Abstract 1827: The prospective Dutch colorectal cancer cohort: A prospective nation-wide observational cohort study
Authors: Coebergh van den Braak Robert R.J. , Vink Geraldine R. , van Oijen Martijn G.H. , de Noo Mirre E. , Kurk Sophie A. , Burbach Maarten J.P. , Couwenberg Alice M. , May Anne M. , Verkooijen Helena M. , Meijer Gerrit A. , Koopman Miriam 
Published: July 2016

Abstract
The increasingly complex subclassification of tumors based on clinical and molecular characteristics, as well as the large sample sizes needed for clinical trials, pose new challenges to the recruitment of patients for studies. Currently, less than 10% of all cancer patients are enrolled in clinical trials, limiting their external validity, but also leaving room for improvement in the recruitment of patients. Clinical trials are often complicated by low inclusion rates, inadequate data collection, high non-completion rates and costs, and often provide insufficient data for post-hoc subgroup analyses. We believe that a prospective observational cohort study can provide standardized and validated collection of clinical data, tissue and blood samples and patient-reported outcome measures, and can improve patient recruitment for clinical trials. The Prospective Dutch ColoRectal Cancer cohort is a prospective multidisciplinary nation-wide observational cohort study in the Netherlands, a country with a yearly colorectal cancer incidence of 15,000 patients. The goal of the study is to facilitate future basic, translational and clinical research in the field of colorectal cancer for both national and international research groups with short or absent inclusion periods, even for studies with stringent inclusion criteria.
All patients &gt; 18 years with histologically proven colorectal cancer are asked to participate. Four essential features characterize the study: 1) a patient-centered informed-consent approach; 2) a framework to systematically collect long-term clinical follow-up and patient-reported outcomes; 3) an infrastructure for the standardized collection and storage of tissue and blood samples and 4) efficient recruitment for clinical trials which is facilitated by the innovative cohort multiple randomized controlled trial (cmRCT) design. The cmRCT design allows patients to participate in multiple non-conflicting clinical trials. We believe that the key to the development of a sustainable cohort study is the collaboration with existing organizations using their expertise, and preventing duplicate data entry and unnecessary costs. To these ends, close collaborations with other national initiatives, like the national cancer registry (hosted by IKNL), the national pathology registry PALGA, and the national biobanking infrastructure BBMRI-NL have been established. An effective governance structure to secure the privacy of patients and hospitals, and to facilitate research is needed.
This study will provide long-term clinical data, tissue and blood samples, and patient-reported outcome measures collected under a broad informed consent, of a large cohort of patients with colorectal cancer. The available data and tissue will facilitate basic, translational and clinical research. Furthermore, the design of this cohort study can be used as an example for other tumor types.
Citation Format: Robert R.J. Coebergh van den Braak, Geraldine R. Vink, Martijn G.H. van Oijen, Mirre E. de Noo, Sophie A. Kurk, Maarten J.P. Burbach, Alice M. Couwenberg, Anne M. May, Helena M. Verkooijen, Gerrit A. Meijer, Miriam Koopman. The prospective Dutch colorectal cancer cohort: A prospective nation-wide observational cohort study. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1827.