SynthesisMedicine2020
No association between abortion and risk of breast cancer among nulliparous women: Evidence from a meta-analysis.
Synthesis in Medicine, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers, 3 of them syntheses that pooled 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.
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.
Who cites it
9 citing papers in PubMed, 3 syntheses or guidelines pooled it, 11 citations in OpenAlex.
- The association of pregnancy complications/risk factors with the development of cancer in women: an umbrella review.BMC medicine · 2026Pooled it
- Adverse pregnancy outcomes and multiple cancers risk in both mother and offspring: an umbrella review of systematic reviews with meta-analyses of observational studies.BMC medicine · 2024Pooled it
- Pooled it
- Induced abortion, miscarriage, and the risk of breast cancer-A registry-based study from Finland.Acta obstetricia et gynecologica Scandinavica · 2026Article
- Association of reproductive and menstrual factors with the risk of breast cancer in women: a population-based study.BMC cancer · 2025Article
- Early cancer detection: Analysis of a comprehensive screening program in a private clinic in Peru.Journal of public health research · 2025Article
- Abortion and Female Cancer Risks among Women Aged 20 to 45 Years: A 10-Year Longitudinal Population-Based Cohort Study in Taiwan.International journal of environmental research and public health · 2023Observational
- Cancer Progress and Priorities: Breast Cancer.Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology · 2021Review
- Current Resources for Evidence-Based Practice, November 2020.Journal of obstetric, gynecologic, and neonatal nursing : JOGNN · 2020Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 4 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundVarious epidemiological studies have demonstrated the association between abortion and risk of breast cancer among nulliparous women; however, results remain inconclusive. This meta-analysis assessed the association based on previous studies.
methodsPubMed, EMBase, China National Knowledge Infrastructure, Chongqing VIP, and Wanfang databases were searched for relevant articles until February 2018. In this meta-analysis, fixed-effects models were used to estimate the combined effect size and the corresponding 95% confidence interval (CI). All statistical data were analyzed using STATA 12.0.
resultsA total of 14 articles consisting of 6 cohort studies and 8 case-control studies were included in this review. All articles were of high quality, as determined based on the Newcastle Ottawa Scale assessment. The combined risk ratio (RR) indicated no significant association between abortion and breast cancer among nulliparous women (RR = 1.023, 95%CI = 0.938-1.117; Z = 0.51, P = .607). Subgroup analyses revealed no significant associations between risk of breast cancer and induced abortion or between risk of breast cancer and spontaneous abortion (SA) among nulliparous women (RR = 1.008, 95% CI = 0.909-1.118 and RR = 1.062, 95%CI = 0.902-1.250, respectively). Neither 1 nor >2 abortions increased the risk of breast cancer among nulliparous women. Sensitivity analysis showed that our results were reliable and stable.
conclusionCurrent evidence based on epidemiological studies showed no association between abortion and risk of breast cancer among nulliparous women.
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Registered trials
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.