Meta-analysisindependent cross-checkabstract checked I-ORG-129 standard review
Gallbladder removal and bowel cancer: pooled cohorts
The association between cholecystectomy and the risk of colorectal cancer: an updated systematic review and meta-analysis of cohort studies.
Overview
Mu L et al.. Transl Cancer Res 2023 · PMID 37434692 · DOI 10.21037/tcr-22-2049
Overall bowel cancer was not increased, but cancer in the right side of the colon was about 20% more common.
Does the study support the specific claim? Partly · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Pool cohort studies on cholecystectomy and colorectal cancer
- How was the study done?
Meta-analysis
- How many people, animals or samples were studied?
About 3.8 million people
- What was actually found?
No overall link; right colon RR 1.20
- How large was the observed effect?
RR 1.20 (1.04-1.38)
- What do the results mean in everyday life?
Any extra risk is small and limited to one part of the colon
- What are the study's limitations?
Observational
- What does it say about Elawady's specific claim?
Partly supports
- Do the results apply to Germany and Europe?
Applicable
- What can explicitly not be concluded from this study?
Cannot prove causation
Scientific in-depth review
1. Full reference
- Authors
- Mu L et al.
- Journal
- Transl Cancer Res
- Year
- 2023
- Identifier
- PMID 37434692 DOI 10.21037/tcr-22-2049
- Verification
- verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Not stated in abstract.
2. Research question
Is cholecystectomy associated with colorectal cancer?
3. Study design and population
- Study design
- Meta-analysis – Systematic review and meta-analysis of cohort studies
- Population
Cohorts with and without cholecystectomy
- Country
Multinational
- Period
Search to May 2022
- Sample size
18 studies; 1,469,880 cholecystectomy vs 2,356,238 non-cholecystectomy
- Inclusion and exclusion criteria
Cohort studies
4. Methods and endpoints
- Exposure / intervention
Cholecystectomy
- Comparator
No cholecystectomy
- Endpoints
CRC, colon, rectal and subsite cancers
- Statistical methods
Random-effects pooled RR
5. Actual results
- Results
No association with CRC (P = 0.109), colon (P = 0.112) or rectal cancer (P = 0.184). Right-sided colon cancer RR 1.20 (1.04-1.38; P = 0.010), especially caecum/ascending colon/hepatic flexure RR 1.21 (1.05-1.40); no association for transverse, descending or sigmoid colon.
- Absolute risks
Not reported
- Authors' conclusion
No effect on overall CRC, but a harmful effect on proximal right-sided colon cancer.
6. Strengths
- Large pooled sample
- Subsite analysis
7. Weaknesses
- Observational, heterogeneous
- Overlaps with other meta-analyses (e.g. I-ORG-130)
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Cohort-based meta-analysis; confounding by gallstone disease and detection not resolved.
9. Assessment of the statistical interpretation
Subsite RR 1.20 is modest; absolute excess not computable from the abstract.
10. Relevance to the specific claim
Tests the right-colon part of C-ORG-06 (Lagergren 2001).
11. Independent contrary findings
Mendelian randomisation (I-ORG-131) finds no causal effect on CRC.
12. Transferability to Germany and Europe
Includes European cohorts.
13. Overall methodological judgement
Consistent with a small right-sided colon cancer association; no overall CRC effect.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | moderate |
| Directness | direct |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | mixed |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Small-bowel adenocarcinoma not addressed.