Cancer progression is commonly thought of as a process involving the growth of a primary tumor followed by metastasis, in which cancer cells leave the primary tumor and spread to distant organs. A new study by researchers at Memorial Sloan-Kettering Cancer Center shows that circulating tumor cells – cancer cells that break away from a primary tumor and disseminate to other areas of the body – can also return to and grow in their tumor of origin, a newly discovered process called “self-seeding.”

The first detailed search of breast cancer genomes to uncover genomic rearrangements is published today. The team characterised the ways in which the human genome is broken and put back together in 24 cases of breast cancer.