Presentation Authors: Rohith Arcot*, Kevin Ginsburg, Detroit, MI, Ji Qi, Susan Linsell, Deborah Kaye, Ann Arbor, MI, Arvin George, Michael Cher, Detroit, MI, for the Michigan Urological Surgery Improvement Collaborative, Ann Arbor, MI
Introduction: Confirmatory tests may be used after the diagnosis of favorable risk prostate cancer to improve decision-making with regard to active surveillance. How reassuring (RA) or non-reassuring (nonRA) MRI and post-MRI biopsy (pMRI-Bx) results affect decision-making in men considering active surveillance (AS) remains unknown.
Methods: This is a retrospective study of men in the Michigan Urological Surgery Improvement Collaborative (MUSIC) with newly diagnosed favorable risk prostate cancer (any amount of GG1 or â‰¤ 3 cores GG2) who obtained an MRI within 6 months of diagnostic biopsy (dBx). MRI results were either RA (PIRADS â‰¤3) or nonRA (PIRADS â‰¥4). Results of pMRI-Bxs, obtained with or without fusion technology, were considered nonRA if there was any amount of â‰¥GG2 if the dBx was GG1, or >3 cores GG2, >50% GG2 in any individual core, or any volume of â‰¥GG3 if the dBx was GG2.
Results: From June 2016 to April 2017, 157/238 (66%) men had MRI alone and 81/238 (34%) men had MRI and pMRI-Bx. Of 157 men with MRI alone, 105 (67%) had a RA MRI, of which 78/105 (74%) chose AS. In contrast, 52 (33%) men had a nonRA MRI, of which only 18/52 (35%) chose AS. Of the 81 men with MRI and pMRI-Bx, the MRI results were RA and nonRA in 32 (40%) and 49 (60%), respectively. Of the men with RA MRI, 28/32 (88%) had pMRI-Bx results that were RA, of which 26/28 (93%) chose AS. Of the men with a nonRA MRI, 26/49 (53%) had pMRI-Bx results that were RA, of which 25/26 (96%) chose AS. Using Kaplan-Meier analysis, men with RA MRI alone had higher estimated 1 year treatment-free probability than men with nonRA MRI alone (78% vs. 38%, p < .001). Men with either RA or nonRA MRI followed by RA pMRI-Bx had significantly higher 1 year treatment free probability compared with men with nonRA MRI and nonRA pMRI-Bx (96% vs. 96% vs. 35%, p < .001).
Conclusions: MRI results alone informs decision-making in men considering AS; pMRI-Bx is the primary driver as evidenced by the high proportion (~90%) of men with RA-pMRI-Bx who pursued AS regardless of MRI results.
Source of Funding: Blue Cross Blue Shield of Michigan