Objective:

To systematically evaluate the association between preoperative inflammatory and immune-nutritional markers and postoperative pulmonary complications after gastrointestinal cancer surgery.

Approach:

• Study Design: Systematic review following PRISMA 2020 guidelines, searching multiple databases for observational studies on preoperative biomarkers and postoperative pulmonary complications.
• Eligibility Criteria: Included studies evaluated preoperative inflammatory or immune-nutritional markers in adult patients undergoing surgery for gastrointestinal malignancies and reported PPCs or related outcomes.
• Data Synthesis: Findings were synthesized narratively due to substantial heterogeneity in outcome definitions, biomarker selection, and statistical modeling.

Key Findings:

• Fifteen observational studies included, with moderate-to-high methodological quality.
• Adverse preoperative inflammatory and nutritional profiles generally associated with increased postoperative pulmonary risk.
• Inflammatory markers like neutrophil-to-lymphocyte ratio and systemic immune-inflammation index showed strong associations.
• Nutritional indicators such as albumin and controlling nutritional status score indicated elevated risk in patients with poorer nutritional status.
• Findings suggest a combined burden of inflammation and nutritional impairment rather than reliance on a single biomarker.

Interpretation:

A preoperative double burden of heightened systemic inflammation and impaired nutritional status is associated with increased postoperative pulmonary risk after gastric and colorectal cancer surgery.

Limitations:

• Heterogeneity in outcome definitions, biomarker modeling, and effect reporting across studies.
• Most biomarker-specific findings supported by single studies, limiting generalizability.

Conclusion:

Standardized prospective studies are needed before these markers can be reliably integrated into perioperative pulmonary risk stratification.

Sources:

• Systematic Review Registration