Abstracts from the New England Section of the AUA 2020: A Virtual Experience

NE AUA 2020 Abstracts 34 PSA Density Velocity is the Most Important Predictor of Grade Group Progression During Prostate Cancer Active Surveillance AndrewGusev, BA , Florian Rumpf, BA, Dimitar Zlatev, MD, Jeffrey Twum-Ampofo, MD, Carl Ceraolo, BA, Keyan Salari, MD PhD, Douglas Dahl, MD, Matthew Wszolek, MD, Michael Blute, MD, Adam S. Feldman, MD MPH Massachusetts General Hospital, Boston, MA Introduction: Active surveillance (AS) is an established option in the management of appropriately selectedmen with prostate cancer. Prostate-specific antigen density (PSAd) at diagnosis is an important predictor of disease progression, however change in PSAd over time, or PSAd velocity (PSAdv), has not been thoroughly assessed. We sought to investigate the prognostic impact of PSAdv in men on AS. Materials & Methods: Within our institutional database of 1268 men enrolled in AS for prostate cancer between 1997-2016, we retrospectively identified patients with at least two PSAvaluesandprostatevolumemeasurementsbyradiologic imaging.PSAdwascalculated asPSAdividedbyprostatevolumeontransrectalultrasound(TRUS)ormagneticresonance imaging (MRI). PSAdv was calculated as the difference between two PSAd measurements divided by the time between them. The primary outcome was freedom from pathologic progression to grade group (GG) 2 or higher on any follow-up biopsy during AS. Logistic regressionwasused todetermineclinicalfactorspredictiveofGGprogression.Asensitivity and specificity analysis with receiver operator curve (ROC) was utilized to identify the optimal PSAdv threshold for distinguishing risk of GG progression. Using this cut-off point, survival analysis was conducted with the Kaplan-Meier method and log-rank test. Results: 631 patients met criteria and were evaluated in this study. At diagnosis, median values were: age 64 years (IQR 59-69), PSA 5.1 ng/mL (IQR 4.0-6.8), PSAd 0.11 ng/ml/ ml (IQR 0.08-0.16), percent of cores positive 8.3% (IQR 8.3-16.7), maximum single-core involvement 10% (IQR 5-20). The majority of patients had GG 1 (98%) and clinical stage T1c (94%) disease. During AS, median follow-up time was 5.7 years (IQR 4.0-8.3) and number of prostate volume measurements was 2 (IQR 2-3). 404 patients (64%) had PSAd values calculated using volumes only from TRUS, while the rest utilized both TRUS and MRI. Median time between PSAand prostate volume measurement was 37 days (IQR 19- 61) and 16 days (IQR 1-39) for TRUS and MRI, respectively. Median PSAdensity velocity was +0.001 ng/ml/ml per year (IQR -0.02-0.03). 157 patients (25%) had GG progression on surveillance biopsy, with median time to progression 2.8 years (IQR 1.3-4.6). 241 patients (38%) progressed to treatment. On multivariable regression, PSAdv was the most significant predictor of GG progression (p = 0.002) [Table 1]. On sensitivity and specificity analysis, the optimal PSAdv cut-off value was determined to be 0.0055 ng/ml/ml/year. 269 patients in this cohort (43%) with PSAdv above this threshold had a significantly greater risk of GG progression during the course of surveillance (p < 0.001) [Figure 2]. Conclusions: In our analysis, PSAdv is the most significant predictor of GG progression on follow-up biopsy during the course ofAS. It therefore represents an important adjunct measure for prognostication of outcomes for men during AS. Evaluating the Outcomes of Active Surveillance in Gleason Grade Group 2 Prostate Cancer: Prospective Results from the Canary-PASS Cohort Adrian J. Waisman Malaret, MD 1 , Peter Chang, MD, MPH 1 , Kehao Zhu, MD 4 , Yingye Zheng, PhD 2 , Lisa Newcomb, PhD 2 , James D. Brooks, MD 3 , Atreya Dash, MD 4 , Peter Carroll, MD, MPH 5 , Cristopher P. Filson, MD 6 , Martin E. Gleave, MD 7 , Michael Liss, MD 8 , Frances M. Martin, MD 9 , Todd M. Morgan, MD 10 , Peter S. Nelson, MD 2 , Daniel W. Lin, MD 4 , Andrew A. Wagner, MD 1 1 Beth Israel Deaconess Medical Center, Boston, MA; 2 Fred Hutchinson Cancer Research Center, Seattle, WA; 3 Stanford University, Standford, CA; 4 University of Washington, Seattle, WA; 5 University of California, San Francisco, CA; 6 Emory University, Atlanta, GA; 7 University of British Columbia, Vancouver, BC, Canada; 8 University of Texas Health Sciences Center, San Antonio, TX; 9 Urology of Virginia, Virginia Beach, VA; 10 University of Michigan, Ann Arbor, MI Introduction: The safety of Active Surveillance (AS) for grade group 2 (GG2) patients is debated. We sought to compare clinical outcomes of men with GG1 and GG2 prostate cancer undergoing AS in the Canary Prostate Cancer Active Surveillance Study (PASS) cohort. Materials&Methods: Participantswereprospectivelyenrolled inanASstudyonprotocol- directed follow-up at 10 centers nationwide. We included those who had GG1 or GG2 at diagnosis and at least one confirmatory biopsy. Patients were stratified according to GG at diagnosis and whether they were reclassified from initial biopsy. Time from diagnosis to treatment and time from definitive treatment to biochemical recurrence (BCR) were evaluated using Kaplan-Meier method; adverse pathology (AP) at Radical Prostatectomy (RP), defined as GG ≥ 3, ≥ pT3a, or pN1, was analyzed as interval censored data using Weibull regression. Results: BetweenAugust 2008 and February 2019, 1574 patients met the eligibility criteria. At diagnosis, 1440 (91%) patients had GG1 and 134 (9%) had GG2, out of which 102 (76%) presented with single core of GG2. Patients with GG2 were older (66 vs. 62 years) and had shorter median follow-up (5.4 vs. 6.9 years) compared to GG1 patients. Reclassification rate at 5 years occurred in 36% of GG2 and 38% of GG1 patients. Overall, patients with GG2 had shorter time to treatment compared to patients with GG1 (median: 4.3 vs. 10.3 years p < 0.0001). Among those who were not reclassified, patients with GG2 had shorter time to treatment compared to GG1 (median: 4.55 vs. not reached), but had longer time to treatment compared to GG1 and GG2 who got reclassified (Figure). The risk of AP at RP was slightly higher for GG2 than for GG1 (hazard ratio: 1.37; 95% CI: 0.73-2.54). BCR within 3 years of treatment among those treated with surgery or radiation for GG2 was 10% and for GG1 was 13% (p = 0.50). Conclusions: Most GG2 patients enrolled in thisAS protocol had lowvolume GG2 disease. Adverse pathology after RP and BCR after definitive treatment are similar in low volume GG2 patients compared to GG1 patients. Our results show that AS patients with low volume GG2 will have a shorter time to treatment, and limited follow-up post-treatment suggest equal oncologic outcomes. 33 15 Scientific Session IV: Oncology II