Longitudinal Study of Colon and Rectal Cancer

This was a longitudinal prospective observational analytic cohort study that includes patients from nineteen public hospitals representing nine provinces in Spain, all of which operate under the Spanish National Health Service (SNHS), which is responsible for most of the country’s population, with a planned patient follow-up period of 5 years. Patients with colon or rectal cancer scheduled to undergo surgery between June 2010 and December 2012 were informed of the aims of the study and invited to participate. Only patients who provided written informed consent were allowed to enroll in the study. The study was approved by the Basque Ethics Committee (Approval Number: 11/23/2010 and PI2014084) and all study data were kept confidential. Patients were deemed eligible for this study if they were on the surgical waiting list of one of the participating hospitals and had a diagnosis of surgically resectable colon or rectal cancer. Exclusion criteria were in situ cancer, an unresectable tumor, terminal disease, inability to respond to questionnaires for any reason, and any severe mental or physical conditions that might prevent the patient from responding to questionnaires, as well as failure to consent to participate. Detailed information of the protocol has been published elsewhere [20 ].