Cohort studyindependent cross-checkabstract checked★ key study I-CHM-111 standard review

Memory problems after breast cancer chemotherapy

Longitudinal Trajectory and Characterization of Cancer-Related Cognitive Impairment in a Nationwide Cohort Study.

Overview

Janelsins MC et al.. J Clin Oncol 2018 · PMID 30240328 · DOI 10.1200/JCO.2018.78.6624

Patients' memory scores fell during chemotherapy and were still lower 6 months later, unlike controls.

Does the study support the specific claim? Partly · Methodological quality: moderate

Study explained simply

What did the researchers want to find out?: Track thinking skills through chemotherapy
How was the study done?: Prospective cohort with controls
How many people, animals or samples were studied?: 580 patients, 363 controls
What was actually found?: Decline persisting at 6 months
How large was the observed effect?: P<.005 group-by-time
What do the results mean in everyday life?: 'Chemo brain' is real for some
What are the study's limitations?: Short follow-up; cancer itself may contribute
What does it say about Elawady's specific claim?: Supports existence; not 'persistent' long-term
Do the results apply to Germany and Europe?: High
What can explicitly not be concluded from this study?: Cannot show permanent damage

Authors: Janelsins MC et al.
Journal: J Clin Oncol
Year: 2018
Identifier: PMID 30240328 DOI 10.1200/JCO.2018.78.6624
Verification: verified – PubMed efetch 2026-10-26 (PublicationType and CommentsCorrections checked); Crossref 2026-10-26
Retracted: no
Corrections: none
Extent checked: abstract only
Conflicts of interest and funding: NCI grants; COI not stated in abstract.

How does cognition change from before to 6 months after chemotherapy in breast cancer?

Study design: Cohort study – Prospective nationwide observational cohort with controls (NCORP)
Population: Women with stage I-IIIC breast cancer receiving chemotherapy and matched controls
Country: USA
Period: Assessments pre-chemotherapy, post-chemotherapy, 6 months post
Sample size: 580 patients, 363 controls
Inclusion and exclusion criteria: Breast cancer patients scheduled for chemotherapy; non-cancer controls

Exposure / intervention: Chemotherapy
Comparator: Controls without cancer
Endpoints: Visual memory (CANTAB DMS), other memory, attention, executive function
Statistical methods: Longitudinal mixed models adjusted for age, education, race, cognitive reserve, anxiety, depression

Results: Significant group-by-time effect (P<.005) on Delayed Match to Sample; patients declined from pre-chemotherapy to 6 months post (P=.005), controls did not (P=.426); several other tests showed worse performance in patients over time.
Absolute risks: not reported in abstract
Authors' conclusion: Cancer-related cognitive impairment affects multiple domains for at least 6 months after chemotherapy.

Only P values in abstract; no recalculation possible.

Supports real chemotherapy-associated cognitive decline lasting at least 6 months; does not establish permanence.

Kim 2022 (I-CHM-112): effect largest within 1 month, suggesting mainly acute.

Applicable.

Good-quality evidence of medium-term effect.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	moderate
Risk of bias	some concerns
Precision of results	moderate
Directness	direct
Reproducibility	replicated
Consistency with the overall evidence	consistent
Regional transferability	high
Adequacy of the interpretation (by the archive)	not applicable

Persistence beyond 1-2 years.