The link between breast cancer treatment toxicity and gut microbiota : a preliminary study

• Autor(a) principal: Campos, Teresa Gonçalves da Mota Moreira de
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/156985
• topic: Breast cancer; Gut microbiota; Chemotherapy; Toxicity; Nutrição e Metabolismo

Breast cancer (BC) is the most prevalent cancer among women worldwide. Although neoadjuvant chemotherapy (NAC) is one of the possible treatment approaches to manage this disease, it is associated with several adverse outcomes. Evidence suggests that gut microbiota may play a role in modulating chemotherapy-induced toxicity, but this connection has been insufficiently explored in the context of BC. The aim of this preliminary study was to examine the potential relationship between the initial gut microbiota composition of BC (subtype HR+(hormone receptor)/HER2-) patients and NAC-related toxicity, evaluated over a 3-month treatment period. Treatment involved a combination of anthracyclines, cyclophosphamide and paclitaxel. Before the beginning of the anticancer therapy, participants provided one stool sample, as well as information regarding their general and clinical information, biochemical analysis and adherence to the Mediterranean diet. Gut microbiota was analysed through Next Generation Sequencing (NGS) analysis. Treatment toxicity was assessed using Common Terminology Criteria for Adverse Events (CTCAE): the highest mean grade was recorded for each adverse event, during the 3-month treatment period, and all the toxic effects experienced by participants at the end of the study were also documented. A Toxicity score was calculated for each participant, according to the number of experienced adverse events during the study. Eleven patients were enrolled in the study, with a mean age of 51 ± 11 years. It was found that Alpha-diversity and Richness were, respectively, potentially negatively and positively correlated with the incidence rate of toxicities. Bifidobacterium and Ruminococcus were overrepresented in the gut microbiota of participants that manifested more adverse events, whereas Bacteroides, Blautia, Clostridium, Faecalibacterium and Prevotella seemed to be more abundant in the gut microbiota of people that experienced less treatment side-effects. The characterisation of baseline gut microbial composition of BC patients may predict their risk of developing NAC-related toxicities, which could help clinicians anticipate and manage these side-effects more effectively.