Introduction

Active surveillance (AS) of localized prostate cancer (PCa) in the UK involved protocol-driven (P) transrectal repeat biopsies (RB) plus serial digital rectal examination & PSA-testing, until NICE 2014 guidelines recommended multi-parametric magnetic resonance imaging (mpMRI) should drive RB where needed or replace P-RB. Interrogating our AS follow-up (F/U) data, we hypothesized that mpMRI reduces the number of RB required to drive therapeutic intervention (TI).

Methods

445/461 (97%) AS patients had complete F/U data. Cohort features at diagnosis include median age 68.9 years (interquartile range IQR 63.7-74.8), median PSA 7.2ng/mL (IQR 5.6-9.6), median PSAD 0.11 (IQR 0.08-0.18), ≤cT1c in 80%, 54% unilateral Gleason 3+3, 23% unilateral 3+4, 2% unilateral ≥4+3, 18% bilateral ≥3+3, and median Charlson Comorbidity score 3.1 (IQR 2.5-4.2). We examined the drivers for TI and compared the utility of mpMRI prior to potential RB in AS.

Results

132/445 (30%) patients underwent TI (59% external beam radiotherapy/brachytherapy, 22% radical surgery, 19% other) over a median AS (inter-quartile range IQR) F/U of 2.4 (1.2-3.73) years (maximum F/U 11.3 years). Median (IQR) time to TI was 1.55 (0.71-2.4) years. Reasons for TI included rising PSA, patient choice, mpMRI abnormality alone and/or RB Gleason upgrading. Where TI was driven by RB, 43/71 (61%) had undergone mpMRI, and 39% had P-RB without mpMRI. 49/97 (51%) demonstrated upgrading on RB following mpMRI versus 38/115 (33%) for P-RB without mpMRI. Time to TI was similar for those undergoing RB following mpMRI versus P-RB without mpMRI (P=0.877). Of those upgraded at RB, the number of RB procedures needed to upgrade one patient was 1.9 if prior mpMRI was used versus 3.3 for P-RB alone._x000D_

Conclusions

In this UK cancer centre AS cohort, replacement of P-RB with mpMRI ± RB where indicated, benefitted patients by reducing the number of invasive interventions needed to identify disease progression (characterized by Gleason upgrade), leading to treatment intervention.

Funding

None