Taking the Pill for 10 years can reduce risk of ovarian cancer by almost half

[Rich66]

Research has not yet established how factors like the Pill and pregnancy reduce ovarian cancer risk. One theory is that taking the Pill or getting pregnant changes the level of hormones that can affect a woman's risk of the disease.
While the Pill has a protective effect against ovarian cancer, women taking the Pill have an increased risk of breast cancer while using it, but which disappears after use has stopped.

Tricky, this whole endocrine link..