講演情報
[AS1-1]Clinical value of gut microbiota：targeting as next-generation biomarkers for colorectal cancer
Shigenobu Emoto1, Ryo Inoue2, Shin Murai1, Yuriko Inagaki1, Hiroaki Nozawa1, Kazuhito Sasaki1, Koji Murono1, Yuichiro Yokoyama1, Kensuke Kaneko1, Hiroyuki Matsuzaki1, Shinya Abe1, Yuzo Nagai1, Takahide Shinagawa1, Yuichi Tachikawa1, Satoshi Okada1, Masashi Ohno3, Akira Ando3, Soichiro Ishihara1 (1.Department of Surgical Oncology, The University of Tokyo, 2.Laboratory of Animal Science, Setsunan University, 3.Department of Gastroenterology, Shiga University of Medical Science)
Background：The gut microbiota, which varies significantly between individuals, is implicated in various pathological conditions. Its role in the development and progression of colorectal cancer（CRC）has recently garnered significant research attention. In the context of locally advanced rectal cancer（LARC）, preoperative chemoradiotherapy（CRT）is the widely accepted standard treatment. Predicting therapeutic effects and side effects before treatment remains challenging.
Methods：Twenty-one patients with LARC, who had no history of antibiotic or probiotic use, were included in the study. Mucosal samples from tumor and non-tumor areas, as well as stool samples, were collected both before and after CRT. Bacterial DNA was extracted and analyzed using 16S rRNA amplicon sequencing targeting the V3 and V4 regions.
Results：No significant differences were observed in α-diversity and β-diversity between non-pCR and pCR cases, nor between severe and mild diarrhea cases. There was a trend towards a higher proportion of the Fusobacterium genus in all sites post-CRT in pCR cases compared to non-pCR cases. Exploratory studies using Linear discriminant analysis Effect Size（LEfSe）to identify potential biomarkers for predicting pCR and severity of diarrhea found significant associations with higher levels of certain genera. Specifically, bacterial taxa such as Peptostreptococcus, Coprococcus, and Phoceaicola were identified as significant indicators of achieving pCR. Additionally, bacterial taxa such as Clostridium, Haemophilus, and Desulfovibrionaceae were associated with the severity of diarrhea.
Conclusions：These findings highlight the potential of gut microbiota composition as a predictive biomarker for therapeutic efficacy and treatment-related side effects in LARC patients undergoing CRT.
Methods：Twenty-one patients with LARC, who had no history of antibiotic or probiotic use, were included in the study. Mucosal samples from tumor and non-tumor areas, as well as stool samples, were collected both before and after CRT. Bacterial DNA was extracted and analyzed using 16S rRNA amplicon sequencing targeting the V3 and V4 regions.
Results：No significant differences were observed in α-diversity and β-diversity between non-pCR and pCR cases, nor between severe and mild diarrhea cases. There was a trend towards a higher proportion of the Fusobacterium genus in all sites post-CRT in pCR cases compared to non-pCR cases. Exploratory studies using Linear discriminant analysis Effect Size（LEfSe）to identify potential biomarkers for predicting pCR and severity of diarrhea found significant associations with higher levels of certain genera. Specifically, bacterial taxa such as Peptostreptococcus, Coprococcus, and Phoceaicola were identified as significant indicators of achieving pCR. Additionally, bacterial taxa such as Clostridium, Haemophilus, and Desulfovibrionaceae were associated with the severity of diarrhea.
Conclusions：These findings highlight the potential of gut microbiota composition as a predictive biomarker for therapeutic efficacy and treatment-related side effects in LARC patients undergoing CRT.