Contemporary combined hormonal contraceptives protect against ovarian cancer
Contemporary combined hormonal contraceptives, such as desogestrel, gestodene and drospirenone, reduce the risk of ovarian cancer in women of reproductive age, a recent study has shown.
Researchers enrolled 1,879,227 women aged 15–49 years and who had no cancer, venous thrombosis or infertility treatments. Poisson regression analysis was performed to determine the risk of ovarian cancer among those who used any contemporary combined hormonal contraceptives.
Over the study duration of 20 years (21.4 million person-years), researchers documented 1,249 incident ovarian cancers in the study population, with the median age at diagnosis being 44.4 years.
Stratified analysis showed that in never users of any hormone contraceptives, 771 incident ovarian cancers developed over 8,150,250 person-years of follow-up. In comparison, 478 cases over 13,344,531 person-years were reported among ever users.
Moreover, the age-adjusted incidence rate of ovarian cancer was higher in never users vs ever users of any hormonal contraception (7.5 vs 4.3 per 100,000 person-years), resulting in a significant risk difference (adjusted relative risk [RR], 0.66; 95 percent CI, 0.58–0.76).
The protective effect of hormonal contraceptives against ovarian cancer was stronger for women who took combined oral (adjusted RR, 0.53; 0.45–0.64) than progestogen-only (adjusted RR, 0.72; 0.55–0.95) products.
Notably, the effect was diminished with time since last contraceptive use. The risk of ovarian cancer was comparable between never users and ever users by 10 years since last reported use of any hormonal contraception (adjusted RR, 0.80; 0.59–1.08).