Willem H, et al. - Via analyzing 4636 cases of colorectal adenocarcinoma, researchers determined the impact of variations in the cutoff for the definition of synchronous metastases on stage-specific distribution and incidence and the survival of stage IV patients with colorectal cancer. An increase in the incidence of stage IV colorectal cancer was noted, from 6.0/100 000 when metastases diagnosed within the first month were taken into account to 7.1/100 000 when metastases diagnosed until 12 months after the diagnosis of colorectal cancer were considered. For stage IV, stage III, and stage II, the estimated relative variation in the proportion of cancers was +21%, −12%, and −5%, respectively, when the cutoff increased from 1 to 12 months. For scientific epidemiologic exchanges, there is a need for an objective definition of the relevant cutoff to differentiate between synchronous and metachronous metastases. When the cutoff between synchronous and metachronous was over 4 months post- primary diagnosis, significantly better survival was experienced by the metachronous group vs the synchronous group.