Additionally many prostate cancers detected by screening develop so slowly that they would not cause problems during a man's lifetime, making the complications due to treatment unnecessary.

During the transrectal procedure, an ultrasound probe is inserted into the rectum to assist in guiding the biopsy needles.

[9] A study correlating MRI and surgical pathology specimens demonstrated a sensitivity of 59% and specificity of 84% in identifying cancer when T2-weighted, dynamic contrast enhanced, and diffusion-weighted imaging were used together.

[11] In fact, a side-by-side comparison of TRUS versus MRI-guided targeted biopsy that was conducted as a prospective, investigator-blinded study demonstrated that MRI-guided biopsy improved detection of significant prostate cancer by 17.7%, and decreased the diagnosis of insignificant or low-risk disease by 89.4%.

[19][20] PI-RADS v2 created standards for optimal mpMRI image reporting and graded the level of suspicion based on the score of one to five, with the goal to improve early detection (and exclusion) of clinically significant (or aggressive) prostate cancer.

Clinical trials of mpMRI and PI-RADS v2, including NIH-funded studies are underway to further clarify the benefits of targeted prostate biopsy.

Gleason score, PSA, and digital rectal examination together determine clinical risk, which then dictates treatment options.

Tissue samples can be stained for the presence of PSA and other tumor markers in order to determine the origin of malignant cells that have metastasized.