Risk Assessment of Obesity and Diabetes in Cancer Recurrence: A Systematic Review and Meta-analysis Major in Korean Medicine

다국어 초록 (Multilingual Abstract)

Cancer recurrence remains a major clinical challenge. While obesity and diabetes are implicated in poor cancer prognosis, their impact on cancer recurrence has not been comprehensively investigated. PubMed and the Cochrane Library, supplemented by manual searches, were systematically searched from inception to March 2025 following PRISMA guidelines. This systematic review and meta-analysis, based on 118 observational studies (63 on obesity and 63 on diabetes) including 339,884 patients across 15 cancer types, evaluated the association of obesity and diabetes with cancer recurrence using random-effects models, dose–response analyses, subgroup analyses, and meta-regression analyses. Both conditions were significantly associated with increased recurrence risk, with diabetes showing a stronger effect (HR 1.39, 95% CI 1.29– 1.50) than obesity (HR 1.29, 95% CI 1.14–1.46). Recurrence risk rose proportionally with metabolic severity, increasing by 9.8% for every 5 kg/m² BMI increment and by 40% for each 1% rise in HbA1c. Risk magnitude varied across malignancies, with the highest estimates observed for ureteral (HR 2.88) and bladder cancers (HR 1.58) in obesity, and for cervical (HR 2.26), lung (HR 2.08), and renal cancers (HR 2.02) in diabetes. Subgroup analyses and meta-regression identified cancer type, follow-up periods (<5 years), disease stage (stage I–II), and geographic region (higher diabetes-associated risk in Asia) as significant modifiers of recurrence risk. While publication bias was detected only for diabetes, overall findings were robust across sensitivity analyses. This study provides the most comprehensive synthesis to date demonstrating that obesity and diabetes are independent, dose-dependent drivers of cancer recurrence and highlights the need to incorporate metabolic risk assessment and targeted management strategies into survivorship care to improve long-term oncologic outcomes.

목차 (Table of Contents)

• Table of Contents ⅰ
• List of Tables iv
• List of Figures v
• Abstract vi
• Ⅰ. Introduction 1
• Ⅱ. Methods 3
• 1. Clinical question and study design 3
• 2. Database and search strategy 3
• 3. Definition of obesity and diabetes 3
• 4. Study selection 4
• 5. Eligibility Criteria 4
• 6. Data extraction 5
• 7. Assessment of study quality 5
• 8. Assessment of publication bias and robustness of outcome 5
• 9. Statistical analysis 6
• 1) Meta-analysis 6
• 2) Subgroup analysis 6
• 3) Meta-regression 6
• 4) Exploratory meta-analysis 7
• 5) Dose-response meta-analysis 7
• Ⅲ. Results 8
• 1. Characteristics of the included studies and participants 8
• 2. Overall assessment for obesity and diabetes on cancer recurrence risk 11
• 3. Dose-response assessment for obesity on cancer recurrence risk 15
• 4. Dose-response assessment for diabetes on cancer recurrence risk 17
• 5. Assessment of obesity on cancer recurrence risk by cancer type 19
• 6. Assessment of diabetes on cancer recurrence risk by cancer type 23
• 7. Assessment of obesity and diabetes on cancer recurrence risk by study design 25
• 8. Assessment of obesity and diabetes on cancer recurrence risk by follow-up period 25
• 9. Assessment of obesity and diabetes on cancer recurrence risk by cancer stage 26
• 10. Assessment of obesity and diabetes on cancer recurrence risk by study region 26
• 11. Assessment of obesity and diabetes on cancer recurrence risk by publication year 27
• 12. Assessment of obesity and diabetes on cancer recurrence risk by study quality 27
• Ⅳ. Discussion 29
• Ⅴ. Conclusion 35
• References 36
• Abstract in Korean 43
• Appendix 45