Biopsy bacterial signature can predict patient tissue malignancy

Considerable recent research has indicated the presence of bacteria in a variety of human tumours and matched normal tissue. Rather than focusing on further identification of bacteria within tumour samples, we reversed the hypothesis to query if establishing the bacterial profile of a tissue biopsy could reveal its histology / malignancy status. The aim of the present study was therefore to differentiate between malignant and non-malignant fresh breast biopsy specimens, collected specifically for this purpose, based on bacterial sequence data alone. Fresh tissue biopsies were obtained from breast cancer patients and subjected to 16S rRNA gene sequencing. Progressive microbiological and bioinformatic contamination control practices were imparted at all points of specimen handling and bioinformatic manipulation.

Fig: Investigation of the effect of contamination removal on the number of sequencing reads per patient sample. (a) Correlation of reads per sample by tissue type prior to, and following, contamination removal. (b) Box plots of reads per sample by tissue type, prior to, and following, contamination removal. Red lines indicate samples that lost more than half their total reads following contamination removal. (c) Calculation of pairwise distances, before and after contamination removal, between tumour tissue (TT), matched normal tissue (MN), skin swabs (SS).

Differences in breast tumour and matched normal tissues were probed using a variety of statistical and machine-learning-based strategies. Breast tumour and matched normal tissue microbiome profiles proved sufficiently different to indicate that a classification strategy using bacterial biomarkers could be effective. Leave-one-out cross-validation of the predictive model confirmed the ability to identify malignant breast tissue from its bacterial signature with 84.78% accuracy, with a corresponding area under the receiver operating characteristic curve of 0.888. This study provides proof-of-concept data, from fit-for-purpose study material, on the potential to use the bacterial signature of tissue biopsies to identify their malignancy status.

Hogan, G., Eckenberger, J., Narayanen, N. et al. Biopsy bacterial signature can predict patient tissue malignancy. Sci Rep 11, 18535 (2021).

Leave a Reply

Your email address will not be published. Required fields are marked *