Formation of metastases is the major cause of cancer related deaths. Recent studies have sequenced primary endometrial carcinomas yielding data for a single entity in the progression from the birth of a progenitor tumor cell to metastatic disease. However, the progression of these tumors to metastases has not been characterized. We performed whole-exome sequencing of 98 tumor biopsies including complex atypical hyperplasias, primary tumors and paired abdominopelvic metastases to survey the evolutionary landscape of endometrial cancer. We expanded and reanalyzed TCGA-data, identifying novel recurrent alterations in primary tumors, including mutations in the estrogen receptor cofactor NRIP1 in 12% of patients. We found that likely driver events tended to be shared by primary and metastatic tissue-samples, with notable exceptions such as ARID1A mutations. Phylogenetic analyses in cases with multiple metastases indicated these metastases typically arose from one lineage of the primary tumor. These data indicate extensive genetic heterogeneity within endometrial cancers and relative homogeneity across metastatic sites.

Genomic Analysis of Paired Endometrial Cancer Primaries and Metastases