Evidence map›Paper›PMID 38653905›Full record

SynthesisBreast cancer research and treatment2024

Randomized trials of estrogen-alone and breast cancer incidence: a meta-analysis.

Rowan T Chlebowski, Aaron K Aragaki, Kathy Pan, Joanne E Mortimer, Karen C Johnson, Jean Wactawski-Wende, Meryl S LeBoff, Sayeh Lavasani, Dorothy Lane, Rebecca A Nelson and 1 more

Abstract readMeta-Analysis
PubMed Publisher
In one paragraph

Synthesis in Breast cancer research and treatment, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers.

0numbers the graph read from it
0cells of the map it votes in
8citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

8 citing papers in PubMed.

  1. Review
  2. Article
  3. Article
  4. Review
  5. Review
  6. Epidemiology, early detection, and management of breast cancer in China: A comprehensive review.Chinese journal of cancer research = Chung-kuo yen cheng yen chiu · 2025
    Article
  7. Article
  8. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Rowan T ChlebowskiThe Lundquist Institute, 1124 W. Carson Street, Torrance, CA, USA. rowanchlebowski@gmail.com.ORCID http://orcid.org/0000-0002-4212-6184
Aaron K AragakiFred Hutchinson Cancer Center, Seattle, WA, USA.
Kathy PanKaiser Permanente Southern California, Downey, CA, USA.
Joanne E MortimerCity of Hope National Medical Center, Duarte, CA, USA.
Karen C JohnsonUniversity of Tennessee Health Science Center, Memphis, TN, USA.
Jean Wactawski-WendeUniversity at Buffalo, Buffalo, NY, USA.
Meryl S LeBoffBrigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Sayeh LavasaniCity of Hope National Medical Center, Duarte, CA, USA.
Dorothy LaneRenaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA.
Rebecca A NelsonCity of Hope National Medical Center, Duarte, CA, USA.
JoAnn E MansonBrigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.

Funding

Nutrition and Physical Activity Assessment Study (NPAAS)R01CA119171 · NCI · FRED HUTCHINSON CANCER RESEARCH CENTER · PI Marian L Neuhouser · 2006 to 2026
$14.3M
National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. Department of Health and Human Services HHSN268201600018C, HHSN268201600001CNCI NIH HHS R01 CA119171 and R01 CA10921
6 · The paper itself

Abstract

purposeIn the Women's Health initiative (WHI) randomized clinical trial, conjugated equine estrogen (CEE)-alone significantly reduced breast cancer incidence (P = 0.005). As cohort studies had opposite findings, other randomized clinical trials were identified to conduct a meta-analysis of estrogen-alone influence on breast cancer incidence.

methodsWe conducted literature searches on randomized trials and: estrogen, hormone therapy, and breast cancer, and searches from a prior meta-analysis and reviews. In the meta-analysis, for trials with published relative risks (RR) and 95% confidence intervals (CI), each log-RR was multiplied by weight = 1/V, where V = variance of the log-RR, and V was derived from the corresponding 95% CI. For smaller trials with only breast cancer numbers, the corresponding log-RR = (O - E)/weight, where O is the observed case number in the oestrogen-alone group and E the corresponding expected case number, E = nP.

resultsFindings from 10 randomized trials included 14,282 participants and 591 incident breast cancers. In 9 smaller trials, with 1.2% (24 of 2029) vs 2.2% (33 of 1514) randomized to estrogen-alone vs placebo (open label, one trial) (RR 0.65 95% CI 0.38-1.11, P = 0.12). For 5 trials evaluating estradiol formulations, RR = 0.63 95% CI 0.34-1.16, P = 0.15. Combining the 10 trials, 3.6% (262 of 7339) vs 4.7% (329 of 6943) randomized to estrogen-alone vs placebo (overall RR 0.77 95% CI 0.65-0.91, P = 0.002).

conclusionThe totality of randomized clinical trial evidence supports a conclusion that estrogen-alone use significantly reduces breast cancer incidence.

Indexed as

Breast NeoplasmsEstrogensRandomized Controlled Trials as TopicEstrogen Replacement TherapyEstrogens, Conjugated (USP)FemaleHumansIncidenceEstrogensEstrogens, Conjugated (USP)Breast cancer incidenceEstrogen-aloneMeta-analysisRandomized trials

Identifiers

PMID38653905

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.