CEACAM5 and neoplasm: Patient-reported outcomes (PROs) of quality of life (QOL) and symptoms are frequently associated with clinical outcomes for individuals with gastrointestinal cancers.1,2 Clinicians often use biomarkers, such as tumor markers (TMs) (ie, carcinoembryonic antigen [CEA] and carbohydrate antigen 19-9 [CA19-9]) and radiographic response, to guide clinical management,3,4 and novel biomarkers (ie, circulating tumor DNA [ctDNA]) are increasingly used.