CEACAM5 and colorectal carcinoma: Furthermore, a systematic review from 2017 concluded that although patients with stages 1 to 3 CRC may experience a survival benefit, the existence of this benefit is questionable for patients with stage 4 CRC.21 In addition, a randomized controlled trial concluded that intensified carcinoembryonic antigen (CEA) measurements resulted in earlier recurrence detection and a higher proportion of patients who could be treated with curative intent.