Selecting men diagnosed with prostate cancer for active surveillance using a risk calculator: a prospective impact study

Abstract

Study Type - Prognosis (cohort series). Level of Evidence 2a. What's known on the subject? and What does the study add? The present study is one of the first to investigate urologists' and patients' compliance with recommendations based on a risk calculator that calculates the probability of indolent prostate cancer. A threshold was set for a recommendation of active surveillance vs active treatment. Active surveillance recommendations based on a prostate cancer risk calculator were followed by most patients, but 30% with active treatment recommendations chose active surveillance instead. This indicates that the threshold may be too high for urologists and patients.

Objectives: • To assess urologists' and patients' compliance with treatment recommendations based on a prostate cancer risk calculator (RC) and the reasons for non-compliance. • To assess the difference between patients who were compliant and non-compliant with recommendations based on this RC.

Patients and methods: • Eight urologists from five Dutch hospitals included 240 patients with prostate cancer (PCa), aged 55-75 years, from December 2008 to February 2011. • The urologists used the European Randomized Study of Screening for Prostate Cancer RC which predicts the probability of potentially indolent PCa (P[indolent]), using serum prostate-specific antigen (PSA), prostate volume and pathological findings on biopsy. • Inclusion criteria were PSA <20 ng/mL, clinical stage T1 or T2a-c disease, <50% positive sextant biopsy cores, ≤ 20 mm cancer tissue, ≥ 40 mm benign tissue and Gleason ≤ 3 + 3. If the P(indolent) was >70%, active surveillance (AS) was recommended, and active treatment (AT) otherwise. • After the treatment decision, patients completed a questionnaire about their treatment choice, related (dis)advantages, and validated measurements of other factors, e.g. anxiety.

Results: • Most patients (45/55, 82%) were compliant with an AS recommendation. Another 54 chose AS despite an AT recommendation (54/185, 29%). • The most common reason for non-compliance with AT recommendations by urologists was the patient's preference for AS (n= 30). These patients most often reported the delay of physical side effects of AT as the main advantage (n= 19). • Those who complied with AT recommendations had higher mean PSA levels (8 vs 7 ng/mL, P= 0.02), higher mean amount of cancer tissue (7 vs 3 mm, P < 0.001), lower mean P(indolent) (36% vs 55%, P < 0.001), and higher mean generic anxiety scores (42 vs 38, P= 0.03) than those who did not comply.

Conclusions: • AS recommendations were followed by most patients, while 29% with AT recommendations chose AS instead. • Although further research is needed to validate the RC threshold, the current version is already useful in treatment decision-making in men with localized PCa.