Prostate Cancer Screening: Clearing Up the Confusion

It’s been more than two year since a prominent panel of U.S. healthcare experts reversed an earlier stance against the prostate-specific antigen, or PSA, blood test. Now, the U.S. Preventive Services Task Force (USPSTF) says the PSA could be beneficial for preventing prostate cancer in men ages 55 to 69. The task force urges men to consult with their doctors about the PSA’s effectiveness.

Nonetheless, there is still much confusion among men in that age group about the PSA’s accuracy, according to Jose Vazquez, M.D., internal medicine physician with Baptist Health Primary Care.

For years, the PSA has had tendencies to generate positive screening results (or “false-positive” results) in men without prostate cancer, prompting the USPSTF in 2012 to recommend against routine testing for men of all ages. In some cases, a positive PSA test may result in an unnecessary “transrectal ultrasound-guided core-needle biopsy” of the prostate to diagnose prostate cancer.

However, over the past six years since the task force’s anti-PSA position, cases of early prostate-cancer diagnoses started to decline, raising concerns among many in the healthcare community.

‘Still Plenty of Confusion’
“There’s still plenty of confusion,” says Dr. Vazquez. “Part of the confusion is that we don’t have a really good test for prostate cancer. PSA is a decent test, but it’s not a good test. There are a lot of false positives. Now the task force is recommending, and I think appropriately so, that patients consult with their doctors and be properly informed before actually making a decision about PSA screening.”

A nationally representative study published in JAMA Internal Medicine  found that the frequency of PSA blood tests as a screening for prostate cancer is no longer dropping. PSA screening rates had declined from 37.8 percent in 2010 to 30.8 percent in 2013, among men 50 or older, according to a previous report.

The recommendation from the U.S. task force says: “(PSA) screening offers a small potential benefit of reducing the chance of dying of prostate cancer. However, many men will experience potential harms of screening, including false-positive results that require additional testing and possible prostate biopsy; over-diagnosis and overtreatment; and treatment complications, such as incontinence and impotence.”

PSA Testing May Prevent Deaths
The USPSTF says that “adequate evidence from randomized clinical trials shows that PSA-based screening programs in men ages 55 to 69 years may prevent up to one to two deaths per 1,000 men screened for prostate cancer over approximately 13 years.”

An elevated PSA level may be caused by prostate cancer but can also be caused by other conditions, including an enlarged prostate (benign prostatic hyperplasia) and inflammation of the prostate (prostatitis). The USPSTF still recommends against PSA-based screening for prostate cancer in men age 70 years and older.

Dr. Vazquez stresses that the PSA proves to be more effective for men at higher risk for prostate cancer, which includes those with a family history of prostate cancer and African-American men. The new recommendation to consult with a physician about the PSA applies to adult men, 55-69, without symptoms or a previous diagnosis of prostate cancer.

“The PSA is about 30 percent accurate which makes is a poor screening test,” says Dr. Vazquez. “If consistently high PSA readings call for a biopsy, the important thing is for patients to have a good discussion with their doctors about the risk associated with such procedures. A patient’s other risk factors do play a key role.”