Cohort studycited by the Tayebat archiveabstract only checked★ key study A-ORG-06 in-depth review
Gallbladder removal and bowel cancer
Intestinal cancer after cholecystectomy: is bile involved in carcinogenesis?
Overview
Lagergren J et al.. Gastroenterology 2001 · PMID 11522737 · DOI 10.1053/gast.2001.27083
After gallbladder removal, rare small-bowel cancers were about 1.8 times as frequent and right-sided colon cancer 1.16 times as frequent as in the population.
Does the study support the specific claim? Partly · Methodological quality: low
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Cancer risk
- How was the study done?
Register
- How many people, animals or samples were studied?
278,460
- What was actually found?
Higher proximal bowel cancer
- How large was the observed effect?
SIR 1.77/1.16
- What do the results mean in everyday life?
Small extra risk of rare cancers
- What are the study's limitations?
No confounder control
- What does it say about Elawady's specific claim?
Partly supports
- Do the results apply to Germany and Europe?
European
- What can explicitly not be concluded from this study?
Causation; absolute size
Scientific in-depth review
1. Full reference
- Authors
- Lagergren J, Ye W, Ekbom A
- Journal
- Gastroenterology
- Year
- 2001
- Identifier
- PMID 11522737 DOI 10.1053/gast.2001.27083
- Verification
- verified – PubMed E-utilities efetch, 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
COI: not stated in record | Grants: none listed
2. Research question
Bowel cancer after cholecystectomy
3. Study design and population
- Study design
- Cohort study – Register cohort with SIR vs population
- Population
Swedish cholecystectomized patients
- Country
Sweden
- Period
1965-1997
- Sample size
278,460 (3,519,682 person-years)
4. Methods and endpoints
- Exposure / intervention
Cholecystectomy
- Comparator
General population (SIR)
- Endpoints
Intestinal cancer by site
5. Actual results
- Results
Small bowel adenocarcinoma SIR 1.77 (1.37-2.24); small bowel carcinoids SIR 1.71 (1.39-2.08); right colon cancer SIR 1.16 (1.08-1.24); no association distally; persisted up to 33 years.
- Absolute risks
Not reported; small bowel adenocarcinoma is rare, so absolute excess is small
- Authors' conclusion
Cholecystectomy increases intestinal cancer risk declining with distance from the bile duct; bile exposure may be the mechanism.
6. Strengths
- Very large, long follow-up
- Dose-like gradient
7. Weaknesses
- Comparison with general population; gallstone disease itself and lifestyle not controlled
- No confounder adjustment
8. Risk of bias
- Orienting tool
- ROBINS-E
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- high
- Rationale
Confounding by gallstone disease/diet/obesity cannot be excluded with SIR design.
9. Assessment of the statistical interpretation
10. Relevance to the specific claim
Supports C-ORG-06.
11. Independent contrary findings
Later meta-analyses mixed; one PLoS One meta-analysis on cholecystectomy and colorectal cancer carries an Expression of Concern (PMID 38457406, seen during search, not assessed).
12. Transferability to Germany and Europe
European.
13. Overall methodological judgement
Association plausible; causal and absolute importance uncertain.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | low |
| Risk of bias | high |
| 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) | essentially correct but incomplete |
14. Open questions
15. Linked fact checks
- Cholecystectomy causes a persistent long-term excess of proximal small-bowel adenocarcinoma and right-sided colon cancer (Lagergren 2001). – Studies supporting the claim
- Long-term registry data link removal of tonsils, appendix, gallbladder, uterus, ovaries and spleen to higher rates of respiratory disease, autoimmunity, cardiovascular events, gastrointestinal cancers and dementia; each organ does work the body never fully replaces. – Studies supporting the claim
Use by the Tayebat archive
Note: according to the archive, the studies were compiled by the archive operators. Whether Dr. Elawady himself cited this study is not established.
- What the archive says about the study
278,460 cholecystectomy patients followed up to 33 years showed elevated small-bowel adenocarcinoma (SIR 1.77) and right colon cancer (SIR 1.16), gradient with distance from bile duct; AR: changes in bile flow drive carcinogenesis.
- A. What was actually studied?
Cancer after cholecystectomy
- B. What did the authors find?
SIR 1.77 small bowel; 1.16 right colon
- C. What conclusions do the authors themselves draw?
Cholecystectomy increases risk; bile may be mechanism
- D. What does the archive derive from it?
Used to show a long-term cancer price of gallbladder removal.
- E. Is this derivation scientifically justified?
Numbers correct and match the authors' causal wording. Missing: absolute risks are small (rare cancers), and the comparison is with the general population, so gallstone disease itself may contribute.
- Adequacy of the interpretation (by the archive)
- essentially correct but incomplete