Thousands of men in central Pennsylvania received shocking news in the mail this summer: their tests for prostate-specific antigen, an indicator of cancer, may have been inaccurate.
Pinnacle Health of Harrisburg, Pa., sent letters to 7,500 patients to inform them of a faulty chemical in the tests used to measure levels of the protein secreted by their prostate glands. It showed higher levels of the protein than were actually present.
Significant increases in the protein level in the blood often lead doctors to do prostate biopsies because it can be a sign of prostate cancer.
The time tests were used at Pinnacle from May 2012 through June 26, 2013, leaving almost a year for patients to undergo unnecessary biopsies. Unless someone was diagnosed with cancer via a biopsy, however, it's unlikely that a patient underwent chemotherapy.
But the Pinnacle Health patients are likely the tip of the iceberg.
The PSA test recall was "global," according to Siemens Healthcare Diagnostics, which produced the tests that went out to labs across the country just like Pinnacle.
Siemens recalled all lots of the "IMMULITE" PSA tests June 27 because they had a 20 percent to 23 percent "positive bias," according to a company statement. It shipped bad tests to labs from February 2012 through May 2013.
Siemens spokeswoman Erin Brown told ABCNews.com by email that all labs that used the tests were notified to discard them. But when asked how many labs were affected, she declined to answer, as did another Siemens representative, Gian Sachdev.
The Food and Drug Administration, which posts recalls on its website, has not posted the nearly 2-month-old Siemens recall yet because it is still assessing it.
"The FDA takes any problem with a medical device very seriously and works with companies to ensure that the appropriate steps are taken to inform healthcare professionals and protect patients," the FDA said in a statement. "The FDA is continuing to work with the company to identify the cause of false positive readings with the test. Siemens has contacted laboratory and health care facilities impacted by this recall."
Siemens has not posted any statements about this recall on its website.
Memos from labs that got the tests have been posted online in states hundreds of miles from Pennsylvania.
For example, Clear Point Diagnostic Laboratories of Lewisville, Texas, issued an alert about the Siemens recall.
"Since a positive bias in PSA results could impact clinical interpretation of test results, especially with regards to scheduling a biopsy for the patient, our laboratory offers to Re-Test the patients' specimens that were reported to be abnormal in the past Two-Month period at No Charge," the memo reads.
Although Dr. Daniel Barocas, a urologist at Vanderbilt Medical Center in Nashville, Tenn., said he hadn't heard of the recall, he said patients should always ask for a second PSA test before undergoing a biopsy.
A prostate biopsy involves using a transrectal ultrasound to guide a needle as it goes through the rectal wall to prick the prostate 12 times, Barocas said. It carries the risk of infertility, bleeding and urinary retention.
PSA testing is considered controversial. The United States Preventive Services Task Force, the group that sets testing guidelines, recommends against PSA testing. But the American Cancer Society, the American Urological Organization and the American College of Physicians suggest offering the test to patients based on a variety of factors, including age and family history of prostate cancer.
Siemens had another PSA test recall in 2012, when leaking cartridges were thought to "depress" positive test results, according to FDA enforcement actions. They recalled about 1,100 cartridges.
A two-month FDA inspection of Siemens' facility in Tarrytown, N.Y., in 2011 yielded several violations, including failure to review and evaluate complaints to see whether an investigation was necessary. On July 17, 2013, the FDA wrote that all issues had been resolved.