The risk of cervical atypia in oral contraceptive users

Abstract

Background: The interactions of oral contraceptive (OC) use, risk of human papillomavirus (HPV) infection and associated cellular atypia are complex. We investigated the association between history of OC-use, and cytological or histopathological abnormalities in a cohort of non-HPV vaccinated originally 16–17-year-old women participating the PATRICIA trial for 4 years.

Methods: The total number of hepatitis A-virus (control) vaccine recipients participating in the clinical PATRICIA trial in Finland was 2399. Nine-hundred and ninety-nine women returned questionnaires on living conditions-life habits and sexual health after completing the study. Mean age at answering the questionnaire at the end of the clinical trial was 22 years. Age at sexual debut varied between 12 and 16 years for majority of the women. Cervical cytological samples were obtained every 6 months throughout the PATRICIA trial. The relative risk of cervical atypia associated with time since start of oral contraceptives use was calculated as odds ratio (OR) with 95% confidence interval (CI) using logistic regression.

Results: Compared to never-users, the smoking and age-at-sexual-debut adjusted relative risk of cervical intraepithelial neoplasia grade 1 (CIN1) in women who had started the use of oral contraceptives for more than 1 year was low (OR 0.2, 95% CI: 0.1–0.7). Risk of cytological atypia was also reduced (OR 0.6) albeit not significantly (95% CI: 0.3–1.3).

Conclusions: Use of oral contraceptives does not increase the risk of cervical atypia but when established might instead be protective.

摘要：

研究背景：

口服避孕药(OC)的应用、人类乳头瘤病毒(HPV)感染的风险以及相关的宫颈非典型增生病变之间的相互作用是复杂的。我们进行了为期4年的PATRICIA试验：该实验中我们调查了口服避孕药应用史与细胞学或组织病理学异常之间的关系, 参与该实验研究的人群是：未接种HPV疫苗的16 - 17岁的女性。

研究方法：

在芬兰进行甲型肝炎病毒(对照)疫苗接种者总数为2399人, 这些人参与PATRICIA临床试验。在完成实验研究后, 九百九十九名女性完成了关于生活状况、生活习惯和性健康的问卷调查。在临床试验结束时完成问卷人群的平均年龄为22岁。大多数女性初次性行为的年龄在12到16岁之间。在PATRICIA试验期间, 每6个月采集一次宫颈细胞学标本。采用logistic回归方法, 以95%置信区间(CI)的优势比(odds ratio, OR)值来计算口服避孕药使用时间和宫颈非典型性增生病变之间的的相对风险。

研究结果：

与从未服用过口服避孕药的女性相比, 调整了吸烟和初次性行为年龄后, 服用口服避孕药超过1年的患宫颈上皮内瘤变1级(CIN1)女性的相对风险较低(或0.2%, 95% CI: 0.1-0.7)。细胞非典型增生的风险也降低了(或0.6), 尽管不是很显著(95% CI: 0.3-1.3)。

相关结论：

口服避孕药的应用不会增加宫颈非典型增生的风险, 但对已确定的宫颈病变可能具有保护作用。

Keywords:

• ASCUS
• cervical neoplasia
• contraceptives
• HPV
• squamous intraepithelial lesion

Disclosure statement

ML and DA have received grants for HPV vaccination studies from Merck & Co. Inc. and GSK vaccines through their employers, University of Tampere (ML) and Family Federation Finland (DA).

Additional information

Funding

The primary PATRICIA study was funded by GSK Biologicals. The current manuscript reports on an analysis performed on the data from the Finnish study sites under the accountability of the manuscript authors, who received additional funding from the Finnish Cancer Organization and Academy of Finland.