5-aminolevulinic acid-induced accumulation of protoporphyrin IX in rat brain tissue

The aim of the study was to compare the level of accumulation of protoporphyrin IX (ППIX) in the brain of rats in normal conditions and in experimental C6 glioma. Materials and methods. In an experiment on 15 rats, one group of animals (n=5) was intracranially implanted with rat glioma of the C6 line. 14 days after tumor implantation, the animals were injected into the lateral vein of the tail with a photosensitizer — a preparation of 5-aminolevulinic acid (5-ALA) Alasens at a dose of 100 mg / kg. Another group consisted of 5 intact rats, which were also injected with Alasens. The rats were euthanized 4–5 hours after the injection of the photosensitizer, and fluorescent metabolic navigation was performed with illumination of the brain with light with wavelengths of 417 and 435 nm. For objectification, fluorescence biospectroscopy was performed. Similar manipulations were performed with animals of another group (n=5) — intact rats that did not receive Alasens. Results. In contrast to humans, in rats, the 5-ALA metabolite — PPIX accumulates in healthy brain tissue, while the fluorescence intensity does not differ from that visualized in the tumor area. It was also noted that the light of the blue spectrum promotes weak fluorescence of the white matter of the rat brain in the absence of exogenous 5-ALA, which can potentially be explained by the activation of endogenous PPIX or other fluorophores. Conclusion. After the administration of Alasens (5-ALA preparation), the accumulation of PPIX by the rat brain tissue occurs not only by malignant cells, but also by normal brain tissue without signs of malignancy or other pathological changes. A more thorough study of this phenomenon is required, since significant differences in the metabolism of 5-ALA in humans and laboratory animals will call into question the correctness of translation of experimental results into clinical practice.

Review Cancer incidence in Five Continents Vol. XI / Ed. by F. Bray, M. Colombet, L. Mery, M. Piñeros, A. Znaor, R. Zanetti and J. Ferlay. IARC Sci. publ. № 166, Lyon, France, 1545 p.

Presented review "Cancer incidence in Five Continents" Vol. XI / Ed. by F. Bray, M. Colombet, L. Mery, M. Piñeros, A. Znaor, R. Zanetti and J. Ferlay.

Assessment of prognostic factors in extracranial germ cell tumors in children

Germ cell neoplasms in the group of benign and malignant tumors heterogeneous in morphological structure, clinical features and prognosis. A special characteristic of germ cell tumors is their high sensitivity to platinum-containing chemotherapy, which allows cure of up to 80–90% patients. However 20–25% of patients with a common type have overall survival rate of less than 50%. The aim of the study is to assess the survival rate of children with extracranial germ cell tumors and to identify adverse risk factors. Methods. The study includes 116 children with extracranial germ cell tumors treated from 2013 to September 2009. Treatment consisted of tumor resection and platinum based on platinum chemotherapy. Survival rate was assessed by the Kaplan-Mayer method. Prognostic factors are determined according to IGCCCG, MaGIC, MAKEI, RODO. Results. Overall and event free survival rates were 79±5% and 76±4%, respectively. The worst overall survival had patients with extragonadal tumors, advanced stages of a disease, high initial level of AFP (≥10 000 ng/ml), non-seminoma version of state treasury bills and extra pulmonary metastases. Conclusion. Survival rate in children with extracranial germ cell tumors depends on the prognostic factors. Statistically significant predictors of the poor prognosis were extragonadal localization of a tumor and the AFP level ≥10 000 ng/ml.

The value of computer aided detection system FOR mammography in the breast cancer screening: single-center, prospective, randomized clinical trial

Purpose. To assess the influence of mammography mapping with the help of computer-aided detection system (CAD) MammCheck II of our own design on the relapse-free survival (RFS) in breast cancer (BC) patients detected during the combined (mammographic and ultrasound [US]) screening. Materials and methods. 10732 women aged 40-87 years old (mean age: 52.20±8.63) who performed mammography were randomized to the standard screening group (mammography → US of the dense breasts) or to the group of CAD-assisted screening (mammography → CAD → targeted US of suspicious CAD markings, as well as the standard US of the dense breasts; CAD group). The primary endpoint was the 3-years RFS. Results. Totally, in the standard screening group we identified 230 BCs (4.29%), in the CAD group — 248 BCs (4.62%; p>0.05), including 49 (21.20%) и 88 (35.48%) 0-I stage BCs, respectively (p<0.05). Median of the primary tumor size was significantly lower in the CAD group (18 mm) compared to the standard screening group (25 mm; р<0.05). 3-years RFS was significantly higher (87.90%) in the CAD group compared to the standard screening group (81.20%; р<0.05). Conclusion. Breast US after the previous mammography CAD mapping significantly increases the 3-years RFS of women with combined screening-detected BC.

Secondary acquired nasolacrimal duct obstruction due to the toxic effect of antineoplastic agents

In recent years, the use of chemotherapeutic agents in the treatment of cancer became more common. At the same time, the number of complications associated with this is also increasing. Among the rare complications of therapy with some antitumor drugs is the formation of secondary acquired nasolacrimal duct obstruction. The aim was to analyze and systematize information about secondary acquired nasolacrimal duct obstruction due to the toxic effect of antitumor drugs. Materials and methods. The authors analyzed the literature available in the MEDLINE and RSCI search engines in February 2021. The analysis included 55 publications. Results. In the literature, there are indications that such antitumor drugs as 5-fluorouracil and similar drugs, mitomycin C, as well as therapy with radioactive iodine, are characterized by the possibility of developing complications in the form of secondary acquired nasolacrimal duct obstruction. Preliminary screening of the drainage function of the tear ducts, as well as prescribing of local anti-inflammatory and antibacterial treatment in the form of instillations in the conjunctival sac can help to reduce the risk of complications. This explains the need to recommend patients to consult an ophthalmologist if there are relevant complaints before or during treatment. In the absence of timely treatment, obstruction of the tear ducts often becomes an indication for reconstructive interventions. Conclusion. Secondary acquired nasolacrimal duct obstruction is one of the rare, but systematically occurring complications of antitumor therapy. To date, the pathogenesis of these complications is not fully understood, and some of the data is contradictory. In the future, the accumulation of knowledge concerning the pathogenesis of this complication will contribute to the development of personalized methods of prevention.

Clinical case of angiosarcoma of pericardium and pleura

Primary heart tumors are an extremely rare pathology, previously detected only by autopsy data and detected in 0.001%-0.03% of cases. Primary angiosarcomas of the pericardium are even more rare and are presented in the literature with isolated descriptions. The article describes a clinical case of epithelioid angiosarcoma of the pericardium and pleura of high malignancy in a 57-year-old man. The diagnosis was confirmed by immunohistochemical examination and positron emission tomography. For today, chemotherapeutic treatment of angiosarcomas localized in the chest cavity is a palliative treatment method. In this patient, the most effective scheme was the one containing anthracyclines (doxorubicin). Despite the ongoing therapy, the patient died 15 months after the diagnosis was made, with increasing signs of respiratory and heart failure. Thus, when patients, especially young and middle-aged men, show signs of hydropericardium without established etiological prerequisites, it is necessary to remember about the possibility of developing a primary malignant tumor of the heart and / or pericardium as the cause of this condition and include it in the standard diagnostic search.

Properties and functions of TP/PD-ECGF — enzyme and angiogenic factor in norm and in neoplastic pathology

Thymidine phosphorylase is a protein which may has a dual action: it is a rate-limiting enzyme in thymidine metabolism and it is similar to the platelet – derived endothelial cell growth factor (PD/ECGF). The enzyme catalyzes the reversible reaction of phosphorolytic cleavage of thymidine to thymine and deoxyribose-1-phosphate. It has been found that TP has higher activity in tumor tissues. Also it is involved in a proliferative process in a wide variety of chronic inflammatory diseases. Increased expression of PD/ECGF in many tumors is associated with aggressive disease and/or poor prognosis. Its known that high TP activity is related to malignant angiogenesis and invasion. On the other hand, TP inhibits a hypoxia induced apoptotic pathway and enhances expression of various inflammatory cytokines and interferons. This apparent role of enzyme in tumor progression has prompted investigation a large number of TP inhibitors for applicability in chemotherapy backbone regimens. The enzymatic activity of PD/ECGF is being able to generate 5-fluorouracile from capecitabine and other precursors. Thus TP is identified as a prime target for developing novel anticancer therapies. The serum TP level in cancer patients provides useful prognostic information regarding both responses to chemotherapy and length of survival and should be used in planning appropriate therapy. TP could be suggested that control of individual enzyme activity in blood serum may be used as informative tool for monitoring of patients and treatment optimization.

Physico-dosimetric aspects of radiotherapy treatment of breast cancer patients with an established tissue expander

According to the data for 2019, breast cancer occupies a leading position among malignant neoplasms in the female population in the Russian Federation. Currently, there is an increase in the number of young breast cancer patients. In this regard, the requirements for the quality of life of patients, in particular the aesthetic results of special treatment, are increasing, which contributes to the introduction of methods of reconstructive surgery in oncomammology. The two-stage installation of a silicone breast implant is the most common method of breast reconstruction in oncological practice, in which a tissue expander is installed in patients at the first stage after mastectomy, and at the second stage it is replaced with a permanent implant. At the same time, the issue of radiotherapy in patients who have undergone the surgical stage of breast cancer treatment with reconstructive plastic surgery remains relevant to date. As is known, radiotherapy plays an important role in the combined and complex treatment of breast cancer, increasing, in general, locoregional control in operated patients. On the other hand, it may increase the risk of late complications of breast reconstruction, such as the development of capsular contractures and protrusions. It should also be emphasized that at present, the impact of hypofractive radiotherapy regimes, which are the most promising in clinical development, primarily on endoprostheses in patients during two-stage reconstruction, remains insufficiently studied. This article presents a brief analysis of the physical and dosimetric planning of radiotherapy in patients with breast cancer after the installation of a tissue expander who were treated on the basis of the RNCRR.

Interstitial high dose rate brachytherapy boost in early-stage breast cancer: deformable image registration for defining target volume

Purpose: optimization of the technique of additional irradiation of the removed tumor bed using high-dose brachytherapy for breast cancer. Material and Methods: the results of treatment of 28 patients diagnosed with breast cancer were analyzed. After surgical treatment and a course of external radiation therapy, all patients underwent additional irradiation of the removed tumor bed using high-dose brachytherapy. The assessment of the operation protocols, the data of the pathomorphological conclusion was carried out, and on the basis of pre- and postoperative CT images, the formation of irradiation fields for high-dose brachytherapy was carried out. Results: After deformable (nonrigid) registration of pre- and postoperative CT images of 28 patients, it was revealed that in 18 women (64.3% of cases) the location of interstitial markers and the primary tumor focus does not match topographically, which can cause incorrect formation of borders irradiation. In 35.7% of cases, radiopaque markers were located on the chest wall (on the pectoralis major muscle) when the primary tumor was located in the breast tissue. In 25% of cases, the markers were located cranial or caudal to the topography of the primary tumor focus. Label migration occurred in 3.6% of cases. In 35.7% of cases, the topography of the primary tumor node and marks completely coincided. Conclusions: The use of deformable (non-rigid) registration of pre- and postoperative CT images is a simpler method to determine the topography of the removed tumor bed, which subsequently leads to a more accurate formation of the clinical volume of irradiation.

Transtumoral endoprothesis in surgery of colorectal cancer, complicated with colonic obstruction: advantages and disadvantages. A review of the literature

A multifactorial analysis of the literature data on the treatment of acute tumor colonic obstruction using minimally invasive endoscopic surgical technology was carried out. On the basis of the analysis of special publications, the effectiveness of stenting of the large intestine, as a minimally invasive endoscopic method of decompression, is presented. Indications and contraindications for colorectal stenting, advantages and disadvantages, possibilities and prospects of endoscopic decompression of the colon are described in detail. It is postulated that stenting, used in acute tumor obstruction of the colon as a «bridge to surgery», being a worthy alternative to classical colostomy, allows an effective antegrade decompression of the colon and prepares the patient to surgical treatment with the performance of oncological justified primary radical and one-stage restorative operations in more optimal conditions with minimal risk. It is shown that in the late stages of the malignant process and in the presence of neresect-leucorrhoea colorectal cancer, as well as in the presence of absolute contraindications to a radical surgeon Colon stenting can serve as the final treatment for inoperable patients.