В данном разделе указаны критерии оценки клинической значимости применения дорогостоящей противоопухолевой лекарственной терапии в соответствии со шкалой, разработанной экспертной группой (см. стр. 7). В тексте они обозначены, как магнитуда клинической значимости (МКЗ).

This article presents changes to clinical guidelines for the treatment of metastatic colon cancer in 2024. The new provisions in the clinical guidelines are complemented by a brief overview of the research results that underlie them. The changes considered concern not only systemic antitumor treatment, but also surgery and molecular genetic diagnostics. The differences between the recommendations of RUSSCO and the Ministry of Health of Russia are given. The introduction of information to determine the clinical benefit of expensive therapeutic options in relation to the use of the ESMO-MCBS and RUSSCO-MCBS scales is discussed.Aim. Bringing information to a wide range of readers on planned changes in clinical guidelines.

AIM: to find histological prognostic factors for survival in patients with anorectal melanoma.PATIENTS AND METHODS: single center retrospective study of histological specimens of patients with anorectal melanoma (2005-2023). A revision of histological specimens was carried out, using the following criteria: multifocal growth, maximum tumor size, maximum thickness by Breslow, ulceration, perineural and lymphovascular invasion, as well as depth of invasion. Statistical processing was carried out using the Cox regression.RESULTS: twenty-one patients were included in the study. In all patients, treatment started with surgery: 13 (61.9%) — abdominoperineal excision (APE); 8 (28.1%) — local excision). The sample contained patients with the following initial stages of the process: IB–IIB — 12 (57.1%); III — 9 (42.9%). Nine (42.9%) patients developed local recurrence, and 8 (38.1%) — distant metastases. On univariate analysis, DFS was significantly affected by ulceration RR 0.061 (CI 95.0%; 0.004–0.097, p = 0.048), there was a trend towards the role of neurotropism RR 3.654 (CI 95.0%; 0.934–14.297, p = 0.063) and pigmentation RR 2.485 (CI 95.0%; 0.832–7.424, p = 0.103). In multivariate analysis, none of the criteria had a significant effect on DFS. On OS in univariate analysis was a trend towards an effect of Breslow invasion depth of more than 2 cm HR 1.028 (CI 95.0%; 0.998–1.060, p = 0.070) and depth of tumor invasion HR 2.117 (CI 95.0%; 0.990–4.525, p = 0.053). In multivariate analysis, none of the criteria had a significant effect on OS.CONCLUSION: evaluation of the effectiveness by histological features of skin melanoma showed the potential use of neurotropism, Breslow invasion of more than 2 cm and depth of tumor invasion as factors of unfavorable impact on DFS and OS in ARM. More trials are needed.

Aim. The ensuring that changes to clinical guidelines can be discussed more widely before they are formally introduced into clinical practice.Materials and methods. A brief review of the literature and rationale for each proposed major change in the treatment section is presented. The refusal to carry out preoperative radiation therapy for cancer of the upper ampullary rectum, the narrowing of indications for preoperative radiation therapy for cancer of the mid-ampullary rectum, as well as the expansion of indications for total non-adjuvant chemotherapy for rectal cancer with damage to the circular resection margin are discussed. Changes to the drug treatment section are discussed.Results. This article presents planned changes to clinical guidelines for the treatment of non-metastatic colorectal cancer in 2024. The most significant alterations concerned neoadjuvant treatment of rectal cancer and adjuvant treatment of colon cancer. A new algorithm was proposed for choosing rectal cancer neoadjuvant therapy, considering individual treatment decisions.Conclusion. A consensus was achieved concerning the necessity to expand indications for neoadjuvant rectal cancer chemotherapy, but only in patients with good functional status. The most benefit can be achieved in patients, for whom complete clinical response is the aim of the treatment and in patients with positive circumferential resection margin.

Introduction: There is a lack of information on the role of neoadjuvant chemotherapy in upper rectal cancer. The aim of our research was to investigate the role of neoadjuvant chemotherapy in upper rectal cancer treatment.Materials and methods: We conducted a retrospective cohort multicenter study to analyze the medical records of patients with upper rectal cancer from 2007 to 2020 obtained from the archive of Research Institute FSBI «N. N. Blokhin Cancer Research Center» of the Ministry of Health of Russia, A. N. Ryzhikh National Medical Research Centre for Coloproctology, Stavropol regional Clinical oncological Dispensary and Kaliningrad oncological Center. All patients were divided into 2 groups: group 1 included patients who underwent neoadjuvant chemotherapy with CAPOX as the first treatment step, and group 2 included patients who underwent upfront surgery. Primary endpoint was 3‑year disease-free survival (DFS) rate. We also estimated the pathological complete response (pCR) rate, treatment toxicity, postoperative morbidity rate (Clavien – Dindo), degree of tumor regression, local recurrence rate, distant metastases rate, 3‑year overall survival (OS) and the neoadjuvant chemotherapy completion rate.Results: 118 patients were included in the neoadjuvant chemotherapy group and 103 patients — in the surgery group. Study groups were well balanced and comparable for gender, the ASA status and the tumor differentiation grade. More patients in the neoadjuvant chemotherapy group had clinically positive lymph nodes (p = 0.002). Median follow-up period was 36 months. There were no significant differences in 3‑year OS and DFS. The local recurrence rate was 3.9 % in the surgery group versus 0 % in the neoadjuvant chemotherapy group (p = 0.046). There were no significant differences between study groups in the distant metastases rate (p = 0.293). Sixteen (13.6 %) patients had a pCR after neoadjuvant chemotherapy. The neoadjuvant chemotherapy completion rate was 91.5 %. The hematological toxicity grade 3–4 was observed in 3.3 % (4 patients), the non-hematological toxicity grade 3–4 in 3.3 % (4 patients).Conclusion: NACT has an acceptable toxicity profile, does not impede oncological treatment results, and can be used in a selected group of patients for early systemic control.

AIM: to compare the hernia rate and the post-operative morbidity in patients after retroperitoneal and traditional (direct) colostomy during laparoscopic APR.PATIENTS AND METHODS: the retrospective study included patients with rectal and anal cancer after laparoscopic APE in 2019-2022. Direct or retroperitoneal end colostomy were the surgeon’s choice. Primary endpoints were the hernia rate after ≥ 1 year by abdominal CT and post-operative morbidity (Clavien-Dindo).RESULTS: fifty patients were included in the study (30 patients with retroperitoneal colostomy and 20 patients with direct colostomy). There were no significant differences in parameters that could affect the results. Four (13.3%) vs 8 (40%) patients developed parastomal hernias in the retroperitoneal and direct colostomy group, accordingly (p = 0.045). No post-operative morbidity grade 4–5 and no other complications that could be attributed to retroperitoneal colostomy occurred. Post-operative morbidity grade 3 developed in 3 (10%) patients in the retroperitoneal colostomy group and in 1 (5%) — in the direct one (p = 0.64).CONCLUSION: retroperitoneal colostomy in laparoscopic APE may reduce the parastomal hernia rate. It is important to conduct prospective comparative studies.

Introduction . Sporadic cases of squamous cell carcinoma of the rectum (rSCC) do not allow a comparative characterization of tumor aggressiveness and its response to chemoradiotherapy in relation to more common squamous cell entities, in particular, anal squamous cell carcinoma (aSCC). Objective : comparative evaluation of the short- and long-term results of chemoradiation therapy in patients with rSCC and aSCC. Material and Methods . In this retrospective study we included patients with nonmetastatic squamous cell carcinoma of the rectum (rSCC) and anal canal squamous cell carcinoma (aSCC) who received chemoradiotherapy and compared them in a 1:1 ratio using propensity-score matching. The dynamics of tumor response to treatment were compared by Kaplan-Meier survival analysis (OS and RFS) followed by Log-Rank verifcation, rate of complete response after 6 months. Results . A total of 15 pairs of matched patients were evaluated. Patients in both groups had reliably similar sex, age, histological grade, initial primary tumor size, differing only in tumor histological subtype. In the aSCC group, 60 % of patients had metastases to pelvic lymph nodes, while in the rSCC group metastases had 46.67 % (p=1). The median follow-up was 44 months. The 3-year OS in the aSCC group of patients was 76.9 %, and 71.4 % in the rSCC group (p=0.567). The 3-year DFS in the aSCC group was 66.7 %, and in the rSCC group 34.7 % (p=0.406). The rate of achieving complete clinical response to CRT after 6 months was 86.7 % for the aSCC group and only 46.7 % for the rSCC group (p=0.05). Organ-saving treatment was achieved in 93.3 % of aSCC patients and 73.3 % of rSCC patients (p=0.33). Conclusion . Overall and recurrence-free survival rates were not signifcantly decreased for rSCC patients relative to aSCC patients. This indicates a similar course and prognosis in the two diseases, but rSCC is characterized by a signifcantly lower rate of complete response to treatment.

INTRODUCTION: there is a lack of information chemoradiotherapy (CRT) efficacy in signet ring cell carcinoma of the rectum (SRCCR). The aim of our research was to investigate the efficacy of preoperative CRT in patients with SRCCR.PATIENTS AND METHODS: we conducted a retrospective analysis of medical records from the archive of Research Institute FSBI “N.N. Blokhin Cancer Research Center” of the Ministry of Health of Russia and multicenter registry of the Russian Society of Specialists in Colorectal Cancer (RSSCC) from 2000 to 2020 and included in the study group patients with histologically confirmed primary SRCCR who received preoperative CRT. A control group with rectal adenocarcinoma was created using propensity-score matching from the institutional database 1:1 taking into account sex, age, tumor size, the cT and cN clinical stage. We estimated the rate of Dworak tumor regression grade 3-4, RECIST, 5-year overall survival (OS) and disease-free survival (DFS) rates.RESULTS: the study and control group included 22 patients each. The study group included 11 patients (50%) with cT3 and cT4 clinical stage. 10 (45,5%) patients had cT3 clinical stage and 12 (54,5%) patients had cT4 clinical stage in the control group (p = 0,763). The number of patients with cN1-2 clinical stage was 17 (77,3%) and 16 (72,7%) in the study and control group, respectively (p = 0,728). The rate of Dworak tumor regression grade 3–4 was 40,9% in the group of patients with SRCCR and 45,5% in the group of patients with rectal adenocarcinoma (p = 0,761).When assessed by RECIST scale, 9 (40,9%), 12 (54,5%) and 1 (4,5%) patients with SRCCR had partial tumor response, stabilization and progression, respectively. Partial response was observed in 18 (81,8%) patients and stabilization — in 4 (18,2%) patients with rectal adenocarcinoma (p = 0,018). Median followup was 58,8 months. The 5-year OS was 34% in the SRCCR group and 71,3% in the group with rectal adenocarcinoma (p = 0,024), and the 5-year PFS was 30,2% with SRCCR and 52,2% with adenocarcinoma (p = 0,115).CONCLUSIONS: CRT leads to comparable grade 3–4 tumor regression in SRCCR and rectal adenocarcinoma, but the objective response rate is lower. This histological subtype has significantly lower OS values.

Background. The need of neoadjuvant treatment for upper rectal cancer remains the object of discussion, which makes further study of this topic important. Аim. To estimate the postoperative complications rate depending on the type of neoajuvant treatment. Materials and methods. A retrospective cohort multicenter study, that analyzed data of medical records of patients with upper rectal cancer from the archive of N.N. Blokhin Cancer Research Center of the ministry of Health of Russia, Ryzhikh national medical Research Center of Coloproctology of the ministry of Health of Russia and Stavropol Regional Clinical Oncology Center for 2007–2020. Patients were devided into 3 groups: the group of radiotherapy (5*5 gy), the group of neoadjuvant chemotherapy (4 courses of XELOX before surgery) and the group of surgery. The main endpoint was the study of anastomotic leak rate. Also we estimated the postoperative complications rate III–Iv degree (Clavien– Dindo), the sphincter-preserving surgery rate, the stoma creation rate, the postoperative mortality. Results. we included 110 patients in radiotherapy group, 188 patients in neoadjuvant chemotherapy group, 103 patients in surgery group. Study groups were comparable by sex, ASA status and histological grade. Postoperative grade III– Iv complications (in all cases were associated with anastomotic leak) developed in 8 (6.8 %) patients in neoadjuvant chemotherapy group versus 11 (10.0 %) patients in radiotherapy group (p = 0.379) and 12 (11.7 %) patients in surgery group (p = 0.208). There weren»t any significant differences in this parameter between the radiotherapy and the surgery group (p = 0.698). R0-resection was performed in 117 (99.2 %) patients in neoadjuvant chemotherapy group versus 107 (97.3 %) patients in radiotherapy group (p = 0.280) and 103 patients (100 %) in surgery group (p = 0.349). Radiotherapy and surgery groups didn’t differ significantly in R0-resection rate (p = 0.091). 1 patient (0.84 %) in neoadjuvant chemotherapy died before surgery, in other groups there weren’t any lethal outcomes (p = 0.283). Only the male sex, had a statistically significant effect on the anastomotic leak rate (risk ratio (HR) 2.875; 95 % confidence interval (CI) 1.24–6.63; p = 0.003). Conclusions. A study of these case histories of patients with cancer of the upper ampullary rectum, conducted by us, showed that neoadjuvant treatment didn»t affect the postoperative complications rate.

A lack of evidence-based data on the chemoradiotherapy (CRT) efficacy in patients with squamous cell carcinoma of the rectum (SCCR) makes further study of this topic extremely important.Aim: The aim of our research was to estimate the efficacy of CRT in patients with SCCR compared to the rectal adenocarcinoma and squamous cell carcinoma of the anal canal (SCCAC).Materials and methods: Our study was based on analysis of medical records of patients with ICD–X code C20 and ICD-O 8070 / 3, 8070 / 3.1, 80703 in a database from 2007 to 2020 obtained from the archive of Research Institute FSBI “N. N. Blokhin Cancer Research Center” of the Ministry of Health of Russia. We included patients with SCCR who received CRT as initial treatment into the experimental group. Groups with rectal adenocarcinoma and SCCAC were created using propensity-score matching 1:2 taking into account sex, age, the cN clinical stage, histological grade and tumor size. The main study endpoints were 3‑year overall survival (OS) and disease-free survival (DFS) rates, complete clinical response rate and complete clinical or pathological response rate at 6 months after CRT, local recurrence and distant metastases rates, surgery rate.Results: We included 15 patients in SCCR group and 30 patients in rectal adenocarcinoma group and SCCAC group each. There were no significant differences in parameters that could affect the prognosis. The complete clinical response was achieved in 7 (46.7 %) patients with SCCR versus 3 (10.0 %) patients with adenocarcinoma (p = 0.005) and 24 (80.0 %) patients with SCCAC (p = 0.005). The surgery rate was 26.6 % (4 patients) in SCCR group, 6.67 % (2 patients) in SCCAC group, 90 % (27 patients) in adenocarcinoma group (p < 0.001). The recurrence rate was 26.7 % (4 patients) in SCCR group versus 10.0 % (3 patients) in adenocarcinoma group (p = 0.146) and 6.7 % (2 patients) in SCCAC group (p = 0.063). The metastases rate was 26.7 % (4 patients) in SCCR group, 26.7 % (8 patients) in adenocarcinoma group (p > 0.99). In SCCAC group metastases were detected in 1 (3.3 %) patient, which was significantly different compared to the SCCR group (p = 0.019). Median follow up was 44 months. The 3‑year OS was 78.8 % in SCCR group versus 91.0 % in adenocarcinoma group (p = 0.675), and 86.3 % in SCCAC group (p = 0.953). The 3‑year OS in adenocarcinoma and SCCAC groups did not differ (p = 0.996). The 3‑year DFS was 34.7 % in SCCR group versus 55.6 % in adenocarcinoma group (p = 0.504) and 82.9 % in SCCAC group (p = 0.031). The 3‑year DFS differences in adenocarcinoma and SCCAC groups were significant (p = 0.041).Conclusions: We have obtained important data on the CRT comparative efficacy in patients with SCCR, SCCAC and rectal adenocarcinoma. The high complete clinical response rate in SCCR group makes it possible to consider the use of CRT as the main treatment method. Results of our research can be used to plan the treatment of patients with SCCR.

AIM: to evaluate the effectiveness of first-line chemotherapy in patients with colorectal neuroendocrine cancer (NEC).PATIENTS AND METHODS: a retrospective study included patients with metastatic colorectal NEC (2000-2020). The main analyzed parameter was the response rate to treatment according to the RECIST criteria, depending on the regimen used in the first line. The overall survival was additional parameter.RESULTS: the study included 27 patients (13 with initial stage IV disease and 14 with progression after primary radical treatment). Ten patients in the 1st line underwent chemotherapy according to the EP scheme, 4 — XELOX, 2 — FOLFIRI, 2 — Irinotecan and Cisplatin, 1 — Samarium, 1 — Nivolumab, 1 — 5-FU-LV. Most often, the treatment effect (partial response or stabilization) was observed against the background of chemotherapy according to the EP scheme — in 60% of patients. The median OS was 7 months.CONCLUSION: the use of chemotherapy according to the EP regimen is the preferred options for the treatment of metastatic colorectal NEC. The median OS in this group of patients remains extremely low, and new clinical trials are needed.

AIM: to compare long-term outcomes and safety of the addition of paclitaxel to chemoradiotherapy for squamous cell anal carcinoma. PATIENTS AND METHODS : A prospective phase 3 randomized trial included patients with histologically verified non-metastatic anal squamous cell carcinoma. Patients received radiotherapy 52-54 Gy (for T1-T2 tumors) and 56-58 Gy (for T3- T4 tumors) in 2 Gy daily fractions during chemotherapy with mitomycin C (10 mg/m 2 i.v. day 1), capecitabine (625 mg/m 2 2 times a day orally on days of radiation therapy), paclitaxel (45 mg/m 2 i.v. on days 3, 10 , 17, 24, 31) during 2013-2019. In the control group patients received a similar course of RT and chemotherapy with mitomycin C (12 mg/m 2 i.v. day 1 ), capecitabine (825 mg/m 2 2 times a day orally on radiotherapy days). The primary endpoint was 3-year disease-free survival (DFS). Secondary endpoints included complication rate (NCI-CTCAE 4.0), complete clinical response rate at 12 weeks and 26 weeks after completion of CRT, and 3-year overall survival (OS). RESULTS: The study and control groups included 72 patients each. The median follow-up was 39.5 months. A complete clinical response at the 26-week follow-up was recorded in 64 (88.9%) patients in the study group and in 54 (75%) patients in the control group (p=0.049). There were no differences in the incidence of complications of grades 3-4 in the two groups (39/72 [54.2%] in the study group versus 35/72 [48.6%] in the control group (p=0.617)). Three-year progression-free survival in the study group was 87.1%, in the control group - 64.4% (p=0.001). Three-year overall survival in the study group was 95.5%, in the control group - 80.0% (p<0.001). CONCLUSION: CRT with paclitaxel for squamous cell anal carcinoma has acceptable toxicity and may improve long-term treatment outcomes.

The aim of the study was to assess the response to preoperative radiotherapy (RT) in patients with G2-G3 rectal neuroendocrine tumors (NETs). Material and methods. Case reports involving patients who were given treatment at the N.N. Blokhin National Medical Research Center of Oncology from 2000 to 2020 were retrospectively studied. Patients with histologically verified neuroendocrine tumors of the rectum and anal canal (G2 and G3, Ki67>3%), who underwent preoperative radiotherapy (RT) or chemoradiotherapy (CRT) were included into the study. the study excluded patients who received palliative RT/CRT, patients with primary multiple synchronous or metachronous tumors, and patients with unresectable liver metastases. Staging was performed on the basis of MRI of the pelvis, CT scan of the chest and abdomen with intravenous contrast. The main assessment parameter was the response rate to treatment according to the RECIST criteria, and additional parameters were the frequency of pathological response according to DWORAK classification and overall and relapse-free survivals. Statistical analysis was conducted using the IBM SPSS software package (version 25). Results. The median follow-up time was 24 months. the follow-up time of a patient with G3 neuroendocrine cancer was 64 months without the evidence of disease progression. The 5-year OS and DFS for patients with G2-G3 rectal NETs were 64.3 % and 53.3 %, respectively. Conclusion. Long-term progression-free survival in 2 out of 3 patients with G3 neuroendocrine cancer (1 of them with a complete clinical response) and in 3 out of 4 patients with G2 neuroendocrine tumors was obtained.

Objective: to compare short-term and long-term treatment outcomes between patients with lower and middle rectal cancer with complete clinical and pathomorphological response after comprehensive treatment.Materials and methods. we performed retrospective analysis of treatment outcomes in patients with lower and middle rectal cancer. The experimental group included 27 patients with complete clinical response, whereas the control group comprised 31 patients with complete pathomorphological response (ypT0n0m0) who had undergone total mesorectal excision following neoadjuvant therapy. The main evaluated parameters included postoperative complications, proportion of R0 resections, proportion of sphincter-preserving surgeries, 2-year overall survival, and progression-free survival.Results. At a median follow-up time of 41 months (range: 25–114 months), 2 patients from the experimental group had progressive disease registered 18 and 19 months after treatment initiation; both patients underwent abdominoperineal extirpation of the rectum. The remaining 25 patients had sphincter sparing surgeries. At a median follow-up time of 48 months (range: 24–101 months), one patient was found to have liver metastasis 5 months following treatment initiation. He underwent simultaneous surgery that included low anterior resection of the rectum and liver resection and had no postoperative complications. In the group of surgical treatment, all patients underwent radical surgeries (R0), including those with permanent stoma formation (n = 11; 35.5 %) or preventive stoma formation (n = 20; 64.5 %) with subsequent bowel repair. The 2-year overall survival rate was 100 % in both groups. The 2-year progression-free survival rate was 92.6 % in the experimental group and 96.8 % in the control group (p = 0.473).Conclusion. The watch and wait strategy with active dynamic follow-up is a safe alternative to surgery in patients with complete clinical response after neoadjuvant therapy, since it ensures the results equivalent to those in patients with complete pathomorphological response.

Background. Currently available chemoradiotherapy regimens for distal rectal cancer often ensure complete regression of the tumor and lymph node lesions. Therefore, patients with a complete clinical response can be managed with a “watch and wait” (ww) strategy.Objective: to evaluate 2-year overall and progression-free survival in patients with local and locally advanced rectal cancer with a complete clinical response who were managed with the ww strategy.Materials and methods. we performed retrospective analysis of treatment outcomes in patients with newly diagnosed, histologically verified, stage II–III, mrT1–2n1–2m0, T3–4n0–2m0 (within 0–10 cm of the anal verge), and mrT2n0m0 (within 0–5 cm of the anal verge) rectal cancer who had demonstrated complete clinical response to chemoradiotherapy. mandard tumor regression grade (TRg1–2) (assessed using magnetic resonance imaging of the pelvis) and palpatory/visual signs of residual tumor (assessed by digital examination and colonoscopy) were the main parameters evaluated. Overall and disease-free survival was analyzed using the Kaplan–meier method.Results. Twenty-seven patients with a complete clinical response were assigned to the ww group. mRI scans of the pelvis demonstrated that 5 patients (18.5 %) had TRg1, whereas 22 patients (81.5 %) had TRg2. T-downstaging after therapy was observed in 21 participants (77.7 %). n-downstaging was registered in all 14 patients (100 %) with regional lymph nodes affected. median follow-up time was 41 months (range: 25–114 months). Two individuals (7.4 %) developed progressive disease. Both of them had lengthy tumors as demonstrated by digital examination, colonoscopy, and magnetic resonance imaging; they immediately underwent radical surgery. The two-year overall and disease-free survival rates were 100 % and 92.6 %, respectively. Conclusion. The ww strategy with active dynamic follow-up is safe for the management of patients with local and locally advanced middle and lower rectal cancer, provided that inclusion/exclusion criteria are adhered to and patients are carefully followed-up in specialized centers.

Abstract. Rare malignant tumors require complex diagnostics and extended multidisciplinary team discussion. Knowing rare tumours epidemiology is vital for correct organization of clinical work in different departments. The aim of this study was to investigate epidemiological data on rare colorectal and anal malignant tumors in a large-volume tertiary hospital. Methods. A retrospective analysis was carried out in N.N. Blokhin Russian Cancer Research Center during 2000-2020. All patients (both in- and outpatient departments) with colorectal and anal tumors were identified. Rare colorectal and anal malignant tumors were identified using an ICD-X and ICD-O codes. We investigated the incidence of identified tumors. Results. 22 801 unique patients were identified in the registry, 15 490 (67,9%) had malignant tumors. 1443 (9,3%) had rare malignant tumors: squamous-cell cancer in 649 (45%), neuroendocrine tumors in 277 (19%), signet-cell carcinoma in 193 (13%), lymphomas in 119 (8%), melanomas in 83 (6%), sarcomas in 72 (5%), GIST in 22 (2%), other rare tumors in 22 (2%). Conclusions. The burden of rare malignant tumors is high in clinical practice of colorectal cancer specialists. Specialized multidisciplinary teams and referral systems are necessary to improve the quality of care.

Background. Colorectal anastomotic leakage remains on of the most significant challenges in rectal surgery. Objective: to assess the impact of pelvic peritoneal floor reconstruction on the incidence of postoperative complications associated with colorectal anastomosis. Materials and methods. In this retrospective cohort study, we analyzed medical records of rectal cancer patients who had undergone rectal resection with anastomosis formation between 2013 and 2020. we compared patients who had no pelvic peritoneal floor reconstruction (from 2013 to 2017) and those who had it (2018–2020). Only patients with favorable prognosis (tumor located at least 5 cm above the transitional anal fold and no history of chemoradiotherapy) were included. The primary outcome measure was the incidence of peritonitis and colorectal anastomosis leakage. Secondary outcome measures included overall incidence of complications (Clavien–Dindo), mortality rate, blood loss, and duration of surgery. Results. A total of 120 patients were included into the experimental group, while the control group was composed of 125 patients. Ten patients from the control group developed peritonitis (8.0 %), whereas in the experimental group, there were no cases of peritonitis (p = 0.002). Anastomotic leakage was registered in 12 individuals from the experimental group (12.5 %) and 14 controls (11.2 %) (p = 0.753). The overall incidence of postoperative complications was 23.3 % (n = 28) among patients who had pelvic peritoneal floor reconstruction and 18.4 % (n = 23) among those who did not have it (p = 0.342). Colostomy was required in 92 patients from the experimental group (76.7 %) and 78 patients from the control group (62.4 %) (p = 0.018). The postoperative mortality was 0.8 % in the control group (n = 1) and 0 % in the experimental group (p = 1). Conclusion. Pelvic peritoneal floor reconstruction reduces the risk of peritonitis, but does not affect the overall risk of anastomotic leakage. This method is effective for the prevention of severe postoperative complications.

Targeted therapy for colorectal cancer usually includes anti-vEgf and anti-EgfR antibodies. The initiation of first-line therapy for metastatic colorectal cancer depends on the baseline patient’s characteristics, tumor spread, and its mutational status. Despite the wide range of possible combinations of these factors, an oncologist should choose between standard platinum-based chemotherapy regimens and combination of similar chemotherapeutic agents with bevacizumab or cetuximab. Disease progression after first-line therapy poses a dilemma to an oncologist, since the range of potentially beneficial targeted drugs or immunotherapeutic agents is much wider along with the lack of sufficient evidence. This article focuses on the efficacy of aflibercept as a second-line treatment for colorectal cancer, indications for its use, and outlooks.

Background . Anorectal melanoma is a rare malignancy without established standard treatment. Aim . To analyse the Russian Colorectal Cancer Society melanoma registry and to assess optimal surgery with regard to the extent of the disease. Materials and methods . A retrospective analysis of the Russian Colorectal Cancer Society registry was carried out during 2000–2020. Patients with cutaneous melanoma colonic metastases as well as patients with less than 6 months follow-up were excluded. Basic patient group characteristics, overall and disease-free survival (were analyzed depending on disease stage (by A. Stefanou) and surgery type. Results . 16 patients had stage I–IIA, 24 – stage IIB, 29 patients – stage III and 24 patients – stage IV disease. Wide local excision was performed in 15 (93.8 %) patients with stage I–IIA, 15 (62.5 %) patients with stage IIB, 2 (6.9 %) patients with stage III, and 8 (33.3 %) patients with stage IV disease. Abdomino-perineal excision (APE) was performed in 0 patients with stage I–IIA, 7 (29.2 %) patients with stage IIB, 22 (75.9 %) patients with stage III, and 7 (29.2 %) patients with stage IV disease. 2-year overall survival was 74.5 % in stage I–IIA, 49.4 % in stage IIB, 64.3 % in stage III, and 10.4 % in stage IV disease; 2-year disease-free survival was 67 %, 23,4 %, 34,1 % in stage I–IIA, IIB, III disease accordingly. Median overall survival was 17.8 months, 38.3 months and 27.9 months for non-surgical treatment, wide local excision and APR in non-metastatic patients accordingly. Median disease-free survival was 6.0 months, 14.1 months and 12.0 months for non-surgical treatment, wide local excision and APR in non-metastatic patients accordingly. Conclusions . APR should be considered in patients with stage IIB and stage III (by A. Stefanou) anorectal melanoma. Wide local excision is the preferred treatment in other patients.

Introduction: Signet ring cell carcinoma of the rectum (SRCCR) is a rare rectal tumor, therefore, only limited information is available on the management of patients with this diagnosis. Since literature data on the susceptibility of signet ring cell carcinoma to radiation therapy (RT) are controversial, one of the questions that specialists may have is whether the RT is effective as the first stage of treatment.Materials and methods: We conducted a retrospective analysis of medical records of patients with SRCCR treated at Research Institute FSBI «N. N. Blokhin Oncology Center» of the Ministry of Health of Russia from 1998 to 2020. The inclusion criteria were as follows: histologically confirmed primary SRCCR, disease stage I–III, use of RT or chemoradiotherapy at the first stage. A case control study design was used to select a control group of patients with rectal adenocarcinoma, and each case of the control group was compared with the study group by the following criteria: the year of treatment, the cT and cN clinical stage, the use of RT or CRT. The main endpoint was the rate of Dworak tumor regression grade 3–4; secondary endpoints included 5-year overall survival (OS) and progression-free survival (PFS) rates.Results: The study and control groups included 16 patients each. In each group, 14 (87,5 %) patients received CRT and 2 (12,5 %) received RT; cT3, cT4 stages were diagnosed in 7 (43,8 %) and 9 (56,3 %) patients, respectively; cN0 and cN1–2 stages were diagnosed in 3 (18,8 %) and 13 (81,2 %) patients, respectively. Eight (50 %) patients in the SRCCR group and 4 (25,0 %) patients in the control group had Dworak tumor regression grade 3–4 (p = 0.273), and one (6,3 %) patient in each group showed pathological complete response (p > 0.99). The 5-year OS in the SRCCR group and the control group was 34,9 % and 51,4 %, respectively (p = 0.833); the 5-year PFS was 30,8 % and 35,6 %, respectively (p = 0.094).Conclusions: SRCCR is at least as susceptible to RT / CRT as rectal adenocarcinoma, for which neoadjuvant RT / CRT is the standard of care; the use of combination therapy produces comparable long-term results.