Baseline serum albumin level as a predictive factor for the efficacy of trifluridine/tipiracil plus bevacizumab in metastatic colorectal cancer: A retrospective cohort study

Background Trifluridine/tipiracil (FTD/TPI) combined with bevacizumab (BEV) has become a standard later-line therapy for metastatic colorectal cancer (mCRC). However, predictive biomarkers of treatment efficacy remain limited. Serum albumin (Alb)—reflecting nutritional and inflammatory status—has been reported as a prognostic factor in various malignancies, but its predictive value in patients receiving FTD/TPI plus BEV is unclear. This study examined whether baseline Alb levels are linked to treatment outcomes in patients with metastatic CRC receiving FTD/TPI plus BEV, aiming to clarify if Alb could serve as a predictive marker of therapeutic efficacy. Methods We retrospectively analyzed patients with unresectable or recurrent mCRC treated with FTD/TPI plus BEV at Fukuyama Medical Center between December 2017 and March 2024. Patients were divided into High- or Low-Alb groups based on an optimal cutoff derived from receiver operating characteristic (ROC) analysis for progression-free survival (PFS). The primary endpoint was PFS, and the secondary endpoint was overall survival (OS). Survival outcomes were assessed using the Kaplan–Meier method and Cox proportional hazards models. Results Sixty-nine patients were included (median age, 69 years). ROC analysis identified an Alb cutoff of 3.7 g/dL (area under the curve: 0.740). Using this cutoff, 39 patients (56.5%) were included in the High-Alb group. Patients in the High-Alb group had significantly lower lactate dehydrogenase (LDH) and C-reactive protein levels than those in the Low-Alb group. The median PFS (5.2 vs. 3.0 months; p < 0.01) and OS (15.6 vs. 6.0 months; p < 0.01) were significantly longer in the High-Alb group than in the Low-Alb group. In the multivariate analysis, Alb ≥ 3.7 g/dL was independently associated with improved PFS (hazard ratio [HR]: 0.40, 95% confidence interval [CI]: 0.22–0.73, p = 0.003), whereas LDH ≥ 338 U/L was associated with shorter PFS (HR: 2.31, 95% CI: 1.28–4.32, p = 0.009). Conclusions Baseline serum albumin levels were associated with survival outcomes in patients with mCRC treated with FTD/TPI + BEV. Thus, Alb may represent a simple and clinically accessible marker with potential predictive value. Initiating FTD/TPI plus BEV before a substantial decline in nutritional or inflammatory status may help achieve more favorable outcomes.