How times and technology change! Take, for example, the shift from a tangible book like the Yellow Pages to a digital one. At one time, paper copies of the Yellow Pages business directory were delivered to virtually every household in America. This hefty local book was the ultimate resource for finding a business or service in any category. While a small number of paper copies are still published and delivered, mostly for senior citizens not using computers, today’s Real Yellow Pages is alive and well in a user-friendly online format. It’s a welcome alternative to keeping a physical bundle of pages on hand.

From tangible biopsy to virtual imaging

A similar shift from tangible to virtual is occurring in the management of Active Surveillance (AS). AS is increasingly offered to men diagnosed with low-risk (PI-RADS 1-2) prostate cancer (PCa). Now, the nature of low-risk PCa is under debate: some believe it doesn’t behave like cancer because in many cases it doesn’t seem to progress; while others remind us that cancer is cancer so don’t trust it.

This is why it’s important to monitor patients on AS. There is no universal protocol, so typically doctors start with a recommended standard and adapt it to each person’s case. Johns Hopkins point out, Medical experts offer various recommendations regarding frequency of testing and when to start treatment during active surveillance. The American Society of Clinical Oncology recommends the following periodic evaluations while under active surveillance for prostate cancer:

• PSA testing every three to six months
• A digital rectal exam (DRE) at least once a year
• A prostate biopsy at least every two to five years (after the follow-up biopsy within six to 12 months of diagnosis).

A biopsy is a tangible physical way to check if the tumor is upgrading, meaning getting more aggressive. If you cringe at the idea of monitoring biopsies, you’re not alone. A 2023 study involving 4000 men on AS found that over time, slightly less than a third cooperated with all repeat biopsies as required by protocol. In fact, “66-90% of repeat biopsies may be considered redundant as they do not show [emphasis mine] histological progression [meaning upgrading] which is now the main trigger for discontinuing AS … The burden and fear of biopsies can also lead the patient to discontinue AS.”^[i] The authors suggest that fewer and less frequent biopsies, when it is safe to do so [emphasis mine], may improve compliance when a biopsy is indicated.

So, here’s the question: how do we know if it’s safe to skip a monitoring biopsy for an AS patient who is scheduled for one according to protocol? Exploration is in progress to create a virtual way to identify tumor activity. It would be a great addition to physical testing by means of blood draw, DRE and needle biopsy.

Here’s one example. A research team led by Laurence Klotz (Sunnybrook Health Sciences, Toronto) found that incorporating serial MRI imaging into their AS protocol is a way to identify which patients have PCa that is unlikely to progress, and therefore can safely skip a biopsy. The key lies in invisible new progression. In other words, their monitoring images are negative for new activity. The team followed 530 AS patients for an average of 8.5 years. Biopsies were done only “for cause,” that is, their MRI revealed a higher PI-RADS score. On the other hand, men whose initial and repeat MRI’s had no visible suspicion of clinically significant were able to skip a biopsy at that time.

The authors found that the lower the PI-RADS score, the longer the period of time in which suspicious activity remained invisible. They write:

MRI invisible cancers demonstrated dramatically reduced rates of progression and no patient required intervention. Despite the absence of routine biopsies in the MR negative group, none of these patients progressed over time to GG≥3 or metastatic disease. This suggests that, in men on active surveillance, image guided management, restricting biopsies to targeted biopsies of regions of interest, is sufficient to identify clinically significant cancers.^[ii]

MRI alone – not for the final decision

Indeed, the news from the Klotz team is promising, but it’s too soon to send up victory flares. More recently, at the Feb. 2025 annual meeting of ASCO’s Genitorurinary Cancers Symposium, Dr. Matthew Cooperberg presented his team’s study, “Can magnetic resonance imaging safely replace a confirmatory biopsy in patients on active surveillance for prostate cancer?” They correlated biopsy and MRI results for over 1000 men on AS and found that MRI averaged 75% negative predictive value—that is, MRI was correctly predicting invisible (no significant PCa) 74-75% of the time. As Dr. Cooperberg stated, “Negative MRI—as defined by PI-RADS 1-2—does not consistently rule out the presence of GG≥2 prostate cancer and therefore cannot safely replace confirmatory biopsy.”^[iii]

To return to the transition from Yellow Pages books to digital website, I noted that hard copies are still being printed and distributed. The shift is not 100% complete because need for a book still exists. Similarly, the shift to MRI alone as a way to know if a patient can safely remain on AS is not yet possible. The need for definitive biopsy still exists. On the other hand, evidence that in many cases MRI can spare patients from unnecessary biopsy continues to grow.

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] de Vos II, Luiting HB, Roobol MJ. Active Surveillance for Prostate Cancer: Past, Current, and Future Trends. J Pers Med. 2023 Apr 3;13(4):629.
[ii] Klotz L, Loblaw A, Zhang L, Mamedov A, Vesprini D. Prognostic value of MR visibility/invisibility in men on Active Surveillance. Prostate Cancer Prostatic Dis. 2025 Jan 17.
[iii] Cooperberg, et al. https://meetings.asco.org/abstracts-presentations/242180 Feb. 2025.