Prostate Cancer: Advancements In Screenings
Dr. Christian Paul Pavlovich
You may know thatprostate canceris one of the most common cancer types in men. The good news is that thereare many treatment and management options, even if the cancer is caught ata later stage.
What you may not know: There are several options when it comes toprostate cancer screening. After considering multiple factors, your doctor may recommend theprostate-specific antigen test, and/or one of the newer screeningtests that are now available.
Johns Hopkins urologistChristian Pavlovich, M.D., explains what you should know.
Data Extraction And Quality Assessment
Data were extracted independently by 2 authors and then crosschecked. For each study, the following information was collected: last name of the first author, publication year, study design and ethnicity, age, PSA, sample size and the values of true positive , false positive , false negative , true negative , and area under the curve if available. When more than one article was published using the same population, we selected the most recent or most informative report. Disagreements between the two authors were resolved by consensus. The quality of the selected studies was assessed using quality assessment of diagnostic accuracy studies . The QUADAS tool consists of a set of 14 questions, each of which is scored as yes, no, or unclear.
Search Strategy And Study Selection
A comprehensive, computerized literature search was performed in PubMed and Embase for work published through December 2014 using a combination of the following key words: AND AND . Then, the reference sections of the identified publications were searched to identify additional potentially relevant articles. Studies included in our meta-analysis had to meet the following criteria: case-control or cohort design diagnostic test using PCA3 itself or in combination with other biomarkers and prostate biopsy as the gold standard.
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Prostate Cancer Testing: Psa Vs Pca3posted On Bynaturmend Staff 0 Comments
Although its not prostate cancer month, I decided to write about prostate health, because it has been a popular topic of discussion at my last few seminars. Prostate Specific Antigen testing is most commonly used to determine the health of the prostate gland and can be tested simply through a blood test. For a long time now, high PSA levels have shown to be correlated with prostate cancer. However, PSA levels can also be equally elevated in other non-cancerous conditions such as: Benign Prostate Hypertrophy , urinary tract infections and prostate infections . So, if PSA levels can be elevated in a variety of conditions, how would you know if your high PSA levels are due to cancer or another prostate condition? The answer is you dont know.
But, there is another laboratory test you could do! The Prostate Cancer Antigen 3 test has been shown to be extremely effective in helping patients/doctors come to a biopsy decision, investigate further for an initial cancer diagnosis and even monitor the progression of cancer numerically while undergoing active treatments. The PCA3 test is not a blood test. A digital rectal examination is performed by the physician the purpose being to massage the prostate gland and mobilize PCA3 from the prostate into the urine. Immediately following the DRE, first-urine is collected. This first-urine is rich in PCA3 and is sent to the laboratory for testing.
Pca3 Not Entirely Accurate
However, the PCA3 urine test is not 100% accurate. There have been many reports of men with PCA3 scores of > 100 who have been found to be negative for prostate cancer after multiple biopsies, according to one author. Nonetheless, it still has value for patients who have already had one or more biopsies that did not find cancer. For them, several published studies support that the PCA3 test can help avoid an unnecessary repeat biopsy if it returns a score under 35.
Not having to have a prostate biopsy is usually a relief. No one enjoys undergoing a transrectal ultrasound guided biopsy with its risks of pain, bleeding, and infection. Patients suspected of having prostate cancer, or those who have been treated but may be at risk for recurrence, all wish there were a simple liquid biopsy that did not involve sticking needles into the prostate gland but was accurate.
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Review Of Key Questions
For all EPC reviews, key questions were reviewed and refined as needed by the EPC with input from Key Informants and the Technical Expert Panel to assure that the questions are specific and explicit about what information is being reviewed. In addition, for comparative effectiveness reviews, the key questions were posted for public comment and finalized by the EPC after review of the comments.
What Is Being Tested
The prostate cancer antigen 3 test detects genetic material ) that is produced only by the prostate. The protein PCA3 and its associated mRNA are present at low levels in normal prostate tissue. PCA3 is present in increased amounts in about 90% of prostate cancers. Prostate specific antigen is also produced in increased amounts by prostate cancers but can be increased in a
The prostate cancer antigen 3 test detects genetic material ) that is produced only by the prostate. The protein PCA3 and its associated mRNA are present at low levels in normal prostate tissue. PCA3 is present in increased amounts in about 90% of prostate cancers. Prostate specific antigen is also produced in increased amounts by prostate cancers but can be increased in a number of benign conditions as well.
This test measures PCA3 mRNA and PSA mRNA in the first urine sample collected following a digital rectal exam . Laboratories report a score based on the ratio of PCA3 mRNA to PSA mRNA called the PCA3 score.
Prostate cancer is the uncontrolled growth of cells in the prostate, a small gland that encircles the urethra in men. Some men may choose to undergo screening for prostate cancer using a PSA blood test. An increased PSA level is associated with an increased risk of prostate cancer, but PSA can also be increased with benign prostatic hyperplasia , prostatitis, infection, and a variety of other temporary conditions.
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How Can The Progensa Pca3 Assay Help In Making Better Initial Biopsy Decisions
Evidence from published data
An elevated PSA level can present a dilemma for the physician and patient: perform a biopsy or not?
The PCA3 score has been shown to be predictive of initial biopsy outcome.18-21 An increasing PCA3 score corresponds with an increasing risk of finding prostate cancer in the biopsy.18-21
PCA3 performed better than serum PSA, PSA doubling time and percent free PSA in predicting the outcome of an initial biopsy.19-20
The independent study by the NCI EDRN validated the role for PCA3 in the initial diagnosis of prostate cancer.18 It showed that at a PCA3 score cut-off of 60 the PPV for initial biopsy was 80%.18 This means that at a PCA3 score > 60 the PCA3 test predicted a positive initial biopsy 80% of the time.18 The NCI EDRN concluded that a PCA3 score > 60 increases the probability that cancer will be detected on Initial biopsy. A PCA3 score of < 20, however, is necessary to rule out a biopsy in the initial setting.18
The Progensa PCA3 assay can aid physicians and patients in the dilemma to perform an initial prostate biopsy in men with an elevated PSA level.11 It can help to avoid unnecessary biopsies while maintaining the sensitivity to detect clinically significant cancer.11
Psa Test: The Current Prostate Screening Standard
Before recommending when you should be screened for prostate cancer, yourdoctor will consider many factors, such as:
- Family history, particularly whether any of your family members have had prostate cancer
- Race, as African-American men have a higher risk of developing prostate cancer
If your doctor determines you should undergo screening, he or she will mostlikely recommend the PSA test. For more than 30 years, the PSA test hasbeen the gold standard in prostate cancer screening. This simple blood testmeasures how much prostate-specific antigen is in your blood.
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What Is A Pca3 Test
The PCA3 test is a genetic test based on DNA technology which provides a different measurement of prostate cancer risk than the standard Prostate Specific Antigen test.
Advances in medical technology have enabled scientists to detect miniscule processes within cells, such as the way genes express their coded information.
PCA3 is the expression of genes found in prostate cancer cells. Up to 100 times more PCA3 is present in prostate cancer cells than non-cancerous cells.
If a patient has a high proportion of PCA3, this can be detected in the patients urine.
The PCA3 test may be combined with a rectal examination and a negative test can reassure patients and together with an MRI scan, may help avoid the need for prostate biopsies.
This test can prevent many men from having unnecessary, repeated biopsies and indicate whether men are likely to have significant and aggressive prostate cancer.
We advise patients whether a PCA3 test is likely to be helpful in establishing a precise assessment of your prostate cancer risk.
When Is It Ordered
The test may be ordered when a man has had an elevated PSA blood test and/or abnormal digital rectal exam and one or more previous negative prostate biopsies. It may be ordered when another biopsy would normally be recommended and a healthcare practitioner wants to evaluate the likelihood that the repeat biopsy would be positive.
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Ask A Laboratory Scientist
This form enables patients to ask specific questions about lab tests. Your questions will be answered by a laboratory scientist as part of a voluntary service provided by one of our partners, American Society for Clinical Laboratory Science. Please allow 2-3 business days for an email response from one of the volunteers on the Consumer Information Response Team.
Potential Usefulness Of Pca3 And Epca
I believe it is premature to comment on the potential usefulness of these new tests, PCA3 and EPCA-2, for early detection prostate cancer.
Both tests have been developed by good scientists. The PCA3 test is already available through certain clinical laboratories.
The basis of the PCA3 test is that it measures RNA from a gene that is over-expressed in many prostate cancers. In performing the test, a physician performs a rectal examination to massage fluid from the prostate gland into the urethra.
If the patient has prostate cancer, cancer cells will be present in the prostatic fluid. Then the patient is asked to urinate and the urine is tested for the amount of PCA3 RNA present in the cells. If cancer is present, there will be a considerable amount.
Thus, it is almost a way to diagnose cancer without the need to perform a biopsy, but not quite. A biopsy always has to be done to establish the diagnosis of cancer. One limitation of the PCA-3 test is that not all prostate cancers are in contact with the prostate glands ductal system and, therefore, may not appear in the urine. This situation would give a falsely negative result.
Another problem is that some men without cancer can have high PCA3 levels.
Currently, PCA3 is most commonly used to determine which men who have an elevated PSA and a negative biopsy need to have a repeat biopsy. It is possible that genes other than PCA3 will become more useful than PCA3 in a similar diagnostic platform.
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Pca3 Test And Prostate Cancer
Taking a biopsy of prostate cancer is one of the most widely debated steps to diagnose and treat men with lower urinary tract symptoms.
It is the gold-standard procedure to give men a final diagnosis of prostate cancer and stage the disease.
However, it does have severe side effects and long-lasting health outcomes.
This is especially the case because biopsies are often performed more than once, and they are sometimes an undue risk .
Among the side effects of a prostate biopsy, we can have:
- Chronic bleeding of the urinary tract.
- Chronic urinary pain .
Doctors should use every diagnostic tool available before resulting to unnecessary prostate biopsies.
Even so, the PSA test, digital rectal examination, and imaging tests may still give out false positives.
Recent investigations have pointed out that the PCA3 test might soon become the solution to this medical dilemma.
Diagnosis Of Prostate Cancer
Check out this factsheet for a summary of the video.
Diagnosis is the process of finding out the cause of a health problem. Diagnosing prostate cancer usually begins with a visit to your family doctor. Your doctor will ask you about any symptoms you have and do a physical exam. Based on this information, your doctor may refer you to a specialist called a urologist or order tests to check for prostate cancer or other health problems. A urologist is a doctor who specializes in treating conditions of the genital and urinary tracts, including the prostate.
The process of diagnosis may seem long and frustrating. It’s normal to worry, but try to remember that other health conditions can cause similar symptoms as prostate cancer. It’s important for the healthcare team to rule out other reasons for a health problem before making a diagnosis of prostate cancer.
The following tests are usually used to rule out or diagnose prostate cancer. Many of the same tests used to diagnose cancer are used to find out the stage . Your doctor may also order other tests to check your general health and to help plan your treatment.
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What To Expect During A Pca3 Test
Prostate cancer PCA samples are taking following a two-step procedure. During the first step, your urologist will need to perform a digital rectal exam or a prostate massage.
This procedure is performed by inserting one or two lubricated and gloved fingers in the rectum and pushing forward to meet and feel the prostate gland. In the process, your prostate will release a sample of cells into the prostatic urethra.
During the second step, you will need to provide a urine sample. It is essential to take the first stream of urine instead of the midstream doctors will recommend in other tests.
This initial stream drags along the prostatic cells in your prostatic urethra, and the sample is taken to the lab for PCR analysis. 20 to 30 mL of the first catch urine is what the laboratory will need for testing.
How Does It Differ From The Psa Test
Patients may have a hard time understanding the difference between the PCA3 test and the PSA test .
They are both antigens, they are useful to diagnose prostate cancer, and their acronyms are similar. However, they are quite different in everything else.
PSA tests require a blood sample, while PCA3 tests are based on urine samples. Even if they are both antigens, one of them requires a relatively cheap technique, while the other is much more expensive.
Moreover, false positives in PCA3 tests are much lower. It also has high sensitivity and specificity to detect real cases of prostate cancer. PSA tests are modified for a high number of causes, including :
- Digital rectal examination of the prostate.
- Using urinary catheters.
- Benign prostatic hyperplasia and other benign prostate conditions.
PCA3 will only turn out to be positive in cases of prostate cancer. This is as non-carcinogenic cells do not have this gene activated .
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Should I Have A Pca3 Test
Expert guidelines suggest that the early detection of cancer should begin with a visit to your doctor or urologist, to discuss personal risk and the pros and cons of assessment, screening and diagnosis. Also note that those with close relatives who have had prostate cancer are more prone to the disease, as are African American men or those with BRCA gene mutations.The PCA3 test has proven more successful than two different PSA tests. Combining negative PCA3 test results with both a rectal examination and MRI scan, could help avoid needless prostate biopsies, while gauging a patients likelihood of having significant or aggressive prostate cancer. Additionally, PCA3 levels are often much higher in patients with aggressive tumours.
Can The Test Be Performed In My Healthcare Practitioner’s Office
The DRE will be performed in your healthcare practitioners office and, most likely, so will the urine collection as it is the first urine collected after the DRE. However, the testing requires specialized equipment and your sample will be sent to a laboratory for testing. Not all labs perform this test, so your sample may be sent to a reference laboratory.
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B Searching For The Evidence: Literature Search Strategies For Identification Of Relevant Studies To Answer Key Questions
The research librarian in collaboration with the review team will develop and implement search strategies designed to identify evidence relevant to each KQ. The bibliographies of both primary studies and systematic reviews will be hand searched to assure complete identification of relevant articles. The time frame for the search will be limited to literature published after January 1, 1990 through the final search date in 2011. Literature searches will be restricted to the English language, with the exception of published articles in other languages for which English translations are made available. Two studies have demonstrated that excluding nonâEnglish-language studies has little impact on effect size estimates or conclusions relative to the resources required for translation.14, 15 In this case, the results of most studies of PCA3 conducted in other countries are being published in English-language journals, so a small impact on results is anticipated.
Comprehensive searches for primary studies will be conducted in the following databases:
- Cochrane Central Register of Controlled Trials
âProstatic Neoplasmsâ AND
along with key terms in titles and abstracts . Proposed search strategies are shown in Appendix A. Limits include âHumansâ and âPublication Date 1990/01/01 to 2011/08/29.â