Prostate cancers with higher levels of aneuploidy—an abnormal number of chromosomes—also come with higher lethality risk for patients, according to a new study from a Bridge Project team co-led by Angelika Amon, KI member and Kathleen and Curtis Marble Professor in Cancer Research, and Harvard T.H. Chan School of Public Health faculty member Lorelei Mucci. Using a collection of prostate cancer tumor samples, researchers extrapolated the degree of aneuploidy from each sample's genetic sequencing information and compared it to information about patient outcomes. Patients with a higher degree of aneuploidy were five times more likely to die from the disease. The findings, published in Proceedings of the National Academy of Sciences, suggest that aneuploidy could be used to more accurately predict patients' prognosis and to identify patients who might need more aggressive treatment.