Analyzing data from 523 patients stored in The Cancer Genome Atlas (TCGA)—the largest biological database for several cancer types—the study, published in Cancer and Metastasis Reviews, identified the important role of genetic differences in association with gene mutations or changes that drive how quickly tumor cells divide and whether they will respond to chemotherapy or spread to other organs.

The researchers found that ancestry, rather than self-identified race, was a stronger predictor of genetic differences between the tumors.