Could Prostate MRI See Growing Role in Active Surveillance?

Could Prostate MRI See Growing Role in Active Surveillance?

Men diagnosed with prostate cancer face a difficult decision when it comes to making a treatment decision, with standard options including active surveillance or radical treatments, such as radical prostatectomy and radiation therapy. While radical prostatectomy and radiation therapy are appropriate and potentially life-saving treatment options in many instances, evidence suggests they are relied upon too often and that many men suffer from adverse effects resulting from radical treatments even when prostate cancer posed little threat to their lives.

Radical Prostatectomy & Radiation Therapy Are Overused in Prostate Cancer Treatment

In patients with aggressive prostate cancers and intermediate to high risk for recurrence, radiation therapy may be an appropriate decision depending on a range of factors, including age, overall health and well-being, and personal priorities. Generally, these patients include those with:  

  • Cancer staged at or above T2b;
  • Gleason score of 7 or above;
  • Prostate-specific antigen (PSA) levels greater than 10.

Radiation therapy and/or radical prostatectomy may be an appropriate decision for other patients with less aggressive cancers and lower risk for recurrence, particularly those diagnosed at a younger age.

The problem arises when men diagnosed at an elderly age are recommended radical prostatectomy and/or radiation therapy, even though they are unlikely to die from their disease. Take a look at prostate cancer survival rates provided by the American Cancer Society:

  • 5-year relative survival rate is nearly 100 percent;
  • 10-year relative survival rate is nearly 99 percent;
  • 15-year survival rate is 94 percent.

The Prostate Intervention Versus Observation Trial (PIVOT), which lasted 1994-2002, tracked more than 700 men with life expectancies of 10 years or greater who were diagnosed with localized prostate cancer at age 75 or younger. It found a statistically insignificant difference in all-cause mortality rates among men who received radical prostatectomy and those who opted for active surveillance: 47 percent versus 49.9 percent, respectively.

In many instances, the risks associated with radical prostatectomy may outweigh the potential reward. The 5-year follow-up results to the Prostate Cancer Outcomes Study (PCOS), which surveyed 1,187 men who had previously been diagnosed with prostate cancer, found that approximately 15 percent of men who received radical prostatectomy experienced frequent incontinence or no urinary control and approximately 79 percent reported an inability to have or sustain an erection.

Active Surveillance & Prostate MRI

ProstateCancerActiveSurveillanceActive surveillance, or watchful waiting, will not be an appropriate prostate cancer treatment choice for some men, particularly those who are younger and those with aggressive, fast-growing cancers. However, based on the numbers outlined above, active surveillance may be a more appropriate choice for many men who may otherwise choose a radical therapy. Although treatment options vary on a case-to-case basis, active surveillance is generally appropriate for prostate cancer patients with:

  • Cancer staged from T1a to T2a;
  • Gleason score of 6 or lower;
  • PSA levels less than 10;
  • Life expectancy of less than 20 years.

During active surveillance of slow-growing prostate cancers, patients are required to make regular visits to their physician for the purpose of monitoring their disease. These visits have traditionally included:

  • Digital rectal examinations;
  • PSA testing;
  • Transrectal ultrasound-guided (TRANS) biopsy.

While TRUS was for a long time the best option available for diagnosing prostate cancer, it is not necessarily a precise procedure. TRUS removes samples randomly from the prostate, which means it can miss cancers altogether or sample areas where cancer is not clinically significant. This inaccuracy often results in misdiagnosis and poor treatment recommendations.

Magnetic resonance imaging (MRI) is emerging as an alternative to TRUS, which may prove more effective at detecting and grading prostate cancer. MRI can more effectively visualize the interior of the prostate than TRUS, and pinpoint the exact location of a possibly cancerous tumor. MRI images can then be used during real-time TRUS to more accurately biopsy the prostate gland. Using special techniques, such as dynamic contrast-enhanced and diffusion weighted imaging, radiologists can also estimate a cancer’s rate of growth and measure its volume. This information can be invaluable when deciding whether active surveillance is an appropriate course.

Early research suggests it can help physicians more accurately assess prostate cancers. When compared with three existing clinical assessments for scoring prostate cancer, MRI performed better than the D’Amico scoring system, the Epstein criteria and the Cancer of the Prostate Risk Assessment (CAPRA) system, according to a study published March 2013 in Radiology.

While the role of MRI in the active surveillance of prostate cancer is still unclear, early results have been promising and it seems likely that MRI could soon play a much more integral part in the diagnosis and treatment of prostate cancer. At RadNet, we’ve excitedly tracked developments in prostate imaging and MRI technology to ensure we can provide prostate cancer patients with greater clarity regarding their condition. We hope this allows patients to make informed treatment choices that match their priorities.

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