Women consuming oral contraceptives containing cyproterone acetate and ethinylestradiol show a higher risk of thyroid cancer than nonusers

Sep 28, 2026

Uploaded by Jacob

This study explored whether the risk of thyroid cancer in Asian women is associated with consumption of oral contraceptives (Diane-35). A population-based, retrospective cohort was conducted using Taiwan National Health Insurance Research Database data. The Diane-35 cohort included 9,865 women aged 18–65 prescribed Diane-35 from 2000–2012, compared with 39,460 nonusers frequency-matched by age and index year, followed until 2013. Cox proportional hazards models estimated hazard ratios and 95% confidence intervals. Thyroid cancer incidence was 1.80-fold higher in the Diane-35 group with HR 1.91 (95% CI 1.10–3.30), and risk was notably elevated among ages 30–39 (HR 5.58).

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages6

Reading Time15 min

AccessFree to download

Introduction

Oral contraceptives mechanisms and Diane-35 description

Abstract

Study design and cohorts

Thyroid cancer incidence and hazard ratios

® Observational Study Women consuming oral contraceptives containing cyproterone acetate and ethinylestradiol show a higher risk of thyroid cancer than nonusers Pei-Hsuan Lai, MDa , Weishan Chen, PhDb ,c , Chung Y. Hsu, MD, PhDd , Jen-Hung Wang, MSe , Dah-Ching Ding, MD, PhDa ,f,* | Abstract
This study explored whether the risk of thyroid cancer in Asian women is associated with consumption of oral contraceptives (Diane-35) . We conducted a population-based, retrospective cohort study using the Taiwan National Health Insurance Research Database. From the database, 9865 women aged 18 to 65 years who were prescribed Diane-35 between 2000 and 2012 were included in the Diane-35 group, and 39,460 women who were not prescribed Diane-35 were included in the comparison group and were frequency-matched by age and index year. Both groups were followed until 2013 to calculate the incidence of thyroid cancer. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazard model. The median (standard deviation) follow-up duration was 7.08 (3 .63) and 7.04 (3 .64) years in the Diane-35 and the comparison group, respectively. The incidence of thyroid cancer was 1.80-fold higher in the Diane-35 group than in the comparison group (2 .72 vs 1.51 per 10,000 person-years) . The cumulative incidence of thyroid cancer was significantly higher in the Diane-35 group than in the comparison group (log-rank test, P = .03) . An elevated hazard ratio of thyroid cancer was observed in the Diane-35 group than in the comparison group (HR: 1.91, 95% CI: 1.10–3.30) . In subgroup analysis, patients aged 30 to 39 years showed a higher hazard ratio of developing thyroid cancer after consuming Diane-35 than those in the comparison group (HR: 5.58, 95% CI: 1.84–16.91) . The study provides evidence that women aged 30 to 39 years consuming Diane-35 are at increased risk of thyroid cancer. Nevertheless, a larger population with a longer follow-up may be necessary to confirm causality. | | --- | | Abbreviations: CI = confidence intervals, E = estrogen, FTC = follicular thyroid carcinoma, ICD-9-CM = International Classification of Diseases, Ninth Revision, Clinical Modification, MHT = menopausal hormone therapy, OCs = oral contraceptives, P = progesterone, PCOS = polycystic ovarian disease, PR = progesterone receptor, PTC = papillary thyroid carcinoma. | | Keywords: Diane-35 , oral contraceptives, thyroid cancer | 1. Introduction Oral contraceptives (OCs) are hormone-containing products used to prevent pregnancy. Inhibition of ovulation and prevention of sperm penetration into the cervix are the main mechanisms for avoiding pregnancy.[1] Prevention of ovulation is the main mechanism of contraceptives of combined oral contraceptives. The most common forms of oral contraceptives are synthetic female hormones – estrogen (E) and progesterone (P) . This typeof pill is called a combined oral contraceptive. Another form of oral contraceptives, such as minipill, contains progestin alone. Diane-35 (Bayer Weimer GmbH und Co., Weimer, Germany) is a combined form of an oral contraceptive containing 2 mg cyproterone acetate and 0.035 mg ethinylestradiol. Indications for Diane-35 include acne, seborrhea, hirsutism, polycystic ovarian Oral contraceptives and thyroid cancer risk. This study was partly supported by the China Medical University Hospital (DMR- 110-105) and the Tseng-Lien Lin Foundation, Taichung, Taiwan. Informed consent was waived due to low risk of patient safety and approved by the committee. The authors have no conflicts of interest to disclose. The datasets generated during and/or analyzed during the current study are not publicly available, but are available from the corresponding author on reasonable request. The Research Ethics Committee at China Medical University and Hospital approved the use of NHRI-provided data for studies (institutional review board permit number: CMUH-104-REC2-115). a Depar

FAQs

What is the study design and data source?

The study used a population-based retrospective cohort design with data from the Taiwan National Health Insurance Research Database. Women prescribed Diane-35 were compared with nonusers who were frequency-matched by age and index year.

How much higher was thyroid cancer incidence in the Diane-35 group?

Thyroid cancer incidence was 1.80-fold higher in the Diane-35 group than in the comparison group (2.72 vs 1.51 per 10,000 person-years). The cumulative incidence was also significantly higher (log-rank test, P = .03).

Which age group showed the strongest increased risk?

In subgroup analysis, women aged 30 to 39 years had a higher hazard ratio for developing thyroid cancer after consuming Diane-35 (HR: 5.58, 95% CI: 1.84–16.91).

Sep 28, 2026

Uploaded by Jacob