7 Healthcast: Birth control & ovarian cancer

It's called the silent killer because often there are no symptoms until the disease has progressed into a later, more deadly stage. But now there's evidence that the birth control pill could protect women from ovarian cancer.

For years scientists have known that birth control pills substantially reduce a woman's risk of ovarian cancer.

But today's survey of 45 studies involving more than 100,000 women around the world provides even better news.

"That protection seems to last quite a long time," said Dr. Jean Calle. "It seems to last out 20 even 30 years after pill use has stopped."

The effect is so strong that researchers estimate that worldwide, oral contraceptives have already prevented 100,000 deaths from ovarian cancer and will prevent tens of thousands more in coming years.

"It is really fairly unusual to see long term protection of this nature due to a medication," Dr. Calle said.

The risk reduction depends on how long a woman takes the pill. Women who took the pill for five years or more cut their risk by half

Of course the main purpose of the pill is to protect against pregnancy. And it can have serious side effects including a risk of blood clots and a possible tiny increase in breast cancer risk.

Some of the symptoms of ovarian cancer include stomach swelling and bloating and problems urinating. If you experience any symptoms daily for two or three weeks you should see a doctor.

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