To PSA or Not to PSA

United States Preventative Services Task Force recommends against PSA screenings

/ Author:  / Reviewed by: Joseph V. Madia, MD

Prostate cancer is something all men have to think about. A new recommendation may affect screenings and how men find answers about prostate cancer.

In October  2011, the United States Preventative Service Task Force (USPSTF) issued a draft recommendation against using Prostate-Specific Antigen tests for prostate cancer diagnosis. A draft is not the final recommendation by the USPSTF, but the initial results of a study that are subject to final review. 

A Prostate-Specific Antigen (PSA) test has been a common tool used to help diagnosis prostate cancer. The test measures antigens found only in the prostate. If these levels are too high, it is considered a risk factor and a biopsy may be needed to diagnose prostate cancer. 

USPSTF Recommendations for PSA Tests

The USPSTF does not recommend the test for "men in the U.S. population that do not have symptoms that are highly suspicious for prostate cancer, regardless of age, race, or family history." According to the USPSTF, the risks outweighed the benefits of the test, which the panel concludes does not prolong life.

The reason for this recommendation is due to possible over-diagnosis which could lead to over-treatment. These unnecessary treatments can lead to many more risks associated with more evaluation and treatment - all of which far outweigh any benefit, according to the USPSTF. Nearly 95 percent who had a PSA detected tumor were alive after 12 years. 

Prostate cancer is the most commonly diagnosed non-skin cancer for men. The lifetime risk of being diagnosed with prostate cancer is close to 16 percent, while the risk of dying from prostate cancer is close to three percent. The widespread nature of this disease has led to recommended annual screenings for men, using a PSA test, ultrasound or digital rectal exams. These guidelines are altered based on existing risk factors such as age, race and family history. 

The PSA test, while it detects prostate cancer, cannot distinguish between types of cancer that can be harmful. A tumor found using a PSA could be a slow-growing tumor that provides no harm to the man for his entire life, or it could be an aggressive form of cancer. Because of the inability to distinguish between types of tumors, many men who do not need a biopsy will get one, and that increases the risk of more harm than good being done with further evaluation.

Possible Risks of Over-Diagnosis

According to the USPSTF, false-positives make up close to 80 percent of all PSA tests when using a certain threshold. A false-positive can then lead to a biopsy and possibly even more treatment. A biopsy is the only clinical way to determine if a man has prostate cancer. Each step of the way, a man will undergo all the associated risks with these treatments and receive none of the benefits. 

There is a small chance men will be hospitalized after a biopsy due to pain, fever or bleeding. With early detection, preventative treatments such as surgery, radiotherapy or hormone therapy can be used.

For surgery, 5 out of 1,000 men die within a month of surgery and an additional 10 to 70 men have serious complications but survive. Hormone therapy that's often prescribed following surgery has its own set of serious side effects, including erectile dysfunction in 400 out of 1,000 men. For radiotherapy, erectile dysfunction or the inability to control urination occurs in 200 to 300 men out of 1,000 total patients.

Since a man may have a PSA-detected tumor that is not harming him, there is a significant increase in exposure to these negative side effects over a long period of time. There are also psychological factors that can affect a man due to a false-positive. 

Additionally, the USPSTF recommended against PSA testing for men in certain age groups. For men aged between 50 and 75, a PSA test did not reduce prostate cancer deaths. Studies have found that even if cancer is detected, the likelihood of him dying from cancer rather than another cause, is minimal or the cancer is an advanced stage that no treatment can really help. 

This recommendation has not universally been accepted.

  • The American Society for Radiation Oncology (ASTRO) agreed with the USPSTF, but recommended against a "blanket no-testing policy." 
  • The American Urological Association (AUA) believes that "the Task Force’s recommendations will ultimately do more harm than good to the many men at risk for prostate cancer, both here in the United States and around the world."
  • The Prostate Cancer Foundation (PCF) is in support of continued use of PSA tests, but understands certain limitations of the test.
  • The PCF also used a cost analysis result recently published in The Journal of Urology that calculates total costs equalling " $5,227,306 per patient to prevent one U.S. prostate cancer death."

According to the PCF,  it is up to the man and his health care provider to make this choice. The PCF does agree with other cancer institutions that there needs to be "better processes of informed patient decision-making both prior to, and after, PSA screening in healthy men."

In light of the recent USPSTF recommendation against using PSA testing for prostate cancer, as well as the support for PSA testing, dailyRx talked to Dr. Ganesh Palapattu with The Methodist Hospital in Houston, Texas. Dr Palapattu is the chief of Urologic Oncology and an associate member of The Methodist Hospital Research Institute.

QuestionWhat are your comments about the recent recommendation by the USPSTF and for men who are thinking about PSA screenings?

Dr. Palapattu: I believe the comments are made with good intentions. However, I think it may be an over-simplification of a complex clinical situation. Without a doubt, prostate cancer is diagnosed very commonly in this country and it is very likely over-treated.

I think the recommendations to not screen anybody are potentially as hurtful as is the edict to screen everybody. I don't believe we should screen everybody, nor do I believe we should screen nobody. So, I think a more measured approach, a middle path, identifying men likely to harbor the disease may make the more sense.

Nonetheless, I also recognize the report that's coming out soon and the literature they cite, looking at the PSA test even in the context of men who are likely to harbor the disease. In other words, men who have higher risk factors like African-American men or men who have a family history of prostate cancer that the PSA test and their analysis did not bear out a benefit versus the risk.

My basic retort to the USPSTF recommendation is that they don't address a fundamental observation that many of us in the field have had over the past 15 years or so. That is, since the inception of PSA screening's wide adoption in the mid 1990's, prostate cancer mortality rate in this country has come down by approximately 40 percent.

Precise reasons for that are unknown but most in the field agree, or believe, that it's some of combination of both screening as well as better treatment. I think it's hard to ignore that data.

Possible Risks for Not Screening Anyone

Dr. Palapattu: I think if we were to not screen anybody, we run the risk of intervening in some men in whom we may help. From a bigger picture, I would say that the discussion on prostate cancer screening is an important one and really should allow us to focus our efforts now on identifying biomarkers of aggressive disease.

That means diagnosing prostate cancer is not so much the problem but rather the real problem is identifying cancers that are likely to hurt men from those men who are unlikely to be hurt from the disease. In this way, we will be able to better identify men with prostate cancer and intervene in patients who are likely to benefit from the treatment and not treat those patients who are unlikely to benefit from the treatment.

I think another thing a person needs to understand is that diagnosing prostate cancer does not necessarily mean that every one of these diagnoses is going to get treated. There are multiple decision points along the continuum of getting your PSA checked.

One is should I even get it all or not, then getting it checked and determining its value with an expert like a urologist, then deciding if you need a biopsy and if you get a biopsy interpreting the results, if you get a diagnosis of prostate cancer then what am I going to do. Not every one is treated the same along this continuum and each one of these points a decision needs to be made between physician and health care provider.

It's not a foregone conclusion that if you get your PSA checked your prostate is coming out. It's important to understand the PSA test is not perfect. It's not a pregnancy test. A high PSA level does not mean you have a cancer and a low one does not mean you don't. It's not “cancer specific” it's “prostate-specific antigen” not “prostate cancer-specific antigen” and therein lies the problem. 

The major problem most people have with PSA's is low specificity, there is a high false positive rate and that's the problem." 

For Dr. Palapattu, ASTRO, AUA and the PCF all support men consulting their long-term health care provider and choosing to get a PSA test. It is up to men to understand prostate cancer and make informed decisions about screenings as well as test results.

Review Date: 
October 25, 2011