Carbohydrate antigen 19-9 (CA19-9) is widely used as a tumor marker in gastrointestinal malignancies; however, its clinical significance in patients undergoing resection for colorectal liver metastases (CRLM) remains unclear. This review summarizes current evidence regarding the prognostic value of CA19-9 in CRLM, with particular emphasis on its role compared with carcinoembryonic antigen (CEA) and its integration into modern prognostic models. Across multiple cohort studies, elevated preoperative CA19-9 levels have consistently been associated with worse recurrence-free and overall survival after hepatectomy. In several multivariable analyses, CA19-9 emerged as a significant prognostic factor whereas CEA did not. CA19-9 has also been incorporated into several prognostic scoring systems and nomograms, including the JSHBPS nomogram (Beppu score) and the Imai nomogram, highlighting its value as a surrogate marker of potentially unfavorable tumor biology. Reported cutoff values vary widely across studies, ranging from near-normal levels (34–37 U/mL) to higher thresholds (100–200 U/mL), and the optimal cutoff remains uncertain. In addition to its role as a categorical risk factor, dynamic changes in CA19-9 during preoperative chemotherapy may provide additional prognostic information. Routine assessment of CA19-9 together with CEA at CRLM diagnosis and during perioperative management may improve risk stratification and guide personalized multidisciplinary treatment strategies.
Masuda et al. (Sun,) studied this question.