May 24, 2017
font size

Prostate Cancer (cont.)

Medical Author:
Medical Editor:

Prostate cancer biopsy results

The result of the pathologist's analysis of the biopsy cores under the microscope is the only way to diagnose prostate cancer. The prostate biopsy technique samples many areas of the prostate but rarely the biopsy can miss small areas of prostate cancer in the prostate. Thus, if the initial biopsy results are negative but the urologist is still suspicious based on the results of the examination, the ultrasound images seen during the procedure, or the PSA, additional biopsies or tests may be recommended.

The pathologist's report on the biopsy sample showing prostate cancer will contain much detailed information. The size of the biopsy core and the percentage of involvement of each core will be reported. Most importantly the prostate cancer present will be assigned a numerical score, which is usually expressed as a sum of two numbers (for example, 3 + 4) and is referred to as the Gleason Score. This characterizes the appearance of the cancer cells and helps predict its likely level of aggressiveness in the body. It is often also referred to as the grade of the prostate cancer.

The Gleason score and the extent of involvement of the biopsy core expressed as a percentage, as well as the PSA level as well as your general state of health and otherwise estimated life expectancy all help the doctors make their best recommendations for you regarding how your cancer should be treated.

The accuracy of the PSA test

The PSA test is a tool for use by your doctor, but it is not a perfect way to tell whether or not a patient has prostate cancer because is not sensitive enough to pick up all prostate cancers. It is not specific enough in that it may be elevated in people without prostate cancer, such as those whose prostate glands are infected, inflamed, or enlarged but not cancerous. The PSA level can be affected by medications used to treat benign enlargement of the prostate (BPH), 5 alpha reductase inhibitors (finasteride, dutasteride), which lower the PSA by approximately 50% within six months to a year of being on this medication. It is also elevated for several days after a digital rectal exam or after ejaculation. Nevertheless, it accurately measures the amount of PSA in the blood at the time that it is drawn. Once a single PSA test has been obtained, the level of the PSA on follow-up tests is not as important as the rate of change of the PSA (how quickly it is increasing).

The interpretation of the PSA result must be done with care. PSA results must be, for example, interpreted in the context of the patient's age. Younger men (under 70 and definitely under 60) may have either more aggressive prostate cancers or live long enough to experience the adverse effects of undetected/untreated prostate cancer. Conversely, men over 70 often have more indolent or slow-growing prostate cancers or other medical conditions that may be greater threats to their lives over the next 10 years than may prostate cancer, and thus less aggressive evaluation and treatment may be warranted.

Prostate cancer risk increases as men age. It is estimated 16% of men will be diagnosed with prostate cancer in their lifetime, and yet only 3% will die of it. Many men likely have small prostate cancers present by the time they are over 60 years of age, with estimates ranging from 30%-40% having prostate cancer cells in their prostates. The presence of developing these small cancers also likely further increases with age. Most of these cancers are very slow-growing and not aggressive in their tendency to spread as they are never discovered or symptomatic during the men's lives. Diagnosing these prostate cancers may only increase the cost and result in treatment-related complications in these men.

Talk to your doctor about the risks and benefits of having PSA testing if you are 40 years of age with a family history of prostate cancer (or age 50 if you do not have a family history), or are of African American ancestry. The test results should be considered in the context of the man's urinary symptoms, if any, his family history, his race and ethnicity, his diet, weight, and physical findings. Further there should be attention given to the pattern of change in his serial PSA measurements.

Numerous different ways to refine the use of PSA testing have been attempted. Some of these include evaluations of the:

  • PSA doubling time, which refers to how long it has taken for the PSA to double.
  • PSA velocity, which looks at how rapidly the PSA values have changed over time.
  • PSA density, which looks at the PSA result and considers the prostate gland volume as determined on ultrasound evaluation.
  • PSA fractionation, which is another test that measures the amount of free PSA versus protein-bound PSA in the bloodstream. The lower the percentage of free PSA, the higher the risk of cancer.

In patients with prostate cancer whose PSA was initially elevated, the PSA is an excellent tool to assist in decisions about care and in follow up both during and after treatment.

Other tests which may help evaluate risk for prostate cancer and need for biopsy are used to decide treatment.

Several prostate cancer risk calculators have been developed to help determine the risk of having prostate cancer using multiple factors. Some of these risk calculators include Sunnybrook-, ERSPC-, and PCPT-based risk calculators. The calculators take determine the risk of having prostate cancer on biopsy by combining several factors including age, family history of prostate cancer, race, DRE, and PSA. These calculators may help determine the need for biopsy but should be used in conjunction with your doctor's clinical judgment and patient preferences.

The use of MRI (magnetic resonance imaging), multiparametric MRI, to select individuals who need a prostate biopsy or to guide needle placement during the biopsy, is controversial. Currently, the NCCN does not recommend that MRI alone should be used to decide whether a biopsy should be performed and notes that a negative MRI does not indicate that a biopsy should be deferred in a man with indications for a first-time biopsy. The NCCN also doesn't uniformly support the use of this study to direct prostate biopsy needle placement at this time.

Biomarkers have been developed to help define the probability of prostate cancer prior to proceeding to biopsy. The goals of the biomarker tests are to decrease the risk of unnecessary biopsies and increase the likelihood of cancer detection, without missing a significant number of prostate cancers. The biomarker tests may be most useful in men with PSA levels between 3 and 10 ng/mL. Currently, the NCCN recommends consideration of percent free PSA (%fPSA), Prostate Health Index (PHI), and 4Kscore in patients with PSA levels > 3 ng/mL who have not had an initial prostate biopsy. For individuals who have had at least one negative prostate biopsy but who are thought to be at higher risk for prostate cancer (increasing PSA), the NCCN recommends %fPSA, PHI, 4Kscore, PCA3, and ConfirmMDx. At present, no test has been established to be superior to another. Prior to having such studies done, it is advisable to ensure that your insurance company covers these tests.

Medically Reviewed by a Doctor on 11/9/2016

Source: MedicineNet.com
http://www.medicinenet.com/prostate_cancer/article.htm

Cancer

Get the latest treatment options.

advertisement
advertisement
Use Pill Finder Find it Now See Interactions

Pill Identifier on RxList

  • quick, easy,
    pill identification

Find a Local Pharmacy

  • including 24 hour, pharmacies

Interaction Checker

  • Check potential drug interactions
Search the Medical Dictionary for Health Definitions & Medical Abbreviations