Prostate cancer is the most common cancer in men. So far, the only tools available to detect and diagnose prostate cancer include: the PSA test and the transrectal ultrasound guided biopsy. Every year, about 20 million PSA tests are performed and about 1.2 million men undergo a biopsy. Traditional techniques such as the TRUS biopsy only sample the lower portion of the prostate – yet almost 30% of cancers are found outside this area. For this reason, only 30-40% of the 1.2 million biopsies performed on men each year are positive for prostate cancer.