Assisted reproductive technology treatment and risk of breast cancer: a population-based cohort study

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Assisted reproductive technology treatment and risk of breast cancer : a population-based cohort study. / Vassard, D; Pinborg, A; Kamper-Jørgensen, M; Lyng Forman, J; Glazer, C H; Kroman, N; Schmidt, L.

In: Human Reproduction, Vol. 36, No. 12, 2021, p. 3152–3160.

Research output: Contribution to journalJournal articlepeer-review

Harvard

Vassard, D, Pinborg, A, Kamper-Jørgensen, M, Lyng Forman, J, Glazer, CH, Kroman, N & Schmidt, L 2021, 'Assisted reproductive technology treatment and risk of breast cancer: a population-based cohort study', Human Reproduction, vol. 36, no. 12, pp. 3152–3160. https://doi.org/10.1093/humrep/deab219

APA

Vassard, D., Pinborg, A., Kamper-Jørgensen, M., Lyng Forman, J., Glazer, C. H., Kroman, N., & Schmidt, L. (2021). Assisted reproductive technology treatment and risk of breast cancer: a population-based cohort study. Human Reproduction, 36(12), 3152–3160. https://doi.org/10.1093/humrep/deab219

Vancouver

Vassard D, Pinborg A, Kamper-Jørgensen M, Lyng Forman J, Glazer CH, Kroman N et al. Assisted reproductive technology treatment and risk of breast cancer: a population-based cohort study. Human Reproduction. 2021;36(12):3152–3160. https://doi.org/10.1093/humrep/deab219

Author

Vassard, D ; Pinborg, A ; Kamper-Jørgensen, M ; Lyng Forman, J ; Glazer, C H ; Kroman, N ; Schmidt, L. / Assisted reproductive technology treatment and risk of breast cancer : a population-based cohort study. In: Human Reproduction. 2021 ; Vol. 36, No. 12. pp. 3152–3160.

Bibtex

@article{30465688f2da4e5abf278b553d2af75d,
title = "Assisted reproductive technology treatment and risk of breast cancer: a population-based cohort study",
abstract = "STUDY QUESTION: Is there an increased risk of breast cancer among women after ART treatment including ovarian hormone stimulation?SUMMARY ANSWER: The risk of breast cancer was slightly increased among women after ART treatment compared to age-matched, untreated women in the background population, and the risk was further increased among women initiating ART treatment when aged 40+ years.WHAT IS KNOWN ALREADY: The majority of breast cancer cases are sensitive to oestrogen, and ovarian hormone stimulation has been suggested to increase the risk of breast cancer by influencing endogenous oestrogen levels. Previous studies on ART treatment and breast cancer have varied in their findings, but several studies have small sample sizes or lack follow-up time and/or confounder adjustment. Recent childbirth, nulliparity and higher socio-economic status are breast cancer risk factors and the latter two are also associated with initiating ART treatment.STUDY DESIGN, SIZE, DURATION: The Danish National ART-Couple II (DANAC II) cohort includes women treated with ART at public and private fertility clinics in 1994-2016.PARTICIPANTS/MATERIALS, SETTING, METHODS: Women with no cancer prior to ART treatment were included (n = 61 579). Women from the background population with similar age and no prior history of ART treatment were randomly selected as comparisons (n = 579 760). The baseline mean age was 33.1 years (range 18-46 years). Results are presented as hazard ratios (HRs) with corresponding CIs.MAIN RESULTS AND THE ROLE OF CHANCE: During follow-up (median 9.69 years among ART-treated and 9.28 years among untreated), 5861 women were diagnosed with breast cancer, 695 among ART-treated and 5166 among untreated women (1.1% versus 0.9%, P < 0.0001). Using Cox regression analyses adjusted for nulliparity, educational level, partnership status, year, maternal breast cancer and age, the risk of breast cancer was slightly increased among women treated with ART (HR 1.14, 95% CI 1.12-1.16). All causes of infertility were slightly associated with breast cancer risk after ART treatment. The risk of breast cancer increased with higher age at ART treatment initiation and was highest among women initiating treatment at age 40+ years (HR 1.37, 95% CI 1.29-1.45). When comparing women with a first birth at age 40+ years with or without ART treatment, the increased risk among women treated with ART persisted (HR 1.51, 95% CI 1.09-2.08).LIMITATIONS, REASONS FOR CAUTION: Although this study is based on a large, national cohort of women, more research with sufficient power and confounder adjustment is needed, particularly in cohorts with a broad age representation.WIDER IMPLICATIONS OF THE FINDINGS: An increased risk of breast cancer associated with a higher age at ART treatment initiation has been shown. Ovarian stimulation may increase the risk of breast cancer among women initiating ART treatment when aged 40+ years. Age-related vulnerability to hormone exposure or higher hormone doses during ART treatment may explain the increased risk.STUDY FUNDING/COMPETING INTEREST(S): This work was supported by a PhD grant to D.V. from the Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Funding for establishing the DANAC II cohort was received from the Ebba Rosa Hansen Foundation. The authors report no conflict of interest.TRIAL REGISTRATION NUMBER: N/A.",
author = "D Vassard and A Pinborg and M Kamper-J{\o}rgensen and {Lyng Forman}, J and Glazer, {C H} and N Kroman and L Schmidt",
note = "{\textcopyright} The Author(s) 2021. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.",
year = "2021",
doi = "10.1093/humrep/deab219",
language = "English",
volume = "36",
pages = "3152–3160",
journal = "Human Reproduction",
issn = "0268-1161",
publisher = "Oxford Academic",
number = "12",

}

RIS

TY - JOUR

T1 - Assisted reproductive technology treatment and risk of breast cancer

T2 - a population-based cohort study

AU - Vassard, D

AU - Pinborg, A

AU - Kamper-Jørgensen, M

AU - Lyng Forman, J

AU - Glazer, C H

AU - Kroman, N

AU - Schmidt, L

N1 - © The Author(s) 2021. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

PY - 2021

Y1 - 2021

N2 - STUDY QUESTION: Is there an increased risk of breast cancer among women after ART treatment including ovarian hormone stimulation?SUMMARY ANSWER: The risk of breast cancer was slightly increased among women after ART treatment compared to age-matched, untreated women in the background population, and the risk was further increased among women initiating ART treatment when aged 40+ years.WHAT IS KNOWN ALREADY: The majority of breast cancer cases are sensitive to oestrogen, and ovarian hormone stimulation has been suggested to increase the risk of breast cancer by influencing endogenous oestrogen levels. Previous studies on ART treatment and breast cancer have varied in their findings, but several studies have small sample sizes or lack follow-up time and/or confounder adjustment. Recent childbirth, nulliparity and higher socio-economic status are breast cancer risk factors and the latter two are also associated with initiating ART treatment.STUDY DESIGN, SIZE, DURATION: The Danish National ART-Couple II (DANAC II) cohort includes women treated with ART at public and private fertility clinics in 1994-2016.PARTICIPANTS/MATERIALS, SETTING, METHODS: Women with no cancer prior to ART treatment were included (n = 61 579). Women from the background population with similar age and no prior history of ART treatment were randomly selected as comparisons (n = 579 760). The baseline mean age was 33.1 years (range 18-46 years). Results are presented as hazard ratios (HRs) with corresponding CIs.MAIN RESULTS AND THE ROLE OF CHANCE: During follow-up (median 9.69 years among ART-treated and 9.28 years among untreated), 5861 women were diagnosed with breast cancer, 695 among ART-treated and 5166 among untreated women (1.1% versus 0.9%, P < 0.0001). Using Cox regression analyses adjusted for nulliparity, educational level, partnership status, year, maternal breast cancer and age, the risk of breast cancer was slightly increased among women treated with ART (HR 1.14, 95% CI 1.12-1.16). All causes of infertility were slightly associated with breast cancer risk after ART treatment. The risk of breast cancer increased with higher age at ART treatment initiation and was highest among women initiating treatment at age 40+ years (HR 1.37, 95% CI 1.29-1.45). When comparing women with a first birth at age 40+ years with or without ART treatment, the increased risk among women treated with ART persisted (HR 1.51, 95% CI 1.09-2.08).LIMITATIONS, REASONS FOR CAUTION: Although this study is based on a large, national cohort of women, more research with sufficient power and confounder adjustment is needed, particularly in cohorts with a broad age representation.WIDER IMPLICATIONS OF THE FINDINGS: An increased risk of breast cancer associated with a higher age at ART treatment initiation has been shown. Ovarian stimulation may increase the risk of breast cancer among women initiating ART treatment when aged 40+ years. Age-related vulnerability to hormone exposure or higher hormone doses during ART treatment may explain the increased risk.STUDY FUNDING/COMPETING INTEREST(S): This work was supported by a PhD grant to D.V. from the Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Funding for establishing the DANAC II cohort was received from the Ebba Rosa Hansen Foundation. The authors report no conflict of interest.TRIAL REGISTRATION NUMBER: N/A.

AB - STUDY QUESTION: Is there an increased risk of breast cancer among women after ART treatment including ovarian hormone stimulation?SUMMARY ANSWER: The risk of breast cancer was slightly increased among women after ART treatment compared to age-matched, untreated women in the background population, and the risk was further increased among women initiating ART treatment when aged 40+ years.WHAT IS KNOWN ALREADY: The majority of breast cancer cases are sensitive to oestrogen, and ovarian hormone stimulation has been suggested to increase the risk of breast cancer by influencing endogenous oestrogen levels. Previous studies on ART treatment and breast cancer have varied in their findings, but several studies have small sample sizes or lack follow-up time and/or confounder adjustment. Recent childbirth, nulliparity and higher socio-economic status are breast cancer risk factors and the latter two are also associated with initiating ART treatment.STUDY DESIGN, SIZE, DURATION: The Danish National ART-Couple II (DANAC II) cohort includes women treated with ART at public and private fertility clinics in 1994-2016.PARTICIPANTS/MATERIALS, SETTING, METHODS: Women with no cancer prior to ART treatment were included (n = 61 579). Women from the background population with similar age and no prior history of ART treatment were randomly selected as comparisons (n = 579 760). The baseline mean age was 33.1 years (range 18-46 years). Results are presented as hazard ratios (HRs) with corresponding CIs.MAIN RESULTS AND THE ROLE OF CHANCE: During follow-up (median 9.69 years among ART-treated and 9.28 years among untreated), 5861 women were diagnosed with breast cancer, 695 among ART-treated and 5166 among untreated women (1.1% versus 0.9%, P < 0.0001). Using Cox regression analyses adjusted for nulliparity, educational level, partnership status, year, maternal breast cancer and age, the risk of breast cancer was slightly increased among women treated with ART (HR 1.14, 95% CI 1.12-1.16). All causes of infertility were slightly associated with breast cancer risk after ART treatment. The risk of breast cancer increased with higher age at ART treatment initiation and was highest among women initiating treatment at age 40+ years (HR 1.37, 95% CI 1.29-1.45). When comparing women with a first birth at age 40+ years with or without ART treatment, the increased risk among women treated with ART persisted (HR 1.51, 95% CI 1.09-2.08).LIMITATIONS, REASONS FOR CAUTION: Although this study is based on a large, national cohort of women, more research with sufficient power and confounder adjustment is needed, particularly in cohorts with a broad age representation.WIDER IMPLICATIONS OF THE FINDINGS: An increased risk of breast cancer associated with a higher age at ART treatment initiation has been shown. Ovarian stimulation may increase the risk of breast cancer among women initiating ART treatment when aged 40+ years. Age-related vulnerability to hormone exposure or higher hormone doses during ART treatment may explain the increased risk.STUDY FUNDING/COMPETING INTEREST(S): This work was supported by a PhD grant to D.V. from the Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Funding for establishing the DANAC II cohort was received from the Ebba Rosa Hansen Foundation. The authors report no conflict of interest.TRIAL REGISTRATION NUMBER: N/A.

U2 - 10.1093/humrep/deab219

DO - 10.1093/humrep/deab219

M3 - Journal article

C2 - 34580714

VL - 36

SP - 3152

EP - 3160

JO - Human Reproduction

JF - Human Reproduction

SN - 0268-1161

IS - 12

ER -

ID: 282466909