Timo Soeterik

14 CHAPTER 1 basis of the classification system recommended by the European Association of Urology (Table 3). 17 Information regarding the likelihood of prostate cancer progression after initial radical therapy can facilitate tailored treatment approaches, wherein treatment intensity can be either increased or decreased based on the expected disease course. For instance, in patients with high-risk prostate cancer selected for radical prostatectomy, a wide resection can be preferred over a nerve sparing approach, in order to minimize the risk of positive surgical margins and thus the risk of disease recurrence. 17 Clinical nomograms Besides risk classification systems, clinical nomograms are also frequently used for disease prognostication. A nomogram is based on a mathematical formula that can be used to calculate the probability of an event to occur. It is used as a graphical display of a prediction model or calculation tool in such way that multiple variables can be taken into account. In the traditional implementation of the nomogram, the user draws pencil lines between axes, counts up points, and then reads off a prediction. 20 An advantage of nomograms over risk classification systems is the ability of establishing an individualized risk prediction, wherein the probability for a specific outcome is based on the characteristics of the individual patient. An example of an established nomogram, based on PSA, clinical T-stage and Gleason score is the preoperative nomogram for prediction of disease recurrence after radical prostatectomy, developed by Kattan et al. 21 Another well-established nomogram based on the same parameters includes a nomogram for prediction of pelvic lymph node invasion. 22 Over the years, several novel nomograms have emerged such as the Memorial Sloan Kettering Cancer Center (MSKCC) pre-radical prostatectomy nomogram and the Briganti nomogram, which can be used to predict presence of pelvic lymph node metastasis. 23,24 The nomograms include additional prognostic factors such as relative number of positive biopsy cores taken on systematic biopsy at diagnosis. 23,24 For prostate cancer staging and treatment selection, several nomograms are recommended by the current EAU guidelines to support clinical decision-making. 17 TABLE 3. EAU risk groups for biochemical recurrence of localised and locally advanced prostate cancer Definition Low-risk Intermediate-risk High-risk PSA < 10 ng/mL PSA 10-20 ng/mL PSA > 20 ng/mL any PSA and GS < 7 (ISUP grade 1) or GS 7 (ISUP grade 2/3) or GS > 7 (ISUP grade 4/5) any GS (any ISUP grade) and cT1-2a or cT2b or cT2c cT3-4 or cN+ Localised Locally advanced