PD54-10: Differences of quality of life between German and Dutch prostate cancer patients, who are treated with robot-assisted radical prostatectomy: Implications for international multicenter randomized controlled trials

Christian Wagner, Jorn Witt, Gronau, Germany, Merkourios Kolvatzis, Thessaloniki, Greece, Nikolaos Liakos, Theodoros Karagiotis, Mikolaj Mendrek, Lukas Esch, Thomas Jankowski, Andreas Schuette, Sami-Ramzi Leyh-Bannurah*, Gronau, Germany

Introduction: Validated tools such as the European Organization for Research and Treatment of Cancer Quality of Life (QoL) Questionnaire Core 30 (EORTC QLQ -C30) are essential to measure QoL impact of treatment modalities such as radical prostatectomy (RP) in prostate cancer (PCa) patients and are regularly utilized in international randomized controlled trials. Previous series indicated international differences in EORTC functional, symptom scales and QoL. We explore differences in Dutch and German patients treated with robot-assisted radical prostatectomy (RARP) within the same high-volume center.

Methods: We identified consecutive Dutch and German PCa patients, who were treated with RARP at our institution between 5/2006 and 12/2018 and had complete information of pre- vs. postoperative EORTC QLQ-C30 global quality of life (QL) and EORTC Summary Score. A multivariable linear mixed model for repeated measurement analyses (MVA) examined the effect of nationality on the respective EORTC QLQ-C30 scales for a) the QoL and b) the Summary Score. The model was also adjusted for the EORTC QLQ-C30 scale baseline values, patient age, Charlson Comorbidity Index, PSA value at RP, surgical expertise, pathological and nodal stage Gleason ISUP Grade, nerve sparing status, surgical margin status, 30-d Clavien-Dindo Classification, events of urinary continence recovery, biochemical recurrence(BCR) and adjuvant/salvage radiotherapy(RT).

Results: Overall, 1,934 Dutch and 6,594 German RARP patients were identified. For QoL, MVA revealed higher preoperative QL (est. 0.36 95%CI 0.34-0.38), urinary continence recovery (est. 8.8 95%CI 7.7-10) and Dutch nationality (est. 6.0 95%CI 4.4-7.6) as positive estimates for higher QL, whereas e.g. BCR (est.-3.7 95%CI-4-4—2.9) and RT (est. 1.9 95%CI -2.8- -0.96) were negative (each <0.001). MVA of the EORTC Summary Score were similar including Dutch nationality as a significant positive estimate, indicating an average EORTC Summary Score increase of +2.9 (95%CI 2.5-3.4; p<0.001).

Conclusions: Our multivariable analyses of international PCa patients treated with RARP suggest differences between Dutch and German patients with regard to patient reported QoL and functional and symptom scales. Accordingly, randomized control trials should account for such potential differences, which might be aggravated if certain populations are unproportionally represented in international studies.

Source of Funding: This research received no specific grant.