What is a PSA test?

Prostate-specific antigen (PSA) is a protein produced by both cancerous (malignant) and noncancerous (benign) prostate tissue. PSA helps liquefy the semen. A small amount enters the bloodstream. Cancer cells usually make more PSA than do benign cells, causing PSA levels in your blood to rise. However, determining what a high PSA score means can be complicated. Besides the PSA number itself, your doctor will consider a number of other factors to evaluate your PSA scores:

* Your age

* The size of your prostate gland

* How quickly your PSA levels are changing

* Whether you're taking medications that affect PSA measurements, such as finasteride (Propecia, Proscar), dutasteride (Avodart) and even some herbal supplements

When elevated PSA isn't cancer

While high PSA levels can be a sign of prostate cancer, a number of conditions other than prostate cancer also can cause PSA levels to rise. These other conditions could cause what's known as a "false-positive" — meaning a result that falsely indicates you might have prostate cancer when you don't. Conditions that could lead to an elevated PSA level in men who don't have prostate cancer include:

* Benign prostate enlargement (benign prostatic hyperplasia)

* A prostate infection (prostatitis)

* Other less common conditions

False-positives are common. Only about one in four men who have a positive PSA test turns out to have prostate cancer.

Why you Should Consider a Prostate Cancer Psa Test Today

Prostate Cancer kills if allowed to grow. If ever there was a good reason to have a simple blood test, this is it. The Prostate cancer PSA (Prostate Specific Antigen) test is one of the tests given to determine if cancer cells are present in an otherwise healthy prostate. It is a simple blood test to help doctors diagnose and identify the existence of prostate cancer.

The PSA test, although considered a prostate specific test is not really an absolute definitive test for the cancer. Depending on the research conducted, the PSA test is known to be somewhere between 85 and 95% accurate in identifying prostate cancer.

While an elevated PSA test may suggest the presence of prostate cancer, it's not an absolute. If however you have an elevated result, your doctor will probably want to do additional testing for a more complete and accurate assessment of the potential cancer. The last thing you want to do is to allow prostate cancer to grow beyond the prostate gland.

The good news is that BPH or Benign Prostatic Hyperplasia, better known as an enlarged prostate can also elevate the PSA test results. Even Prostatitis and Lower Urinary Tract symptoms can show elevated levels of PSA so if you have an elevated test result don't panic! A normal result from a PSA test, doesn't guarantee that your free from cancer, nor does a higher than normal result means you do have cancer

It's critical that you follow your doctor's lead in regard to dealing with the Prostate Specific Antigen test results. The results are an indication in a tool only to develop a complete diagnosis. To complicate matters more, PSA levels can also increase with age. Oh and the relative size of your prostate also plays a factor in interpreting the results.

Remember that as many as two out of three people with elevated the PSA readings DO NOT have a malignancy

Here's a quick list of the benefits and reasons why you should consider getting a PSA test

1. It's possible to detect a cancerous condition before any symptoms are known

2. Early detection catches prostate cancer before it is spread increasing the chances of a complete cure

3. The PSA blood test has been recognized as a contributing factor that has significantly reduced the number of prostate cancer death

The PSA test also delivers a false positive, which is a normal PSA level in about 20% of the time. It is still recognized as a good indicator of potential cancerous conditions and should be taken seriously. A 2005 Harvard study indicated that men having an annual PSA test were almost 3 times LESS likely to die of prostate cancer than men who didn't bother with the test. So the best reason to have the test is that without it, you greatly increase the chances of dying from prostate cancer!

What if the test results show a rising PSA level after treatment for prostate cancer?

A man should discuss rising PSA test results with his doctor. Doctors consider a number of factors before recommending further treatment. Additional treatment based on a single PSA test result is often not recommended. Rather, a rising trend in PSA test results over a period of time combined with other findings, such as an abnormal DRE, positive prostate biopsy results, or abnormal CT (computed tomography) scan results, may lead to a recommendation for further treatment.

According to the National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology for Prostate Cancer (4), additional treatment may be indicated based on the following PSA test results:

* For men who have been in the watchful waiting phase—their PSA level has doubled in fewer than 3 years or they have a PSA velocity (change in PSA level over time) of greater than 0.75 ng/mL per year, or they have a prostate biopsy showing evidence of worsening cancer (4).

* For men who have had a radical prostatectomy (removal of the prostate gland)—their PSA level does not fall below the limits of detection after surgery or they have a detectable PSA level (> 0.3 ng/mL) that increases on two or more subsequent measurements after having no detectable PSA (4).

* For men who have had other initial therapy, such as radiation therapy with or without hormonal therapy—their PSA level has risen by 2 ng/mL or more after having no detectable PSA or a very low PSA level (4).

Please note that these are general guidelines. Prostate cancer is a complex disease and many variables need to be considered by each patient and his doctor.

What is a normal PSA level?

Most authorities agree that if you have a PSA greater than 4 ng/ml, you should have further investigations. Some suggest that if your PSA is greater than the 'normal for age' range shown in Table 1, or if it is rising rapidly, it should be investigated.

Depending on your age and family history, your doctor may then refer you directly to a Urologist, or may repeat the test before referring you for further investigation.

If cancer is present, the level of PSA in the blood rises as the tumour grows. This means that small rises in PSA are found in association with small tumours which may be still confined to the prostate gland (localised). PSA levels of 10ng/ml or less have the best chance of being localised 3. The PSA level and the cancerous characteristics of the tumour cells themselves (called "grade") can indicate the risk that a tumour has grown beyond the prostate.

If cancer is present, the rate at which the PSA level increases over a series of tests (called PSA velocity) also gives information about the risk that cancer will recur after treatment

Why is the PSA test controversial in screening?

Using the PSA test to screen men for prostate cancer is controversial because it is not yet known for certain whether this test actually saves lives. Moreover, it is not clear that the benefits of PSA screening outweigh the risks of follow-up diagnostic tests and cancer treatments. For example, the PSA test may detect small cancers that would never become life threatening. This situation, called overdiagnosis, puts men at risk of complications from unnecessary treatment.

The procedure used to diagnose prostate cancer (prostate biopsy) may cause harmful side effects, including bleeding and infection. Prostate cancer treatments, such as surgery and radiation therapy, may cause incontinence (inability to control urine flow), erectile dysfunction (erections inadequate for intercourse), and other complications. For these reasons, it is important that the benefits and risks of diagnostic procedures and treatment be taken into account when considering whether to undertake prostate cancer screening.

What is the PSA test and who might have it done?

It is a blood test that measures the level of PSA in your blood. PSA stands for Prostate Specific Antigen. PSA is a protein made by the prostate which naturally leaks into the bloodstream.

Some men with symptoms of a prostate problem may consider having the test. The symptoms of benign prostate enlargement can be similar to the symptoms of a developing prostate cancer. Some men without any symptoms consider having the test to 'screen' for prostate cancer.

However, in both of these situations, the decision to have a PSA test is controversial as there are pros and cons.

Why is the PSA test performed?

The U.S. Food and Drug Administration (FDA) has approved the use of the PSA test along with a digital rectal exam (DRE) to help detect prostate cancer in men 50 years of age or older. During a DRE, a doctor inserts a gloved finger into the rectum and feels the prostate gland through the rectal wall to check for bumps or abnormal areas. Doctors often use the PSA test and DRE as prostate cancer screening tests; together, these tests can help doctors detect prostate cancer in men who have no symptoms of the disease.

The FDA has also approved the use of the PSA test to monitor patients who have a history of prostate cancer to see if the cancer has recurred (come back). If a man’s PSA level begins to rise, it may be the first sign of recurrence. Such a “biochemical relapse” typically precedes clinical signs and symptoms of a relapse by months or years. However, a single elevated PSA measurement in a patient with a history of prostate cancer does not always mean the cancer has come back. A man who has been treated for prostate cancer should discuss an elevated PSA level with his doctor. The doctor may recommend repeating the PSA test or performing other tests to check for evidence of a recurrence. The doctor may look for a trend of rising PSA measurements over time rather than a single elevated PSA level.

It is important to note that a man who is receiving hormone therapy for prostate cancer may have a low PSA level during, or immediately after, treatment. The low level may not be a true measure of the man’s PSA level. Men receiving hormone therapy should talk with their doctor, who may advise them to wait a few months after hormone treatment before having a PSA test.

When prostate cancer doesn't increase PSA

Some prostate cancers, particularly those that grow quickly, may not produce much PSA. In this case, you might have what's known as a "false-negative" — a test result that incorrectly indicates you don't have prostate cancer when you do.

Because of the complexity of these relating factors, it's important that a physician experienced in interpreting PSA levels evaluates your situation. You want to avoid unnecessary follow-up testing and treatment, but you want to be aware of false-negatives, so don't ignore warning signs.

What if I have got early prostate cancer?

Even if you are diagnosed as having prostate cancer, there is still some disagreement among experts as to when to treat it, and if so, what is the best treatment. The decision to treat depends on factors such as the type, grade and stage of the cancer. (See leaflet called Prostate Cancer for details.)

For example, there is no proof that treating early prostate cancers helps men live any longer than they would have done. Most men with early prostate cancer will not die as a result of it; in particular older men in their 70's or 80's, or those with a slow-growing cancer. Also, some of the treatments for prostate cancer can cause serious side effects in some cases.

What is the prostate-specific antigen (PSA) test?

Prostate-specific antigen (PSA) is a protein produced by cells of the prostate gland. The PSA test measures the level of PSA in the blood. The doctor takes a blood sample, and the amount of PSA is measured in a laboratory. Because PSA is produced by the body and can be used to detect disease, it is sometimes called a biological marker or a tumor marker.

It is normal for men to have a low level of PSA in their blood; however, prostate cancer or benign (not cancerous) conditions can increase a man’s PSA level. As men age, both benign prostate conditions and prostate cancer become more common. The most frequent benign prostate conditions are prostatitis (inflammation of the prostate) and benign prostatic hyperplasia (BPH) (enlargement of the prostate). There is no evidence that prostatitis or BPH causes cancer, but it is possible for a man to have one or both of these conditions and to develop prostate cancer as well.

A man’s PSA level alone does not give doctors enough information to distinguish between benign prostate conditions and cancer. However, the doctor will take the result of the PSA test into account when deciding whether to check further for signs of prostate cancer.

What's risky about a PSA test?

You may wonder how getting a test for prostate cancer could have a downside. After all, there's little risk involved in the test itself — it requires simply drawing blood for evaluation in a lab. However, there are some potential dangers once the results are in. These include:

* Worry about false-positive results caused by elevated PSA levels from something other than prostate cancer.

* Invasive, stressful, expensive or time-consuming follow-up tests.

* False reassurance from a PSA test that doesn't reveal cancer (false-negative), leading to a missed diagnosis of aggressive prostate cancer that needs treatment.

* Stress or anxiety caused by knowing you have a slow-growing prostate cancer that doesn't need treatment.

* Deciding to have surgery, radiation or other treatments that cause side effects that are more harmful than untreated cancer.

What research is being done to validate and improve the PSA test?

The benefits of screening for prostate cancer are still being studied. The National Cancer Institute (NCI), a component of the National Institutes of Health, is currently conducting the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, or PLCO trial, to determine whether certain screening tests can help reduce the number of deaths from these cancers. The PSA test and DRE are being evaluated to determine whether yearly screening to detect prostate cancer will decrease a man’s chances of dying from this disease.

Initial results from the trial showed that annual PSA testing for 6 years and annual DRE testing for 4 years (performed in the same years as the first four PSA tests) did not reduce the number of deaths from prostate cancer through a median follow-up period of 11.5 years (range 7.2 to 14.8 years) (5). At 7 years of follow-up, a point in time when follow-up of the participants was essentially complete, 23 percent more cancers had been diagnosed in the screening group than in the control group. In the control group, men were randomly assigned to “usual care.”

These results suggest that many men were diagnosed with, and treated for, cancers that would not have been detected in their lifetime without screening and, as a consequence, were exposed to the potential harms of unnecessary treatments, such as surgery and radiation therapy. Nevertheless, it remains possible that a small benefit from the earlier detection of these “excess” cancers could emerge with longer follow-up. Follow-up of the PLCO participants will continue, therefore, until all participants have been followed for at least 13 years.

In contrast, initial results from another large randomized, controlled trial of prostate cancer screening, called the European Randomized Study of Screening for Prostate Cancer (ERSPC), found a 20 percent reduction in prostate cancer deaths associated with PSA testing every 4 years (6). At the time the results were reported, the participants had been followed for a median of 9 years. The average number of PSA tests per participant in ERSPC was 2.1. Most participating centers in this study used a lower PSA cutoff value as an indicator of abnormality than was used in the PLCO trial (3.0 ng/mL versus 4.0 ng/mL). As in the PLCO trial, many more cancers were diagnosed in the screening group than in the control group. The ERSPC researchers estimated that 1,410 men would have to be screened and 48 additional cancers would have to be detected to prevent one death from prostate cancer (6).

Scientists are also researching ways to improve the PSA test, hopefully to allow cancerous and benign conditions, as well as slow-growing cancers and fast-growing, potentially lethal cancers, to be distinguished from one another. Some of the methods being studied include the following:

* PSA velocity: PSA velocity is the change in PSA level over time. A sharp rise in the PSA level raises the suspicion of cancer and may indicate a fast-growing cancer. A 2006 study found that men who had a PSA velocity above 0.35 ng/mL per year had a higher relative risk of dying from prostate cancer than men who had a PSA velocity less than 0.35 ng/mL per year (7). More studies are needed to determine if a high PSA velocity more accurately detects prostate cancer early.

* PSA density: PSA density considers the relationship between the level of PSA and the size of the prostate. In other words, an elevated PSA level might not arouse suspicion if a man has a very enlarged prostate. The use of PSA density to interpret PSA results is controversial because cancer might be overlooked in a man with an enlarged prostate.

* Free versus attached PSA: PSA circulates in the blood in two forms: Free or attached to a protein molecule. The free PSA test is more often used for men who have higher PSA values. Free PSA may help tell what kind of prostate problem a man has. With benign prostate conditions (such as BPH), there is more free PSA, while cancer produces more of the attached form. If a man’s attached PSA level is high but his free PSA level is not, the presence of cancer is more likely. In this case, more testing, such as a prostate biopsy, may be done. Researchers are exploring additional ways of measuring PSA and comparing these measurements to determine whether cancer is present.

* Alteration of PSA cutoff level: Some researchers have suggested lowering the cutoff levels used to determine whether a PSA measurement is normal or elevated. For example, a number of studies have used cutoff levels of 2.5 or 3.0 ng/mL (rather than 4.0 ng/mL). In such studies, PSA measurements above 2.5 or 3.0 ng/mL are considered elevated. Researchers hope that using these lower cutoff levels will increase the chance of detecting prostate cancer; however, this method may also increase overdiagnosis and false-positive test results and lead to unnecessary medical procedures. (See ERSPC trial results above.)

What happens if my PSA level is high?

There are no hard and fast rules, and even the experts don't always agree on the best course of action. What happens next depends on whether or not you have any symptoms, your personal risk of prostate cancer, how high the PSA level is, and your age (the older you are, the higher your PSA level is likely to be whether or not you have prostate cancer).

As a rough guide, there are three main options after a PSA test:

* PSA not raised: Highly unlikely to have cancer. No further action.

* PSA slightly raised: Probably not cancer, but might need to repeat the test.

* PSA definitely raised: Probably need a biopsy to find out if you have prostate cancer.

What other methods are being studied to detect prostate cancer?

Researchers are investigating several other ways to detect prostate cancer that could be used alone or together with the PSA test and DRE. Some of these include the following:

* MicroRNA patterns: MicroRNAs are small, single-strand molecules of ribonucleic acid (RNA) that regulate important cellular functions. Researchers have found that the pattern of microRNAs in a cell can differ depending on the type of cell and between healthy cells and abnormal cells, such as cancer cells. Some research also suggests that the microRNA patterns in early-stage prostate cancer and late-stage prostate cancer may be different.

* Non-mutation gene alterations: The activity of a gene can be altered in ways that do not involve a change (mutation) to its DNA code. This can occur by modifying the gene’s DNA through a process known as methylation or by modifying the proteins that bind to the gene and help control how it is configured in the chromosome on which it is located. These types of gene alterations are called epigenetic alterations. Research has already shown that certain genes become hypermethylated and inactivated during the development and progression of prostate cancer. Scientists hope to identify DNA methylation changes and protein modifications that will be able to identify prostate cancer early and help predict tumor behavior.

* Gene fusions: Sometimes genes on different chromosomes can come together inappropriately and fuse to form hybrid genes. These hybrid genes have been found in several types of cancer, including prostate cancer, and may play a role in cancer development. The gene fusions found in prostate cancer involve members of the ETS family of oncogenes, which are genes that cause cancer when mutated or expressed at higher than normal levels. Researchers are investigating whether diagnostic or prognostic tests based on gene fusions can be developed.

* PCA3: PCA3, also known as DD3, is a prostate-specific RNA that is reported to be expressed at high levels in prostate tumor cells. It does not appear to contain the genetic code for a protein. A urine test for this RNA, to be used in addition to current prostate cancer screening tests, has the potential to be useful and is under study.

* Differential detection of metabolites: Molecules produced by the body’s metabolic processes, or metabolites, may be able to help distinguish between benign prostate tissue, localized prostate cancer, and metastatic prostate cancer. One such molecule, known as sarcosine, has been identified and may be associated with prostate cancer’s invasiveness and aggressiveness. Ongoing research is investigating whether a test based on sarcosine can be developed.

* Proteo-imaging: Proteo-imaging is the ability to localize and follow changes at the molecular level, through imaging, of the protein distributions in specific tissues. Being able to see different patterns of protein expression in healthy prostate tissue versus abnormal prostate tissue may help classify early prostate changes that may one day lead to cancer.

* Protein patterns in the blood: Researchers are also studying patterns of proteins in the blood to see if they can identify one or more unique patterns that indicate the presence of prostate cancer and allow more aggressive cancers to be distinguished from less aggressive ones.

Should I get a PSA test for prostate cancer?

A new study shows that screening for prostate cancer doesn’t necessarily save lives

Prostate cancer screening is about to get a whole lot cloudier.

Published this morning in the NEJM, the results of the study by the National Cancer Institute showed that, for men who were screened with both a PSA and digital rectal exam, there was no difference when compared to men who received “usual care.”

The results confirm the suspicions that many physicians already had, namely, that screening for prostate cancer does not appear to save lives.

As I have written countless times, there are many other diseases that can raise a PSA level. Combined with the fact that physicians have to act on elevated levels, this can lead to excessive prostate biopsies, as well as treating early cancers that end up not being the ultimate cause of death. All of these procedures expose the patient to a host of side effects, including bleeding and infection from the biopsy, and impotence and urinary incontinence from prostate cancer treatment.

The study was paired with the findings from a concurrent European study, which was not quite as negative. Nonetheless, the benefit of prostate cancer screening was minimal, with “7 fewer prostate cancer deaths for every 10,000 men screened and followed for nine years.”

Already, the USPSTF is shying away from endorsing prostate cancer screening by updating their guidelines last year, no longer recommending a PSA test for men older than 75.

So, what to do if you’re a patient? I think it’s more imperative than ever not to accept the dogma that “more screening is better medicine.” If anything, the decision of obtaining a PSA test needs to be thoroughly discussed with your doctor. Suddenly, the benefits of going down the path of screening doesn’t necessarily outweigh the risks.

Many may find that counterintuitive, and to be honest, it’s a hard truth to swallow. But these findings can help counter the pervading myth that obtaining every conceivable screening test is a sure way to improve health, when in actuality, it isn’t.

Routine Prostate Cancer Screening With PSA Test

Two papers published on bmj.com today report that there is unsatisfactory evidence to support population-wide screening for prostate cancer using the prostate specific antigen (PSA) test.

The PSA test cannot differentiate lethal from harmless prostate cancer, according to the authors. This could lead to over diagnosis and overtreatment of healthy men.

Prostate specific antigen (PSA) is a protein formed in the cells of the prostate gland. It is present in small quantities in the blood of healthy men. It is frequently elevated in men with prostate cancer and in men with benign prostatic enlargement.

Although it remains controversial, PSA screening is commonly used in many countries. The latest study suggests that prostate cancer deaths were lower among screened men but at a cost of significant over diagnosis and treatment.

A Swedish team of researchers set out in the first study to evaluate how well prostate specific antigen predicted a potential prostate cancer diagnosis.

They used PSA test results from 540 men diagnosed with prostate cancer measured several years before diagnosis and from 1,034 healthy controls. Results indicated that the PSA test did not reach the probability ratios. It is a measure used to predict disease required for a screening test. Only very low concentrations of PSA (less than 1ng/ml) virtually ruled out a diagnosis of prostate cancer during monitoring.

The researchers inform that there is a need for other biomarkers for early detection of prostate cancer and before population based screening for prostate cancer should be introduced.

US researchers looked at the benefits and risks of PSA screening in a second analysis paper. They concluded that data on costs and benefits remain insufficient to support population based screening. In addition, they recommend further accurate measuring of the financial and psychological costs of false positive results, over diagnosis and overtreatment of prostate cancer.

In conclusion, they consider that men should be entirely informed of the benefits, harms and uncertainties associated with the PSA test before they are screened.

This observation is supported in a complementary editorial by researchers at Monash University in Australia.

Dr Dragan Ilic and Professor Sally Green write: "Clinicians and patients are faced with many uncertainties when considering whether or not to undergo prostate screening."

They remark: "Further research is required to develop and evaluate a valid screening test for prostate cancer." Until such a test exists, the choice to undertake screening should follow a shared decision making approach

The PSA Test - How Does It Work

The purpose of this article is to remove some of the mystery surrounding the PSA test and its use in signaling the potential presence of prostate cancer.

The cells of the prostate gland produce prostate-specific antigen. A rectal exam and a PSA (prostate-specific antigen) test will help detect prostate cancer in men age 50 or over. The Federal Drug Administration approved the use of the PSA test to detect prostate cancer and to see if the cancer has recurred. A high PSA level is a sign that cancer is present. There are other reasons for a high PSA level and PSA screening has some limits.

The PSA test measures the level of protein produced by the prostate gland. The doctor will take a blood sample and send it to a laboratory. This test is sometimes called a biological marker for cancer tumors. Men normally have low levels of PSA in their blood. If the rate is high, it could point to prostate cancer but it can mean there are other non-cancer conditions present in the prostate. As men get older, prostate cancer and other prostate problems become more of a problem. Enlarged prostate and prostatitis may raise the PSA levels in the blood. Neither of these problems causes cancer but it is possible for a man with one of these problems to develop prostate cancer.

The PSA level will not tell the doctor if the patient has a benign prostate problem or cancer. The doctor will use the PSA test to decide if there should be a check for other signs of prostate cancer.

The Federal Drug Administration approved the PSA test to be used with a rectal exam to check for any abnormalities in the prostate. The doctor will insert a gloved finger into the rectum to check for lumps or areas that seem abnormal. The PSA test is used with this rectal exam to detect cancer in men, especially those who have no symptoms. The FDA also approved the test for patients who have had prostate cancer to see if the cancer has come back.

The PSA test is highly recommended for men over the age of 50. If the patient has a high risk factor for prostate cancer, the doctor may recommend PSA testing to start at age 45. There are some risk factors a man should look at if a doctor recommends routine screening. Age is the most common risk factor, but if there is a family history of prostate cancer you have a greater chance of having it too. African-American has the largest risk of contacting prostate cancer. Native American and Asian men have the lowest rates of this disease. Some think this might be because a diet that is high in animal fat may increase the chance of getting prostate cancer.

If a man shows a high PSA level in his blood the doctor may look for other causes before doing more screening for prostate cancer. If the patients have no other symptoms, you may be advised to watch for any changes in urination habits and take another PSA test in a few months.

So, in summary, pros and cons of the PSA test?

Possible benefits of having the test

* It may provide reassurance if the test result is normal.

* It can help to detect prostate cancer before any symptoms develop.

* Treatment in the early stages of prostate cancer could help you live longer and avoid the complications of cancer (although there is no good evidence that this is so).

Possible disadvantages

* It might detect a slow-growing cancer that may never cause any symptoms or shorten your life span. But the diagnosis of 'cancer' may cause you significant anxiety which could affect your quality of life.

* It may lead you to have treatment for early prostate cancer which might not help you live longer. Also, the main treatments for early prostate cancer do carry some risk and can cause side-effects.

* It could miss cancer in the prostate, and falsely reassure you that all is well.

* It could lead to anxiety and a biopsy when you have no cancer.

Ultimately, the decision should be taken by yourself in conjunction with your GP who can advise further and who knows your particular circumstances.

Prostate-Specific Antigen (PSA) Blood Test

Prostate-specific antigen (PSA) is a substance produced by the prostate gland. Elevated PSA levels may indicate prostate cancer or a noncancerous condition such as prostatitis or an enlarged prostate.

Most men have PSA levels under four (ng/mL) and this has traditionally been used as the cutoff for concern about risk of prostate cancer. Men with prostate cancer often have PSA levels higher than four, although cancer is a possibility at any PSA level. According to published reports, men who have a prostate gland that feels normal on examination and a PSA less than four have a 15% chance of having prostate cancer. Those with a PSA between four and 10 have a 25% chance of having prostate cancer and if the PSA is higher than 10, the risk increases to 67%.

In the past, most experts viewed PSA levels less than 4 ng/mL as normal. Due to the findings from more recent studies, some recommend lowering the cutoff levels that determine if a PSA value is normal or elevated. Some researchers encourage using less than 2.5 or 3 ng/mL as a cutoff for normal values, particularly in younger patients. Younger patients tend to have smaller prostates and lower PSA values, so any elevation of the PSA in younger men above 2.5 ng/mL is a cause for concern.

Just as important as the PSA number is the trend of that number (whether it is going up, how quickly, and over what period of time). It is important to understand that the PSA test is not perfect. Most men with elevated PSA levels have noncancerous prostate enlargement, which is a normal part of aging. Conversely, low levels of PSA in the bloodstream do not rule out the possibility of prostate cancer. However, most cases of early prostate cancer are found by a PSA blood test.

How Is The PSA Screening Test Done?

The test involves drawing blood, usually from the arm. The results are usually sent to a laboratory and most often come back within several days.

When Should I Have My PSA Levels Tested?

PSA blood tests and digital rectal exams should be done every year for men beginning at age 50, and earlier (age 40) for African American men and men with a family history of prostate cancer.

If your doctor is concerned that you might have prostate cancer based on either your PSA level or a rectal exam, a biopsy (a lab testing of a small amount of tissue from the prostate) will be this next step This is the only way to positively identify the presence of cancer.

What does the PSA test tell me about my prostate?

A raised PSA level can be a sign that you have prostate cancer. The PSA level is often raised well before any symptoms of prostate cancer develop. So the test can help to detect early prostate cancers (which may have a better chance of being successfully treated than more advanced prostate cancers.) As a rule, the higher the PSA level, the more likely that you have prostate cancer.

However, a raised PSA level can also occur in other prostate conditions such as some cases of benign enlargement of the prostate and inflammation of the prostate (prostatitis). In particular, a PSA level that is mildly or moderately raised has a good chance of being due to a benign condition, but could be due to prostate cancer. Overall, about 2 in 3 men with a raised PSA level do not have prostate cancer.

Also, if you do have prostate cancer, a single PSA test cannot tell you whether a prostate cancer is slow or fast growing.

And also, in some cases, the PSA level may be normal even when there is cancer there. Up to 1 in 5 men with prostate cancer have a normal PSA level.

So, the PSA test is not an accurate test for prostate cancer.