A case-control study of the joint effect of reproductive factors and radiation treatment for first breast cancer and risk of contralateral breast cancer in the WECARE study

Jennifer D Brooks; John D Boice; Roy E Shore; Anne S Reiner; Susan A Smith; Leslie Bernstein; Julia A Knight; Charles F Lynch; Esther M John; Kathleen E Malone; Lene Mellemkjaer; Rikke Langballe; Xiaolin Liang; Meghan Woods; Marc Tischkowitz; Patrick Concannon; Daniel O Stram; Jonine L Bernstein; WECARE Study Collaborative Group

doi:10.1016/j.breast.2020.07.007

Back

A case-control study of the joint effect of reproductive factors and radiation treatment for first breast cancer and risk of contralateral breast cancer in the WECARE study

Journal article

Open access

Peer reviewed

A case-control study of the joint effect of reproductive factors and radiation treatment for first breast cancer and risk of contralateral breast cancer in the WECARE study

Jennifer D Brooks, John D Boice, Roy E Shore, Anne S Reiner, Susan A Smith, Leslie Bernstein, Julia A Knight, Charles F Lynch, Esther M John, Kathleen E Malone, …

Breast (Edinburgh), Vol.54, pp.62-69

12/2020

DOI: 10.1016/j.breast.2020.07.007

PMCID: PMC7494790

PMID: 32927238

Files and links (1)

url

https://doi.org/10.1016/j.breast.2020.07.007View

Published (Version of record) Open Access

Abstract

To examined the impact of reproductive factors on the relationship between radiation treatment (RT) for a first breast cancer and risk of contralateral breast cancer (CBC). The Women’s Environmental Cancer and Radiation Epidemiology (WECARE) Study is a multi-center, population-based case-control study where cases are women with asynchronous CBC (N = 1521) and controls are women with unilateral breast cancer (N = 2211). Rate ratios (RR) and 95% confidence intervals (CI) were estimated using conditional logistic regression to assess the independent and joint effects of RT (ever/never and location-specific stray radiation dose to the contralateral breast [0, >0-<1Gy, ≥1Gy]) and reproductive factors (e.g., parity). Nulliparous women treated with RT (≥1Gy dose) were at increased risk of CBC compared with nulliparous women not treated with RT, although this relationship did not reach statistical significance (RR = 1.34, 95% CI 0.87, 2.07). Women treated with RT who had an interval pregnancy (i.e., pregnancy after first diagnosis and before second diagnosis [in cases]/reference date [in controls]) had an increased risk of CBC compared with those who had an interval pregnancy with no RT (RR = 4.60, 95% CI 1.16, 18.28). This was most apparent for women with higher radiation doses to the contralateral breast. Among young female survivors of breast cancer, we found some evidence suggesting that having an interval pregnancy could increase a woman’s risk of CBC following RT for a first breast cancer. While sampling variability precludes strong interpretations, these findings suggest a role for pregnancy and hormonal factors in radiation-associated CBC. •Radiation treatment is associated with increased contralateral breast cancer risk in some women.•Reproductive status at the time of treatment may modify this relationship.•Some evidence that pregnancy after radiation treatment increases contralateral breast cancer risk.

Contralateral breast cancer

Radiation treatment

Reproductive factors

WECARE Study

Details

Title: Subtitle: A case-control study of the joint effect of reproductive factors and radiation treatment for first breast cancer and risk of contralateral breast cancer in the WECARE study
Creators: Jennifer D Brooks - University of Toronto, Dalla Lana School of Public Health Sciences, Toronto, Canada
John D Boice - Vanderbilt University Medical Center and the Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
Roy E Shore - New York University School of Medicine, New York, NY, USA
Anne S Reiner - Memorial Sloan Kettering Cancer Center, New York, NY, USA
Susan A Smith - The University of Texas M.D. Anderson Cancer Centre, Houston, TX, USA
Leslie Bernstein - Beckman Research Institute, City of Hope National Medical Centre, Duarte, CA, USA
Julia A Knight - University of Toronto, Dalla Lana School of Public Health Sciences, Toronto, Canada
Charles F Lynch - University of Iowa, Iowa City, IA, USA
Esther M John - Department of Epidemiology & Population Health and Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
Kathleen E Malone - Fred Hutchinson Cancer Research Center, Seattle, WA, USA
Lene Mellemkjaer - Danish Cancer Society Research Center, Copenhagen, Denmark
Rikke Langballe - Danish Cancer Society Research Center, Copenhagen, Denmark
Xiaolin Liang - Memorial Sloan Kettering Cancer Center, New York, NY, USA
Meghan Woods - Memorial Sloan Kettering Cancer Center, New York, NY, USA
Marc Tischkowitz - Department of Medical Genetics, NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge, UK
Patrick Concannon - Genetics Institute and Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL, USA
Daniel O Stram - Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
Jonine L Bernstein - Memorial Sloan Kettering Cancer Center, New York, NY, USA
WECARE Study Collaborative Group
Resource Type: Journal article
Publication Details: Breast (Edinburgh), Vol.54, pp.62-69
DOI: 10.1016/j.breast.2020.07.007
PMID: 32927238
PMCID: PMC7494790
NLM abbreviation: Breast
ISSN: 0960-9776
eISSN: 1532-3080
Publisher: Elsevier Ltd
Grant note: DOI: 10.13039/100000054, name: United States National Cancer Institute, award: CA129639, CA083178, CA097397, CA114236, P30 CA008748
Language: English
Date published: 12/2020
Academic Unit: Epidemiology
Record Identifier: 9984214684002771

Metrics

14 Record Views

4 Times Cited - Web of Science