PhD defence D.F. (Daniël) Osses

Main objective of this thesis is to study whether the use of risk stratification strategies at time of prostate cancer detection (Part I) and at initiation and during an active surveillance strategy for low-risk prostate cancer (Part II) could safely reduce the harms of prostate cancer screening without affecting the benefit of screening, and reduce the harms of unnecessary immediate active treatment while having full cancer control. In Part I it was shown that the use of the ERSPC Rotterdam Prostate Cancer Risk Calculator (RPCRC) in the primary care could safely reduce the rate of men with a prostate-specific antigen (PSA) level ≥3.0 ng/ml referred to the urologist with almost 50%. In addition, Part I provides evidence that the ERSPC RPCRC can be used as upfront risk stratification tool for the selection of biopsy-naïve candidates for an MRI and biopsy procedure in the urology outpatient clinic. In Part II it is shown that the currently applied one size fits all approach in most Active Surveillance (AS) protocols could result in a lot of unnecessary follow-up testing and related costs. Combining data of clinical predictors, MRI outcome and potentially visible changes on MRI is advisable as risk stratification strategy before deciding to perform a repeat biopsy procedure in men on AS. Doing so, substantial unnecessary follow-up biopsy procedures will be avoided, while maintaining a high detection rate of upgrading to high-risk prostate cancer.

The public defence will take place at the Prof. Andries Queridoroom, 3rd floor Education Center, Erasmus MC. The ceremony will begin exactly at 10.30 AM. In light of the solemn nature of the ceremony, we recommend that you do not take children under the age of 6 to the first part of the ceremony.