Effect of diagnostic biopsy practice location on grade/volume reclassification in active surveillance for prostate cancer: A multicenter analysis from the Canary PASS cohort
Adrian J. Waisman Malaret, MD1, Peter Chang, MD, MPH1, Catrina Crociani, MPH1, Kyle McAnally, BS1, Lisa Newcomb, PhD2, Daniel W. Lin, MD3, Anna Faino, BS4, Yingye Zheng, PhD2, Michael Garcia, MS2, James D. Brooks, MD5, Atreya Dash, MD3, Christopher Filson, MD6, Martin Gleave, MD7, Michael Liss, MD8, Frances Martin, MD9, Todd Morgan, MD10, Peter Carroll, MD, MPH11, Peter Nelson, MD2, Adrew A. Wagner, MD1
1Beth Israel Deaconess Medical Center, Boston, MA, 2Fred Hutchinson Cancer Research Center, Seattle, WA, 3University of Washington, Seattle, WA, 4Seattle Children's Research Institute, Seattle, WA, 5Stanford University, Stanford, CA, 6Emory University, Atlanta, GA, 7University of British Columbia, Vancouver, BC, Canada, 8University of Texas Health Sciences Center, San Antonio, TX, 9Urology of Virginia, Virginia Beach, VA, 10University of Michigan, Ann Arbor, MI, 11University of California, San Francisco, San Francisco, CA
BACKGROUND: During active surveillance (AS) for localized prostate cancer, after the diagnostic biopsy (DxBx), a confirmatory biopsy (Bx1) is typically performed within 1-2 years. Grade/volume reclassification between DxBx and Bx1 occurs in about 20% of cases and is more often due to differences in prostate sampling completeness or biopsy technique rather than true cancer progression. Prior single center studies have demonstrated higher re-classification rates when patients had their DxBx at a tertiary site as opposed to a community urology setting. We analyzed the Canary PASS (Prostate Cancer Active Surveillance Study), a large prospective AS cohort at 10 academic centers, to determine if patients who had DxBx at an off-site practice were at higher risk of reclassification than those having their DxBx at a PASS-site.
METHODS: Out of 1648 participants in PASS, 983 had DxBx with Gleason score ≤3+3=6 and <34% positive cores, and were evaluated for grade/volume reclassification in this study at Bx1. Participants who underwent prostate MRI were excluded from the analysis. Reclassification was defined as an increase of Gleason score >6 and/or increase to ≥34% of positive cores. We used multivariable logistic regression to evaluate our primary outcome: whether location of DxBx (on-site vs off-site) was associated with reclassification after controlling for age, the ratio of positive cores on DxBx, BMI, prostate size, PSA, and DxBx-Bx1 time interval. We used Fisher’s exact test to compare rates of definitive prostate cancer treatment by DxBx location.
RESULTS: Of 519 men who had off-site DxBx and on-site Bx1, 102 (19.7%) had grade/volume reclassification compared to 72 (18.6%) out of 399 patients who had on-site DxBx and on-site Bx1. After controlling for potential confounders, location of DxBx was not associated with grade/volume reclassification. Uropathologic re-review occurred in approximately half (52%) of off-site DxBx, and was not significantly associated with grade reclassification. Participants with an off-site DxBx were more likely to elect definitive treatment than participants with an on-site DxBx (37% vs 29%, p=0.01).
CONCLUSIONS: In this evaluation of a large multicenter AS cohort, diagnostic biopsy practice location was not associated with significant differences in grade/volume reclassification on confirmatory biopsy at academic institutions. These findings support the continued safety of active surveillance in all urologic practice settings.
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