Perfil metabolômico das águas fecais de pacientes com carcinoma colorretal através de espectroscopia de ressonância nuclear magnética

Abstract

Colorectal Carcinoma (CRC) is one of the leading causes of cancer-related mortality worldwide. In order to reduce the morbidity and mortality of this disease, screening techniques for asymptomatic patients are extensively studied in the literature. Biopsy by videocolonoscopy is widely used, but presents a considerable rate of morbidity inherent in invasive diagnostic procedures. In view of the above, metabolomics have emerged as a viable alternative and with acceptable sensitivity and specificity for CRC diagnosis. The metabolic study of faecal material has been shown to be more effective because of its proximity to the mucosa of the large intestine and because it is a direct product of interactions between dietary compounds and intestinal microbiota. In an attempt to distinguish a metabolic pattern of healthy patients in relation to patients with CRC, fecal analysis of these distinct groups was performed by magnetic resonance spectroscopy (MRE). Objectives: to differentiate a typical metabolic profile of CRC patients versus the control group (CG) and to compare these results with a systematic review of theliterature (SRL). Method: 11 patients from GC and 5 patients with CRC were selected at the HUPAA coloproctology outpatient clinic. Faecal MRE analysis and subsequent evaluation of MRI spectra by statistical correlation (STOCSY) were performed by SIMCA software (umetrics.com). SRL was performed in the PubMed, Web of Science, Cochrane and Scopus databases, using key words related to colon cancer and MRE, considering studies published in English from 1992 to 2018. Results: CRC patients showed reduction in practically all metabolic pathways. Short chain fatty acids - SCFA (acetate, propionate and butyrate) and amino acids (alanine and glycine) were reduced against CG (ANOVA, P <0.05). In the SRL, 386 studies were identified, of which 5 respond directly to the established research question, allowing us to verify that in the fecal samples the SCFA and amino acids are present in reduced amounts in CRC patients. Conclusions: MRE of faecal extract is a feasible method for CRC screening. However, an increase in the interest of the scientific community in publications in high impact factor journals is necessary to establish it as a gold standard method of screening and early diagnosis of colon and rectal cancer.