Abstract. Colorectal cancer (CRC) is one of the most frequent cancers worldwide. Adenoma is the main precursor lesion and, recently, the serrated polyps were described as a group of colorectal lesions with malignant potential. The morphologic and biologic characterizations of serrated polyps remain limited. The aim of the present study was to determine the frequency of KRAS and BRAF mutations and microsatellite instability (MSI) in CRC precursor lesions, to evaluate the association between molecular, pathologic and morphologic alterations in precursor lesions and to compare with the alterations detected in CRC. A series of 342 precursor lesions were removed from 155 patients during colonoscopy. After morphologic classification, molecular analysis was performed in 103 precursor lesions, and their genetic profile compared with 47 sporadic CRCs. Adenomas were the main precursor lesions (70.2%). Among the serrated polyps, the main precursor lesion was hyperplastic polyps (HPs) (82.4%), followed by sessile serrated adenomas (12.7%) and traditional serrated adenomas (2.0%). KRAS mutations were detected in 13.6% of the precursor lesions, namely in adenomas and in HPs, but in no serrated adenoma. BRAF mutations were found in 9 (8.7%) precursor lesions, mainly associated with serrated polyps and absent in adenomas (P<0.001). High MSI (MSI-H) was absent in precursor lesions. In the 47 CCR cases, 46.8% exhibited KRAS mutation, 6.5% BRAF mutations and 10.6% MSI-H. This study confirms the role of KRAS and BRAF mutations in CRC carcinogenesis, a crucial step in implementing CRC screening strategies.
Colonization of the colon and rectum by intestinal spirochetes is detected for the first time in Brazil in 4 of 282 (1.41%) patients who had undergone sigmoidoscopy and/or colonoscopy with a histopathological diagnosis of chronic non specific-colitis. This frequency is probably understimated, since surgically obtained specimens were not considered in the present study. Histopathological diagnosis was performed using routine stains like hematoxylin-eosin which showed the typical, of 3-µm thick hematoxyphilic fringe on the brush border of the surface epithelium, and by silver stains like the Warthin-Starry stain. Immunohistochemical procedures using two, polyclonal, primary antibodies, one against Treponema pallidum and the other against Leptospira interrogans serovar copenhageni serogroup Icterohaemorrhagiae cross-reacted with spirochetal antigen/s producing a marked contrast of the fringe over the colonic epithelium, preserving the spiral-shaped morphology of the parasite. In one case with marked diarrhea, immunohistochemistry detected spirochetal antigen/s within a cell in an intestinal crypt, thus demonstrating that the infection can be more widely disseminated than suspected using routine stains. Immunohistochemical procedures, thus, greatly facilitate the histological diagnosis of intestinal spirochetosis and may contribute to a better understanding of the pathogenesis of the disease. Transmission and scanning electron microscopy performed in one case showed that the spirochete closely resembled the species designated as Brachyspira aalborgi.
There was an association by univariate conditional logistic regression between AG and ECSS in this sample of Latin-American population.
BackgroundIn the cancer of the esophagus, with recent technologic advances, self-expanding metal stents (SEMS) are at the forefront of the armamentarium for re-establishing luminal patency. Weighed against the numerous advantages of stents are the import conditions and the cost. In light of this, we tested new low cost prostheses having the basic needs and characteristics to aim a significant benefit to poor people having advanced esophageal cancer, in a Brazilian regional public hospital.MethodsThis initial experience included fifteen patients (eleven men and four women, 55 ± 6.17 years old), presenting esophageal cancer, located at the medium third of the thoracic esophagus, extending for 5.5-8 cm long, not suitable for surgical procedure because they had been staged on fourth grade of the disease, two of them having fistula communicating esophagus to respiratory tree. The stents were placed under endoscopic and fluoroscopic guidance, after attempting an esophageal dilatation. An appropriate covered stent was then deployed, twelve of 10 cm and three of 13 cm in length. A chest X-ray was done 2 h after the procedure and a barium swallow was performed within 12 hours. Seven days and monthly until complete a six month follow-up after the procedure the patients were questioned about presence of pain, regurgitation, heartburn, cough, and their alimentary behavior.ResultsThere were no severe complications and transient mild chest pain resolved until the seventh day after the stent deployment. Chest X-ray demonstrated expansion of the stent in all patients. In 2 cases of fistula, a barium swallow showed its complete sealing. The completion of the proposed follow-up was not achieved in three cases, limited by the patient's death until the third month, due to cancer progression. Recurrent dysphagia to paste food accounted for by tumor overgrowth proximal or distal to the stent and stent migration were not observed in the series.ConclusionsThe new low cost endoprostheses is effective and forthcoming increased experience and prospective trials including questionnaires to analyze quality of life will allow for more informed decisions tailoring to a particular patient situation or to unexpected complications.
Dear Editor: Chronic radiation proctopathy (CRP) is the most frequent radiotherapy complication of patients with pelvic malignancies, occurring in 5-20 % of cases. CRP is characterized by endothelial dysfunction, microvascular injury with ischemia, tissue fibrosis, and telangectasias, leading frequently to rectal bleeding. Argon plasma coagulation (APC) has been the preferred modality of invasive treatment for most of these patients presenting rectal bleeding due to its accessibility, effectiveness, and low risk of complications. APC is a non-contact coagulating method that uses a high-frequency electrosurgically ionized argon gas for tissue coagulation within 0.5 to 3 mm of deepness. The APC-related complications seem to be associated to higher argon flow rates and power settings. Our previous experience in the treatment of CRP with APC at 40-50 power and 2.0-2.5 L/min was associated with high rates of complications including deep and large rectal ulcers. Based in ex vivo experiments, it has been suggested that APC treatment was optimal at a power of 40 W and a gas flow rate at a 1.2 L/ min. However, there is still no consensus on the optimal settings of electric power and argon gas flow rate. Therefore, the aim of this study was to compare the efficacy and safety of two different settings of APC in the treatment of CRP (40 W power and 1.2 L/min versus 40-50 power and 2.0-2.5 L/min).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.