Bastiaenen VP, et al. - In pT4N0-2 M0 colon cancer patients who have completed primary treatment, researchers assessed the yield of second look diagnostic laparoscopy (DLS) as well as the added value of third look DLS following negative second look DLS in identifying occult peritoneal metastases (PM). At 6 months after the surgery, an abdominal CT (computed tomography) will be performed, this will be followed by a second look DLS within 1 month in cases wherein no PM or other metastases not amenable for local treatment will be found. Afterward, those with no PM will be randomly assigned to routine follow-up including 18 months abdominal CT, or an experimental arm with a third look DLS, if there were no PM or incurable metastases at the 18 months abdominal CT. They expect second look DLS to detect 10% occult PM and expect detection of an additional 10% of PM by third look DLS after negative second look DLS vs routine follow-up alone in patients with pT4 colon cancer. The proportion of patients eligible for curative intent treatment are supposed to be increased as a result of the detection of PM at an early stage, and consequently, an improved survival will be achieved, given the consistently recorded direct link between the extent of peritoneal disease and survival.