Do I Really Need a Prostate Biopsy?
The introduction of new techniques and technologies always shakes up existing medical practices.
Doctors use these new tools to try to solve problems that have presented long-standing challenges. The new product or practice then becomes the gold standard for years or even decades, until eventually, experts gather enough data to begin analyzing the deeper nuances of the practice. Then the cycle repeats: The use of this new technology gradually declines until it gives way to some other wondrous advancements.
Take the prostate biopsy. For some time, it has been the No. 1 prostate cancer diagnostic tool out there. With the advancement over the past 10 to 15 years of magnetic resonance imaging (MRI) techniques and other screening methods, however, doctors have adopted a much less rigid approach to how and when prostate biopsies are performed.
"I think some of the things that are best for one patient aren't always best for all of the patients," said L. Spencer Krane, M.D., chief of urology for Southeast Louisiana Veterans Health Care System. "And I understand that argument, too. I'm the chief of the VA; I see how things work on a healthcare scale, but there still needs to be some individualization associated with that."
A prostate biopsy is used to screen for the presence of cancer. Biopsies are generally performed when a doctor suspects the patient may be at risk of developing prostate cancer. Doctors may recommend a prostate biopsy because of digital imaging, results from blood work or the discovery of a nodule during a digital rectal exam (DRE). The biopsy is typically performed by a urologist using a needle to collect tissue samples from the prostate. Metastatic biopsies are also performed on patients with advanced prostate cancer.
Prostate biopsies are often performed based on the results of a test to determine the level of prostate-specific antigen (PSA) in the blood of the patient. PSA is a protein produced by both normal and cancerous cells in the prostate gland. Levels are generally quantified in terms of nanograms of PSAs per milliliter (ng/mL) of blood. Doctors will sometimes recommend a prostate biopsy when a patient's PSA level deviates from the normal range for people of similar age and medical/biological background.
But elevated or unusual PSA levels are not necessarily the end-all indicator of the presence of prostate cancer. While PSAs are still a vital tool for determining risk, doctors are now using a wide range of additional resources to figure out whether patients need a prostate biopsy.
"You don't want to do a biopsy just based on the numbers. You want to have more than just a single value. You want a time course where you saw how your PSA changed over time or as it was rising rapidly or, let's say, an alternate explanation for the PSA value," said Kevin T. McVary, M.D., director of the Center for Male Health and a professor of urology at the Stritch School of Medicine at Loyola University Medical Center in Illinois.
Those numbers referred to by McVary cover a lot of ground, but their efficacy can also be bolstered by medical imaging techniques and a collaborative effort between medical providers and patients.
Changes in biopsy approach
Certain risks associated with prostate biopsies, along with an increased awareness that elevated PSA levels don't always equate to the risk of prostate cancer, have curtailed the omnipresent practice of age- or PSA-based biopsies. There is some debate as to whether the detection that occurs through prostate biopsy screening is effective at improving a patient's odds of survival following a cancer diagnosis.
These factors, along with the risk of false positives or false negatives from PSA results, have encouraged experts to recommend that patients discuss the need for a biopsy with their doctor, as well as explore other screening methods that may be less invasive or prone to error.
PSA values still provide an excellent metric for certain conditions but not necessarily for prostate cancer screening.
"It is an excellent biomarker for patients with metastatic disease," said Krane, who is an assistant professor of urology at the Tulane University School of Medicine. "In patients with localized disease, PSA is not the greatest of all detectors because PSA can go up for any number of reasons. It's higher in patients who have cancer but it can also be higher because you have a large prostate, because you have a urinary tract infection, because you had recent prostatitis or because sometimes the PSA just goes up and we're not really sure [why]."
Risks and additional considerations
Prostate biopsies come with their own risks and special considerations.
Patients can expect a certain amount of bleeding following the procedure, and this bleeding can be observed through several bodily functions. Rectal bleeding or blood in the urine is usually minor but common following a biopsy, and a mild rust color or visible blood in the semen can persist for weeks following the procedure.
Some men experience difficulty urinating after a prostate biopsy and in rare cases may need a urinary catheter. Though uncommon, infections in the urinary tract or prostate are not unheard of and may require treatment using antibiotics.
With all of these possibilities in mind, it's easy to understand why doctors highly value and MRI and other potential alternatives to biopsy.
"Low-risk prostate cancer essentially doesn't kill anyone," Krane said. "Essentially, all men will develop low-risk prostate cancer if they live long enough. What you really want to identify is intermediate- to high-risk disease. So the MRI is good at subsetting intermediate- and high-risk disease."
Your doctor may delay a prostate biopsy if a urinary screening reveals a urinary tract infection, which should be treated before the procedure. Antibiotics are also recommended before a biopsy to reduce the risk of infection, and patients are advised to stop taking blood thinners or medicines and herbal supplements that may increase the risk of bleeding for a few days prior to the biopsy.
Advancements in PSA screening and MRI practices might mean prostate cancer will be identified in the near future without the need for a biopsy.
For now, though, biopsies are still an important part of the process leading to timely detection of prostate cancer. If your doctor recommends a biopsy, it's most likely for good reason, though medical researchers do hope to keep developing practices that make biopsies and other invasive procedures less necessary over time.