A recent study demonstrates that the alternate biopsy procedure for the prostate is more complicated.
A biopsy is often the next step if a screening test for prostate cancer indicates an abnormality. This is generally always accomplished in the United States by inserting a biopsy needle through the rectum into the prostate. Doctors can see the needle's path using an ultrasound machine. This treatment, referred to as transrectal ultrasonography (TRUS) biopsy, carries a minor but growing risk of infections that are becoming increasingly resistant to current medications.
To further reduce infection risk, surgeons can thread the biopsy needle into the perineum, a region of skin between the anus and scrotum. This circumvents rectal bacteria. Additionally, these so-called transperineal (TP) biopsies enable improved access to the tip (or apex) of the prostate, which accounts for 30% of malignancies. They are, however, more painful for the patient. They were formerly performed exclusively in hospital operating rooms under general anesthesia.
Today, technological advancements enable doctors to do TP biopsies in their own offices under local anesthetic. And as a result of this progress, the urge to minimize infections through the use of this strategy is increasing.
Harvard researchers have compared the two approaches in terms of cancer detection and complication rates. The trial enrolled 260 men, all of whom were highly matched in terms of age, race, prostate-specific antigen levels, and other diagnostic results. Between 2014 and 2020, half of the men received TRUS biopsies and the other half received TP biopsies. All operations were conducted at a single medical practice. To prepare, all males in the TRUS group received prophylactic antibiotics according to established clinical standards. In comparison, only 43% of males in the TP group received antibiotics, which was consistent with physician recommendations.
When it came to finding cancer, 62% of TP patients were found to have it, whereas 74% of TRUS patients had it found. There were no significant variations in cancer detection rates. However, 15% of men with cancer in the TP group had apical tumors that the TRUS biopsies "may have missed," according to the study's authors.
Additional problems with the TP strategy
Complications include an infection in one man in the TRUS group that required numerous doses of oral antibiotics. None of the TP-biopsied men developed an infection, but eight developed other complications: one developed urinary blood clots that required hospitalization, two required catheterizations for acute urinary retention, three required medical evaluation for dizziness, and two developed temporary scrota swelling.
Why was the incidence of noninfectious complications associated with TP higher?
That is not really obvious. For a variety of reasons, doctors took more prostate samples (called cores) from men in the TP group than from those in the TRUS group on average. The authors speculate that if an equal number of cores were collected from men in both groups, the complication rates could have been more comparable. (In fact, larger comparison studies conducted in hospital settings demonstrate no difference in complication rates when the same number of cores is acquired.) However, doctors in the current trial had more experience with TRUS biopsies, which the authors think could potentially account for the discrepancy. Additionally, when physicians gain experience with the TP technique, complication rates may decrease.
Dr. Marc Garnick is a professor of medicine at Harvard Medical School and a publisher of the Harvard Health Publishing Annual Report on Prostate Diseases and Editor in Chief of HarvardProstateKnowledge.org, noted encouraging findings from the study, including a reduced requirement for antibiotics with TP technique and the discovery of apical tumors that TRUS biopsies may have missed. Garnick further emphasized the "steep learning curve" associated with TP biopsies, as well as the fact that some of the noninfectious consequences necessitated hospitalization. "The ability to perform TP biopsies in an office environment should allow for future TRUS comparisons, which will aid in determining whether this innovative TP approach has enduring utility," he said.
