Poster Topical Area: Diet and Cancer
Poster Board Number: 193
Intestinal microbiota plays an essential role in many diseases such as obesity, IBD and cancer.
Our aim is to characterize fecal microbiota from early stage breast cancer patients compared to healthy controls.
Feces (n=25) from newly diagnosed breast cancer patients, before any therapeutic treatment, and control feces (n =30), were collected[n1] . Targeted metagenomic analyses were conducted on the 16S rDNA gene V3V4 regions, using a MiSeq sequencing platform (Illumina). Descriptive statistics (at the Phylum, Family and Genus levels) were performed and focus was done on richness and diversity indices.
Patients and controls were comparable for menopausal status and BMI, while patients were older than controls (63,0 y vs 55,1 p=0,0056[n2] ). Most patients have ductal (81%), HR+ (> 80%), grade II (62.5%) breast cancer. Shannon index was statistically lower in the breast cancer group, compared to controls (4,9 vs 5,2, p=0,0082). No significant difference between groups was observed for richness (Chaos1 index). A significant higher relative abundance of Firmicutes Phylum (61.6% vs. 54.2%, padj = 0.031) and a lower abundance of Bacteroidetes Phylum (27, 2% vs 37.0%, padj = 0.006) were observed in patients, compared with controls. At the family level, no significant difference was observed between groups. Coprococcus (Firmicutes), Odoribacter and Butyricimonas (Bacteroidetes) genera were found in a less relative abundance in patients, compared to controls (1,4% vs 2,8%, padj=0 ,030; 0,1% vs 0,3%, padj=0 ,104 et 0,1% vs 0,3%, padj =0,052, respectively).Conversely, Clostridium XVIII and Lachnospira (Firmicutes) were in a higher relative abundance in patients (0,8 % vs 0,3%, padj=0 ,056 and 1,2% vs 0,6%, padj=0,10).
This preliminary study suggests that breast cancer patients may differ from healthy subjects for their intestinal microbial composition. Further studies are needed to explore the relationship between microbiome and breast cancer.
ICO-René Gauducheau, UNAM Université de Nantes
Nantes, Pays de la Loire, France