Cross-sectional studycited by the Tayebat archiveabstract only checked A-CHM-09 standard review
Some long-term survivors show memory problems after chemotherapy
Neuropsychologic impact of standard-dose systemic chemotherapy in long-term survivors of breast cancer and lymphoma.
Overview
Ahles TA et al.. J Clin Oncol 2002 · PMID 11786578 · DOI 10.1200/JCO.2002.20.2.485
39% of chemotherapy-treated vs 14% of locally treated survivors scored in the lowest quarter on memory/thinking tests.
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?
Compare cognition by treatment.
- How was the study done?
Cross-sectional testing.
- How many people, animals or samples were studied?
128 survivors (sum of four reported groups: 35+36+35+22).
- What was actually found?
Lower verbal memory and psychomotor scores.
- How large was the observed effect?
39% vs 14% lowest quartile.
- What do the results mean in everyday life?
Some survivors notice thinking problems; support exists.
- What are the study's limitations?
Small, no baseline.
- What does it say about Elawady's specific claim?
Supports a subgroup effect.
- Do the results apply to Germany and Europe?
Moderate.
- What can explicitly not be concluded from this study?
That all patients suffer lasting decline.
Scientific in-depth review
1. Full reference
- Authors
- Ahles TA, Saykin AJ, Furstenberg CT, Cole B, Mott LA, Skalla K, Whedon MB, Bivens S, Mitchell T, Greenberg ER, Silberfarb PM
- Journal
- J Clin Oncol
- Year
- 2002
- Identifier
- PMID 11786578 DOI 10.1200/JCO.2002.20.2.485
- Verification
- verified – PubMed E-utilities efetch, 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
not stated in abstract | Grants: NCI NIH HHS
2. Research question
Long-term cognitive function after standard-dose chemotherapy vs local therapy.
3. Study design and population
- Study design
- Cross-sectional study – Cross-sectional comparison of neuropsychological test performance
- Population
5-year disease-free survivors of breast cancer or lymphoma
- Country
USA (not stated in abstract)
- Period
not stated
- Sample size
128 (71 chemotherapy [35 breast + 36 lymphoma], 57 local therapy [35 breast + 22 lymphoma]; totals calculated)
- Inclusion and exclusion criteria
5 years post diagnosis, disease-free, not on treatment
4. Methods and endpoints
- Exposure / intervention
Systemic chemotherapy
- Comparator
Local therapy only
- Endpoints
Neuropsychological battery; self-report
- Statistical methods
MANOVA controlling for age and education
5. Actual results
- Results
Chemotherapy group scored lower overall (P<.04), especially verbal memory (P<.01) and psychomotor functioning (P<.03); 39% vs 14% in lower quartile of Neuropsychological Performance Index (P<.01); more self-reported working-memory problems (P<.02).
- Absolute risks
39% vs 14% scoring in lowest quartile
- Authors' conclusion
Chemotherapy can impair cognition, but only a subgroup may experience long-term deficits.
6. Strengths
- Standardised test battery
- 5-year follow-up point
7. Weaknesses
- Small sample
- Cross-sectional; no pre-treatment baseline
- Groups differ in disease/treatment
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
No baseline; confounding by disease severity likely.
9. Assessment of the statistical interpretation
Statistically significant group differences; effect concentrated in a subgroup.
10. Relevance to the specific claim
Supports existence of long-term cognitive effects in some survivors.
11. Independent contrary findings
A-CHM-10: average deficits small.
12. Transferability to Germany and Europe
Moderate.
13. Overall methodological judgement
Early, small cross-sectional study; supports existence, not magnitude.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | low |
| Risk of bias | high |
| Precision of results | low |
| Directness | direct |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | mixed |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | essentially correct but incomplete |
14. Open questions
Prospective data with baselines.
15. Linked fact checks
- Chemotherapy causes persistent cognitive decline ('chemo fog'). – 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
Neurocognitive harm is real, the 'chemo fog' confirmed by Ahles and Jim's meta-analysis; summary: 'persistent cognitive decline'.
- A. What was actually studied?
Cognition 5 years after chemotherapy.
- B. What did the authors find?
Lower scores, mainly in a subgroup.
- C. What conclusions do the authors themselves draw?
Only a subgroup may have long-term deficits.
- D. What does the archive derive from it?
Chemo fog is real and persistent.
- E. Is this derivation scientifically justified?
Essentially yes, but the authors' restriction to a subgroup is not mentioned.
- Adequacy of the interpretation (by the archive)
- essentially correct but incomplete