Gestational breast cancer in New South Wales: A population-based linkage study of incidence, management, and outcomes

Nadom Safi; Christobel Saunders; Andrew Hayen; Antoinette Anazodo; Kei Lui; Zhuoyang Li; Marc Remond; Michael Nicholl; Alex Y Wang; Elizabeth Sullivan

doi:10.1371/journal.pone.0245493

Gestational breast cancer in New South Wales: A population-based linkage study of incidence, management, and outcomes

PLoS One. 2021 Jan 22;16(1):e0245493. doi: 10.1371/journal.pone.0245493. eCollection 2021.

Authors

Nadom Safi^{1

2}, Christobel Saunders³, Andrew Hayen¹, Antoinette Anazodo^{4

5}, Kei Lui⁴, Zhuoyang Li², Marc Remond², Michael Nicholl⁶, Alex Y Wang¹, Elizabeth Sullivan^{1

2}

Affiliations

¹ School of Public Health, University of Technology Sydney, Sydney, NSW, Australia.
² Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia.
³ Faculty of Health and Medical Sciences, The University of Western Australia, Crawley, WA, Australia.
⁴ School of Women's and Children's Health, University of New South Wales, Sydney, NSW, Australia.
⁵ Nelune Comprehensive Cancer Centre, Prince of Wales Hospital, Randwick, NSW, Australia.
⁶ Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.

Abstract

Background: The incidence of gestational breast cancer (GBC) is increasing in high-income countries. Our study aimed to examine the epidemiology, management and outcomes of women with GBC in New South Wales (NSW), Australia.

Methods: A retrospective cohort study using linked data from three NSW datasets. The study group comprised women giving birth with a first-time diagnosis of GBC while the comparison group comprised women giving birth without any type of cancer. Outcome measures included incidence of GBC, maternal morbidities, obstetric management, neonatal mortality, and preterm birth.

Results: Between 1994 and 2013, 122 women with GBC gave birth in NSW (crude incidence 6.8/ 100,000, 95%CI: 5.6-8.0). Women aged ≥35 years had higher odds of GBC (adjusted odds ratio (AOR) 6.09, 95%CI 4.02-9.2) than younger women. Women with GBC were more likely to give birth by labour induction or pre-labour CS compared to women with no cancer (AOR 4.8, 95%CI: 2.96-7.79). Among women who gave birth by labour induction or pre-labour CS, the preterm birth rate was higher for women with GBC than for women with no cancer (52% vs 7%; AOR 17.5, 95%CI: 11.3-27.3). However, among women with GBC, preterm birth rate did not differ significantly by timing of diagnosis or cancer stage. Babies born to women with GBC were more likely to be preterm (AOR 12.93, 95%CI 8.97-18.64), low birthweight (AOR 8.88, 95%CI 5.87-13.43) or admitted to higher care (AOR 3.99, 95%CI 2.76-5.76) than babies born to women with no cancer.

Conclusion: Women aged ≥35 years are at increased risk of GBC. There is a high rate of preterm birth among women with GBC, which is not associated with timing of diagnosis or cancer stage. Most births followed induction of labour or pre-labour CS, with no major short term neonatal morbidity.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Breast Neoplasms / diagnosis
Breast Neoplasms / epidemiology*
Breast Neoplasms / pathology
Cohort Studies
Female
Hospitalization / statistics & numerical data
Humans
Incidence
Infant, Newborn
Labor, Induced
Neoplasm Staging
New South Wales / epidemiology
Pregnancy
Pregnancy Complications / diagnosis
Pregnancy Complications / epidemiology*
Pregnancy Complications / pathology
Prognosis
Retrospective Studies

Grants and funding

This study received funding from the following sources: Cancer Council NSW grant (reference RG 18-02, awarded to ES); University of Technology Sydney (UTS), Faculty of Health (awarded to ES); UTS Doctoral Scholarship (awarded to NS); and Australian Government Research Training Program (awarded to NS).