Effects of intestinal flora on the degree of infiltration of tumor-infiltrating lymphocytes in breast cancer

Abstract

Objective: To investigate whether the abundance or diversity of intestinal flora in breast cancer (BC) patients effects on the degree of tumor infiltration lymphocytes in breast cancer tissues. Methods: Between March 2017 and October 2017, a total of 80 biopsy-confirmed female patients with BC were enrolled in the present study at the Breast Center of the Fourth Hospital of Hebei Medical University (Shijiazhuang, China), age distribution ranged from 37 to 74 years, which were divided into three groups based on the infiltration of tumor-infiltrating lymphocytes, as follows: high infiltration of TILs (TIL-H) 25 cases, medium infiltration of TILs (TIL-M) 34 cases and low infiltration of TILs (TIL-L) 21 cases. DNA of the intestinal flora was determined by Illumina sequencing and taxonomy of 16S ribosomal RNA genes. Compare the differences in the abundance or diversity of intestinal flora between these three groups. The relationship between tumor-infiltrating lymphocytes and clinical characteristics was analyzed by χ2 tested, and the relationship with intestinal flora was analyzed by β diversity. Results: There were 3, 174, 2, 996, and 2, 877 different OUTs in the TIL-H, TIL-M, and TIL-L groups. The β-diversity distribution was statistically significant (weighted UniFrac, P<0.01; unweighted UniFrac, P<0.01) when comparing the three groups (TIL-H vs. TIL-M vs. TIL-L), the differences between TIL-L and TIL-H groups were greatest. Conclusions: The infiltration level of tumor-infiltrating lymphocytes in breast cancer patients was closely related to the diversity of intestinal flora.