What false-negative rates of non-invasive testing are active surveillance patients and uro-oncologists willing to accept in order to avoid prostate biopsy?

INTRODUCTION: Repeat prostate biopsies in active surveillance patients are associated with significant complications. Novel imaging and blood/urine-based non-invasive tests are being developed to better predict disease grade and volume progression. We conducted a theoretical study to determine what test performance characteristics and costs would a non-invasive test(s) require in order for patients and their physicians to comfortably avoid biopsy.

METHODS: Surveys were administered to two populations to determine an acceptable false-negative rate and cost for such test(s). Active surveillance patients were recruited at time of followup in clinic at Princess Margaret Cancer Centre. Physician members of the Society of Urological Oncology were targeted via an online survey. Participants were questioned about their demographics and other characteristics that might influence chosen error rates and cost.

RESULTS: 136 patients and 670 physicians were surveyed, with 130 (95.6%) and 104 (15.5%) responses obtained, respectively. A vast majority of patients (90.6%) were comfortable with a non-invasive test(s) in place of biopsy, with 64.8% accepting a false-negative rate of 5-20%. Most physicians (93.3%) were comfortable with a non-invasive test, with 77.9% accepting a rate of 5-20%. Most patients and physicians felt that a cost of less than $1000 per administration would be reasonable.

CONCLUSIONS: Most patients/physicians are comfortable with a non-invasive test(s). Although a 5% error rate seems acceptable to many, a substantial subset feels that 99% or higher negative predictive value is required. Thus, a personalized approach with shared decision-making between patients and physicians is essential to optimize patient care in such situations.