C-reactive protein/albumin ratio in immunochemotherapy for advanced gastric cancer: Prognostic value, clinical challenges, and future directions

Table 1 Comparison of representative biomarkers relevant to advanced gastric cancer

Biomarker	Main strength	Main limitation	Most appropriate clinical role at present	Ref.
PD-L1 CPS	Most widely used immunotherapy-enrichment marker	Heterogeneity, assay variability, imperfect negative predictive value	Treatment selection and contextual risk interpretation	[1,3,48,49,51]
MMR/MSI status	Strong biologic rationale and clinically actionable for a small subset	Low prevalence in advanced gastric cancer	Identification of highly immunotherapy-sensitive disease	[4,5,8]
HER2/claudin 18.2	Direct linkage to targeted treatment pathways	Does not capture host reserve or inflammatory state	Drug selection and sequencing	[50-52]
NLR/PLR	Simple inflammatory markers with extensive literature	Sensitive to transient hematologic fluctuations; limited nutritional context	Adjunctive prognostication and dynamic monitoring	[41-47]
Glasgow Prognostic Score	Established inflammation-based score	Categorical rather than continuous; less granular than CAR	Broad risk stratification	[45]
CAR	Integrates inflammation and nutrition in a cheap, universally available index	Nonspecific; threshold inconsistency; largely retrospective evidence	Complementary host-state biomarker integrated with tumor and clinical variables	[16,31,33,37-40]

PD-L1: Programmed death ligand 1; CPS: Combined positive score; MMR: Mismatch repair; MSI: Microsatellite instability; NLR: Neutrophil-to-lymphocyte ratio; PLR: Platelet-to-lymphocyte ratio; CAR: C-reactive protein/albumin ratio.