Abortion and Female Cancer Risks among Women Aged 20 to 45 Years: A 10-Year Longitudinal Population-Based Cohort Study in Taiwan

Cheng-Ting Shen & Hui-Min Hsieh et al. · 2023-02-19

Background: Female cancers, including breast, cervical, uterine, and ovarian cancer, remain among the ten most common cancers among women worldwide, but the relationship between female cancers and abortion from previous studies is inconsistent. This study aimed to investigate risks of incident female cancers among women aged 20 to 45 years who underwent abortion in Taiwan compared with those who did not. Method: A longitudinal observational cohort study was conducted using three nationwide population-based databases in Taiwan, focusing on 20- to 45-year-old women, with 10 years of follow-up. Matched cohorts were identified with propensity score 1-to-3 matching between 269,050 women who underwent abortion and 807,150 who did not. Multivariable Cox proportional hazard modeling was used for analysis after adjusting for covariates including age, average monthly payroll, fertility, diabetes mellitus, polycystic ovarian syndrome, endometrial hyperplasia, endometriosis, hormone-related drugs, and Charlson comorbidity index. Results: We found lower risk of uterine cancer (hazard ratio [HR]: 0.77, 95% CI: 0.70–0.85) and ovarian cancer (HR: 0.81, 95% CI: 0.75–0.88), but no significant difference in risk of breast cancer or cervical cancer, among matched abortion compared with non-abortion cohorts. Regarding subgroup analysis, cervical cancer risk was higher for parous women who underwent abortion, and uterine cancer risk was lower for nulliparous women who underwent abortion compared with non-abortion groups. Conclusions: Abortion was related to lower uterine and ovarian cancer risk but was not associated with risks of incident breast cancer or cervical cancer. Longer follow-up may be necessary to observe risks of female cancers at older ages.

Links
DOIPubMed
Journal
International Journal of Environmental Research and Public Health
Institutions
Kaohsiung Municipal Ta Tung HospitalKaohsiung Medical University Chung Ho Memorial HospitalKaohsiung Medical University
Authors
Cheng-Ting Shen, Yu-Hsiang Tsao, Hui-Min Hsieh
Funding

Kaohsiung Municipal Ta-Tung Hospital

KMTTH-110-012

Kaohsiung Municipal Ta-Tung Hospital

MOST 109-2423-H-037-001-SS3

Kaohsiung Municipal Ta-Tung Hospital

MOST 111-2410-H-037-011-

Kaohsiung Municipal Ta-Tung Hospital

KMU-M108007

Kaohsiung Municipal Ta-Tung Hospital

KMUTC109B08

Kaohsiung Municipal Ta-Tung Hospital

KMU-TC109A01-1

Kaohsiung Municipal Ta-Tung Hospital

KMUTC110B05

Kaohsiung Municipal Ta-Tung Hospital

KMU-TC111A01

Kaohsiung Municipal Ta-Tung Hospital

KMUTC111IFSP01

the Ministry of Science and Technology grant

KMTTH-110-012

the Ministry of Science and Technology grant

MOST 109-2423-H-037-001-SS3

the Ministry of Science and Technology grant

MOST 111-2410-H-037-011-

the Ministry of Science and Technology grant

KMU-M108007

the Ministry of Science and Technology grant

KMUTC109B08

the Ministry of Science and Technology grant

KMU-TC109A01-1

the Ministry of Science and Technology grant

KMUTC110B05

the Ministry of Science and Technology grant

KMU-TC111A01

the Ministry of Science and Technology grant

KMUTC111IFSP01

Kaohsiung Medical University Research Center Grant

KMTTH-110-012

Kaohsiung Medical University Research Center Grant

MOST 109-2423-H-037-001-SS3

Kaohsiung Medical University Research Center Grant

MOST 111-2410-H-037-011-

Kaohsiung Medical University Research Center Grant

KMU-M108007

Kaohsiung Medical University Research Center Grant

KMUTC109B08

Kaohsiung Medical University Research Center Grant

KMU-TC109A01-1

Kaohsiung Medical University Research Center Grant

KMUTC110B05

Kaohsiung Medical University Research Center Grant

KMU-TC111A01

Kaohsiung Medical University Research Center Grant

KMUTC111IFSP01

the Research Center for Precision Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan

KMTTH-110-012

the Research Center for Precision Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan

MOST 109-2423-H-037-001-SS3

the Research Center for Precision Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan

MOST 111-2410-H-037-011-

the Research Center for Precision Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan

KMU-M108007

the Research Center for Precision Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan

KMUTC109B08

the Research Center for Precision Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan

KMU-TC109A01-1

the Research Center for Precision Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan

KMUTC110B05

the Research Center for Precision Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan

KMU-TC111A01

the Research Center for Precision Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan

KMUTC111IFSP01

the Kaohsiung Medical University Research Center Grant

KMTTH-110-012

the Kaohsiung Medical University Research Center Grant

MOST 109-2423-H-037-001-SS3

the Kaohsiung Medical University Research Center Grant

MOST 111-2410-H-037-011-

the Kaohsiung Medical University Research Center Grant

KMU-M108007

the Kaohsiung Medical University Research Center Grant

KMUTC109B08

the Kaohsiung Medical University Research Center Grant

KMU-TC109A01-1

the Kaohsiung Medical University Research Center Grant

KMUTC110B05

the Kaohsiung Medical University Research Center Grant

KMU-TC111A01

the Kaohsiung Medical University Research Center Grant

KMUTC111IFSP01

Division of Medical Statistics and Bioinformatics, Department of Medical Research, Kaohsiung Medical University Hospital

KMTTH-110-012

Division of Medical Statistics and Bioinformatics, Department of Medical Research, Kaohsiung Medical University Hospital

MOST 109-2423-H-037-001-SS3

Division of Medical Statistics and Bioinformatics, Department of Medical Research, Kaohsiung Medical University Hospital

MOST 111-2410-H-037-011-

Division of Medical Statistics and Bioinformatics, Department of Medical Research, Kaohsiung Medical University Hospital

KMU-M108007

Division of Medical Statistics and Bioinformatics, Department of Medical Research, Kaohsiung Medical University Hospital

KMUTC109B08

Division of Medical Statistics and Bioinformatics, Department of Medical Research, Kaohsiung Medical University Hospital

KMU-TC109A01-1

Division of Medical Statistics and Bioinformatics, Department of Medical Research, Kaohsiung Medical University Hospital

KMUTC110B05

Division of Medical Statistics and Bioinformatics, Department of Medical Research, Kaohsiung Medical University Hospital

KMU-TC111A01

Division of Medical Statistics and Bioinformatics, Department of Medical Research, Kaohsiung Medical University Hospital

KMUTC111IFSP01

the Center for Big Data Research, Kaohsiung Medical University

KMTTH-110-012

the Center for Big Data Research, Kaohsiung Medical University

MOST 109-2423-H-037-001-SS3

the Center for Big Data Research, Kaohsiung Medical University

MOST 111-2410-H-037-011-

the Center for Big Data Research, Kaohsiung Medical University

KMU-M108007

the Center for Big Data Research, Kaohsiung Medical University

KMUTC109B08

the Center for Big Data Research, Kaohsiung Medical University

KMU-TC109A01-1

the Center for Big Data Research, Kaohsiung Medical University

KMUTC110B05

the Center for Big Data Research, Kaohsiung Medical University

KMU-TC111A01

the Center for Big Data Research, Kaohsiung Medical University

KMUTC111IFSP01