Glossary of Terms for Men Considering Active Surveillance

Cancer that is more likely to grow, spread, or require treatment sooner. One of the main goals of Active Surveillance is to watch for signs that a cancer may be acting more aggressively than it first appeared.

A way of describing how abnormal the cancer cells look under the microscope. Lower-grade cancers usually grow more slowly than higher-grade cancers.

A way of describing where the cancer is located and whether it has spread. Men on Active Surveillance usually have localized prostate cancer.

A way of describing how far the cancer appears to have grown based on exams, imaging, and biopsy information. You may hear terms such as T1c or T2a, which help describe whether the cancer seems confined to the prostate. These terms can be part of deciding whether Active Surveillance is a reasonable option.

A follow-up biopsy done after diagnosis to confirm the original findings and make sure a more aggressive cancer was not missed. This can be an important part of deciding whether Active Surveillance is a safe option.

A group between low-risk and higher-risk prostate cancer. Some men in this category may still discuss Active Surveillance with their doctors, depending on the details of their biopsy, PSA, MRI, and overall health.

A pathologist who specializes in cancers of the urinary and male reproductive systems, including prostate cancer. Some men seek a second review from this type of specialist when treatment decisions feel close or uncertain.

A system used to describe how prostate cancer cells look under the microscope. It helps estimate how aggressive the cancer may be.

A newer grading system for prostate cancer, from 1 to 5. Grade Group 1 is the least aggressive-looking cancer and is the group most often associated with Active Surveillance.

Prostate cancer that falls between low-risk and high-risk. Some men with favorable intermediate-risk disease may still be considered for Active Surveillance, depending on their situation.

Cancer that appears to be confined to the prostate and has not spread elsewhere. This is the setting in which Active Surveillance may be considered.

Prostate cancer that appears unlikely to grow or spread quickly based on PSA, biopsy findings, and other test results. Many men offered Active Surveillance fall into this group.

A doctor who examines biopsy tissue under the microscope and determines whether cancer is present and how aggressive it looks.

A general way of describing how likely a cancer is to grow or spread. Common categories include low-risk, intermediate-risk, and high-risk.

When repeat testing shows the cancer is more aggressive than first thought. This can be one reason to move from Active Surveillance to treatment.

A way of managing low-risk or favorable prostate cancer with careful monitoring instead of immediate treatment. The aim is to avoid or delay treatment unless the cancer changes. Follow-up usually includes PSA tests, clinical exams, repeat biopsy, and often MRI.

Your first recorded PSA result, used as a starting point for comparing future PSA tests over time.

A test that adds information about how likely a prostate cancer is to be more aggressive or need treatment. It is usually considered alongside MRI, biopsy results, PSA, and other clinical information.

A procedure in which small pieces of prostate tissue are taken and examined under a microscope.

A shorter type of prostate MRI that uses fewer imaging sequences than a multiparametric MRI and does not use contrast dye. In some centres it may be used to assess the prostate while reducing scan time, although mpMRI remains the more established approach in prostate imaging.

Follow-up testing done after diagnosis to make sure the cancer is truly low risk before settling into Active Surveillance. This may include repeat PSA testing, repeat imaging, repeat biopsy, or selected biomarker or genomic tests.

A physical exam in which a doctor gently feels the prostate through the rectum to check for changes such as firmness or lumps.

Testing for inherited gene changes that may affect prostate cancer risk or aggressiveness. It may be discussed more often when there is a strong family history or cancer at a younger age.

A test that looks at the biology of the cancer itself to help estimate risk and support decision-making. These tests can add information, but they do not replace biopsy, MRI, or follow-up monitoring.

Scans or pictures of the body used to look more closely at the prostate and surrounding areas.

A scan that produces detailed images of the prostate. It can help identify suspicious areas and guide biopsies.

A newer, high-resolution ultrasound that can help doctors see suspicious areas in real time and guide a targeted biopsy during the same visit. In some centres, it is being used as another imaging option before biopsy or during follow-up.

The regular follow-up used during Active Surveillance. This often includes PSA tests, MRI scans, doctor visits, and repeat biopsies.

The plan for PSA tests, MRI scans, doctor visits, and biopsies during Active Surveillance. Exact timing varies, but the schedule helps make sure changes are caught early if they happen.

A more detailed kind of prostate MRI that combines different types of images to help assess suspicious areas. It is commonly used in Active Surveillance to help guide monitoring and biopsy decisions.

A scoring system used by radiologists to describe how suspicious an area looks on a prostate MRI. It can help decide whether a biopsy or closer follow-up may be needed.

A scoring system used with micro-ultrasound to describe how suspicious an area looks. Like PI-RADS on MRI, it helps doctors judge whether an area may need closer attention or biopsy.

A protein made by the prostate that can be measured with a blood test. PSA levels can rise for many reasons, not just cancer.

The size of the prostate, usually measured on imaging. This helps doctors calculate PSA density and put a PSA result into better context.

The PSA level in relation to the size of the prostate. This can be especially helpful in Active Surveillance because it may give a clearer sense of whether a PSA result is reassuring or more concerning. A lower PSA density can sometimes support a more reassuring picture when it is considered together with MRI and biopsy findings.

How PSA changes over time, such as how quickly it rises. During Active Surveillance, PSA changes are usually looked at alongside MRI findings, biopsy results, and other information rather than on their own.

A repeat PSA blood test done to make sure an elevated result is real and not caused by something temporary, such as infection, recent ejaculation, biking, or a recent procedure.

A scan that looks for prostate cancer using a tracer that attaches to a protein called PSMA. It is most often used when doctors are concerned that cancer may have spread or returned after treatment, so it is not usually part of standard Active Surveillance.

A biopsy done during follow-up to see whether the cancer still appears low-risk or has changed. This can help show whether Active Surveillance continues to be a safe choice.

A biopsy that samples several standard areas of the prostate rather than aiming at one specific suspicious spot. It is sometimes described as a standard biopsy.

A biopsy aimed directly at a suspicious area seen on MRI or micro-ultrasound. This can help doctors sample the part of the prostate that looks most concerning.

A biopsy taken through the skin between the scrotum and anus rather than through the rectum. In Active Surveillance, this approach is often discussed because it may lower infection risk and can sometimes sample the prostate more thoroughly, including areas toward the front of the gland.

A biopsy taken through the rectum, often using ultrasound guidance. This has been widely used for many years, though some centres now prefer the transperineal approach because of infection concerns.

An ultrasound done through the rectum, often used during prostate biopsy.

An imaging method that uses sound waves to create pictures. It is commonly used during prostate biopsies.

One small sample of prostate tissue taken during a biopsy.

A change on MRI or micro-ultrasound that makes an area look more suspicious than before. This might include a new lesion, growth of an existing lesion, or a higher imaging score.

A growth pattern seen on biopsy that can suggest the cancer may behave more aggressively than the Grade Group alone might suggest.

A general way of saying that cancer was found in more of the biopsy samples, in a greater percentage of a sample, or in a broader area of the prostate than expected.

A biopsy finding that is usually treated as a warning sign for more aggressive disease elsewhere in the prostate.

An area on imaging that looks different from the surrounding prostate tissue and may need closer attention.

A more aggressive-looking prostate cancer pattern seen under the microscope. In biopsy reports, even a small amount of pattern 4 can matter.

A high-grade prostate cancer pattern that looks more concerning under the microscope and is associated with more aggressive disease.

A biopsy core that contains cancer.

Evidence that the cancer may be changing over time, such as a higher grade on biopsy, more concerning imaging, or a worrisome overall pattern.

A general way of saying that, based on the test results and the overall picture, Active Surveillance may be a reasonable and safe option to discuss. Being a candidate does not mean every doctor will make the same recommendation, but it means the option is worth reviewing carefully.

A research study that tests a medical approach, test, or monitoring strategy. Some men on Active Surveillance choose to participate in studies related to imaging, biomarkers, monitoring, or quality of life.

The pattern of cancer in your close relatives, such as a father, brother, or several family members with prostate, breast, ovarian, or pancreatic cancer. Family history can affect how doctors think about inherited risk and whether extra testing may help.

An estimate of how long a person is likely to live based on age and overall health. In prostate cancer care, it can help guide whether Active Surveillance, watchful waiting, or treatment makes the most sense.

Treatment that may not have been necessary, especially when a cancer was unlikely to cause harm. One of the main goals of Active Surveillance is to reduce overtreatment.

A second look at biopsy slides by another pathologist, often to confirm the grade and check for important features that may affect treatment decisions. Some men find this especially helpful when their case seems close to the line between Active Surveillance and treatment.

When another doctor reviews your diagnosis or treatment options. This can be helpful when deciding whether Active Surveillance is right for you.

A process in which you and your healthcare team make decisions together based on the medical facts and what matters most to you. This is especially important in Active Surveillance, where more than one reasonable path may exist.

A change in results that suggests treatment may now be the safer choice. This may be based on biopsy findings, imaging, PSA-related changes, or a combination of factors.

The period of time a man remains safely on Active Surveillance without needing treatment. For some men this may be many years, and for others treatment may eventually become the better option if the cancer changes.

A less intensive approach than Active Surveillance, usually focused on symptom management rather than cure. It is more often considered for men who are older, have other significant health issues, or are unlikely to benefit from repeated testing or curative treatment. This distinction matters because Active Surveillance is meant for careful monitoring with the option of curative treatment later if needed.

A result that does not suggest cancer. In prostate care, a benign explanation may include a larger prostate, inflammation, or another non-cancerous cause of symptoms or PSA change.

An enlarged prostate that is not cancer. This is common as men get older and can affect PSA levels and urinary symptoms.

Inflammation of the prostate, sometimes called prostatitis. This can raise PSA and may cause pelvic discomfort or urinary symptoms, even when cancer is not the reason for the change.

Urinary symptoms such as frequency, urgency, weak stream, or getting up at night.

The muscles that help control urination and support organs in the pelvis.

A term often used when talking about how a diagnosis or management approach affects day-to-day living. Quality of life is one reason many men consider Active Surveillance when it is safe to do so.

Symptoms such as frequent urination, urgency, a weak stream, or getting up at night to urinate. These symptoms can have many causes and do not necessarily mean the cancer is worsening.