Birth-control pills not only prevent pregnancy but protect women from two forms of cancer, even decades after they have stopped taking them, say leading experts.
Oxford University researchers say in the past 10 years, taking the pill has prevented 200,000 cases of womb cancer in high-income countries. In 2008, the Oxford epidemiologists, analysing the data from 45 studies involving 100,000 women, found that regular use for 15 years can halve the risk of ovarian cancer.
In both cases, the protection can last for more than 30 years, long after women have stopped using contraceptives. Women in their 70s who took the pill in their youth are still enjoying its protection, says Prof Valerie Beral, lead author of the new study on the pill and endometrial (womb) cancer in the Lancet Oncology journal.
“There are two conditions where we have this really big effect that is long-lasting,” said Beral. “There is an increase in cancer of the breast and cervix, but it is really quite small and they don’t persist.”
Once a woman stops taking the pill, her increased chances of breast or cervical cancer quickly disappear.
“What it means is that women in their 50s and 60s who took the pill are less likely to get cancer than women who did not, and the longer they have taken it the less likely they are. That is pretty important.