Phylogenetic analysis reveals divergent modes of clonal spread and intraperitoneal mixing in high grade serous ovarian cancer

Sohrab Shah1,2

1BC Cancer Agency Research Centre, Vancouver, BC, Canada,2University of British Columbia, Vancouver, BC, Canada


To study the properties of intraperitoneal spreading patterns in high grade serous ovarian cancers, we performed phylogenetic analysis of the evolutionary histories of individual clones across multiple intraperitoneal sites. Tumour specimens were synchronously obtained at the time of primary debulking surgery, including 68 primary ovarian and intraperitoneal foci from seven patients. Whole genome sequencing and targeted deep sequencing from bulk tissues combined with single nucleus sequencing of >1500 cells was performed to compute phylogenetic clonal reconstructions from somatic genomic aberrations and establish clonal mixtures present in each sample. I will discuss at least two divergent modes of intraperitoneal metastasis, highlighting the interplay between genomically diverse clones and their migratory potential prior to therapeutic intervention in high grade serous ovarian cancers.