverse pathology (budding, KRAS/BRAF mutations, and nodal metastases) than older patients with MSI cancers.

Ключевые слова: рак толстой кишки, кишечная микро биота, дисбактериоз В в е д е н и е . В настоящее время трудно недооценить роль влияния кишечной микробиоты на организм человека. С развитием технологий в области молекулярной генетики значительно изменились представления о качественном и количественном составе микроорганизмов.По современным представлениям, абсолютное большинство (89%) в составе микробиоты здорового человека занимают микроорганизмы, относящиеся к двум крупным сообществам -бак тероидам (Bacteroidetes) и фирмикутам (Fir mi cutes), каждое из которых состоит из множества родов. Бактероидыгруппа анаэробных грамотрицательных бактерий трех классов (Bacteroidetes, Flavobacteria и Sphingobacteria). Фирмикуты -преимущественно грамположительные бактерии двух основных классов -бацилл и клост ридий. К фирмикутам относятся стрептокок ки, стафилококки, лактобациллы, эн терокок ки и менее известные большинству врачей, но более многочисленные вейлонеллы, руминококки, эубактерии, пептострептококки. Самые же распространенные фирмикуты -клостридии. Установлено, что общее количество всех бифидобактерий, которые входят в семейство актиномицетов, обычно не превышает 5% от общего количества бактерий толстой кишки, а лактобацилл -не более 1%. [7] В отечественной литературе достаточно много публикаций, в которых изучались особенности микробиоты толстой кишки у больных с колоректальным раком (КРР), в том числе применительно к хирургической практике. Большинство российских исследователей для определения состава микробиоты использовали бактериологический метод. В результате практически у всех пациентов выявлены различной степени нарушения микробиоценоза кишечника в виде снижения количества лакто-и бифидобактерий и роста условно-патогенной флоры [2,[4][5][6].Несмотря на современные возможности хирургии и интенсивной медицины, небольшое число осложнений после операций, соблюдение протоколов ранней реабилитации пациентов, сохраняется определённый процент осложнений, ведущую роль в патогенезе которых играет кишечная микрофлора (абдоминальный сепсис, антибиотикоассоциированные колиты, несостоятельности кишечных анастомозов) [3,9].Предложены множество путей коррекции кишечных дисбиозов -от назначения эубиотиков и пробиотиков до фекальной трансплантации,