[Active surgical approach for retroperitoneal liposarcoma]. / Rol' aktivnoi khirurgicheskoi taktiki pri zabryushinnoi liposarkome.

OBJECTIVE: To assess the influence of active surgical approach on the long-term postoperative outcomes in patients with retroperitoneal liposarcoma. MATERIAL AND METHODS: A retrospective study included 190 patients with retroperitoneal liposarcoma. The effect of malignancy grade, adjuvant chemotherapy, number of separate tumor nodes in primary neoplasm and the first relapse, as well as the number of previous total resections on survival rate was analyzed. RESULTS: Overall and relapse-free survival is significantly worse in patients with high-grade retroperitoneal liposarcoma (G2-3) compared to low-grade (G1) tumor (plog-rank=0.000). Multifocal growth of primary tumor (p=0.869; plog-rank=0.607) and multiple (>1) separately located nodes in abdominal cavity and retroperitoneal space at the first relapse (plog-rank=0.158 to 0.985) did not significantly impair prognosis after total resection of all types of retroperitoneal liposarcoma regardless malignancy grade. Adjuvant chemotherapy does not significantly improve relapse-free survival. Overall survival was significantly higher in patients who underwent ≥4 previous total resections compared to 1 surgical treatment for all types of retroperitoneal liposarcoma regardless malignancy grade (p=0.000; plog-rank=0.001). CONCLUSION: The only potentially radical treatment for patients with retroperitoneal liposarcoma is surgery. We reported the advantages of active surgical approach for improvement of long-term outcomes in patients with retroperitoneal liposarcoma.

[Surgical and combined treatment of patients with duodenal stromal tumors]. / Osobennosti khirurgicheskogo i kombinirovannogo lecheniya bol'nykh stromal'noi opukhol'yu dvenadtsatiperstnoi kishki.

OBJECTIVE: To evaluate the immediate and long-term results of surgical and combined treatment of patients with duodenal stromal tumors. MATERIAL AND METHODS: There were 47 patients with duodenal stromal tumors for the period 2002-2019. All patients underwent treatment at the Blokhin National Cancer Research Center. Six patients had metastatic disease, 2 ones - a rare syndrome of duodenal stromal tumor associated with neurofibromatosis type 1, other 39 patients had a localized and locally-advanced disease. Surgical treatment was performed in 37 patients (limited resections (LR) in 24 cases and gastropancreaticoduodenectomy in 13 cases).Incidence of postoperative complications was significantly lower after limited resections compared to gastropancreaticoduodenectomy (22.2% (6/24) vs. 61.5% (8/13), respectively). Severe complications (Clavien-Dindo grade 3) occurred in 4.2% (1/24) vs. 15.3% (2/13) of patients, respectively. Postoperative mortality was absent in both groups. We observed no significant differences in long-term results. Overall 5-year survival was 91% and 70% (p=0.5960), 5-year recurrence-free survival - 65 and 70% (p=0.6226), respectively. CONCLUSION: Considering similar survival rates, lower postoperative morbidity and better quality of life, limited duodenal resections are preferred for duodenal stromal tumors.

[Gastrointestinal stromal duodenal tumors: diagnostic mistakes and modern approaches to treatment]. / Gastrointestinal'nye stromal'nye opukholi dvenadtsatiperstnoi kishki: oshibki diagnostiki i sovremennye podkhody k lecheniyu.

Gastrointestinal stromal duodenal tumors are rare diseases of small intestine. Duodenal GISTs may be giant; these neoplasms can also simulate malignancies of other organs. These features result diagnostic and treatment mistakes. Neoadjuvant therapy with imatinib results tumor shrinkage and ensures organ-sparing surgery. We report duodenal GISTs in patients with primary diagnosis «retroperitoneal tumor¼, «pancreatic cyst¼ and «retroperitoneal abscess¼, who were treated at the Blokhin National Cancer Research Centre in 2019-2020.

[Differentiated surgical approach for retroperitoneal non-organ liposarcoma]. / Differentsirovannyi podkhod v khirurgii zabryushinnykh neorgannykh liposarkom.

OBJECTIVE: To determine the indications for combined and organ-sparing surgery depending on malignancy grade of retroperitoneal liposarcoma. MATERIAL AND METHODS: A retrospective study included 190 patients with retroperitoneal liposarcoma. Influence of malignancy grade, lesion of adjacent organs and resection/excision of adjacent organs on the overall and recurrence-free survival was studied. Moreover, we analyzed the issue of kidney-sparing surgery and nephrectomy. RESULTS: Overall and recurrence-free survival were significantly worse in high grade (G2-3) compared to low-grade tumors (G1) (p=0.0001; log-rank test). Visceral invasion was revealed in 23% of patients with low-grade (G1) tumors and 53% of patients with high-grade (G2-3) neoplasms. Visceral invasion significantly impairs overall and recurrence-free survival in both low grade (G1) and high-grade (G2-3) tumors (p=0.0001; log-rank test). In case of low grade (G1) retroperitoneal liposarcoma, overall and recurrence-free survival was similar after combined surgery without histologically confirmed visceral invasion of liposarcoma and organ-sparing surgery (p=0.006; p=0.053; log-rank test). On the contrary, high grade (G2-3) tumor was followed by significantly better overall and recurrence-free survival after combined surgery without histologically confirmed visceral invasion compared to organ-sparing surgery (p=0.006; p=0.053; log-rank test). Recurrence-free survival was similar after kidney-sparing surgery and nephrectomy among patients with low-grade (G1) tumor (p=0.456; log-rank test). In case of high-grade retroperitoneal liposarcoma (G2-3), recurrence-free survival was significantly worse after kidney-sparing surgery compared to nephrectomy (p=0.039; log-rank test). CONCLUSION: Surgery is the only potentially radical treatment of patients with retroperitoneal liposarcoma. Organ-sparing including kidney-sparing surgery is advisable for low-grade liposarcoma (G1). On the contrary, organ-sparing surgery impairs long-term results and prognosis in patients with high-grade tumors (G2-3). Combined operations including nephrectomy are justified for high-grade retroperitoneal liposarcoma (G2-3).

[Retroperitoneal dedifferentiated liposarcomas: semi-quantitative assessment of the dedifferentiated component and prognosis]. / Zabryushinnye dedifferentsirovannye liposarkomy: polukolichestvennaya otsenka dedifferentsirovannogo komponenta i prognoz.

OBJECTIVE: To evaluate the impact of malignancy grade and the proportion of the dedifferentiated component (DC) in retroperitoneal dedifferentiated liposarcomas (DDLS) on the course and prognosis of the disease. MATERIAL AND METHODS: The retrospective study enrolled 74 patients with primary retroperitoneal DDLS who underwent radical surgical treatment in the N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia. Histological surgery specimens from all cases of DDLS were reexamined and reclassified. According to malignancy grades and the proportion of the dedifferentiated component in the tumor, the patients were divided into the comparison groups included in the intergroup analysis of overall and relapse-free survival (OS and RFS) rates. The authors also analyzed the relationship between the proportion of the dedifferentiated component in DDLS and the frequency of adjacent organ invasion. RESULTS: Patients with a more than 15% dedifferentiated component had significantly lower OS rates than those with a less than 15% one (p=0.0001; log-rank test). The median OS in the DDLS group with a less than 15% dedifferentiated component was 91 months (95% CI, 82-100); that in the DDLS group with a more than 15% dedifferentiated component was 29 months (95% CI 17-41). The 5-year overall survival rates in the groups with less than 15% and more than 15% dedifferentiated components were 69% and 2%, respectively. The group with a more than 15% dedifferentiated component had significantly lower RFS rates than that with a less than 15% one (p=0.0001; log-rank test). In the DDLS groups with less than 15% and more than 15% dedifferentiated components, the median RFS rates were 25 months (95% CI 23-27) and 13 months (95% CI 8-18), respectively. In these groups, the 2-year RFS rates were equal to 50% and 9%, respectively. In the DDLS groups with less than 15% and more than 15% dedifferentiated components, pathologically confirmed invasion into the adjacent organs was observed in 32% and 63% of cases, respectively. There were no statistically significant differences in the OS and RFS of patients with DDLS according to tumor grade (p=0.069; p=0.102). CONCLUSION: This investigation suggests that DDLS have a more aggressive course with an increasing proportion of the dedifferentiated component in the tumor. Considering the histological variability in the dedifferentiated component, which is demonstrated in the research and scientific literature, as well as lack of a prognostic impact of histological grade, the authors believe that semi-quantitative assessment of the proportion of the dedifferentiated component in DDLS is able to serve as a simple and efficient morphological marker for the course of the disease and prognosis in retroperitoneal DDLS.

[Distal duodenectomy: a new option of surgical treatment for duodenal tumors]. / Distal'naya duodenal'naya rezektsiya: novyi sposob khirurgicheskogo lecheniya pri opukholevom porazhenii dvenadtsatiperstnoi kishki.

OBJECTIVE: To assess severity, safety and functional advisability of distal pancreatectomy using original surgical technique developed in the Blokhin National Medical Research Centre of Oncology. MATERIAL AND METHODS: There were 10 patients with duodenal malignancies who have undergone distal pancreatectomy in the Blokhin National Medical Research Centre of Oncology for the period 2006-2018. Distal pancreatectomy for primary duodenal tumors was performed in 8 patients, 2 patients underwent surgery for external invasion of the duodenum. RESULTS: Postoperative complications Clavien-Dindo grade 1 and 2 occurred in 4 (40%) patients. Surgical complication grade 2 occurred in 1 (10%) patient (pancreatic fistula with effective conservative management). There were no cases of leakage of duodenal stump and duodenojejunostomy, impaired bile flow and stenosis of anastomosis with delayed stomach emptying. CONCLUSION: Distal duodenectomyis associated with low postoperative morbidity, good functionality and quality of life. This procedure is preferred for non-epithelial and neuroendocrine tumors, as well as with secondary malignant duodenal invasion.

[Spleen-preserving D2-lymphodissection in gastric cancer surgery].

Oncological advisability of spleen removal during surgical treatment of gastric cancer is arguable at present time. It is presented technique of spleen-preserving D2-lymphodissection used for gastric body and proximal part cancer which was applied in 155 patients. Control group included 197 patients who underwent gastrectomy with splenectomy. Spleen-preserving D2-lymphodissection increased duration of surgery but decreased frequency of subdiaphragmatic abscess and pancreatic fistulas and duration of hospital stay. 5-years survival (Kaplan-Meier) was 59% in main group, in control group - 55% (p>0.05). We consider that spleen-preserving D2-lymphodissection is radical and safe surgical method for locally advanced cancer of gastric body and proximal part.

[Results of combined treatment of patients with metastatic gastric cancer. Case study].

We present the clinical observation of combined treatment of a patient with metastatic gastric cancer. The patient underwent combined chemotherapy for initially inoperable gastric cancer with metastases to the liver, paragastric lymph nodes, and peritoneal carcinomatosis with complete regression of distant metastases, which allowed radical surgery. The patient is currently under regular team observation without signs of disease. His present survival is 44 months.

[Combined operations by retroperitoneal liposarcomas].

Retrospective analysis of 228 patients with retroperitoneal liposarcoma, operated on in the Russian Oncology Center during 1971-2010, has been done. Of 223 performed operations, 124 were combined, i.e., required multi-organ resection. The kidney was the most frequently removed organ both in cases of primary and recurrent tumors. 10-year survival rate was 26% after combined operations and 35% after surgery, they did not need the multiorgan resection.

[Clinico-morphological properties and surgical treatment results in retroperitoneal liposarcomas].

The separate clinico-morphological features of nonorganic retroperitoneal liposarcoma (NRL) and their prognostic value were studied in 200 patients. The type of primary NRL is histologically erentiated in 65.5%, myxoid in 16.1%, dedifferentiated in 9.2%, pleomorphic in 4.6% and mixed in 2.3%. There is a positive elation between overall survival, lyposarcoma hystologic type < 0.007) and completeness of tumor resection (p < 0.0008). Differentiated and myxoid NRL with cell volume less than 5.0% are characterized by better prognosis. Myxoid NRL with cell volume more than 5.0%, dedifferentiated and pleomorphic NRL types are unfavorable prognostic factors. Radical surgical resectio leads to 5-year and 10-year overall survival of 57.5% and 7.8%. Palliative surgery lead to worse results with 3-year and 5-year overall survival of 50.0% and 31.8% respectively. Therefore, the most important prognostic factors in NRL are histological type and completeness of resection.

[Signet ring cancer of the stomach: clinico-morphological features, postsurgical results and prognosis].

Clinico-morphological features of signet ring cancer of the stomach were evaluated in 372 out of 2,308 gastric cancer patients undergoing gastroectomy or stomach resection. Signet ring tumor pathology occurs mostly in young females and younger patients generally. It features high incidence of early cancers, low frequency of metastatic spreading to lymph nodes (T1-T2), high frequency of immediate involvement of perigastric fatty tissues, peritoneum and ovaries and infrequent spreading to the liver. Post-surgical survival rates among patients with T1-T2 were relatively high, yet declining in cases of extension through the serous membrane of the stomach. D2-lymphdissection failure to improve the end-results of surgical treatment of signet ring cancer might be accounted for by the predominance of peritoneal metastases of this morphological pattern. Histochemical assay of mucines might be contribute additional data on prognosis.

[A theoretical model for assessing the relationship between "stage migration" and survival of gastric cancer patients after variable lymph node dissection].

Standard histological procedures identify metastatic gastric cancer in approximately 15% of cases of macroscopically unaltered lymph nodes. Such metastases evade detection after surgery due to inadequate lymph node dissection, thus increasing staging error. Consequently, about 15% of patients suffer from tumor which is actually more advanced than one diagnosed originally.

[Surgery for gastric carcinoma in patients with high risk of peritoneal metastases].

Survival in 242 cases of lymph dissection (D2) and 319 patients with (D1) operated on for gastric cancer was compared. D2 lymph dissection was not followed by higher survival rates in dealing with such gastric malignancies involving high risk of peritoneal metastases as signet ring cell, undifferentiated cell, diffuse-infiltrative, Borrmann type IV gastric cancer and complete involvement of the stomach. When D2 lymphoadenectomy was carried out for gastric adenocarcinoma, generally known to be rarely accompanied by peritoneal metastases, the end results were much better, even in cases of serosal invasion.

[Basic directions in studying cancer of the resected stomach]. / Osnovnye napravleniia v izuchenii problemy raka opeirovannogo zheludka.

The causes, incidence of, and the time of occurrence of cancer of the stomach resected for benign diseases are analyzed. The outcomes of 384 operations for recurrent gastric cancer, including 174 radical ones, are presented. The highest resectability was noted in late recurrence and following Bilroth-II gastrectomy with long-loop forward colonic anastomosis. The late outcomes depend on the time of recurrence, its location in the remaining part of the stomach, and the presence of lymphogenic metastases. Experience of 16 extirpations of esophagojejunal anastomosis was used to show whether recurrent gastric cancer after gastrectomy with satisfactory immediate and long-term outcomes can be surgically treated. The fate of 292 patients with gastric cancer in whom tumor cells were detected along the line of resection is traced. Preventive resurgery in this group of patients is not unjustifiable as in 80.8% of them recurrence fails to occur at all or is followed by late metastases.

[Molecular biological and clinical-morphological studies of gastric tumors associated with Epstein-Barr virus]. / Molekuliarno-biologicheskoe i kliniko-morfologicheskoe issledovaniia opukholei zheludka, assotsiirovannykh s virusom Epshteina-Barr.

The paper presents the results of the studies of gastric cancer (GC) associated with Epstein-Barr virus (EBV) among the patients residing in 4 geographical regions. In situ hybridization (ISH) techniques revealed that 49(11.4%) of the 430 examinees were EBV positive (EBV+), the virus-specific marker mRNA-1 of EBV, EBER-1) was found to be present in 80-100) of tumor cells. The proportion of EBV(+)-associated GC cases in different geographic regions ranged from 7.3 to 15%. These tumors were predominant in males (15%) as opposite to females (5.5%). Histological types most common among EBV+ tumors and their location in the stomach are also described. Serological findings indicated that the increased anti-EDV antibody response in 70% of GC cases coincided with the presence of the viral genetic information detected by ISH. In contrast to a humoral response to EBV, a humoral response to Helicobacter pylori was equal both in patients with EBV(+)- and EBV(-)-associated gastric tumors. Further molecular biological analysis of EBV isolates from virus positive and virus negative GC may answer the question whether there are really the so-called tumor and non-tumor variants of EBV.

[Non-sporulating anaerobic bacteria and anastomosis failure in patients with gastric carcinoma]. / Nesporoobrazuiushchie anaéroby pri razvitii nesostoiatel'nosti anastomozov u bol'nykh rakom zheludka.

Cases of anastomosis suture failure within the period from 1977 to 1987 and from 1988 to 1998 in 139 patients after various surgical operations for gastric carcinoma were analyzed. Infection in the cases of the anastomosis sUture failure at the early terms was mainly due to representatives of Enterobacteriaceae and at the later terms the failure was mainly due to non-sporulating anaerobes belonging to Bacteroidaceae. The data are indicative of the fact that the use of antimicrobials requires a differential approach.

[Detection and characterization of gastric carcinoma associated with epstein-barr herpes virus]. / Obnaruzhenie i kharakteristika opukholei zheludka, assotsiirovannykh s virusom gerpesa épstein-barr.

The present investigation was carried out to estimate the incidence of Epstein-Barr virus (EBV)-associated cases among gastric carcinoma (GC) patients in Russia. Carcinoma specimens from 184 patients with GC treated at the Cancer Research Center were investigated by EBV encoded RNA-1 (EBER-1) in situ hybridization. Seventeen (9.24%) cases showed uniform EBER-1 expression restricted to the carcinoma cells. Hybridized signals were not detected in the non-neoplastic gastric epithelium. EBV involvement was significantly more frequent among males, especially in the tumors belonging to less differentiated types (moderately differentiated tubular adenocarcinomas and poorly differentiated solid adenocarcinomas) and located in the upper stomach (cardia and middle part). Most EBV-positive GCs were characterized by great lymphoid compartment involvement. The findings of the distribution of EBV-positive. GCs by sex, site, and histology are similar to those in Japan; however, the detection rate of EBV-positive cases in Russia is higher than that in Japan (6.7%) and lower than that in the USA (16%).

[Possibilities of surgical treatment of gastric cancer recurrences depending on the type of previous resection]. / Vozmozhnosti khirurgicheskogo lecheniia retsidiva raka zheludka v zavisimosti ot tipa predshestvuiushchei rezektsii.

The study deals with the end results of 375 surgeries performed for recurrent cancer of the stomach. Radical surgery was carried out in 168 cases (extirpation of the remaining part of stomach--140; repeated resection of stomach--12; extirpation of esophagoenterostomy--16). Stomach resection after Billroth-II with anterior long-loop colostomy created the best conditions for radical extirpation of the remaining stomach, while Billroth-I resection--the worst. The end results were worse when tumor relapsed earlier than three years after primary resection of the stomach and on sites in gastroenterostomy area, as compared to relapse at later stage and outside anastomosis area.

[Current principles of diagnosis and surgical treatment of non-organ retroperitoneal tumors]. / Sovremennye printsipy diagnostiki i khirurgicheskogo lecheniia neorgannykh zabriushinnykh opukholei.

The data on surgical treatment of 455 patients operated on for primary and recurrent non-organ retroperitoneal tumors (NRT) are discussed. 64.2% of tumors were resected; postoperative lethality was 8.2%. Particular emphasis is placed on the complex nature of diagnosis and an algorithm of examination is suggested. The sequence of main procedures and stages are described; 43% of radical procedures were performed in combination with one another. NRTs tended to relapse and malignant tumors recurred most frequently within the first 18 months. In the course of 182 operations, 54.4% of NRTs were resected: postoperative lethality was 11.1%. The end results were determined by a number of factors, primarily, nature of tumor (benign or malignant), tumor process (primary or recurrent), tumor size and histological pattern. Because of the poor end results, surgical procedures should be improved and their range should be extended.