Cohort studyindependent cross-checkabstract checked I-CAN-129 standard review
Refusing colon cancer surgery linked to much shorter survival
Refusal of cancer-directed treatment by colon cancer patients: Risk factors and survival outcomes.
Overview
Kaltenmeier C et al.. Am J Surg 2020 · PMID 32680623 · DOI 10.1016/j.amjsurg.2020.04.022
Patients who refused recommended surgery lived a median of 6.8 months vs 24 months.
Does the study support the specific claim? No · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Effects of refusing surgery.
- How was the study done?
Registry cohort.
- How many people, animals or samples were studied?
924,290 patients.
- What was actually found?
Much worse survival after refusal.
- How large was the observed effect?
HR 3.41.
- What do the results mean in everyday life?
Do not delay or refuse curative treatment.
- What are the study's limitations?
Observational.
- What does it say about Elawady's specific claim?
Contradicts the claim.
- Do the results apply to Germany and Europe?
Moderate.
- What can explicitly not be concluded from this study?
Reasons for refusal.
Scientific in-depth review
1. Full reference
- Authors
- Kaltenmeier C et al.
- Journal
- Am J Surg
- Year
- 2020
- Identifier
- PMID 32680623 DOI 10.1016/j.amjsurg.2020.04.022
- Verification
- verified – PubMed efetch 2026-10-26 + Crossref
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
NCI grant (PubMed); COI not stated in abstract
2. Research question
Incidence, risk factors and survival impact of refusing recommended surgery for colon cancer
3. Study design and population
- Study design
- Cohort study – Retrospective registry cohort (NCDB)
- Population
Patients with potentially treatable colon cancer
- Country
USA
- Period
1998-2012
- Sample size
924,290; 7,152 refused surgery
- Inclusion and exclusion criteria
Potentially treatable colon cancer
4. Methods and endpoints
- Exposure / intervention
Refusal of recommended surgery
- Comparator
Treated patients
- Endpoints
Overall survival
- Statistical methods
Multivariable logistic and Cox regression
5. Actual results
- Results
Median survival 6.8 vs 24 months; Cox HR 3.41 (95% CI 3.12-3.60) for refusal of surgery. Refusal more likely in older, female, African American and Medicaid patients. 11,334 patients with stage III disease refused adjuvant chemotherapy.
- Absolute risks
Median survival 6.8 vs 24 months
- Authors' conclusion
Refusal of treatment affects survival and is associated with socioeconomic factors.
6. Strengths
- Very large
- Refusal coded independently of CAM
7. Weaknesses
- Observational; confounding by health status
- Reasons for refusal unknown
8. Risk of bias
- Orienting tool
- ROBINS-E
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Confounding by frailty/comorbidity likely.
9. Assessment of the statistical interpretation
Reported CI 3.12-3.60 around 3.41 is slightly asymmetric on log scale (see script).
10. Relevance to the specific claim
Direct evidence on the decision the claim implies (not starting curative treatment), independent of the CAM coding criticised in I-CAN-128.
11. Independent contrary findings
12. Transferability to Germany and Europe
Moderate.
13. Overall methodological judgement
Supports the safety message: forgoing curative surgery is associated with much shorter survival.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | high |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
15. Linked fact checks
- Cancer will respond to the Tayebat system; a patient with a malignant tumour should start the system now (diet as cancer treatment). – Studies contradicting or limiting the claim