Presentation Information
[SY7-2]Gut Microbiota Profiles in Reactive and Metastatic Lymphadenopathy in Colorectal Cancer
*Toru Miyake1,2, Masatsugu Kojima1, Soichiro Tani1, Keiji Muramoto1, Nobuhito Nitta1, Reiko Otake1, Haruki Mori1, Hiromitsu Maehira1, Sachiko Kaida1, Tomoharu Shimizu2 (1. Department of Gastrointestinal and General Surgery, Shiga University of Medical Science, Japan, 2. Medical Safety Section, Shiga University of Medical Science Hospital, Japan)
Purpose: In advanced colorectal cancer, pre-operative lymphadenopathy may represent either metastasis or reactive changes. This study aimed to compare the gut microbiota between patients with reactive and metastatic lymphadenopathy and explore its association with non-metastatic lymph node swelling.
Methods: This study was a retrospective observational analysis of fecal and tumour tissue samples from colorectal cancer patients, utilizing 16S rRNA gene sequencing, conducted at Shiga University of Medical Science Hospital between 2018 and 2021. A comparison was made of the bacterial profiles in patients with reactive and metastatic lymphadenopathy. Sixty-three patients with a pre-operative diagnosis of lymphadenopathy who underwent resection were included. DNA was extracted from both fecal samples collected pre-operatively and surgically resected tumour tissues.
Results: Median age was 70 years, with 49% male. Among 63 patients with preoperative lymphadenopathy, 34 (54%) had pathological metastasis and 29 (46%) were diagnosed with reactive lymphadenopathy. Fecal samples had higher alpha diversity than tumour samples. Proteobacteria were enriched in metastatic tumours, while Firmicutes predominated in non-metastatic cases. Metabolic pathways related to oxygen-dependent metabolism were active in metastatic cases, whereas anaerobic glycolysis and lipopolysaccharide synthesis pathways were more active in non-metastatic cases.
Conclusion: Distinct microbiota compositions were identified between reactive and metastatic lymphadenopathy in colorectal cancer patients, suggesting that bacterial-induced inflammation may be involved in reactive lymphadenopathy.
Methods: This study was a retrospective observational analysis of fecal and tumour tissue samples from colorectal cancer patients, utilizing 16S rRNA gene sequencing, conducted at Shiga University of Medical Science Hospital between 2018 and 2021. A comparison was made of the bacterial profiles in patients with reactive and metastatic lymphadenopathy. Sixty-three patients with a pre-operative diagnosis of lymphadenopathy who underwent resection were included. DNA was extracted from both fecal samples collected pre-operatively and surgically resected tumour tissues.
Results: Median age was 70 years, with 49% male. Among 63 patients with preoperative lymphadenopathy, 34 (54%) had pathological metastasis and 29 (46%) were diagnosed with reactive lymphadenopathy. Fecal samples had higher alpha diversity than tumour samples. Proteobacteria were enriched in metastatic tumours, while Firmicutes predominated in non-metastatic cases. Metabolic pathways related to oxygen-dependent metabolism were active in metastatic cases, whereas anaerobic glycolysis and lipopolysaccharide synthesis pathways were more active in non-metastatic cases.
Conclusion: Distinct microbiota compositions were identified between reactive and metastatic lymphadenopathy in colorectal cancer patients, suggesting that bacterial-induced inflammation may be involved in reactive lymphadenopathy.