Positron emission tomography-computed tomography (PET/CT) with ¹⁸F-fluorodeoxyglucose in colorectal cancer is a highly sensitive imaging technique that detects malignant foci characterized by increased glucose metabolism. Currently, an increasing number of studies indicate the added value of PET/CT for the diagnosis and preoperative restaging of recurrent colorectal cancer. A special problem is a group of patients suffering from colorectal cancer, with negative or ambiguous results of radiology methods, but with an elevated level of сarcinoembryonic antigen. Many studies confirm the opinion that early use of PET/CT with ¹⁸F- fluorodeoxyglucose may have predictive value in the treatment of such patients.

This review reveals the anatomical, physiological and embryogenetic features of the proximal colon to explain the reasons for such frequent localization of mucinous phenotype of adenocarcinoma (MAC) here. It was shown that later differentiation in embryogenesis causes relative insufficiency of the proximal part as a structure of the digestive and immune systems. Physiologically lower lymphoid tissue (GALT) density here leads to the formation of a certain composition of the intestinal microbiota, which is different from that in the distal part, which is a significant link in the etiopathogenesis of proximal colon cancer. It is confirmed also by different composition of biofilms on the surface of epithelial tumors in the right and left halves of the colon, as well as differences in the molecular mechanisms of carcinogenesis, depending on the location of the cancer. Common for proximal part genetic changes, called as CIMP-phenotype, microsatellite instability and BRAF proto-oncogene mutation lead to excessive secretion of specific mucin fractions (mainly MUC2 and MUC5AC), the imbalance of its composition and the formation of MAC. An earlier age of onset, frequent association with hereditary non-polypous colorectal carcinoma, the predominance of MUC2 and MUC5AC fractions, similar to the embryonic period, as well as a higher level of cancer-embryonic antigen in patients with MAC indicate the influence of anatomical, physiological and embryogenetic features of the proximal colon on carcinogenesis long before its formation. Thus, a detailed understanding of MAC carcinogenesis is necessary for an adequate assessment of its effective prevention in time, as well as dealing with it as with specific nosological unit requiring specific treatment principles.

The decrease of frequency of postoperative complications and leakage of colorectal anastomosis is one of the most important and actual problem of colorectal surgery. The formation of preventive stoma is a standard method of colorectal anastomotic leakage prevention. However, this method can bear to postoperative complications and disable patients. In this review article we discuss the results of transabdominal and transanal reinforcement of colorectal anastomosis as a method of leakage prevention.

Objective: to identify factors associated with efficacy of an aflibercept-chemotherapy combination in patients with metastatic colon cancer.

Materials and methods. This retrospective multicenter study was conducted in 20 clinics from 15 regions of the Russian Federation. The main efficacy outcome was progression-free survival (PFS). We performed univariate and multivariate analysis to assess the impact of various factors of PFS.

Results. Two hundred and fifty-seven patients received aflibercept-containing chemotherapy; of them, 175 participants (68.1 %) received it as a second-line therapy. The objective response rate and median PFS were 18.7% and 5 months (95% confidence interval (CI) 4.2—5.8) respec -tively. The following factors were found to have a positive effect of PFS at multivariate analysis: grade I—II adverse events to aflibercept therapy (hazard ratio (HR) 0.58; 95 % CI 0.38—0.89; p = 0.01), therapy for concomitant diseases (HR 0.47; 95 % CI 0.29—0.76; p = 0.002), and ECOG performance status of 0 (HR 0.53; 95 % CI 0.34—0.81; p = 0.004). Patient with all 3 factors present had median PFS of 9 months, whereas patients without them demonstrated PFS of only 3 months (HR 1.9; 95 % CI 1.5—2.6; p <0.001).

Conclusions. Satisfactory performance status, adequate therapy for concomitant diseases, and adverse events to aflibercept therapy were associated with better PFS in patients receiving aflibercept-containing chemotherapy.

Objective: to evaluate the outcomes of emergency surgeries for complicated colorectal cancer performed in hospitals for general surgery and to assess risk factors and their impact on both short-term and long-term treatment outcomes.

Materials and methods. This study included 677patients that underwent emergency surgeries for complicated colorectal cancer in 3 hospitals for general surgery in Smolensk over the last 13 years. Severity of postoperative complications was graded using the Clavien—Dindo classification. The length of follow-up varied between 0 and 60 months. Kaplan—Meier survival curves were constructed to assess relapse-free and overall survival. The Cox proportional regression model was used to estimate the risk factors for survival.

Results. The main risk factors affecting short-term treatment outcomes were the severity of the overall condition (grave and critical) and time from symptom onset to hospital admission (>24 h). Using univariate and multivariate analysis, we identified independent prognostic factors associated with poorer 5-year relapse-free survival. They included presence of cancer cells at the resection margin (R1 resection) (hazard ratio (HR) 1.36; 95 % confidence interval (CI) 1.284—1.450; p <0.0001), rectal tumor (HR 1.085; 95 % CI 0.974—1.209; p = 0.009), and one-stage surgery (HR 1.141; 95 % CI 1.034—1.259;p <0.0001).

Conclusions. Positive resection margin (R1 resection) was an independent prognostic factor associated with poorer overall and relapse-free survival in patients with complicated colorectal cancer.

Background. In this article, we analyze a 30-year experience of treating patients with rectal cancer and outcomes of sphincter-sparing surgeries (SSS) with manual coloanal anastomosis or mechanical colorectal anastomosis combined with various therapies.

Objective: to optimize the indications for SSS considering tumor stage, treatment strategy, and overall performance status of a patient.

Materials and methods. We analyzed short-term and long-term treatment outcomes of 1,440 patients with stage T2—3N0—2M0 rectal adenocarcinoma who underwent both surgery and various neoadjuvant therapies. A total of1,038 SSS were included into the final analysis. Four hundred and eighty-one patients underwent anterior rerections (AR) with mechanical anastomosis; 557patients underwent abdominoanal resections (AAR) with manual coloanal anastomosis; of them, 289 individuals had modified abdominoanal resection.

Results. The overall frequency of postoperative complications after SSS was 24.3 %. The frequency of anastomosis leakage after AAR and AR was 9.5 % and 15 % respectively. Among patients with middle rectal cancer, there was no association between the type of surgery (AR or AAR) and the probability of relapse (p = 0.1823). In the subgroup with lower rectal cancer, patients that underwent abdominoperineal resection were more likely to have a relapse than those who underwent AAR (p = 0.042). The five-year overall survival rate reached 80 % in the group of SSS and 71 % in the group of abdominoperineal resection (p = 0.013). Year-on-year analysis of relapse-free survival after SSS demonstrated that it had significantly increased (from 63.5 % to 72.5%; p = 0.00077). The complex of rehabilitation measures in the early postoperative period after SSS ensures good functional effect in 51.5 % of cases.

Conclusions. SSS planning should be considered from the standpoint of clinical experience as well as multivariate analysis of short-term and long-term treatment outcomes. Successful outcomes can be achieved by a combination of adequate surgical techniques and conservative rehabilitation even in patients with very low rectal cancer. Such combination ensures not only good cancer outcome, but also satisfactory functional results.

Colitis cystica profunda is a rare nonmalignant disease, characterized by an inflammation of mucous coat of intestine and formation of submucous cysts. The clinical picture of this pathology and oncological diseases of colon and rectum is similar. It is very difficult and important to differentiate this disease from colorectal cancer to protect the patient from unjustified mutilating surgery. Nowadays either in Russian and foreign scientific literature there are single reports dedicated to this disease. In our opinion the publication of this clinical case and analysis of scientific literature devoted to this subject is currently important.

In this article there is a short review of modern state of problem of diagnostics and treatment of colitis cystica profunda. Also there is an own rare clinical observation of a patient who was diagnosed with colitis cystica profunda.