Smoking and Complications After Cancer Surgery: A Systematic Review and Meta-Analysis.

Summary

Across 24 studies (n=39,499), smoking within 4 weeks before cancer surgery increased postoperative complications versus quitting ≥4 weeks and versus never smoking. No significant difference was seen between smoking within 2 weeks vs stopping 2 weeks–3 months, but smoking within 1 year remained riskier than quitting ≥1 year.

Key Findings

• Smoking within 4 weeks preoperatively increased complications versus ceasing ≥4 weeks (OR 1.31; 95% CI 1.10–1.55; n=14,547, 17 studies).
• Current smoking versus never smoking markedly increased complications (OR 2.83; 95% CI 2.06–3.88; n=9,726, 14 studies).
• No significant difference between smoking within 2 weeks vs stopping 2 weeks–3 months (OR 1.19; 95% CI 0.89–1.59; n=5,341, 10 studies).
• Smoking within 1 year increased complications vs quitting ≥1 year (OR 1.13; 95% CI 1.00–1.29; N=31,238, 13 studies).

Clinical Implications

Integrate intensive cessation support early and aim for ≥4 weeks of abstinence before cancer surgery when feasible; avoid unnecessary delays while prioritizing rapid initiation of cessation. Use these ORs in shared decision-making.

Limitations

• Predominantly observational evidence with potential residual confounding
• Heterogeneity across cancer types, surgeries, and smoking assessment

Future Directions

Pragmatic randomized or quasi-experimental cessation timing trials embedded in cancer pathways to define optimal delay vs. proceed strategies; standardized, biochemical verification of abstinence.