Catholic nuns should go on the Pill, two experts have argued.
Experts Dr Kara Britt and Professor Roger Short say that taking the contraceptive pill would protect nuns from breast, ovarian and womb cancer.
Deaths from all three diseases are known to be greater among "nulliparous" women, such as nuns, who never have children.
The suggestion that nuns should be given the Pill is made in a comment article published online by medical journal The Lancet.
Childless women have more menstrual cycles than mothers, which is said to increase cancer risk.
The risk reduces if women have their first child at a young age, bear larger numbers of children and breastfeed.
Studies have shown that overall mortality among women using the Pill is 12% lower than among never-users, say the Australian experts.
The risk of developing cancer of the ovaries and womb lining is 50% to 60% lower in Pill users, they point out.
This protection is known to persist for 20 years. On the other side of the coin, the combined oestrogen/progestogen Pill can increase the risk of blood clots.
The two authors, from Monash and Melbourne universities, refer to Pope Paul VI's "Humanae Vitae", a controversial encyclical letter written in 1968 that condemned all forms of contraception.