Presentation Authors: Michael Ahdoot*, Amir H. Lebastchi, Johnathan Bloom, Patrick Gomella, Sandeep Gurram, Thomas Sanford, Johnathan DiBianco, Samuel Gold, Graham R. Hale, Sherif Mehralivand, Vladimir Valera Romero MD, Maria Merino, Bethesda, MD, M. Minhaj Siddiqui, College Park, MD, Peter L. Choyke, Brad Wood MD, Howard Parnes, Barris Turkbey, Peter A. Pinto, Bethesda, MD
Introduction: Active surveillance(AS) has become a more common management strategy of low and favorable intermediate risk prostate cancers. In the age of MRI targeted biopsy risks of under-staging have declined. However, once a patient pursues active surveillance the likelihood of disease upgrading over time is poorly characterized. We seek to define the risk of upgrading among patients on AS in the MRI era.
Methods: Men were prospectively enrolled in a trial of active surveillance(AS) with Gleason 3+3=6 or 3+4=7 disease diagnosed in the community. Upon entry into the protocol a confirmatory MRI targeted plus systematic 12 core biopsy were performed to confirm the diagnosis of low or favorable intermediate risk prostate cancer. Patients without cancer detected on confirmatory biopsy or patients with high volume disease were considered eligible for active surveillance. Patient demographics, PSA, prostate volume, PIRADs scores, targeted and sextant biopsy yield, and Gleason scores were recorded upon study enrollment and at the time most recent follow up biopsy.
Results: 289 men aged 42-79 years old (mean 62.4) with a mean prostate volume 53.4ml reached eligibility criteria for active surveillance after initial MRI targeted plus systematic biopsy. All patients demonstrated Gleason 3+3=6 or Gleason 3+4=7 disease upon study enrollment. Over a mean follow up of 32.6 months (3.2-109.3 months), 35.1% demonstrated Gleason Score upgrading and 14.6% (n=42) of patients were upgraded to 4+3=7 or higher disease on repeat MRI targeted fusion plus systematic biopsy. On a per year basis, this translated to a 4.8% rate of any upgrading, and a 2.3% rate of upgrading to clinically significant (Gleason Score â‰¥4+3) disease per year. Rates of upstaging appear to level off at approximately 5 years of follow up.
Conclusions: In the age of MRI targeted biopsy, approximately 5% of patients will undergo upgrading prostate biopsy per year while on active surveillance. Of these upgrading events, 2.3% per year will represent upgrading to clinically significant disease. Additionally, rates of prostate cancer upstaging on prostate biopsy appears to approach zero at approximately 5 years following initial diagnosis. These data suggest prostate biopsies should be done with more frequency early after initiating active surveillance and less frequently after 5 years on AS.
Source of Funding: This research was supported by the Intramural Research Program of the NIH, National Cancer Institute, Center for Cancer Research.