Prostate cancer is usually detected with a combination of a prostate-specific antigen test (i.e., a PSA test, in which the levels of a protein in the blood are assessed) and digital rectal exam (DRE), where the doctor feels for any enlarged, irregular, or firm areas on the prostate. Elevated PSA levels and/or an abnormal DRE will usually prompt the doctor to perform a biopsy of the prostate. Typically during this procedure, a transrectal ultrasound (TRUS) is used to visualize the prostate and help the physician guide the biopsy needle. A prostate biopsy is usually performed in the doctor’s office with the patient under local anesthesia. The biopsy sample is then sent to a lab and assessed by a pathologist, who specializes in diagnosing diseases by examining tissue, blood and body fluids. If cancer is present in the biopsy sample, then further testing, such as a computed tomography (CT) scan, magnetic resonance imaging (MRI), positron emission tomography-CT (PET-CT) scans, or bone scans may be recommended to determine the stage of cancer.