Limitations of the study
Our study is not without limitations. First, this is a retrospective
analysis and selection bias could be an issue like all studies of this
kind. Second, this is a multi-institutional study and there are more
than one operating surgeons who performed the operations and
uro-pathologists who assessed RP specimens. Both surgeon experience and
surgical technique (open, robot assisted or laparoscopic) might have
influenced patient outcomes. Our study marked the date of prostate
biopsy as the reference point to calculate the time to surgery, but this
may not always reflect the actual duration of the disease, since
patients’ first admission to the physician and timing of the prostate
biopsy may differ between various institutions even within the same
hospital system. An attempt to overcome bias, we stratified patients
based on their D’Amico risks groups in order to provide more balanced
distribution between cohorts. The median delay time in patient cohort
waited longer than 90 days was nearly 4 months in our study. This is a
limiting factor for this study in order to comment on longer delay times
and specify a safe surgical time cut-off.