Prospective study of active surveillance outcomes after template-guided mapping biopsy among patients with prostate cancer

Active surveillance (AS) is the preferred management strategy for patients with low-risk prostate cancer, but its safety depends on accurate baseline risk assessment. Conventional transrectal biopsy may undersample clinically significant disease, whereas multiparametric MRI may miss some clinically significant cancers. A prospective study at Dana-Farber Cancer Institute (Boston, MA) evaluated transperineal template-guided mapping biopsy (TTMB) for baseline risk assessment. The study included 374 patients with clinically localized prostate cancer who underwent TTMB for possible AS enrollment. Follow-up included PSA testing every 4 months and annual digital rectal examination (DRE). Repeat biopsy was not performed routinely and was recommended for a PSA doubling time less than 3 years, change in DRE, or patient request. The primary endpoint was freedom from therapeutic intervention. The median PSA level at enrollment was 5.2 ng/ml (IQR 1.5-22.2), and 357 patients (95.5%) had GG1 disease. The median number of biopsy cores was 71.0 (IQR 29.0-11.5), with 3.0 (1.0-28.0) positive cores. At a median follow-up of 6.5 years (IQR 3.8-9.7) 18 patients underwent definitive treatment at a median interval of 5.9 years (IQR 3.8-9.0). The 8- and 12-year landmark cumulative incidence of therapeutic intervention were 5.2% and 8.7%. No distant metastases or prostate cancer-related deaths were observed. Fifty patients (13.4%) died during follow-up, with cardiovascular disease and other malignant tumors as leading causes of death. QoL measures remained generally stable over time. The authors conclude that in this study, AS after baseline TTMB was associated with a low rate of therapeutic intervention and no distant metastases or prostate cancer-related deaths.