Presentation Authors: Samuel Haywood*, Amy Tin, James Eastham, Vincent Laudone, Karim Touijer, Peter Scardino, Andrew Vickers, Behfar Ehdaie, New York, NY
Introduction: Among men with low risk prostate cancer (PCa) managed with active surveillance (AS), upgrade to Gleason Grade Group (GG) â‰¥2 has been used to trigger treatment. We aimed to compare the outcomes of men with GG2/3 PCa undergoing immediate radical prostatectomy (RP) with men who initially met AS eligibility but were upgraded on confirmatory biopsy and subsequently underwent RP.
Methods: We retrospectively reviewed a prospectively maintained database of men who were treated with RP at Memorial Sloan Kettering Cancer Center from 2000 to 2016. Two cohorts were selected: an &[Prime]immediate RP&[Prime] group with GG 2/3 PCa treated initially (within 6 months of diagnostic biopsy) and a second group of men initially eligible for AS (&[Prime]AS group&[Prime]) with GG1 but upgraded to GG2/3 on confirmatory biopsy within 12 months. We compared probabilities of biochemical recurrence (BCR) and salvage therapy using two separate multivariable Cox regression models, with risk-adjustment by a nomogram predicting preoperative BCR. Rates of adverse pathology were also compared, utilizing two definitions varying on inclusion of extracapsular extension (ECE).
Results: We identified 4011 patients in the immediate RP group and 321 patients in the AS group. Overall, 789 patients experienced a BCR with median follow-up of 3.9 years in BCR-free survivors. BCR risk was lower in men upgraded on confirmatory biopsy, although differences did not meet statistical significance (hazard ratio, HR 0.73; 95% CI 0.50, 1.06; p=0.10; rates at one-year (6.2% vs. 4.6%) and three-years (16% vs. 8.1%); Figure). Results were similar for salvage-treatment-free survival (HR 0.67, 95% CI 0.42, 1.06, p-value = 0.088), with estimated rates in the AS and immediate RP groups at one-year as 2.8% vs. 4.2% and three-years as 5.4% vs. 12%. The AS group had significantly lower rates of adverse pathology, excluding ECE (27% vs. 35%, p=0.003).
Conclusions: We found evidence that men with low-risk prostate cancer upgraded on confirmatory biopsy have better outcomes than men with identical tumors found at initial biopsy. These results would need to be confirmed in other and larger series before we counsel men that upgrading on confirmatory biopsy does not portend the same prognosis as a high-grade tumor found on initial biopsy.
Source of Funding: National Institutes of Health/National Cancer Institute (NIH/NCI) with a Cancer Center Support Grant to Memorial Sloan Kettering Cancer Center [P30 CA008748]