Prostate Biopsy: Friend or Foe?
When a man’s PSA is rising and his physician recommends he have a prostate biopsy, many patients almost immediate experience fear. Naturally, there’s worry that they might have cancer—a scary proposition. But the immediate dread concerns the actual process of firing hollow collection needles into his prostate. Often, the more internet research he conducts, the greater the anxiety grows. A man may understand that the purpose of a biopsy is actually in his self-interest in two ways:
- It can help to rule cancer in or out, and
- If cancer is found, it can give the essential information on aggressiveness and location, two of the most important factors in choosing a treatment.
In that sense, a prostate biopsy is a man’s friend. However, there are three general concerns about a transrectal ultrasound (TRUS) biopsy that rattle patients’ confidence: accuracy, pain, and side effects.
TRUS biopsy accuracy
Less than 15 years ago, a 6-needle (sextant) biopsy was the norm, based on a conceptual model of a prostate divided into six segments: mentally divide the prostate in half from front to back, picture each half divided into three sections, and use ultrasound to “see” each needle take a single sample from each of the 6 segments. By the new millennium, it was clear that this method was missing up to 54% of cancers, and often the highest Gleason grade was missed.[i]
Such findings led to the conclusion that more needles were needed, so the average number was increased to 10-12 samples. Still, such biopsies can miss significant cancer over 50% of the time, and underestimate the Gleason score in almost 40% of cases.[ii] When a man’s pathology report comes back from the lab saying there is no cancer, but in fact cancer was there, it’s called a “false negative.”
A biopsy that misses cancer can lead to repeat biopsies. Presumably, the man’s PSA will continue to rise, and there is a risk that the Gleason score of a low-risk tumor will migrate upward as the cancer multiplies and mutates. There is no guarantee that a second, or even third, biopsy will produce accurate results. Thus, false negatives are something to be genuinely concerned about. They are not a man’s friend.
Again, looking back 15 years, sextant TRUS biopsies were usually performed with no local (injected) anesthesia. It was assumed that a man could tolerate brief “discomfort” for six samples. Even the use of a numbing gel on the ultrasound wand/needle gun took the edge off, at best. Patients later said things like, “After the fourth needle I felt like my bottom was being hit by a baseball bat.” Or, “The gun sounded like a mousetrap snapping. By the third needle, I dreaded hearing that noise.” Or, “He hurt me.”
Even today, not all urologists take the extra time to inject a numbing agent (lidocaine) into the levatores prostatae, an area rich in nerves that serve the prostate. Even when they do, they sometimes don’t wait long enough for the drug to work. One study that compared two groups of TRUS biopsy patients (with and without local anesthesia) found that those with the anesthesia still reported some minor discomfort but, as expected, tolerated the biopsy much better. Even with the nerve block, some patients still have enough discomfort the next day that they self-medicate with over-the-counter pain killers. Here too, we must conclude that a 10-12 core TRUS biopsy with no local anesthesia is no friend to patients.
TRUS biopsy has certain risks, though statistically they are the vast minority of this approach. Risks include infection, urinary or rectal bleeding, and in rare cases, biopsy-related erectile dysfunction. Though these are not prevalent side effects, most patients understandably associate a greater number of needles with increased risks.
Another possible side effect that elicits much internet discussion, and that is the idea of “needle tracking,” also called tract seeding or needle tracking. This is the idea that as the needle containing cancer cells is withdrawn from the prostate, it can “seed” microscopic disease along the path of the needle, thus implanting living prostate cancer cells into tissue outside the prostate gland. If this were so, a prostate biopsy would indeed be more of a foe than a friend. In fact, there have been no authoritative studies with compelling evidence that this has ever occurred—not with prostate cancer or any other cancer. Even if it has occurred, it would be very difficult to demonstrate with certainty. If the risk exists at all, our opinion is that it’s exceedingly rare. The knowledge gained about a patient’s cancer from an accurate biopsy into the tumor would far outweigh the percentage.
Overcoming biopsy fears
Today, we are at a point where we have a highly accurate and specific noninvasive way to gain a great deal of information about prostate cancer cell lines. Diffusion Weighted imaging allows us to closely approximate the actual Gleason score or aggressiveness of the tumor. However, we are not yet at the point where we can recommend forgoing a biopsy. The biopsy is still an extremely useful tool that when used in conjunction with multiparametric MRI allows us to most accurately determine tumor aggressiveness.
That said, our approach to prostate biopsy at the Sperling Prostate Center is truly more friendly than standard TRUS biopsies, because it is
- Far more accurate with fewer needles
- Far less pain due to use of a small number of needles under local anesthesia
- Fewer needles reduces all side effect risks across the board.
- Assurance that MOST AGGRESSIVE portion of tumor will be sampled and accurate staging attained.
Read more about our MRI-guided prostate biopsy at https://sperlingprostatecenter.com/mri-guided-biopsy-new-york-city/ to find out what we do to make biopsy patient-friendly.
[i] Bak JB, Landas SK, Haas GP. Characterization of prostate cancer missed by sextant biopsy. Clin Pros Cancer 2003 Spe;2(2):115-8.
[ii] Washington SL, Bonham M, Whitson JM et al. Transrectal ultrasonography-guided bipsy does not reliable identify dominant cancer location in men with low-risk prostate cancer. BJU Int 2012 Jul;110(1):50-5.