Prognostic Value of Albumin-to-CEA Ratio in Metastatic Colorectal Cancer: A Retrospective Study

<b>Background:</b> Finding dependable prognostic biomarkers for metastatic colorectal cancer (mCRC) is crucial. The albumin-to-carcinoembryonic antigen (CEA) ratio (ACR), a measure of nutritional-inflammatory status and tumor load, has emerged as a promising prognostic indicator. This study assessed ACR's prognostic value of ACR in patients with mCRC. <b>Methods:</b> This retrospective study included 125 patients with mCRC followed at our institution between July 2010 and March 2022. ROC curve analysis was used to determine the optimal cutoff values for ACR, prognostic nutritional index (PNI), lymphocyte-to-monocyte ratio (LMR), and CEA. Kaplan-Meier and Cox regression analyses were used to evaluate progression-free survival (PFS) and overall survival (OS). <b>Results:</b> PFS and OS were 13.3 and 26.0 months, respectively. Patients with an ACR ≥ 4.24 experienced significantly longer PFS (16.8 vs. 11.0 months; <i>p</i> = 0.001) and OS (32.0 vs. 22.3 months; <i>p</i> < 0.001) compared with those with ACR < 4.24. In univariable analyses, ACR was significantly associated with both PFS and OS, whereas PNI, LMR, and CEA were associated with OS only. In multivariable Cox regression models ACR showed a significant association with both PFS (HR 0.413; 95% CI: 0.265-0.643; <i>p</i> < 0.001) and OS (HR 0.341; 95% CI: 0.210-0.551; <i>p</i> < 0.001), while maintenance therapy was significantly associated with PFS only and ECOG performance status, LMR and PNI with OS only. <b>Conclusions:</b> ACR appears to be a cost-effective biomarker that is associated with PFS and OS in mCRC. These findings suggest that ACR may have potential value for prognostic assessment and risk stratification in patients with mCRC.