The Prospective Dutch Colorectal Cancer (PLCRC) cohort: real-world data facilitating research and clinical care
Authors: Derksen Jeroen W. G. , Vink Geraldine R. , Elferink Marloes A. G. , Roodhart Jeanine M. L. , Verkooijen Helena M. , van Grevenstein Wilhelmina M. U. , Siersema Peter D. , May Anne M. , Koopman Miriam ,   The PLCRC Study Group, Beets Geerard L. , Belt Eric J. Th. , Berbée Maaike , Beverdam Frederique H. , Blankenburgh Ruud , Coene Peter Paul L. O. , van Cruijsen Hester , Dekker Jan Willem T. , van Dodewaard-de Jong Joyce M. , Erdkamp Frans L. G. , de Groot Jan Willem B. , Haringhuizen Annebeth W. , Helgason Helgi H. , Hendriks Mathijs P. , de Hingh Ignace H. J. T. , Hoekstra Ronald , Ijzermans Jan N. M. , Jansen Jan , Kloppenberg Frank W. H. , van Lent Anja U. G. , Los Maartje , Meijerink Martijn R. , Mekenkamp Leonie J. M. , Nieboer Peter , Peeters Koen C. M. J. , Peters Natascha A. J. B. , Polée Marco B. , Pruijt Johannes F. M. , Punt Cornelis J. A. , van Ufford-Mannesse Patricia Quarles , Rietbroek Ron C. , Schiphorst Anandi H. W. , van der Velden Arjan Schouten , Schrauwen Ruud W. M. , Sie Mark P. S. , Simkens Lieke , Sommeijer Dirkje W. , Sonneveld Dirk J. A. , Spierings Leontine E. A. , Stockmann Hein B. A. C. , Talsma Koen , Terheggen Frederiek , ten Tije Albert J. , Tjin-A-Ton Manuel L. R. , Valkenburg-van Iersel Liselot B. J. , Veenstra Renzo P. , van der Velden Ankie M. T. , Vermaas Maarten , Vles Wouter J. , Vogelaar Jeroen F. J. , van Voorthuizen Theo , de Vos Aad I. , Wegdam Johannes A. , de Wilt Johannes H. W. , Zimmerman David D. E. 
Published: February 2021

Real-world data (RWD) sources are important to advance clinical oncology research and evaluate treatments in daily practice. Since 2013, the Prospective Dutch Colorectal Cancer (PLCRC) cohort, linked to the Netherlands Cancer Registry, serves as an infrastructure for scientific research collecting additional patient-reported outcomes (PRO) and biospecimens. Here we report on cohort developments and investigate to what extent PLCRC reflects the “real-world”. Clinical and demographic characteristics of PLCRC participants were compared with the general Dutch CRC population (n = 74,692, Dutch-ref). To study representativeness, standardized differences between PLCRC and Dutch-ref were calculated, and logistic regression models were evaluated on their ability to distinguish cohort participants from the Dutch-ref (AU-ROC 0.5 = preferred, implying participation independent of patient characteristics). Stratified analyses by stage and time-period (2013–2016 and 2017–Aug 2019) were performed to study the evolution towards RWD. In August 2019, 5744 patients were enrolled. Enrollment increased steeply, from 129 participants (1 hospital) in 2013 to 2136 (50 of 75 Dutch hospitals) in 2018. Low AU-ROC (0.65, 95% CI: 0.64–0.65) indicates limited ability to distinguish cohort participants from the Dutch-ref. Characteristics that remained imbalanced in the period 2017–Aug’19 compared with the Dutch-ref were age (65.0 years in PLCRC, 69.3 in the Dutch-ref) and tumor stage (40% stage-III in PLCRC, 30% in the Dutch-ref). PLCRC approaches to represent the Dutch CRC population and will ultimately meet the current demand for high-quality RWD. Efforts are ongoing to improve multidisciplinary recruitment which will further enhance PLCRC’s representativeness and its contribution to a learning healthcare system.