ArticleJournal of the National Cancer Institute2006
Pregnancies, breast-feeding, and breast cancer risk in the International BRCA1/2 Carrier Cohort Study (IBCCS).
Article in Journal of the National Cancer Institute, 2006. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT03667417 (Genetic Predisposition to Breast and Ovarian Cancer), which is not on this map. Cited by 71 papers, 2 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.
Genetic Predisposition to Breast and Ovarian Cancer: Prospective Study of BRCAx Gene Mutation
Who cites it
71 citing papers in PubMed, 2 syntheses or guidelines pooled it, 231 citations in OpenAlex.
- Breastfeeding and maternal health outcomes: a systematic review and meta-analysis.Acta paediatrica (Oslo, Norway : 1992) · 2015Pooled it
- Modifiers of cancer risk in BRCA1 and BRCA2 mutation carriers: systematic review and meta-analysis.Journal of the National Cancer Institute · 2014Pooled it
- Differential miRNA Expressions Linking Environmental Risk Factors to Triple-Negative Breast Cancer Stages at Diagnosis.Cancers · 2025Article
- A New Inverse Probability of Selection Weighted Cox Model to Deal With Outcome-Dependent Sampling in Survival Analysis.Biometrical journal. Biometrische Zeitschrift · 2025Article
- Breast Cancer Risk Modification in Women with Pathogenic Variants in BRCA1, BRCA2, ATM, CHEK2, and PALB2.Cancer research communications · 2025Article
- Insights into genetic modifiers of breast cancer risk in carriers of BRCA1 and BRCA2 pathogenic variants.Hereditary cancer in clinical practice · 2025Review
- Oncogenic activation of SMYD3-SHCBP1 promotes breast cancer development and is coupled with resistance to immune therapy.Cell death & disease · 2025Article
- Understanding Susceptibility to Breast Cancer: From Risk Factors to Prevention Strategies.International journal of molecular sciences · 2025Review
- Validation of the BOADICEA model in a prospective cohort ofJournal of medical genetics · 2024Article
- Age-specific breast and ovarian cancer risks associated with germlineThe Lancet regional health. Western Pacific · 2024Article
- Ranking of Modifiable Lifestyle Risk Factors for Breast Cancer in Saudi Women: Population Attributable Risk and Nomogram.Breast cancer (Dove Medical Press) · 2024Article
- Prospective validation of the BOADICEA multifactorial breast cancer risk prediction model in a large prospective cohort study.Journal of medical genetics · 2022Article
- Review
- A bibliometric analysis of the top 100 most cited papers and research trends in breast cancer related BRCA1 and BRCA2 genes.Medicine · 2022Article
- Predictors of cardiopulmonary fitness in cancer-affected and -unaffected women with a pathogenic germline variant in the genes BRCA1/2 (LIBRE-1).Scientific reports · 2022Article
- A review on the relationship between anti-mullerian hormone and fertility in treating young breast cancer patients.BMC women's health · 2021Review
- A new hybrid record linkage process to make epidemiological databases interoperable: application to the GEMO and GENEPSO studies involving BRCA1 and BRCA2 mutation carriers.BMC medical research methodology · 2021Article
- Comprehensive Breast Cancer Risk Assessment forJCO precision oncology · 2021Article
- Review
- Prevalence and Determinants of Exclusive Breastfeeding Practice among Mothers of Children Aged 6-24 Months in Hail, Saudi Arabia.Scientifica · 2021Article
11 more citing papers are in PubMed but not listed here.
Corrections and comments
- Commented on by
Authors and funding
23 authors at 5 institutions in 3 countries.
Funding
Abstract
backgroundMultiparity, young age at first childbirth, and breast-feeding are associated with a reduced risk of breast cancer in the general population. The breast cancer predisposition gene, BRCA1, regulates normal cell differentiation. Because mammary gland cells divide and differentiate during pregnancy, reproductive factors may influence breast cancer risk in BRCA1/2 mutation carriers differently than they do in noncarriers.
methodsWe performed a retrospective cohort study of 1601 women in the International BRCA1/2 Carrier Cohort Study cohort, all of whom carried a mutation in BRCA1 or BRCA2. Information on reproductive factors was obtained from a questionnaire. At the time of interview 853 subjects were classified with breast cancer. Data were analyzed by using a weighted cohort approach. All statistical tests were two-sided.
resultsThere was no statistically significant difference in the risk of breast cancer between parous and nulliparous women. Among parous women, an increasing number of full-term pregnancies was associated with a statistically significant decrease in the risk of breast cancer (Ptrend = .008); risk was reduced by 14% (95% confidence interval [CI] = 6% to 22%) for each additional birth. This association was the same for carriers of mutations in either BRCA1 or BRCA2 and was restricted to women older than 40 years. In BRCA2 mutation carriers, first childbirth at later ages was associated with an increased risk of breast cancer compared with first childbirth before age 20 years (20-24 years, hazard ratio [HR] = 2.33 [95% CI = 0.93 to 5.83]; 25-29 years, HR = 2.68 [95% CI = 1.02 to 7.07]; > or = 30 years, HR = 1.97 [95% CI = 0.67 to 5.81]), whereas in BRCA1 mutation carriers, first childbirth at age 30 years or later was associated with a reduced risk of breast cancer compared with first childbirth before age 20 years (HR = 0.58 [95% CI = 0.36 to 0.94]). Neither history of interrupted pregnancies (induced abortions or miscarriage) nor history of breast-feeding was statistically significantly associated with the risk of breast cancer.
conclusionsBRCA1 and BRCA2 mutation carriers older than 40 years show a similar reduction in breast cancer risk with increasing parity as non-carriers.
Indexed as
Identifiers
What OpenQuestion holds
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.