Evidence map›Paper›PMID 40817821›Full record

ArticleInternational journal of cancer2026

Reproductive factors and risk of contralateral breast cancer by age and hormone receptor status: The California Breast Cancer Survivorship Consortium.

Esther M John, Jocelyn Koo, Theresa H Keegan, Scarlett L Gomez, Sue A Ingles, Allison W Kurian, Marilyn L Kwan, Susan L Neuhausen, Salma Shariff-Marco, Iona Cheng and 1 more

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in International journal of cancer, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing 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

1 citing paper in PubMed.

  1. Article
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.

Esther M JohnDepartment of Epidemiology & Population Health, Stanford University School of Medicine, Stanford, California, USA.ORCID https://orcid.org/0000-0003-3259-8003
Jocelyn KooStanford Cancer Institute, Stanford University School of Medicine, Stanford, California, USA.
Theresa H KeeganDivision of Hematology and Oncology, UC Davis Comprehensive Cancer Center, University of California, Davis, California, USA.
Scarlett L GomezDepartment of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, California, USA.
Sue A InglesDepartment of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
Allison W KurianDepartment of Epidemiology & Population Health, Stanford University School of Medicine, Stanford, California, USA.
Marilyn L KwanDivision of Research, Kaiser Permanente Northern California, Pleasanton, California, USA.ORCID https://orcid.org/0000-0001-8863-3950
Susan L NeuhausenDepartment of Population Sciences, Beckman Research Institute of City of Hope, Duarte, California, USA.
Salma Shariff-MarcoDepartment of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, California, USA.
Iona ChengDepartment of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, California, USA.
Anna H WuDepartment of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.

Funding

Core-001U01CA164920 · NCI · COLUMBIA UNIVERSITY HEALTH SCIENCES · PI Irene Andrulis, Sarah Violet Colonna · 2018 to 2026
$17.0M
Molecular Profiles and Lifestyle Factors in Breast Cancer PrognosisR01CA129059 · NCI · KAISER FOUNDATION RESEARCH INSTITUTE · PI CAAN, BETTE J · 2009 to 2013
$3.6M
Long Term Health Outcomes in Breast Cancer SurvivorsR01CA106764 · NCI · KAISER FOUNDATION RESEARCH INSTITUTE · PI CAAN, BETTE J · 2004 to 2007
$2.1M
BREAST CANCER RISK FACTORS IN HISPANIC WOMENR01CA063446 · NCI · NORTHERN CALIFORNIA CANCER CENTER · PI JOHN, ESTHER M · 1995 to 1998
–
California Breast Cancer Research Program 10PB-0038California Breast Cancer Research Program 1RB-0287California Breast Cancer Research Program 3PB-0120California Breast Cancer Research Program 5PB-0018California Breast Cancer Research Program 7PB-0068California Breast Cancer Research Program B28IB5487CDC HHS Y01-HD-7022NCI NIH HHS CA106764NCI NIH HHS CA129059NCI NIH HHS CA164920NCI NIH HHS CA63446NCI NIH HHS CA77305NCI NIH HHS N01-HD-3-3175NCI NIH HHS R01 CA063446NCI NIH HHS R01 CA106764NCI NIH HHS R01 CA129059NCI NIH HHS U01 CA164920U.S. Department of Defense DAMD17-96-1-6071
6 · The paper itself

Abstract

Associations between reproductive factors and the risk of developing a contralateral second primary invasive breast cancer (CBC) are inconclusive. A pooled cohort of women with a first primary invasive breast cancer (FBC) from five California-based studies (8045 stage I-III FBC diagnosed from 1994 to 2009) was linked with the California Cancer Registry; 532 CBC were identified. We analyzed harmonized data and evaluated associations with reproductive factors using Fine and Gray regression to estimate hazard ratios (HR) and 95% confidence intervals (CI), adjusted for study, age at FBC diagnosis, race and ethnicity, and other risk factors previously identified in this pooled dataset (hormone receptor status, first-degree family history of breast cancer). Associations with reproductive factors were observed only in younger FBC survivors diagnosed at age <50 years. Higher risk of CBC was associated with nulliparity (HR = 1.37, CI = 1.03-1.81) and a recent full-term pregnancy (FTP) before FBC diagnosis (<10 vs. ≥20 years: HR = 2.04, CI = 1.13-3.66). In younger survivors of hormone receptor-negative FBC, higher risk was associated with longer duration of breast-feeding (≥12 vs. <12 months: HR = 2.96, CI = 1.48-5.89). No heterogeneity in associations by race and ethnicity was observed, except for nulliparity. In older survivors, reproductive factors were not associated with the risk of CBC. Younger FBC survivors who are nulliparous or had a FTP less than 10 years before FBC diagnosis may benefit from more regular surveillance screening after FBC diagnosis.

Indexed as

Breast NeoplasmsNeoplasms, Second PrimaryReceptors, EstrogenReproductive HistoryAdultAgedAge FactorsCaliforniaCancer SurvivorsFemaleHumansMiddle AgedPregnancyReceptors, ProgesteroneRegistriesRisk FactorsReceptors, EstrogenReceptors, Progesteronecontralateral breast cancerepidemiologyhormone receptor statusreproductive factors

Identifiers

PMID40817821
PMCPMC13158858

What Socratic holds

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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 Socratic graph.