Pill use offers long term ovarian cancer protection
Oral contraception offers long term protection against ovarian cancer, persisting for at least three decades after use, say researchers from Cancer Research UK.
Data from 45 studies involving 23 527 women with ovarian cancer were compared with 87 303 women without the disease.
Overall 31% of women with cancer had ever used an oral contraceptive compared with 37% of control. The longer the use the greater the reduction in risk and the protection persisted for more than 30 years after women had stopped using the Pill.
The risk reduction did not vary substantially by women's ethnicity, education, age her periods began, family history of breast cancer, use of hormone replacement therapy, body-mass index, height, or consumption of alcohol or tobacco.
The authors conclude: ‘Use of oral contraceptives confers long-term protection against ovarian cancer. These findings suggest that oral contraceptives have already prevented some 200 000 ovarian cancers and 100 000 deaths from the disease, and that over the next few decades the numbers of cancers prevented will rise to at least 30000 per year.'
They also found that although oestrogen doses in oral contraceptives have decreased significantly over the years (preparations in the 1960s typically contained more than double the oestrogen dose of preparations in the 1980s), there was no apparent variation in the relative risk of ovarian cancer between women whose oral contraceptive use was during the 1960s, 1970s or 1980s.