The majority of surgical departments adhere to national Danish guidelines for surveillance after colorectal cancer surgery.

INTRODUCTION In 2003 the use of post-operative surveillance (POS) after surgery for colorectal cancer (CRC) in Denmark was studied. Diversity in the choice and frequency of surveillance modalities was found. Subsequently, the Danish Colorectal Cancer Group (DCCG) has published guidelines for POS. In the same period, the number of departments performing CRC surgery has been reduced by 50% nationally. The aim of the present study was to describe the POS after CRC in Denmark following a reduction in the number of departments performing operations for CRC and the DCCG's publication of national recommendations for POS programmes. MATERIAL AND METHODS Questionnaires were sent to all 19 departments that performed operations for CRC. Questions concerned the diagnostic modalities used for detecting recurrences and metachrone cancers. RESULTS All departments returned their questionnaires. All departments had a formal POS programme. The recommendations given by the DCCG were met by 17 departments (89%) with regard to liver metastases, by 16 departments (84%) with regard to lung metastases and by 16 departments (84%) with regard to metachrone cancers. CONCLUSION As opposed to what was observed in 2003, all departments offered a POS programme after CRC surgery in 2012. Almost all departments met the DCCG recommendations, probably owing to the centralization of CRC surgery and the DCCG's introduction of national guidelines. Hopefully, this will contribute to a better survival for CRC patients in the future, although more research is needed to establish optimal post-operative surveillance. FUNDING not relevant. TRIAL REGISTRATION not relevant.