The prostate-specific antigen (PSA) blood test and digital rectal exam (DRE) can be used to detect prostate cancer when no symptoms are present. They may catch the disease at an early stage when treatment may be more effective and potentially have fewer side effects. Average-risk men should talk to their doctor about PSA screening at 45; Black men and those with a strong family history of prostate or other cancers should have this discussion at 40.

If the PSA is elevated, a doctor may order an MRI or other tests. A needle biopsy — commonly done through the rectum, or, increasingly, through the perineum — is needed to establish the diagnosis. If cancer is detected, doctors assess its stage using five important pieces of information:

How much and how quickly PSA rises over time.

How aggressive the cancer cells look under a microscope, expressed as a Gleason score (range of 6-10; 10 is the most abnormal) or a Grade Group score (range of 1-5).

Number of biopsy cores, or samples, with cancer.

Whether the cancer cells are limited to inside the prostate or have spread into the neighboring pelvic areas.

Whether the cancer has invaded lymph nodes and/or spread to more distant parts of the body.

Localized and locally advanced prostate cancer (cancer that is in the prostate or the region around it) is assigned a risk group ranging from very low to very high based on these criteria. Doctors may recommend patients with high- risk or metastatic cancer may receive a recommendation to have additional testing of their tumor for gene mutations (e.g., alterations to BRCA1 or BRCA2), as well as genetic testing for inherited cancer risk.