No abstract

84 Background: Esophageal squamous cell carcinoma (ESCC) is 2 to 8 times more frequent in men than in women. Tumor progression is directly connected with plasmin participation in destruction of the extracellular matrix and the basement membrane surrounding tumor. The purpose of the study was a comparative analysis of plasminogen (PG), free plasmin (P) and plasmin bound in complex with α2-antiplasmin (PAP) in ESCC tissues of men (M) and women (W). Methods: ESCC tumor tissue (T) and its perifocal zone (PZ) were studied by the ELISA (19 men and 8 menopausal women aged 58-72, st II, G2, T2-3N0-1M0-1). The results were compared to the histologically unchanged tissue from the resection line (RL). PG, P and PAP were measured in 10% homogenates prepared in sterile saline, with recalculation per 1 g wet tissue). Data were processed using Statistica 10. Results: PG content in RL was 1.5 times higher in M than in W. PG in T of M was decreased by 2 times, in W by 3.3 times, in PZ of M – by 2.9 times, in W – by 2.3 times. PG in T and PZ of M was 2.5 and 1.2 times higher than in W. P content in RL of all patients was significantly lower than in other samples, but 1.4 times higher in M than in W. P in T and PZ of M was 3 and 2.5 times higher than in RL, in T and PZ of W – 3.5 and 2.8 times higher than in RL. Significant differences were observed between P levels in T (but not in PZ): 1.3 times higher in M than in W. PAP content was relatively constant in all tissues, with a slight prevalence in T and PZ of W. P/PAP ratio was elevated in all tissues compared to RL, but in T and PZ of M it was 1.4 and 1.2 times higher than in W. P/PAP in RL of M was 1.4 times higher than in W. Conclusions: The results show a higher aggressiveness of P in PZ and T of M, while P formation in T of W was less active. We reported on a higher content of PG activators in T and PZ of M, and taking into account the morbidity statistics and literature data we suppose the effect of androgens on the conditions of PG activation into P and manifestation of its biological features. P in PZ of both M and W can contribute in the expansion of a “tumor field”. P binding in PAP complex was similar in all studied tissues.

Раково-тестикулярным антигенам (РТА) свойственно проявление гетерогенности транскрипции в зависимости от клинико-патологических особенностей опухоли. Проведены многочисленные исследования экспрессии генов РТА (РТ-генов) в опухолях различных нозологий, однако экспрессия этих генетических локусов при раке толстой кишки изучена недостаточно хорошо. Целью исследования стал анализ транскрипционного профиля РТ-генов, характерных для опухолевой ткани толстой кишки пациентов с регионарными метастазами и без. Методом ПЦР в режиме реального времени выполнен анализ экспрессии 16 генов (MAGE-A1,

No abstract

e23579 Background: Retroperitoneal tumors are rare heterogeneous malignant tumors. Due to their poor response to chemoradiotherapy, surgery is the main treatment option. Currently, there is little data on treatment outcomes in patients who underwent en block resection of retroperitoneal tumors and major vessels. Our purpose was to analyze surgical and oncological results in patients with retroperitoneal tumors and major blood vessel involvement. Methods: 27 patients received surgery for retroperitoneal tumors with major vessel resection in 2015-2019. Results: The mean tumor diameter was 17 cm (11-39 cm). The most frequent histological types were moderately differentiated liposarcoma (33.4%), well differentiated (18.5%), poorly differentiated sarcoma (18.5%), pleomorphic liposarcoma (22.2%), leiomyosarcoma (7.4%). Resection of the suprarenal inferior vena cava (IVC) with prosthetics was performed in 4 cases, resection of its renal segment with renal vein reimplantation - 1, resection of the infrarenal IVC with prosthetics - 8. PTFE prostheses were used as a conduit in all cases. Marginal excision of the suprarenal IVC was performed in one patient, that of the infrarenal IVC - in 5 patients; resection of the infrarenal IVC without the reconstruction - in one case. The iliac venous segment resection was required in 6 patients, in one case – with the iliac arterial segment resection and prosthetics. Macroscopic complete resection (R0-R1) was achieved in 92.6%. The postoperative morbidity was 25.9%, with no fatal outcomes. Despite the anticoagulant therapy, the frequency of thrombosis of the venous reconstruction area in the early postoperative period (1 month) was 7.4%. The median relapse-free survival was 14 months; the median overall survival was not achieved. Conclusions: Combined surgeries with simultaneous removal of retroperitoneal tumor and angioplasty demonstrate an acceptable level of morbidity and mortality. Radical removal of tumors with major blood vessel involvement allows increasing the survival in patients often considered inoperable.

258 Background: Our purpose was to study the protease/protease inhibitor (P/PI) balance in the blood plasma of patients with cancer of the head of the pancreas before and after pancreatoduodenal resection (PDR) with postoperative complications. Methods: The study was performed using clinical observation, biochemical examinations and statistical analysis in Microsoft Office Excel 2010. The blood plasma of 92 patients with pancreatic head cancer (53 men and 39 women aged 45-76 years, Т2-4N0M0) was studied before the surgery (b/s) and on days 1, 7, 14 and 17 after PDR. The patients were divided into two groups: g1 – 69 patients without postoperative (p/o) complications and g2 – 23 patients with p/o complications: generalization – 7, thrombosis - 8, acute postoperative pancreatitis - 2, gastrostasis - 2, anastomotic leakage - 4 patients. Kinetics of trypsin-like proteases (TLP) and α-1-proteinase inhibitor (α1PI) was studied by spectrophotometry. The data were compared with the blood plasma of 39 healthy donors (N). Results: TLP activity b/s exceeded N in g1 and g2 by 4.1 and 10.6 times; TLP in g2 was 2.6 times higher than in g1. The α1PI activity b/s was higher than N by 1.2 times (p < 0.05) in g1 and lower than N by 2.0 times in g2; α1PI in g2 was 2.4 times lower than in g1. After PDR, activity of TLP increased in all patients on day 1 but decreased on days 7-14 in g1 remaining 2.7 times higher than N by the discharge. The TLP activity in g2 by the discharge was similar to levels b/s and exceeded g1 by 4.4 and N by 12.1 times. The α1PI activity after PDR increased in all patients on days 1-17, but in g1 by the discharge it was similar to N and in g2 it was 1.5 times lower than N. The TLP/α1PI ratio was higher in g2 than in g1 at all times. Conclusions: A high TLP activity and a low α1PI activity, compared to N, were maintained in the blood plasma of all patients with p/o complications, despite their types. The P/PI balance in g2 was shifted to the left being 5.5-9.0 times higher than in g1 at all times which allowed the prognosis of postoperative complications before the surgery, perioperatively or on day 1 after the surgery.

e16196 Background: Microsatellite instability (MSI), as an acquired feature of malignant tumors, is a predictive and prognostic marker. The less aggressive nature of MSI-positive tumors has been associated with high immunogenicity. In the present study, MSI was assessed in NET samples of different localizations. Methods: The sample included 50 patients with a diagnosis of pancreatic NET (G1-G3) and NET of colon (G2-G3). MSI was analyzed by fragment analysis of five microsatellite loci (Bat25, Bat26, NR21, NR24, NR27). The level of MLH1 methylation was detected by pyrosequencing. Results: MSI was noted in 25.8% cases of the NET of colon and in 13.3% cases of the NET of the pancreas. In the case of pancreatic NET, only MSI low level was identified (instability at 1/5 loci), while in the case of NET of colon, most cases were classified as MSI high level. The incidence of MSI of pancreatic NET was consistent with literature data for small intestinal NET (14%), unlike MSI NET and BRAF V600 mutated adenocarcinomas of colon, MSI-positive pancreatic NET were not associated with hypermethylation of the MLH1 promoter. MSI was more often detected in women over 60 years old, at stages of the tumor process without distant metastases (p = 0.49). The sample size did not allow us to determine significant differences in the studied clinical and pathological groups of NETs, however, we note that in all cases of an unfavorable course of the disease (progression, death), was noted MSS status of tumors. Conclusions: Thus, MSI-positive NET of colon resembles MSI-positive adenocarcinomas of colon in frequency and pathogenetic mechanisms, while in terms of the identified frequency of MSI in pancreatic NET resembles the NET of the small intestine.

Adenocarcinoma and squamous cell carcinoma are the most common types of esophageal cancer with a constant tendency to increase the incidence of growth on the background of the high mortality, which makes particularly the development of new biomarkers that complement and improve the early diagnosis of this disease. Despite the impressive number of studies in routine clinical practice is used only marker of esophageal cancer - ERBB2/HER2 status. This review summarizes data on the identified epigenetic markers of the aberrant methylation of the genome, which may be useful for early detection of esophageal cancer, prognosis estimation and / or prediction of response to treatment. The development of new high-tech genome-wide screening, such as beadarray and immunoprecipitation sequencing method used for the wideband genotyping, but for the analysis of transcriptome and metilom, provides a comprehensive picture of genetic and epigenetic changes during tumorigenesis. Note the need to verify the most biomarkers on large representative samples for the development of valid diagnostic panels, suitable for large-scale screening of risk groups.