The present disclosure provides genomic arrangements of the chromosome 3q13 region that are associated with prostate cancer, such as rearrangements between the ZBTB20 and LSAMP genes, including gene fusions between the ZBTB20 gene and the LSAMP gene and deletions spanning both genes. The ZBTB20/LSAMP genomic rearrangement serves as a biomarker for prostate cancer and can be used to stratify prostate cancer based on ethnicity or the severity or aggressiveness of prostate cancer and/or identify a patient for prostate cancer treatment. Another aspect involves discovering that deletions of the PTEN gene are observed predominately in prostate cancer from subjects of Caucasian descent. Also provided are kits for diagnosing and prognosing prostate cancer.