Let’s say a real estate investor buys a dilapidated house, intending to tear it down and develop the property with a larger, up-to-date home. Since the house will be demolished, the investor decides to skip going through the rooms for an on-site inspection. If any furnishings were left behind, when the bulldozers come to do their job, it will be “bye-bye house, goods and all.”

In today’s standard-of-care guidelines for prostate cancer (PCa), a high or rising PSA and/or an abnormal DRE suggests PCa. Patients are sent for a needle biopsy. Conventional biopsies are guided by transrectal ultrasound (TRUS), which has very limited ability to detect a tumor. Therefore, using a mental map of the prostate divided into separate areas (like rooms in a house), doctors take 12 or more needles for a sort of on-site inspection of each “room”.

TRUS biopsies have risks of side effects such as bleeding, infection, pain, and sexual dysfunction. Even worse, they are subject to an average 30% rate of inaccuracies, including over-detection of insignificant PCa and under-detection of significant disease. But currently, only tissue samples can prove PCa.

Refusing a biopsy

What happens, then, if a man were to refuse to have a biopsy. Can a doctor still responsibly treat him? A recent German study by Meissner, et al. (2021) reported on 25 patients who said NO to a biopsy. The Meissner team turned to two advanced imaging methods, multiparametric MRI (mpMRI) and PSMA PET scan. The results for each patient revealed “high suspicion” for localized prostate cancer.^[i] These findings qualified the patients for radical prostatectomy (RP), or surgical gland removal. Medscape Medical News writes that all patients “…chose to have radical prostatectomies based on the results of mpMRI and PSMA-PET imaging without biopsy, despite the surgeon’s recommendation to undergo biopsy.”

In keeping with the teardown house image, it makes sense that if you’re going to demolish the prostate, why bother with an “on-site inspection” using 12+ needles when it’s “bye-bye prostate, cancer and all”?

High degree of confidence

Today’s mpMRI and PSMA PET scanning give a high degree of confidence that significant cancer is present in the gland (mpMRI) but not elsewhere in the body (PSMA PET scan). In fact, it’s becoming more acceptable to use mpMRI before a biopsy is even done, to determine if a biopsy can be safely avoided. Thus, it was reasonable for the Meissner team to go out on a limb, departing from the standard pathway of biopsy to diagnose PCa and guide the treatment plan. Fortunately, all their patients were indeed found to have PCa based on the surgically removed specimens. The results justified their actions.

Three years earlier, a Chinese team also explored the idea of performing prostatectomy without physical evidence (biopsy tissue) of PCa, but based solely on mpMRI and PSMA PET scan.^[ii] Their paper described 11 patients whose imaging strongly suggested PCa. After the surgery, however, it was determined that 10 cases had cancer, but the 11th was benign prostatic hyperplasia (BPH). In other words, one patient would not have had to undergo major surgery after all. However, as explained in their published paper, “The patient was very satisfied with the treatment since he recovered very well without major complications, while his lower urinary tracts symptoms disappeared. Therefore, it is acceptable even the final pathology is benign for some patients who received radical prostatectomy.”

Debating the idea of RP without biopsy

The Meissner paper has stirred some debate regarding the merits of skipping the biopsy before RP. Reading both the German and Chinese papers reveals their decisions were not done lightly, or irresponsibly. As the Chinese team points out, the critical concern is overtreating a patient who turns out not to have cancer. At this point, no one is suggesting that this pathway is a new standard of care. Rather, there is universal agreement that it should only be done as an ethical, board-approved clinical trial until further consistent evidence is amassed.

Nonetheless, both published studies have merit. Dr. Michael Leapman, professor of urology at Yale U. School of Medicine, commented on the German study, “In this small and very carefully selected group of patients, prostate MRI and PSMA-PET imaging were successful in identifying prostate cancer in all patients…This work is intriguing because it may suggest the possibility of a diagnostic pathway that avoids prostate biopsy, an invasive procedure that is uncomfortable, costly, and does exposure patients to potential risks.”^[iii]

It is our position at the Sperling Prostate Center that mpMRI can help avoid a biopsy. However, if mpMRI indicates the likelihood of significant PCa, a biopsy is necessary in order to a) confirm cancer and b) plan treatment. If biopsy is indicated, we offer real time in-bore MRI-guided targeted biopsy. By using only the minimal number of needles, we greatly reduce biopsy-associated risks. Thanks to mpMRI’s high accuracy of locating the size and shape of the tumor, we are able to access those cancer cells most likely to be aggressive, giving us a true picture in order to match the best treatment for each patient.

Meanwhile, we’ll be observing the ongoing influence of mpMRI over the future of urologic PCa treatments such as RP.

NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.

References

[i] i Meissner VH, Rauscher I, Schwamborn K, Neumann J et al. Radical Prostatectomy Without Prior Biopsy Following
Multiparametric Magnetic Resonance Imaging and Prostate-specific Membrane Antigen Positron Emission Tomography. Eur Urol. 2021 Dec 6:S0302-2838(21)02194-1.
[ii] Xing NZ, Wang MS, Fu Q, et al. Feasibility of prostatectomy without prostate biopsy in the era of new imaging
technology and minimally invasive techniques. World J Clin Cases. 2019;7(12):1403-1409.
[iii] Charnow, Jody. “Study: Prostate Cancer Surgery Without Prior Biopsy Possible.” Renal & Urology News, Dec. 22,
2021.