This week’s Guest Post is by highly regarded expert in the early detection of prostate cancer, Dr. Stacy Loeb. Stacy takes questions on prostate biopsy, and discusses its use, potential problems, and some developments in the field.
Dr Stacy Loeb is an Assistant Professor of Urology and Population Health at New York University (NYU) and the Manhattan Veterans Affairs Medical Center, specializing in prostate cancer. Dr. Loeb has published over 170 peer-reviewed articles and 8 book chapters, primarily on prostate cancer. She is on the Editorial Board for the British Journal of Urology International and Reviews in Urology, and authored the chapter on “Early Detection, Diagnosis, and Staging of Prostate Cancer” for Campbell-Walsh Urology, the primary textbook for the field. Stacy also frequently gives international lectures and courses on prostate cancer for other urologists, and hosts the Men’s Health Show on Sirius XM 81 satellite radio.
Stacy, TRUS biopsy is the most common technique for the diagnosis of prostate cancer. Can you give us an idea of the potential complications and the rates at which they occur?
The most common complication of prostate biopsy is bleeding, which can be in the urine, stool or ejaculate. Fortunately in most cases it is mild and self-limiting. Less common but often more serious is the potential for infection after biopsy. Indeed, the frequency of serious infections requiring hospitalization after prostate biopsy has increased in recent years. Other potential complications of prostate biopsy include pain and urinary difficulties, which are usually transient.
Is it a painful procedure to have done, and what techniques are used to reduce pain?
Prostate biopsy can cause both discomfort and anxiety, although there are many ways to mitigate these problems. Optimising patient positioning and simple relaxation techniques (such as deep breathing, listening to music, or even medication) may be useful to reduce anxiety. For pain, many different anesthetic options are available. For transrectal biopsy, several studies have shown that lidocaine jelly can ease insertion of the ultrasound probe, which is among the more uncomfortable parts of the procedure. Periprostatic nerve block is also commonly employed to successfully reduce pain during outpatient transrectal prostate biopsies. Other forms of biopsy such as the transperineal approach are frequently performed under sedation/general anesthesia, also effective forms of pain control. Overall, there are very few high-quality studies comparing the different methods for pain reduction during prostate biopsy, so the choice may be governed by patient-specific and procedural factors.
Some men require more than one biopsy to diagnose prostate cancer. There has been concern that repeat biopsies can predispose men to erectile dysfunction; can you comment on this?
There is conflicting evidence on the link between repeat prostate biopsies and the risk of erectile dysfunction. A study from the Johns Hopkins active surveillance program suggested that greater biopsy number was associated with erectile dysfunction after adjusting age, prostate volume and PSA, but a similar study from UCSF failed to confirm these results. Possible mechanisms for a link between repeated biopsies and erectile dysfunction include psychological factors as well as potential inflammation in the area around that prostate that houses the nerves involved in erections. Although this issue remains unresolved at this time, each procedure has potential risks making careful patient selection of critical importance. Hopefully, ongoing improvements in markers and imaging will reduce the need for repeat biopsies in the future.
You mentioned infection rates above. Are we seeing a rise in infection following TRUS biopsy of the prostate, and if so, why?
In the United States Medicare population, our research group reported a recent increase in hospitalisations for infection after prostate biopsy. Similar results have been confirmed in other populations, including Canada and Europe. The most likely explanation for these findings is increasing antimicrobial resistance in the community. Traditionally, the majority of patients were given fluoroquinolones as prophylaxis for prostate biopsy, but fluoroquinolone resistance has been on the rise. As a result, recent studies have explored other options for prostate biopsy prophylaxis, One option is to use more broad-spectrum antibiotics, although this may ultimately lead to greater antibiotic resistance in the future. An alternative option is to tailor the antimicrobial regimen based upon the local hospital antibiogram or individual rectal swab cultures performed at the visit prior to prostate biopsy. Other key recommendations are to assess the patient for risk factors for a prostate biopsy infection (such as diabetes, recent antibiotic use and foreign travel) and to counsel patients to seek immediate medical attention at the first sign of an infection.
Transperineal biopsy is another way to biopsy the prostate. Can you outline the advantages and disadvantages of this technique?
In the United States, most prostate biopsies are performed in the outpatient clinic through the rectum (transrectal) using ultrasound guidance. An alternate way to access the prostate for tissue sampling is through the skin of the perineum. Recent studies have suggested that the transperineal approach may reduce the risk of infectious complications. However, unlike transrectal biopsy, it is typically performed in the operating theatre with general anesthesia, thus involving greater time and expense. Transperineal prostate biopsies may also involve a greater risk of urinary retention, a situation where the patient is temporarily unable to urinate.
There has been a lot of interest in the use of MRI as a way of reducing 'unnecessary' biopsies. What are your views on this?
MRI technology has advanced substantially in recent years. At New York University, we have a well-established prostate imaging program using a 3 Tesla multiparametric MRI without an endorectal coil. Most patients tolerate the procedure well and it provides a very detailed anatomic view of the entire prostate, including regions that are poorly sampled during a traditional prostate biopsy. Suspicious lesions found on MRI can then be targeted during the prostate biopsy as a way to increase diagnostic yield. MRI may be particularly useful for men with a persistently elevated PSA and previous negative prostate biopsies, as well as for monitoring patients during active surveillance.
You can read more about Stacy by following the link to NYU Langone Medical Centre and you can follow her @loebstacy on Twitter.