Risk of Metastasis in Men with Grade Group 2 Prostate Cancer Managed with Active Surveillance at a Tertiary Cancer Center

Abstract

Purpose: To study the risk of metastatic prostate cancer development in men with Grade Group 2 disease being managed with active surveillance (AS) at Memorial Sloan Kettering Cancer Center. Materials and Methods: 219 men with Grade Group 2 prostate cancer were managed with AS between 2000–2017. Biopsy was performed every 2–3 years or upon changes in magnetic resonance imaging, prostate-specific antigen (PSA) level, or digital rectal examination. The primary outcome was development of distant metastasis. The Kaplan-Meier method was used to estimate treatment-free survival. Results: The median age at diagnosis was 67 years (IQR 61–72), the median PSA was 5 ng/mL (IQR 4–7), and most patients (69%) had non-palpable disease. During follow-up, 64 men received treatment: 36/64 (56%) radical prostatectomy; 20/64 (31%) radiotherapy; 3/64 (5%) hormone therapy; and 5/64 (8%) focal therapy. Of the 36 patients who underwent radical prostatectomy, 32/36 (89%) had Grade Group 2 disease on pathology and 4/36 (11%) had Grade Group 3. Treatment-free survival was 61% (95% CI 52%–70%) at 5 years and 49% (95% CI 37%–60%) at 10 years. Three men experienced biochemical recurrence, no men developed distant metastasis, and no men died of prostate cancer during the follow-up. The median follow-up was 3.1 years (IQR 1.9–4.9). Conclusions: AS appears to be a safe initial management strategy in the short term for carefully selected and closely monitored men with Grade Group 2 prostate cancer managed at a tertiary cancer center. Definitive conclusions await further follow-up.