52. Resection of the primary tumour for asymptomatic incurable metastatic colorectal cancer – A EURECCA international comparison

Background: The indication for resection of the primary tumour in patients with asymptomatic metastatic colorectal cancer is under debate. So far, there are no results from RCTs; the CAIRO4 study is still enrolling patients and these results should be awaited. Several retrospective studies suggested a survival benefit in patients who underwent resection of the primary tumour, but bias due to confounding by indication is highly likely. Comparative Effectiveness Research, by using country as instrumental variable, could provide clues to the best treatment strategy for asymptomatic incurable metastatic colorectal cancer.