SUO 2017: MRI Fusion Biopsy is Associated with a Higher Rate of Pathologic Downgrading at Radical Prostatectomy
The authors reviewed their institutional database to identify 589 prostate cancer patients who received a radical prostatectomy between February 2014 and October 2015. All preoperative biopsies were re-reviewed by a genitourinary pathologist. Gleason score concordance of biopsy and final pathology was compared between standard biopsy and fusion biopsy groups. Downgrading was defined as the change from Gleason Group 3, 4 or 5 on biopsy to Gleason Group 1 or 2 on RP pathology. Additional clinical and pathologic factors associated with downgrading were analyzed. Statistical analysis was performed using Student’s t-test or Mann Whitney U test for continuous variables and Chi-square or Fisher's exact tests for categorical variables. Multivariate analysis was done using a binomial logistic regression model.
There were no significant differences between the two groups (standard biopsy: n=476; fusion biopsy: n=104) in terms of PSA (p=0.49), PSA density (p=0.17), maximum % core (p=0.83), clinical stage (p=0.13), MRI volume (p=0.10) and MRI ECE (p=0.13). The fusion biopsy group had more patients who downgraded on final pathology compared with standard biopsy (18.5% vs. 9.7%, p=0.01) Downgrading did not impact pathological outcome. Downgrading was not associated with pathologic stage (p=0.53), extraprostatic extension (p=0.39), lymph node invasion (p=0.24), nor positive surgical margin status (p=0.41). A multivariate regression model including PSA, maximum % core, MRI volume and MRI ECE demonstrated that targeted biopsy was the only factor independently associated with downgrading after radical prostatectomy (p=0.01)
In summary, the authors observed increased downgrading from high/intermediate risk groups to low risk groups after fusion biopsy compared with standard biopsy. This information should be used in shared decision making for prostate cancer management.
References:
1. Siddiqui MM, Rais-Bahrami S, Turkbey B, et al. Comparison of MR/ultrasound fusion-guided biopsy with ultrasound-guided biopsy for the diagnosis of prostate cancer. JAMA 2015;313(4):390-397.
Presented by: Alp Tuna Beksac, MD¹
Co-Authors: Shivaram Cumarasamy MD², Akriti Gupta MD², Kanika Mahajan BDS, MPH², Ugo Falagario MD², Sonya Prasad BA², Isuru Jayaratna MD², Andrew Charap BS², Emma Rosenbluth BA², Sara Pasik BA² and Ash Tewari MD²
Affiliation: ¹Icahn School of Medicine at Mount Sinai, New York City, NY; ²Icahn School of Medicine at Mount Sinai, New York, NY
Written by: Zachary Klaassen, MD, Society of Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre @zklaassen_md at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC